Squashed 'oxigraph/' content from commit c5e23fb0

git-subtree-dir: oxigraph
git-subtree-split: c5e23fb0dd1a6b6cc36a4d021276df46f55bc6e4

Cargo.toml

@@ -0,0 +1,59 @@
+[package]
+name = "oxigraph"
+version.workspace = true
+authors.workspace = true
+license.workspace = true
+readme = "README.md"
+keywords = ["RDF", "SPARQL", "graph-database", "database"]
+categories = ["database-implementations"]
+repository = "https://github.com/oxigraph/oxigraph/tree/main/lib/oxigraph"
+homepage = "https://oxigraph.org/"
+documentation = "https://docs.rs/oxigraph"
+description = """
+a SPARQL database and RDF toolkit
+"""
+edition.workspace = true
+rust-version.workspace = true
+
+[features]
+js = ["getrandom/js", "oxsdatatypes/js", "js-sys"]
+
+
+[dependencies]
+digest.workspace = true
+hex.workspace = true
+json-event-parser.workspace = true
+md-5.workspace = true
+oxilangtag.workspace = true
+oxiri.workspace = true
+oxrdf = { workspace = true, features = ["rdf-star", "oxsdatatypes"] }
+oxrdfio = { workspace = true, features = ["rdf-star"] }
+oxsdatatypes.workspace = true
+rand.workspace = true
+regex.workspace = true
+sha1.workspace = true
+sha2.workspace = true
+siphasher.workspace = true
+sparesults = { workspace = true, features = ["rdf-star"] }
+spargebra = { workspace = true, features = ["rdf-star", "sep-0002", "sep-0006"] }
+sparopt = { workspace = true, features = ["rdf-star", "sep-0002", "sep-0006"] }
+thiserror.workspace = true
+
+[target.'cfg(not(target_family = "wasm"))'.dependencies]
+libc = "0.2"
+rocksdb.workspace = true
+
+[target.'cfg(all(target_family = "wasm", target_os = "unknown"))'.dependencies]
+getrandom.workspace = true
+js-sys = { workspace = true, optional = true }
+
+[target.'cfg(not(target_family = "wasm"))'.dev-dependencies]
+codspeed-criterion-compat.workspace = true
+zstd.workspace = true
+
+[lints]
+workspace = true
+
+[package.metadata.docs.rs]
+rustdoc-args = ["--cfg", "docsrs"]
+

README.md

@@ -0,0 +1,82 @@
+Oxigraph
+========
+
+[![Latest Version](https://img.shields.io/crates/v/oxigraph.svg)](https://crates.io/crates/oxigraph)
+[![Released API docs](https://docs.rs/oxigraph/badge.svg)](https://docs.rs/oxigraph)
+[![Crates.io downloads](https://img.shields.io/crates/d/oxigraph)](https://crates.io/crates/oxigraph)
+[![actions status](https://github.com/oxigraph/oxigraph/workflows/build/badge.svg)](https://github.com/oxigraph/oxigraph/actions)
+[![Gitter](https://badges.gitter.im/oxigraph/community.svg)](https://gitter.im/oxigraph/community)
+
+Oxigraph is a graph database library implementing the [SPARQL](https://www.w3.org/TR/sparql11-overview/) standard.
+
+Its goal is to provide a compliant, safe and fast on-disk graph database.
+It also provides a set of utility functions for reading, writing, and processing RDF files.
+
+Oxigraph is in heavy development and SPARQL query evaluation has not been optimized yet.
+
+Oxigraph also provides [a CLI tool](https://crates.io/crates/oxigraph-cli) and [a Python library](https://pyoxigraph.readthedocs.io/) based on this library.
+
+
+Oxigraph implements the following specifications:
+* [SPARQL 1.1 Query](https://www.w3.org/TR/sparql11-query/), [SPARQL 1.1 Update](https://www.w3.org/TR/sparql11-update/), and [SPARQL 1.1 Federated Query](https://www.w3.org/TR/sparql11-federated-query/).
+* [Turtle](https://www.w3.org/TR/turtle/), [TriG](https://www.w3.org/TR/trig/), [N-Triples](https://www.w3.org/TR/n-triples/), [N-Quads](https://www.w3.org/TR/n-quads/), and [RDF/XML](https://www.w3.org/TR/rdf-syntax-grammar/) RDF serialization formats for both data ingestion and retrieval.
+* [SPARQL Query Results XML Format](https://www.w3.org/TR/rdf-sparql-XMLres/), [SPARQL 1.1 Query Results JSON Format](https://www.w3.org/TR/sparql11-results-json/) and [SPARQL 1.1 Query Results CSV and TSV Formats](https://www.w3.org/TR/sparql11-results-csv-tsv/).
+
+A preliminary benchmark [is provided](../bench/README.md). Oxigraph internal design [is described on the wiki](https://github.com/oxigraph/oxigraph/wiki/Architecture).
+
+The main entry point of Oxigraph is the [`Store`](store::Store) struct:
+```rust
+use oxigraph::store::Store;
+use oxigraph::model::*;
+use oxigraph::sparql::QueryResults;
+
+let store = Store::new().unwrap();
+
+// insertion
+let ex = NamedNode::new("http://example.com").unwrap();
+let quad = Quad::new(ex.clone(), ex.clone(), ex.clone(), GraphName::DefaultGraph);
+store.insert(&quad).unwrap();
+
+// quad filter
+let results = store.quads_for_pattern(Some(ex.as_ref().into()), None, None, None).collect::<Result<Vec<Quad>,_>>().unwrap();
+assert_eq!(vec![quad], results);
+
+// SPARQL query
+if let QueryResults::Solutions(mut solutions) =  store.query("SELECT ?s WHERE { ?s ?p ?o }").unwrap() {
+    assert_eq!(solutions.next().unwrap().unwrap().get("s"), Some(&ex.into()));
+}
+```
+
+It is based on these crates that can be used separately:
+* [`oxrdf`](https://crates.io/crates/oxrdf), datastructures encoding RDF basic concepts (the [`oxigraph::model`](crate::model) module).
+* [`oxrdfio`](https://crates.io/crates/oxrdfio), a unified parser and serializer API for RDF formats (the [`oxigraph::io`](crate::io) module). It itself relies on:
+  * [`oxttl`](https://crates.io/crates/oxttl), N-Triple, N-Quad, Turtle, TriG and N3 parsing and serialization.
+  * [`oxrdfxml`](https://crates.io/crates/oxrdfxml), RDF/XML parsing and serialization.
+* [`spargebra`](https://crates.io/crates/spargebra), a SPARQL parser.
+* [`sparesults`](https://crates.io/crates/sparesults), parsers and serializers for SPARQL result formats (the [`oxigraph::sparql::results`](crate::sparql::results) module).
+* [`sparopt`](https://crates.io/crates/sparesults), a SPARQL optimizer.
+* [`oxsdatatypes`](https://crates.io/crates/oxsdatatypes), an implementation of some XML Schema datatypes.
+
+To build the library locally, don't forget to clone the submodules using `git clone --recursive https://github.com/oxigraph/oxigraph.git` to clone the repository including submodules or `git submodule update --init` to add submodules to the already cloned repository.
+
+It is possible to disable the RocksDB storage backend to only use the in-memory fallback by disabling the `rocksdb` default feature:
+```toml
+oxigraph = { version = "*", default-features = false }
+```
+This is the default behavior when compiling Oxigraph to WASM.
+
+## License
+
+This project is licensed under either of
+
+* Apache License, Version 2.0, ([LICENSE-APACHE](../LICENSE-APACHE) or
+  `<http://www.apache.org/licenses/LICENSE-2.0>`)
+* MIT license ([LICENSE-MIT](../LICENSE-MIT) or
+  `<http://opensource.org/licenses/MIT>`)
+
+at your option.
+
+
+### Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Oxigraph by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

src/io/format.rs

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+#![allow(deprecated)]
+
+use oxrdfio::{RdfFormat, RdfParser, RdfSerializer};
+
+/// [RDF graph](https://www.w3.org/TR/rdf11-concepts/#dfn-rdf-graph) serialization formats.
+///
+/// This enumeration is non exhaustive. New formats like JSON-LD will be added in the future.
+#[derive(Eq, PartialEq, Debug, Clone, Copy, Hash)]
+#[non_exhaustive]
+#[deprecated(note = "use RdfFormat instead", since = "0.4.0")]
+pub enum GraphFormat {
+    /// [N-Triples](https://www.w3.org/TR/n-triples/)
+    NTriples,
+    /// [Turtle](https://www.w3.org/TR/turtle/)
+    Turtle,
+    /// [RDF/XML](https://www.w3.org/TR/rdf-syntax-grammar/)
+    RdfXml,
+}
+
+impl GraphFormat {
+    /// The format canonical IRI according to the [Unique URIs for file formats registry](https://www.w3.org/ns/formats/).
+    ///
+    /// ```
+    /// use oxigraph::io::GraphFormat;
+    ///
+    /// assert_eq!(
+    ///     GraphFormat::NTriples.iri(),
+    ///     "http://www.w3.org/ns/formats/N-Triples"
+    /// )
+    /// ```
+    #[inline]
+    pub fn iri(self) -> &'static str {
+        match self {
+            Self::NTriples => "http://www.w3.org/ns/formats/N-Triples",
+            Self::Turtle => "http://www.w3.org/ns/formats/Turtle",
+            Self::RdfXml => "http://www.w3.org/ns/formats/RDF_XML",
+        }
+    }
+
+    /// The format [IANA media type](https://tools.ietf.org/html/rfc2046).
+    ///
+    /// ```
+    /// use oxigraph::io::GraphFormat;
+    ///
+    /// assert_eq!(GraphFormat::NTriples.media_type(), "application/n-triples")
+    /// ```
+    #[inline]
+    pub fn media_type(self) -> &'static str {
+        match self {
+            Self::NTriples => "application/n-triples",
+            Self::Turtle => "text/turtle",
+            Self::RdfXml => "application/rdf+xml",
+        }
+    }
+
+    /// The format [IANA-registered](https://tools.ietf.org/html/rfc2046) file extension.
+    ///
+    /// ```
+    /// use oxigraph::io::GraphFormat;
+    ///
+    /// assert_eq!(GraphFormat::NTriples.file_extension(), "nt")
+    /// ```
+    #[inline]
+    pub fn file_extension(self) -> &'static str {
+        match self {
+            Self::NTriples => "nt",
+            Self::Turtle => "ttl",
+            Self::RdfXml => "rdf",
+        }
+    }
+
+    /// Looks for a known format from a media type.
+    ///
+    /// It supports some media type aliases.
+    /// For example, "application/xml" is going to return `GraphFormat::RdfXml` even if it is not its canonical media type.
+    ///
+    /// Example:
+    /// ```
+    /// use oxigraph::io::GraphFormat;
+    ///
+    /// assert_eq!(
+    ///     GraphFormat::from_media_type("text/turtle; charset=utf-8"),
+    ///     Some(GraphFormat::Turtle)
+    /// )
+    /// ```
+    #[inline]
+    pub fn from_media_type(media_type: &str) -> Option<Self> {
+        match media_type.split(';').next()?.trim() {
+            "application/n-triples" | "text/plain" => Some(Self::NTriples),
+            "text/turtle" | "application/turtle" | "application/x-turtle" => Some(Self::Turtle),
+            "application/rdf+xml" | "application/xml" | "text/xml" => Some(Self::RdfXml),
+            _ => None,
+        }
+    }
+
+    /// Looks for a known format from an extension.
+    ///
+    /// It supports some aliases.
+    ///
+    /// Example:
+    /// ```
+    /// use oxigraph::io::GraphFormat;
+    ///
+    /// assert_eq!(
+    ///     GraphFormat::from_extension("nt"),
+    ///     Some(GraphFormat::NTriples)
+    /// )
+    /// ```
+    #[inline]
+    pub fn from_extension(extension: &str) -> Option<Self> {
+        match extension {
+            "nt" | "txt" => Some(Self::NTriples),
+            "ttl" => Some(Self::Turtle),
+            "rdf" | "xml" => Some(Self::RdfXml),
+            _ => None,
+        }
+    }
+}
+
+impl From<GraphFormat> for RdfFormat {
+    #[inline]
+    fn from(format: GraphFormat) -> Self {
+        match format {
+            GraphFormat::NTriples => Self::NTriples,
+            GraphFormat::Turtle => Self::Turtle,
+            GraphFormat::RdfXml => Self::RdfXml,
+        }
+    }
+}
+
+impl From<GraphFormat> for RdfParser {
+    #[inline]
+    fn from(format: GraphFormat) -> Self {
+        RdfFormat::from(format).into()
+    }
+}
+
+impl From<GraphFormat> for RdfSerializer {
+    #[inline]
+    fn from(format: GraphFormat) -> Self {
+        RdfFormat::from(format).into()
+    }
+}
+
+/// [RDF dataset](https://www.w3.org/TR/rdf11-concepts/#dfn-rdf-dataset) serialization formats.
+///
+/// This enumeration is non exhaustive. New formats like JSON-LD will be added in the future.
+#[derive(Eq, PartialEq, Debug, Clone, Copy, Hash)]
+#[non_exhaustive]
+#[deprecated(note = "use RdfFormat instead", since = "0.4.0")]
+pub enum DatasetFormat {
+    /// [N-Quads](https://www.w3.org/TR/n-quads/)
+    NQuads,
+    /// [TriG](https://www.w3.org/TR/trig/)
+    TriG,
+}
+
+impl DatasetFormat {
+    /// The format canonical IRI according to the [Unique URIs for file formats registry](https://www.w3.org/ns/formats/).
+    ///
+    /// ```
+    /// use oxigraph::io::DatasetFormat;
+    ///
+    /// assert_eq!(
+    ///     DatasetFormat::NQuads.iri(),
+    ///     "http://www.w3.org/ns/formats/N-Quads"
+    /// )
+    /// ```
+    #[inline]
+    pub fn iri(self) -> &'static str {
+        match self {
+            Self::NQuads => "http://www.w3.org/ns/formats/N-Quads",
+            Self::TriG => "http://www.w3.org/ns/formats/TriG",
+        }
+    }
+
+    /// The format [IANA media type](https://tools.ietf.org/html/rfc2046).
+    ///
+    /// ```
+    /// use oxigraph::io::DatasetFormat;
+    ///
+    /// assert_eq!(DatasetFormat::NQuads.media_type(), "application/n-quads")
+    /// ```
+    #[inline]
+    pub fn media_type(self) -> &'static str {
+        match self {
+            Self::NQuads => "application/n-quads",
+            Self::TriG => "application/trig",
+        }
+    }
+
+    /// The format [IANA-registered](https://tools.ietf.org/html/rfc2046) file extension.
+    ///
+    /// ```
+    /// use oxigraph::io::DatasetFormat;
+    ///
+    /// assert_eq!(DatasetFormat::NQuads.file_extension(), "nq")
+    /// ```
+    #[inline]
+    pub fn file_extension(self) -> &'static str {
+        match self {
+            Self::NQuads => "nq",
+            Self::TriG => "trig",
+        }
+    }
+
+    /// Looks for a known format from a media type.
+    ///
+    /// It supports some media type aliases.
+    ///
+    /// Example:
+    /// ```
+    /// use oxigraph::io::DatasetFormat;
+    ///
+    /// assert_eq!(
+    ///     DatasetFormat::from_media_type("application/n-quads; charset=utf-8"),
+    ///     Some(DatasetFormat::NQuads)
+    /// )
+    /// ```
+    #[inline]
+    pub fn from_media_type(media_type: &str) -> Option<Self> {
+        match media_type.split(';').next()?.trim() {
+            "application/n-quads" | "text/x-nquads" | "text/nquads" => Some(Self::NQuads),
+            "application/trig" | "application/x-trig" => Some(Self::TriG),
+            _ => None,
+        }
+    }
+
+    /// Looks for a known format from an extension.
+    ///
+    /// It supports some aliases.
+    ///
+    /// Example:
+    /// ```
+    /// use oxigraph::io::DatasetFormat;
+    ///
+    /// assert_eq!(
+    ///     DatasetFormat::from_extension("nq"),
+    ///     Some(DatasetFormat::NQuads)
+    /// )
+    /// ```
+    #[inline]
+    pub fn from_extension(extension: &str) -> Option<Self> {
+        match extension {
+            "nq" | "txt" => Some(Self::NQuads),
+            "trig" => Some(Self::TriG),
+            _ => None,
+        }
+    }
+}
+
+impl From<DatasetFormat> for RdfFormat {
+    #[inline]
+    fn from(format: DatasetFormat) -> Self {
+        match format {
+            DatasetFormat::NQuads => Self::NQuads,
+            DatasetFormat::TriG => Self::TriG,
+        }
+    }
+}
+
+impl From<DatasetFormat> for RdfParser {
+    #[inline]
+    fn from(format: DatasetFormat) -> Self {
+        RdfFormat::from(format).into()
+    }
+}
+
+impl From<DatasetFormat> for RdfSerializer {
+    #[inline]
+    fn from(format: DatasetFormat) -> Self {
+        RdfFormat::from(format).into()
+    }
+}
+
+impl TryFrom<DatasetFormat> for GraphFormat {
+    type Error = ();
+
+    /// Attempts to find a graph format that is a subset of this [`DatasetFormat`].
+    #[inline]
+    fn try_from(value: DatasetFormat) -> Result<Self, Self::Error> {
+        match value {
+            DatasetFormat::NQuads => Ok(Self::NTriples),
+            DatasetFormat::TriG => Ok(Self::Turtle),
+        }
+    }
+}
+
+impl TryFrom<GraphFormat> for DatasetFormat {
+    type Error = ();
+
+    /// Attempts to find a dataset format that is a superset of this [`GraphFormat`].
+    #[inline]
+    fn try_from(value: GraphFormat) -> Result<Self, Self::Error> {
+        match value {
+            GraphFormat::NTriples => Ok(Self::NQuads),
+            GraphFormat::Turtle => Ok(Self::TriG),
+            GraphFormat::RdfXml => Err(()),
+        }
+    }
+}

src/io/mod.rs

@@ -0,0 +1,39 @@
+//! Utilities to read and write RDF graphs and datasets using [OxRDF I/O](https://crates.io/crates/oxrdfio).
+//!
+//! The entry points of this module are the two [`RdfParser`] and [`RdfSerializer`] structs.
+//!
+//! Usage example converting a Turtle file to a N-Triples file:
+//! ```
+//! use oxigraph::io::{RdfFormat, RdfParser, RdfSerializer};
+//!
+//! let turtle_file = b"@base <http://example.com/> .
+//! @prefix schema: <http://schema.org/> .
+//! <foo> a schema:Person ;
+//!     schema:name \"Foo\" .
+//! <bar> a schema:Person ;
+//!     schema:name \"Bar\" .";
+//!
+//! let ntriples_file = b"<http://example.com/foo> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://schema.org/Person> .
+//! <http://example.com/foo> <http://schema.org/name> \"Foo\" .
+//! <http://example.com/bar> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://schema.org/Person> .
+//! <http://example.com/bar> <http://schema.org/name> \"Bar\" .
+//! ";
+//!
+//! let mut writer = RdfSerializer::from_format(RdfFormat::NTriples).serialize_to_write(Vec::new());
+//! for quad in RdfParser::from_format(RdfFormat::Turtle).parse_read(turtle_file.as_ref()) {
+//!     writer.write_quad(&quad.unwrap()).unwrap();
+//! }
+//! assert_eq!(writer.finish().unwrap(), ntriples_file);
+//! ```
+
+mod format;
+pub mod read;
+pub mod write;
+
+#[allow(deprecated)]
+pub use self::format::{DatasetFormat, GraphFormat};
+#[allow(deprecated)]
+pub use self::read::{DatasetParser, GraphParser};
+#[allow(deprecated)]
+pub use self::write::{DatasetSerializer, GraphSerializer};
+pub use oxrdfio::*;

src/io/read.rs

@@ -0,0 +1,199 @@
+#![allow(deprecated)]
+
+//! Utilities to read RDF graphs and datasets.
+
+use crate::io::{DatasetFormat, GraphFormat};
+use crate::model::*;
+use oxrdfio::{FromReadQuadReader, RdfParseError, RdfParser};
+use std::io::Read;
+
+/// Parsers for RDF graph serialization formats.
+///
+/// It currently supports the following formats:
+/// * [N-Triples](https://www.w3.org/TR/n-triples/) ([`GraphFormat::NTriples`])
+/// * [Turtle](https://www.w3.org/TR/turtle/) ([`GraphFormat::Turtle`])
+/// * [RDF/XML](https://www.w3.org/TR/rdf-syntax-grammar/) ([`GraphFormat::RdfXml`])
+///
+/// ```
+/// use oxigraph::io::{GraphFormat, GraphParser};
+///
+/// let file = "<http://example.com/s> <http://example.com/p> <http://example.com/o> .";
+///
+/// let parser = GraphParser::from_format(GraphFormat::NTriples);
+/// let triples = parser
+///     .read_triples(file.as_bytes())
+///     .collect::<Result<Vec<_>, _>>()?;
+///
+/// assert_eq!(triples.len(), 1);
+/// assert_eq!(triples[0].subject.to_string(), "<http://example.com/s>");
+/// # std::io::Result::Ok(())
+/// ```
+#[deprecated(note = "use RdfParser instead", since = "0.4.0")]
+pub struct GraphParser {
+    inner: RdfParser,
+}
+
+impl GraphParser {
+    /// Builds a parser for the given format.
+    #[inline]
+    pub fn from_format(format: GraphFormat) -> Self {
+        Self {
+            inner: RdfParser::from_format(format.into())
+                .without_named_graphs()
+                .rename_blank_nodes(),
+        }
+    }
+
+    /// Provides an IRI that could be used to resolve the file relative IRIs.
+    ///
+    /// ```
+    /// use oxigraph::io::{GraphFormat, GraphParser};
+    ///
+    /// let file = "</s> </p> </o> .";
+    ///
+    /// let parser =
+    ///     GraphParser::from_format(GraphFormat::Turtle).with_base_iri("http://example.com")?;
+    /// let triples = parser
+    ///     .read_triples(file.as_bytes())
+    ///     .collect::<Result<Vec<_>, _>>()?;
+    ///
+    /// assert_eq!(triples.len(), 1);
+    /// assert_eq!(triples[0].subject.to_string(), "<http://example.com/s>");
+    /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+    /// ```
+    #[inline]
+    pub fn with_base_iri(self, base_iri: impl Into<String>) -> Result<Self, IriParseError> {
+        Ok(Self {
+            inner: self.inner.with_base_iri(base_iri)?,
+        })
+    }
+
+    /// Executes the parsing itself on a [`Read`] implementation and returns an iterator of triples.
+    pub fn read_triples<R: Read>(self, reader: R) -> TripleReader<R> {
+        TripleReader {
+            parser: self.inner.parse_read(reader),
+        }
+    }
+}
+
+/// An iterator yielding read triples.
+/// Could be built using a [`GraphParser`].
+///
+/// ```
+/// use oxigraph::io::{GraphFormat, GraphParser};
+///
+/// let file = "<http://example.com/s> <http://example.com/p> <http://example.com/o> .";
+///
+/// let parser = GraphParser::from_format(GraphFormat::NTriples);
+/// let triples = parser
+///     .read_triples(file.as_bytes())
+///     .collect::<Result<Vec<_>, _>>()?;
+///
+/// assert_eq!(triples.len(), 1);
+/// assert_eq!(triples[0].subject.to_string(), "<http://example.com/s>");
+/// # std::io::Result::Ok(())
+/// ```
+#[must_use]
+pub struct TripleReader<R: Read> {
+    parser: FromReadQuadReader<R>,
+}
+
+impl<R: Read> Iterator for TripleReader<R> {
+    type Item = Result<Triple, RdfParseError>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        Some(self.parser.next()?.map(Into::into).map_err(Into::into))
+    }
+}
+
+/// A parser for RDF dataset serialization formats.
+///
+/// It currently supports the following formats:
+/// * [N-Quads](https://www.w3.org/TR/n-quads/) ([`DatasetFormat::NQuads`])
+/// * [TriG](https://www.w3.org/TR/trig/) ([`DatasetFormat::TriG`])
+///
+/// ```
+/// use oxigraph::io::{DatasetFormat, DatasetParser};
+///
+/// let file = "<http://example.com/s> <http://example.com/p> <http://example.com/o> <http://example.com/g> .";
+///
+/// let parser = DatasetParser::from_format(DatasetFormat::NQuads);
+/// let quads = parser.read_quads(file.as_bytes()).collect::<Result<Vec<_>,_>>()?;
+///
+/// assert_eq!(quads.len(), 1);
+/// assert_eq!(quads[0].subject.to_string(), "<http://example.com/s>");
+/// # std::io::Result::Ok(())
+/// ```
+#[deprecated(note = "use RdfParser instead", since = "0.4.0")]
+pub struct DatasetParser {
+    inner: RdfParser,
+}
+
+impl DatasetParser {
+    /// Builds a parser for the given format.
+    #[inline]
+    pub fn from_format(format: DatasetFormat) -> Self {
+        Self {
+            inner: RdfParser::from_format(format.into()).rename_blank_nodes(),
+        }
+    }
+
+    /// Provides an IRI that could be used to resolve the file relative IRIs.
+    ///
+    /// ```
+    /// use oxigraph::io::{DatasetFormat, DatasetParser};
+    ///
+    /// let file = "<g> { </s> </p> </o> }";
+    ///
+    /// let parser =
+    ///     DatasetParser::from_format(DatasetFormat::TriG).with_base_iri("http://example.com")?;
+    /// let triples = parser
+    ///     .read_quads(file.as_bytes())
+    ///     .collect::<Result<Vec<_>, _>>()?;
+    ///
+    /// assert_eq!(triples.len(), 1);
+    /// assert_eq!(triples[0].subject.to_string(), "<http://example.com/s>");
+    /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+    /// ```
+    #[inline]
+    pub fn with_base_iri(self, base_iri: impl Into<String>) -> Result<Self, IriParseError> {
+        Ok(Self {
+            inner: self.inner.with_base_iri(base_iri)?,
+        })
+    }
+
+    /// Executes the parsing itself on a [`Read`] implementation and returns an iterator of quads.
+    pub fn read_quads<R: Read>(self, reader: R) -> QuadReader<R> {
+        QuadReader {
+            parser: self.inner.parse_read(reader),
+        }
+    }
+}
+
+/// An iterator yielding read quads.
+/// Could be built using a [`DatasetParser`].
+///
+/// ```
+/// use oxigraph::io::{DatasetFormat, DatasetParser};
+///
+/// let file = "<http://example.com/s> <http://example.com/p> <http://example.com/o> <http://example.com/g> .";
+///
+/// let parser = DatasetParser::from_format(DatasetFormat::NQuads);
+/// let quads = parser.read_quads(file.as_bytes()).collect::<Result<Vec<_>,_>>()?;
+///
+/// assert_eq!(quads.len(), 1);
+/// assert_eq!(quads[0].subject.to_string(), "<http://example.com/s>");
+/// # std::io::Result::Ok(())
+/// ```
+#[must_use]
+pub struct QuadReader<R: Read> {
+    parser: FromReadQuadReader<R>,
+}
+
+impl<R: Read> Iterator for QuadReader<R> {
+    type Item = Result<Quad, RdfParseError>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        Some(self.parser.next()?.map_err(Into::into))
+    }
+}

src/io/write.rs

@@ -0,0 +1,185 @@
+#![allow(deprecated)]
+
+//! Utilities to write RDF graphs and datasets.
+
+use crate::io::{DatasetFormat, GraphFormat};
+use crate::model::*;
+use oxrdfio::{RdfSerializer, ToWriteQuadWriter};
+use std::io::{self, Write};
+
+/// A serializer for RDF graph serialization formats.
+///
+/// It currently supports the following formats:
+/// * [N-Triples](https://www.w3.org/TR/n-triples/) ([`GraphFormat::NTriples`])
+/// * [Turtle](https://www.w3.org/TR/turtle/) ([`GraphFormat::Turtle`])
+/// * [RDF/XML](https://www.w3.org/TR/rdf-syntax-grammar/) ([`GraphFormat::RdfXml`])
+///
+/// ```
+/// use oxigraph::io::{GraphFormat, GraphSerializer};
+/// use oxigraph::model::*;
+///
+/// let mut buffer = Vec::new();
+/// let mut writer = GraphSerializer::from_format(GraphFormat::NTriples).triple_writer(&mut buffer);
+/// writer.write(&Triple {
+///     subject: NamedNode::new("http://example.com/s")?.into(),
+///     predicate: NamedNode::new("http://example.com/p")?,
+///     object: NamedNode::new("http://example.com/o")?.into(),
+/// })?;
+/// writer.finish()?;
+///
+/// assert_eq!(
+///     buffer.as_slice(),
+///     "<http://example.com/s> <http://example.com/p> <http://example.com/o> .\n".as_bytes()
+/// );
+/// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+/// ```
+#[deprecated(note = "use RdfSerializer instead", since = "0.4.0")]
+pub struct GraphSerializer {
+    inner: RdfSerializer,
+}
+
+impl GraphSerializer {
+    /// Builds a serializer for the given format
+    #[inline]
+    pub fn from_format(format: GraphFormat) -> Self {
+        Self {
+            inner: RdfSerializer::from_format(format.into()),
+        }
+    }
+
+    /// Returns a [`TripleWriter`] allowing writing triples into the given [`Write`] implementation
+    pub fn triple_writer<W: Write>(self, write: W) -> TripleWriter<W> {
+        TripleWriter {
+            writer: self.inner.serialize_to_write(write),
+        }
+    }
+}
+
+/// Allows writing triples.
+/// Could be built using a [`GraphSerializer`].
+///
+/// <div class="warning">
+///
+/// Do not forget to run the [`finish`](TripleWriter::finish()) method to properly write the last bytes of the file.</div>
+///
+/// ```
+/// use oxigraph::io::{GraphFormat, GraphSerializer};
+/// use oxigraph::model::*;
+///
+/// let mut buffer = Vec::new();
+/// let mut writer = GraphSerializer::from_format(GraphFormat::NTriples).triple_writer(&mut buffer);
+/// writer.write(&Triple {
+///     subject: NamedNode::new("http://example.com/s")?.into(),
+///     predicate: NamedNode::new("http://example.com/p")?,
+///     object: NamedNode::new("http://example.com/o")?.into(),
+/// })?;
+/// writer.finish()?;
+///
+/// assert_eq!(
+///     buffer.as_slice(),
+///     "<http://example.com/s> <http://example.com/p> <http://example.com/o> .\n".as_bytes()
+/// );
+/// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+/// ```
+#[must_use]
+pub struct TripleWriter<W: Write> {
+    writer: ToWriteQuadWriter<W>,
+}
+
+impl<W: Write> TripleWriter<W> {
+    /// Writes a triple
+    pub fn write<'a>(&mut self, triple: impl Into<TripleRef<'a>>) -> io::Result<()> {
+        self.writer.write_triple(triple)
+    }
+
+    /// Writes the last bytes of the file
+    pub fn finish(self) -> io::Result<()> {
+        self.writer.finish()?.flush()
+    }
+}
+
+/// A serializer for RDF graph serialization formats.
+///
+/// It currently supports the following formats:
+/// * [N-Quads](https://www.w3.org/TR/n-quads/) ([`DatasetFormat::NQuads`])
+/// * [TriG](https://www.w3.org/TR/trig/) ([`DatasetFormat::TriG`])
+///
+/// ```
+/// use oxigraph::io::{DatasetFormat, DatasetSerializer};
+/// use oxigraph::model::*;
+///
+/// let mut buffer = Vec::new();
+/// let mut writer = DatasetSerializer::from_format(DatasetFormat::NQuads).quad_writer(&mut buffer);
+/// writer.write(&Quad {
+///    subject: NamedNode::new("http://example.com/s")?.into(),
+///    predicate: NamedNode::new("http://example.com/p")?,
+///    object: NamedNode::new("http://example.com/o")?.into(),
+///    graph_name: NamedNode::new("http://example.com/g")?.into(),
+/// })?;
+/// writer.finish()?;
+///
+/// assert_eq!(buffer.as_slice(), "<http://example.com/s> <http://example.com/p> <http://example.com/o> <http://example.com/g> .\n".as_bytes());
+/// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+/// ```
+#[deprecated(note = "use RdfSerializer instead", since = "0.4.0")]
+pub struct DatasetSerializer {
+    inner: RdfSerializer,
+}
+
+impl DatasetSerializer {
+    /// Builds a serializer for the given format
+    #[inline]
+    pub fn from_format(format: DatasetFormat) -> Self {
+        Self {
+            inner: RdfSerializer::from_format(format.into()),
+        }
+    }
+
+    /// Returns a [`QuadWriter`] allowing writing triples into the given [`Write`] implementation
+    pub fn quad_writer<W: Write>(self, write: W) -> QuadWriter<W> {
+        QuadWriter {
+            writer: self.inner.serialize_to_write(write),
+        }
+    }
+}
+
+/// Allows writing triples.
+/// Could be built using a [`DatasetSerializer`].
+///
+/// <div class="warning">
+///
+/// Do not forget to run the [`finish`](QuadWriter::finish()) method to properly write the last bytes of the file.</div>
+///
+/// ```
+/// use oxigraph::io::{DatasetFormat, DatasetSerializer};
+/// use oxigraph::model::*;
+///
+/// let mut buffer = Vec::new();
+/// let mut writer = DatasetSerializer::from_format(DatasetFormat::NQuads).quad_writer(&mut buffer);
+/// writer.write(&Quad {
+///    subject: NamedNode::new("http://example.com/s")?.into(),
+///    predicate: NamedNode::new("http://example.com/p")?,
+///    object: NamedNode::new("http://example.com/o")?.into(),
+///    graph_name: NamedNode::new("http://example.com/g")?.into(),
+/// })?;
+/// writer.finish()?;
+///
+/// assert_eq!(buffer.as_slice(), "<http://example.com/s> <http://example.com/p> <http://example.com/o> <http://example.com/g> .\n".as_bytes());
+/// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+/// ```
+#[must_use]
+pub struct QuadWriter<W: Write> {
+    writer: ToWriteQuadWriter<W>,
+}
+
+impl<W: Write> QuadWriter<W> {
+    /// Writes a quad
+    pub fn write<'a>(&mut self, quad: impl Into<QuadRef<'a>>) -> io::Result<()> {
+        self.writer.write_quad(quad)
+    }
+
+    /// Writes the last bytes of the file
+    pub fn finish(self) -> io::Result<()> {
+        self.writer.finish()?.flush()
+    }
+}

src/lib.rs

@@ -0,0 +1,12 @@
+#![doc = include_str!("../README.md")]
+#![doc(test(attr(deny(warnings))))]
+#![doc(test(attr(allow(deprecated))))]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![doc(html_favicon_url = "https://raw.githubusercontent.com/oxigraph/oxigraph/main/logo.svg")]
+#![doc(html_logo_url = "https://raw.githubusercontent.com/oxigraph/oxigraph/main/logo.svg")]
+
+pub mod io;
+pub mod model;
+pub mod sparql;
+mod storage;
+pub mod store;

src/model.rs

@@ -0,0 +1,22 @@
+//! Implements data structures for [RDF 1.1 Concepts](https://www.w3.org/TR/rdf11-concepts/) using [OxRDF](https://crates.io/crates/oxrdf).
+//!
+//! Usage example:
+//!
+//! ```
+//! use oxigraph::model::*;
+//!
+//! let mut graph = Graph::default();
+//!
+//! // insertion
+//! let ex = NamedNodeRef::new("http://example.com").unwrap();
+//! let triple = TripleRef::new(ex, ex, ex);
+//! graph.insert(triple);
+//!
+//! // simple filter
+//! let results: Vec<_> = graph.triples_for_subject(ex).collect();
+//! assert_eq!(vec![triple], results);
+//! ```
+
+pub use oxrdf::*;
+
+pub use spargebra::term::GroundQuad;

src/sparql/algebra.rs

@@ -0,0 +1,311 @@
+//! [SPARQL 1.1 Query Algebra](https://www.w3.org/TR/sparql11-query/#sparqlQuery)
+//!
+//! The root type for SPARQL queries is [`Query`] and the root type for updates is [`Update`].
+
+use crate::model::*;
+use crate::sparql::eval::Timer;
+use oxsdatatypes::DayTimeDuration;
+use spargebra::GraphUpdateOperation;
+use std::fmt;
+use std::str::FromStr;
+
+/// A parsed [SPARQL query](https://www.w3.org/TR/sparql11-query/).
+///
+/// ```
+/// use oxigraph::model::NamedNode;
+/// use oxigraph::sparql::Query;
+///
+/// let query_str = "SELECT ?s ?p ?o WHERE { ?s ?p ?o . }";
+/// let mut query = Query::parse(query_str, None)?;
+///
+/// assert_eq!(query.to_string(), query_str);
+///
+/// // We edit the query dataset specification
+/// let default = vec![NamedNode::new("http://example.com")?.into()];
+/// query.dataset_mut().set_default_graph(default.clone());
+/// assert_eq!(
+///     query.dataset().default_graph_graphs(),
+///     Some(default.as_slice())
+/// );
+/// # Ok::<_, Box<dyn std::error::Error>>(())
+/// ```
+#[derive(Eq, PartialEq, Debug, Clone, Hash)]
+pub struct Query {
+    pub(super) inner: spargebra::Query,
+    pub(super) dataset: QueryDataset,
+    pub(super) parsing_duration: Option<DayTimeDuration>,
+}
+
+impl Query {
+    /// Parses a SPARQL query with an optional base IRI to resolve relative IRIs in the query.
+    pub fn parse(
+        query: &str,
+        base_iri: Option<&str>,
+    ) -> Result<Self, spargebra::SparqlSyntaxError> {
+        let start = Timer::now();
+        let query = Self::from(spargebra::Query::parse(query, base_iri)?);
+        Ok(Self {
+            dataset: query.dataset,
+            inner: query.inner,
+            parsing_duration: start.elapsed(),
+        })
+    }
+
+    /// Returns [the query dataset specification](https://www.w3.org/TR/sparql11-query/#specifyingDataset)
+    pub fn dataset(&self) -> &QueryDataset {
+        &self.dataset
+    }
+
+    /// Returns [the query dataset specification](https://www.w3.org/TR/sparql11-query/#specifyingDataset)
+    pub fn dataset_mut(&mut self) -> &mut QueryDataset {
+        &mut self.dataset
+    }
+}
+
+impl fmt::Display for Query {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.inner.fmt(f) // TODO: override
+    }
+}
+
+impl FromStr for Query {
+    type Err = spargebra::SparqlSyntaxError;
+
+    fn from_str(query: &str) -> Result<Self, Self::Err> {
+        Self::parse(query, None)
+    }
+}
+
+impl TryFrom<&str> for Query {
+    type Error = spargebra::SparqlSyntaxError;
+
+    fn try_from(query: &str) -> Result<Self, Self::Error> {
+        Self::from_str(query)
+    }
+}
+
+impl TryFrom<&String> for Query {
+    type Error = spargebra::SparqlSyntaxError;
+
+    fn try_from(query: &String) -> Result<Self, Self::Error> {
+        Self::from_str(query)
+    }
+}
+
+impl From<spargebra::Query> for Query {
+    fn from(query: spargebra::Query) -> Self {
+        Self {
+            dataset: QueryDataset::from_algebra(match &query {
+                spargebra::Query::Select { dataset, .. }
+                | spargebra::Query::Construct { dataset, .. }
+                | spargebra::Query::Describe { dataset, .. }
+                | spargebra::Query::Ask { dataset, .. } => dataset,
+            }),
+            inner: query,
+            parsing_duration: None,
+        }
+    }
+}
+
+/// A parsed [SPARQL update](https://www.w3.org/TR/sparql11-update/).
+///
+/// ```
+/// use oxigraph::sparql::Update;
+///
+/// let update_str = "CLEAR ALL ;";
+/// let update = Update::parse(update_str, None)?;
+///
+/// assert_eq!(update.to_string().trim(), update_str);
+/// # Ok::<_, oxigraph::sparql::SparqlSyntaxError>(())
+/// ```
+#[derive(Eq, PartialEq, Debug, Clone, Hash)]
+pub struct Update {
+    pub(super) inner: spargebra::Update,
+    pub(super) using_datasets: Vec<Option<QueryDataset>>,
+}
+
+impl Update {
+    /// Parses a SPARQL update with an optional base IRI to resolve relative IRIs in the query.
+    pub fn parse(
+        update: &str,
+        base_iri: Option<&str>,
+    ) -> Result<Self, spargebra::SparqlSyntaxError> {
+        Ok(spargebra::Update::parse(update, base_iri)?.into())
+    }
+
+    /// Returns [the query dataset specification](https://www.w3.org/TR/sparql11-query/#specifyingDataset) in [DELETE/INSERT operations](https://www.w3.org/TR/sparql11-update/#deleteInsert).
+    pub fn using_datasets(&self) -> impl Iterator<Item = &QueryDataset> {
+        self.using_datasets.iter().filter_map(Option::as_ref)
+    }
+
+    /// Returns [the query dataset specification](https://www.w3.org/TR/sparql11-query/#specifyingDataset) in [DELETE/INSERT operations](https://www.w3.org/TR/sparql11-update/#deleteInsert).
+    pub fn using_datasets_mut(&mut self) -> impl Iterator<Item = &mut QueryDataset> {
+        self.using_datasets.iter_mut().filter_map(Option::as_mut)
+    }
+}
+
+impl fmt::Display for Update {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.inner.fmt(f)
+    }
+}
+
+impl FromStr for Update {
+    type Err = spargebra::SparqlSyntaxError;
+
+    fn from_str(update: &str) -> Result<Self, Self::Err> {
+        Self::parse(update, None)
+    }
+}
+
+impl TryFrom<&str> for Update {
+    type Error = spargebra::SparqlSyntaxError;
+
+    fn try_from(update: &str) -> Result<Self, Self::Error> {
+        Self::from_str(update)
+    }
+}
+
+impl TryFrom<&String> for Update {
+    type Error = spargebra::SparqlSyntaxError;
+
+    fn try_from(update: &String) -> Result<Self, Self::Error> {
+        Self::from_str(update)
+    }
+}
+
+impl From<spargebra::Update> for Update {
+    fn from(update: spargebra::Update) -> Self {
+        Self {
+            using_datasets: update
+                .operations
+                .iter()
+                .map(|operation| {
+                    if let GraphUpdateOperation::DeleteInsert { using, .. } = operation {
+                        Some(QueryDataset::from_algebra(using))
+                    } else {
+                        None
+                    }
+                })
+                .collect(),
+            inner: update,
+        }
+    }
+}
+
+/// A SPARQL query [dataset specification](https://www.w3.org/TR/sparql11-query/#specifyingDataset)
+#[derive(Eq, PartialEq, Debug, Clone, Hash)]
+pub struct QueryDataset {
+    default: Option<Vec<GraphName>>,
+    named: Option<Vec<NamedOrBlankNode>>,
+}
+
+impl QueryDataset {
+    pub(crate) fn new() -> Self {
+        Self {
+            default: None,
+            named: None,
+        }
+    }
+
+    fn from_algebra(inner: &Option<spargebra::algebra::QueryDataset>) -> Self {
+        if let Some(inner) = inner {
+            Self {
+                default: Some(inner.default.iter().map(|g| g.clone().into()).collect()),
+                named: inner
+                    .named
+                    .as_ref()
+                    .map(|named| named.iter().map(|g| g.clone().into()).collect()),
+            }
+        } else {
+            Self {
+                default: Some(vec![GraphName::DefaultGraph]),
+                named: None,
+            }
+        }
+    }
+
+    /// Checks if this dataset specification is the default one
+    /// (i.e. the default graph is the store default graph and all the store named graphs are available)
+    ///
+    /// ```
+    /// use oxigraph::sparql::Query;
+    ///
+    /// assert!(Query::parse("SELECT ?s ?p ?o WHERE { ?s ?p ?o . }", None)?
+    ///     .dataset()
+    ///     .is_default_dataset());
+    /// assert!(!Query::parse(
+    ///     "SELECT ?s ?p ?o FROM <http://example.com> WHERE { ?s ?p ?o . }",
+    ///     None
+    /// )?
+    /// .dataset()
+    /// .is_default_dataset());
+    ///
+    /// # Ok::<_, Box<dyn std::error::Error>>(())
+    /// ```
+    pub fn is_default_dataset(&self) -> bool {
+        self.default
+            .as_ref()
+            .map_or(false, |t| t == &[GraphName::DefaultGraph])
+            && self.named.is_none()
+    }
+
+    /// Returns the list of the store graphs that are available to the query as the default graph or `None` if the union of all graphs is used as the default graph
+    /// This list is by default only the store default graph
+    pub fn default_graph_graphs(&self) -> Option<&[GraphName]> {
+        self.default.as_deref()
+    }
+
+    /// Sets if the default graph for the query should be the union of all the graphs in the queried store
+    pub fn set_default_graph_as_union(&mut self) {
+        self.default = None;
+    }
+
+    /// Sets the list of graphs the query should consider as being part of the default graph.
+    ///
+    /// By default only the store default graph is considered.
+    /// ```
+    /// use oxigraph::model::NamedNode;
+    /// use oxigraph::sparql::Query;
+    ///
+    /// let mut query = Query::parse("SELECT ?s ?p ?o WHERE { ?s ?p ?o . }", None)?;
+    /// let default = vec![NamedNode::new("http://example.com")?.into()];
+    /// query.dataset_mut().set_default_graph(default.clone());
+    /// assert_eq!(
+    ///     query.dataset().default_graph_graphs(),
+    ///     Some(default.as_slice())
+    /// );
+    ///
+    /// # Ok::<_, Box<dyn std::error::Error>>(())
+    /// ```
+    pub fn set_default_graph(&mut self, graphs: Vec<GraphName>) {
+        self.default = Some(graphs)
+    }
+
+    /// Returns the list of the available named graphs for the query or `None` if all graphs are available
+    pub fn available_named_graphs(&self) -> Option<&[NamedOrBlankNode]> {
+        self.named.as_deref()
+    }
+
+    /// Sets the list of allowed named graphs in the query.
+    ///
+    /// ```
+    /// use oxigraph::model::NamedNode;
+    /// use oxigraph::sparql::Query;
+    ///
+    /// let mut query = Query::parse("SELECT ?s ?p ?o WHERE { ?s ?p ?o . }", None)?;
+    /// let named = vec![NamedNode::new("http://example.com")?.into()];
+    /// query
+    ///     .dataset_mut()
+    ///     .set_available_named_graphs(named.clone());
+    /// assert_eq!(
+    ///     query.dataset().available_named_graphs(),
+    ///     Some(named.as_slice())
+    /// );
+    ///
+    /// # Ok::<_, Box<dyn std::error::Error>>(())
+    /// ```
+    pub fn set_available_named_graphs(&mut self, named_graphs: Vec<NamedOrBlankNode>) {
+        self.named = Some(named_graphs);
+    }
+}

src/sparql/dataset.rs

@@ -0,0 +1,184 @@
+use crate::model::TermRef;
+use crate::sparql::algebra::QueryDataset;
+use crate::sparql::EvaluationError;
+use crate::storage::numeric_encoder::{insert_term, EncodedQuad, EncodedTerm, StrHash, StrLookup};
+use crate::storage::{StorageError, StorageReader};
+use std::cell::RefCell;
+use std::collections::hash_map::Entry;
+use std::collections::HashMap;
+use std::iter::empty;
+
+pub struct DatasetView {
+    reader: StorageReader,
+    extra: RefCell<HashMap<StrHash, String>>,
+    dataset: EncodedDatasetSpec,
+}
+
+impl DatasetView {
+    pub fn new(reader: StorageReader, dataset: &QueryDataset) -> Self {
+        let dataset = EncodedDatasetSpec {
+            default: dataset
+                .default_graph_graphs()
+                .map(|graphs| graphs.iter().map(|g| g.as_ref().into()).collect::<Vec<_>>()),
+            named: dataset
+                .available_named_graphs()
+                .map(|graphs| graphs.iter().map(|g| g.as_ref().into()).collect::<Vec<_>>()),
+        };
+        Self {
+            reader,
+            extra: RefCell::new(HashMap::default()),
+            dataset,
+        }
+    }
+
+    fn store_encoded_quads_for_pattern(
+        &self,
+        subject: Option<&EncodedTerm>,
+        predicate: Option<&EncodedTerm>,
+        object: Option<&EncodedTerm>,
+        graph_name: Option<&EncodedTerm>,
+    ) -> impl Iterator<Item = Result<EncodedQuad, EvaluationError>> + 'static {
+        self.reader
+            .quads_for_pattern(subject, predicate, object, graph_name)
+            .map(|t| t.map_err(Into::into))
+    }
+
+    #[allow(clippy::needless_collect)]
+    pub fn encoded_quads_for_pattern(
+        &self,
+        subject: Option<&EncodedTerm>,
+        predicate: Option<&EncodedTerm>,
+        object: Option<&EncodedTerm>,
+        graph_name: Option<&EncodedTerm>,
+    ) -> Box<dyn Iterator<Item = Result<EncodedQuad, EvaluationError>>> {
+        if let Some(graph_name) = graph_name {
+            if graph_name.is_default_graph() {
+                if let Some(default_graph_graphs) = &self.dataset.default {
+                    if default_graph_graphs.len() == 1 {
+                        // Single graph optimization
+                        Box::new(
+                            self.store_encoded_quads_for_pattern(
+                                subject,
+                                predicate,
+                                object,
+                                Some(&default_graph_graphs[0]),
+                            )
+                            .map(|quad| {
+                                let quad = quad?;
+                                Ok(EncodedQuad::new(
+                                    quad.subject,
+                                    quad.predicate,
+                                    quad.object,
+                                    EncodedTerm::DefaultGraph,
+                                ))
+                            }),
+                        )
+                    } else {
+                        let iters = default_graph_graphs
+                            .iter()
+                            .map(|graph_name| {
+                                self.store_encoded_quads_for_pattern(
+                                    subject,
+                                    predicate,
+                                    object,
+                                    Some(graph_name),
+                                )
+                            })
+                            .collect::<Vec<_>>();
+                        Box::new(iters.into_iter().flatten().map(|quad| {
+                            let quad = quad?;
+                            Ok(EncodedQuad::new(
+                                quad.subject,
+                                quad.predicate,
+                                quad.object,
+                                EncodedTerm::DefaultGraph,
+                            ))
+                        }))
+                    }
+                } else {
+                    Box::new(
+                        self.store_encoded_quads_for_pattern(subject, predicate, object, None)
+                            .map(|quad| {
+                                let quad = quad?;
+                                Ok(EncodedQuad::new(
+                                    quad.subject,
+                                    quad.predicate,
+                                    quad.object,
+                                    EncodedTerm::DefaultGraph,
+                                ))
+                            }),
+                    )
+                }
+            } else if self
+                .dataset
+                .named
+                .as_ref()
+                .map_or(true, |d| d.contains(graph_name))
+            {
+                Box::new(self.store_encoded_quads_for_pattern(
+                    subject,
+                    predicate,
+                    object,
+                    Some(graph_name),
+                ))
+            } else {
+                Box::new(empty())
+            }
+        } else if let Some(named_graphs) = &self.dataset.named {
+            let iters = named_graphs
+                .iter()
+                .map(|graph_name| {
+                    self.store_encoded_quads_for_pattern(
+                        subject,
+                        predicate,
+                        object,
+                        Some(graph_name),
+                    )
+                })
+                .collect::<Vec<_>>();
+            Box::new(iters.into_iter().flatten())
+        } else {
+            Box::new(
+                self.store_encoded_quads_for_pattern(subject, predicate, object, None)
+                    .filter(|quad| match quad {
+                        Err(_) => true,
+                        Ok(quad) => !quad.graph_name.is_default_graph(),
+                    }),
+            )
+        }
+    }
+
+    pub fn encode_term<'a>(&self, term: impl Into<TermRef<'a>>) -> EncodedTerm {
+        let term = term.into();
+        let encoded = term.into();
+        insert_term(term, &encoded, &mut |key, value| {
+            self.insert_str(key, value);
+            Ok(())
+        })
+        .unwrap();
+        encoded
+    }
+
+    pub fn insert_str(&self, key: &StrHash, value: &str) {
+        if let Entry::Vacant(e) = self.extra.borrow_mut().entry(*key) {
+            if !matches!(self.reader.contains_str(key), Ok(true)) {
+                e.insert(value.to_owned());
+            }
+        }
+    }
+}
+
+impl StrLookup for DatasetView {
+    fn get_str(&self, key: &StrHash) -> Result<Option<String>, StorageError> {
+        Ok(if let Some(value) = self.extra.borrow().get(key) {
+            Some(value.clone())
+        } else {
+            self.reader.get_str(key)?
+        })
+    }
+}
+
+struct EncodedDatasetSpec {
+    default: Option<Vec<EncodedTerm>>,
+    named: Option<Vec<EncodedTerm>>,
+}

src/sparql/error.rs

@@ -0,0 +1,84 @@
+use crate::io::RdfParseError;
+use crate::model::NamedNode;
+use crate::sparql::results::QueryResultsParseError as ResultsParseError;
+use crate::sparql::SparqlSyntaxError;
+use crate::storage::StorageError;
+use std::convert::Infallible;
+use std::error::Error;
+use std::io;
+
+/// A SPARQL evaluation error.
+#[derive(Debug, thiserror::Error)]
+#[non_exhaustive]
+pub enum EvaluationError {
+    /// An error in SPARQL parsing.
+    #[error(transparent)]
+    Parsing(#[from] SparqlSyntaxError),
+    /// An error from the storage.
+    #[error(transparent)]
+    Storage(#[from] StorageError),
+    /// An error while parsing an external RDF file.
+    #[error(transparent)]
+    GraphParsing(#[from] RdfParseError),
+    /// An error while parsing an external result file (likely from a federated query).
+    #[error(transparent)]
+    ResultsParsing(#[from] ResultsParseError),
+    /// An error returned during results serialization.
+    #[error(transparent)]
+    ResultsSerialization(#[from] io::Error),
+    /// Error during `SERVICE` evaluation
+    #[error("{0}")]
+    Service(#[source] Box<dyn Error + Send + Sync + 'static>),
+    /// Error when `CREATE` tries to create an already existing graph
+    #[error("The graph {0} already exists")]
+    GraphAlreadyExists(NamedNode),
+    /// Error when `DROP` or `CLEAR` tries to remove a not existing graph
+    #[error("The graph {0} does not exist")]
+    GraphDoesNotExist(NamedNode),
+    /// The variable storing the `SERVICE` name is unbound
+    #[error("The variable encoding the service name is unbound")]
+    UnboundService,
+    /// The given `SERVICE` is not supported
+    #[error("The service {0} is not supported")]
+    UnsupportedService(NamedNode),
+    /// The given content media type returned from an HTTP response is not supported (`SERVICE` and `LOAD`)
+    #[error("The content media type {0} is not supported")]
+    UnsupportedContentType(String),
+    /// The `SERVICE` call has not returns solutions
+    #[error("The service is not returning solutions but a boolean or a graph")]
+    ServiceDoesNotReturnSolutions,
+    /// The results are not a RDF graph
+    #[error("The query results are not a RDF graph")]
+    NotAGraph,
+}
+
+impl From<Infallible> for EvaluationError {
+    #[inline]
+    fn from(error: Infallible) -> Self {
+        match error {}
+    }
+}
+
+impl From<EvaluationError> for io::Error {
+    #[inline]
+    fn from(error: EvaluationError) -> Self {
+        match error {
+            EvaluationError::Parsing(error) => Self::new(io::ErrorKind::InvalidData, error),
+            EvaluationError::GraphParsing(error) => error.into(),
+            EvaluationError::ResultsParsing(error) => error.into(),
+            EvaluationError::ResultsSerialization(error) => error,
+            EvaluationError::Storage(error) => error.into(),
+            EvaluationError::Service(error) => match error.downcast() {
+                Ok(error) => *error,
+                Err(error) => Self::new(io::ErrorKind::Other, error),
+            },
+            EvaluationError::GraphAlreadyExists(_)
+            | EvaluationError::GraphDoesNotExist(_)
+            | EvaluationError::UnboundService
+            | EvaluationError::UnsupportedService(_)
+            | EvaluationError::UnsupportedContentType(_)
+            | EvaluationError::ServiceDoesNotReturnSolutions
+            | EvaluationError::NotAGraph => Self::new(io::ErrorKind::InvalidInput, error),
+        }
+    }
+}

src/sparql/http/dummy.rs

@@ -0,0 +1,34 @@
+//! Simple HTTP client
+
+use std::io::{Empty, Error, ErrorKind, Result};
+use std::time::Duration;
+
+pub struct Client;
+
+impl Client {
+    pub fn new(_timeout: Option<Duration>, _redirection_limit: usize) -> Self {
+        Self
+    }
+
+    #[allow(clippy::unused_self)]
+    pub fn get(&self, _url: &str, _accept: &'static str) -> Result<(String, Empty)> {
+        Err(Error::new(
+            ErrorKind::Unsupported,
+            "HTTP client is not available. Enable the feature 'http-client'",
+        ))
+    }
+
+    #[allow(clippy::unused_self, clippy::needless_pass_by_value)]
+    pub fn post(
+        &self,
+        _url: &str,
+        _payload: Vec<u8>,
+        _content_type: &'static str,
+        _accept: &'static str,
+    ) -> Result<(String, Empty)> {
+        Err(Error::new(
+            ErrorKind::Unsupported,
+            "HTTP client is not available. Enable the feature 'http-client'",
+        ))
+    }
+}

src/sparql/http/mod.rs

@@ -0,0 +1,9 @@
+#[cfg(not(feature = "http-client"))]
+mod dummy;
+#[cfg(feature = "http-client")]
+mod simple;
+
+#[cfg(not(feature = "http-client"))]
+pub use dummy::Client;
+#[cfg(feature = "http-client")]
+pub use simple::Client;

src/sparql/http/simple.rs

@@ -0,0 +1,90 @@
+use oxhttp::model::{Body, HeaderName, Method, Request};
+use std::io::{Error, ErrorKind, Result};
+use std::time::Duration;
+
+pub struct Client {
+    client: oxhttp::Client,
+}
+
+impl Client {
+    pub fn new(timeout: Option<Duration>, redirection_limit: usize) -> Self {
+        let mut client = oxhttp::Client::new()
+            .with_redirection_limit(redirection_limit)
+            .with_user_agent(concat!("Oxigraph/", env!("CARGO_PKG_VERSION")))
+            .unwrap();
+        if let Some(timeout) = timeout {
+            client = client.with_global_timeout(timeout);
+        }
+        Self { client }
+    }
+
+    pub fn get(&self, url: &str, accept: &'static str) -> Result<(String, Body)> {
+        let request = Request::builder(Method::GET, url.parse().map_err(invalid_input_error)?)
+            .with_header(HeaderName::ACCEPT, accept)
+            .map_err(invalid_input_error)?
+            .build();
+        let response = self.client.request(request)?;
+        let status = response.status();
+        if !status.is_successful() {
+            return Err(Error::new(
+                ErrorKind::Other,
+                format!(
+                    "Error {} returned by {} with payload:\n{}",
+                    status,
+                    url,
+                    response.into_body().to_string()?
+                ),
+            ));
+        }
+        let content_type = response
+            .header(&HeaderName::CONTENT_TYPE)
+            .ok_or_else(|| invalid_data_error(format!("No Content-Type returned by {url}")))?
+            .to_str()
+            .map_err(invalid_data_error)?
+            .to_owned();
+        Ok((content_type, response.into_body()))
+    }
+
+    pub fn post(
+        &self,
+        url: &str,
+        payload: Vec<u8>,
+        content_type: &'static str,
+        accept: &'static str,
+    ) -> Result<(String, Body)> {
+        let request = Request::builder(Method::POST, url.parse().map_err(invalid_input_error)?)
+            .with_header(HeaderName::ACCEPT, accept)
+            .map_err(invalid_input_error)?
+            .with_header(HeaderName::CONTENT_TYPE, content_type)
+            .map_err(invalid_input_error)?
+            .with_body(payload);
+        let response = self.client.request(request)?;
+        let status = response.status();
+        if !status.is_successful() {
+            return Err(Error::new(
+                ErrorKind::Other,
+                format!(
+                    "Error {} returned by {} with payload:\n{}",
+                    status,
+                    url,
+                    response.into_body().to_string()?
+                ),
+            ));
+        }
+        let content_type = response
+            .header(&HeaderName::CONTENT_TYPE)
+            .ok_or_else(|| invalid_data_error(format!("No Content-Type returned by {url}")))?
+            .to_str()
+            .map_err(invalid_data_error)?
+            .to_owned();
+        Ok((content_type, response.into_body()))
+    }
+}
+
+fn invalid_data_error(error: impl Into<Box<dyn std::error::Error + Send + Sync>>) -> Error {
+    Error::new(ErrorKind::InvalidData, error)
+}
+
+fn invalid_input_error(error: impl Into<Box<dyn std::error::Error + Send + Sync>>) -> Error {
+    Error::new(ErrorKind::InvalidInput, error)
+}

src/sparql/mod.rs

@@ -0,0 +1,328 @@
+//! [SPARQL](https://www.w3.org/TR/sparql11-overview/) implementation.
+//!
+//! Stores execute SPARQL. See [`Store`](crate::store::Store::query()) for an example.
+
+mod algebra;
+mod dataset;
+mod error;
+mod eval;
+mod http;
+mod model;
+pub mod results;
+mod service;
+mod update;
+
+use crate::model::{NamedNode, Term};
+pub use crate::sparql::algebra::{Query, QueryDataset, Update};
+use crate::sparql::dataset::DatasetView;
+pub use crate::sparql::error::EvaluationError;
+use crate::sparql::eval::{EvalNodeWithStats, SimpleEvaluator, Timer};
+pub use crate::sparql::model::{QueryResults, QuerySolution, QuerySolutionIter, QueryTripleIter};
+pub use crate::sparql::service::ServiceHandler;
+use crate::sparql::service::{EmptyServiceHandler, ErrorConversionServiceHandler};
+pub(crate) use crate::sparql::update::evaluate_update;
+use crate::storage::StorageReader;
+use json_event_parser::{JsonEvent, ToWriteJsonWriter};
+pub use oxrdf::{Variable, VariableNameParseError};
+use oxsdatatypes::{DayTimeDuration, Float};
+pub use spargebra::SparqlSyntaxError;
+use sparopt::algebra::GraphPattern;
+use sparopt::Optimizer;
+use std::collections::HashMap;
+use std::rc::Rc;
+use std::sync::Arc;
+use std::time::Duration;
+use std::{fmt, io};
+
+#[allow(clippy::needless_pass_by_value)]
+pub(crate) fn evaluate_query(
+    reader: StorageReader,
+    query: impl TryInto<Query, Error = impl Into<EvaluationError>>,
+    options: QueryOptions,
+    run_stats: bool,
+) -> Result<(Result<QueryResults, EvaluationError>, QueryExplanation), EvaluationError> {
+    let query = query.try_into().map_err(Into::into)?;
+    let dataset = DatasetView::new(reader, &query.dataset);
+    let start_planning = Timer::now();
+    let (results, plan_node_with_stats, planning_duration) = match query.inner {
+        spargebra::Query::Select {
+            pattern, base_iri, ..
+        } => {
+            let mut pattern = GraphPattern::from(&pattern);
+            if !options.without_optimizations {
+                pattern = Optimizer::optimize_graph_pattern(pattern);
+            }
+            let planning_duration = start_planning.elapsed();
+            let (results, explanation) = SimpleEvaluator::new(
+                Rc::new(dataset),
+                base_iri.map(Rc::new),
+                options.service_handler(),
+                Arc::new(options.custom_functions),
+                run_stats,
+            )
+            .evaluate_select(&pattern);
+            (Ok(results), explanation, planning_duration)
+        }
+        spargebra::Query::Ask {
+            pattern, base_iri, ..
+        } => {
+            let mut pattern = GraphPattern::from(&pattern);
+            if !options.without_optimizations {
+                pattern = Optimizer::optimize_graph_pattern(GraphPattern::Reduced {
+                    inner: Box::new(pattern),
+                });
+            }
+            let planning_duration = start_planning.elapsed();
+            let (results, explanation) = SimpleEvaluator::new(
+                Rc::new(dataset),
+                base_iri.map(Rc::new),
+                options.service_handler(),
+                Arc::new(options.custom_functions),
+                run_stats,
+            )
+            .evaluate_ask(&pattern);
+            (results, explanation, planning_duration)
+        }
+        spargebra::Query::Construct {
+            template,
+            pattern,
+            base_iri,
+            ..
+        } => {
+            let mut pattern = GraphPattern::from(&pattern);
+            if !options.without_optimizations {
+                pattern = Optimizer::optimize_graph_pattern(GraphPattern::Reduced {
+                    inner: Box::new(pattern),
+                });
+            }
+            let planning_duration = start_planning.elapsed();
+            let (results, explanation) = SimpleEvaluator::new(
+                Rc::new(dataset),
+                base_iri.map(Rc::new),
+                options.service_handler(),
+                Arc::new(options.custom_functions),
+                run_stats,
+            )
+            .evaluate_construct(&pattern, &template);
+            (Ok(results), explanation, planning_duration)
+        }
+        spargebra::Query::Describe {
+            pattern, base_iri, ..
+        } => {
+            let mut pattern = GraphPattern::from(&pattern);
+            if !options.without_optimizations {
+                pattern = Optimizer::optimize_graph_pattern(GraphPattern::Reduced {
+                    inner: Box::new(pattern),
+                });
+            }
+            let planning_duration = start_planning.elapsed();
+            let (results, explanation) = SimpleEvaluator::new(
+                Rc::new(dataset),
+                base_iri.map(Rc::new),
+                options.service_handler(),
+                Arc::new(options.custom_functions),
+                run_stats,
+            )
+            .evaluate_describe(&pattern);
+            (Ok(results), explanation, planning_duration)
+        }
+    };
+    let explanation = QueryExplanation {
+        inner: plan_node_with_stats,
+        with_stats: run_stats,
+        parsing_duration: query.parsing_duration,
+        planning_duration,
+    };
+    Ok((results, explanation))
+}
+
+/// Options for SPARQL query evaluation.
+///
+///
+/// If the `"http-client"` optional feature is enabled,
+/// a simple HTTP 1.1 client is used to execute [SPARQL 1.1 Federated Query](https://www.w3.org/TR/sparql11-federated-query/) SERVICE calls.
+///
+/// Usage example disabling the federated query support:
+/// ```
+/// use oxigraph::sparql::QueryOptions;
+/// use oxigraph::store::Store;
+///
+/// let store = Store::new()?;
+/// store.query_opt(
+///     "SELECT * WHERE { SERVICE <https://query.wikidata.org/sparql> {} }",
+///     QueryOptions::default().without_service_handler(),
+/// )?;
+/// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+/// ```
+#[derive(Clone, Default)]
+pub struct QueryOptions {
+    service_handler: Option<Arc<dyn ServiceHandler<Error = EvaluationError>>>,
+    custom_functions: CustomFunctionRegistry,
+    http_timeout: Option<Duration>,
+    http_redirection_limit: usize,
+    without_optimizations: bool,
+}
+
+pub(crate) type CustomFunctionRegistry =
+    HashMap<NamedNode, Arc<dyn (Fn(&[Term]) -> Option<Term>) + Send + Sync>>;
+
+impl QueryOptions {
+    /// Use a given [`ServiceHandler`] to execute [SPARQL 1.1 Federated Query](https://www.w3.org/TR/sparql11-federated-query/) SERVICE calls.
+    #[inline]
+    #[must_use]
+    pub fn with_service_handler(mut self, service_handler: impl ServiceHandler + 'static) -> Self {
+        self.service_handler = Some(Arc::new(ErrorConversionServiceHandler::wrap(
+            service_handler,
+        )));
+        self
+    }
+
+    /// Disables the `SERVICE` calls
+    #[inline]
+    #[must_use]
+    pub fn without_service_handler(mut self) -> Self {
+        self.service_handler = Some(Arc::new(EmptyServiceHandler));
+        self
+    }
+
+    /// Sets a timeout for HTTP requests done during SPARQL evaluation.
+    #[cfg(feature = "http-client")]
+    #[inline]
+    #[must_use]
+    pub fn with_http_timeout(mut self, timeout: Duration) -> Self {
+        self.http_timeout = Some(timeout);
+        self
+    }
+
+    /// Sets an upper bound of the number of HTTP redirection followed per HTTP request done during SPARQL evaluation.
+    ///
+    /// By default this value is `0`.
+    #[cfg(feature = "http-client")]
+    #[inline]
+    #[must_use]
+    pub fn with_http_redirection_limit(mut self, redirection_limit: usize) -> Self {
+        self.http_redirection_limit = redirection_limit;
+        self
+    }
+
+    /// Adds a custom SPARQL evaluation function.
+    ///
+    /// Example with a function serializing terms to N-Triples:
+    /// ```
+    /// use oxigraph::model::*;
+    /// use oxigraph::sparql::{QueryOptions, QueryResults};
+    /// use oxigraph::store::Store;
+    ///
+    /// let store = Store::new()?;
+    ///
+    /// if let QueryResults::Solutions(mut solutions) = store.query_opt(
+    ///     "SELECT (<http://www.w3.org/ns/formats/N-Triples>(1) AS ?nt) WHERE {}",
+    ///     QueryOptions::default().with_custom_function(
+    ///         NamedNode::new("http://www.w3.org/ns/formats/N-Triples")?,
+    ///         |args| args.get(0).map(|t| Literal::from(t.to_string()).into()),
+    ///     ),
+    /// )? {
+    ///     assert_eq!(
+    ///         solutions.next().unwrap()?.get("nt"),
+    ///         Some(&Literal::from("\"1\"^^<http://www.w3.org/2001/XMLSchema#integer>").into())
+    ///     );
+    /// }
+    /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+    /// ```
+    #[inline]
+    #[must_use]
+    pub fn with_custom_function(
+        mut self,
+        name: NamedNode,
+        evaluator: impl Fn(&[Term]) -> Option<Term> + Send + Sync + 'static,
+    ) -> Self {
+        self.custom_functions.insert(name, Arc::new(evaluator));
+        self
+    }
+
+    fn service_handler(&self) -> Arc<dyn ServiceHandler<Error = EvaluationError>> {
+        self.service_handler.clone().unwrap_or_else(|| {
+            if cfg!(feature = "http-client") {
+                Arc::new(service::SimpleServiceHandler::new(
+                    self.http_timeout,
+                    self.http_redirection_limit,
+                ))
+            } else {
+                Arc::new(EmptyServiceHandler)
+            }
+        })
+    }
+
+    #[doc(hidden)]
+    #[inline]
+    #[must_use]
+    pub fn without_optimizations(mut self) -> Self {
+        self.without_optimizations = true;
+        self
+    }
+}
+
+/// Options for SPARQL update evaluation.
+#[derive(Clone, Default)]
+pub struct UpdateOptions {
+    query_options: QueryOptions,
+}
+
+impl From<QueryOptions> for UpdateOptions {
+    #[inline]
+    fn from(query_options: QueryOptions) -> Self {
+        Self { query_options }
+    }
+}
+
+/// The explanation of a query.
+#[derive(Clone)]
+pub struct QueryExplanation {
+    inner: Rc<EvalNodeWithStats>,
+    with_stats: bool,
+    parsing_duration: Option<DayTimeDuration>,
+    planning_duration: Option<DayTimeDuration>,
+}
+
+impl QueryExplanation {
+    /// Writes the explanation as JSON.
+    pub fn write_in_json(&self, write: impl io::Write) -> io::Result<()> {
+        let mut writer = ToWriteJsonWriter::new(write);
+        writer.write_event(JsonEvent::StartObject)?;
+        if let Some(parsing_duration) = self.parsing_duration {
+            writer.write_event(JsonEvent::ObjectKey("parsing duration in seconds".into()))?;
+            writer.write_event(JsonEvent::Number(
+                parsing_duration.as_seconds().to_string().into(),
+            ))?;
+        }
+        if let Some(planning_duration) = self.planning_duration {
+            writer.write_event(JsonEvent::ObjectKey("planning duration in seconds".into()))?;
+            writer.write_event(JsonEvent::Number(
+                planning_duration.as_seconds().to_string().into(),
+            ))?;
+        }
+        writer.write_event(JsonEvent::ObjectKey("plan".into()))?;
+        self.inner.json_node(&mut writer, self.with_stats)?;
+        writer.write_event(JsonEvent::EndObject)
+    }
+}
+
+impl fmt::Debug for QueryExplanation {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut obj = f.debug_struct("QueryExplanation");
+        if let Some(parsing_duration) = self.parsing_duration {
+            obj.field(
+                "parsing duration in seconds",
+                &f32::from(Float::from(parsing_duration.as_seconds())),
+            );
+        }
+        if let Some(planning_duration) = self.planning_duration {
+            obj.field(
+                "planning duration in seconds",
+                &f32::from(Float::from(planning_duration.as_seconds())),
+            );
+        }
+        obj.field("tree", &self.inner);
+        obj.finish_non_exhaustive()
+    }
+}

src/sparql/model.rs

@@ -0,0 +1,371 @@
+use crate::io::{RdfFormat, RdfSerializer};
+use crate::model::*;
+use crate::sparql::error::EvaluationError;
+use crate::sparql::results::{
+    FromReadQueryResultsReader, FromReadSolutionsReader, QueryResultsFormat,
+    QueryResultsParseError, QueryResultsParser, QueryResultsSerializer,
+};
+pub use sparesults::QuerySolution;
+use std::io::{Read, Write};
+use std::sync::Arc;
+
+/// Results of a [SPARQL query](https://www.w3.org/TR/sparql11-query/).
+pub enum QueryResults {
+    /// Results of a [SELECT](https://www.w3.org/TR/sparql11-query/#select) query.
+    Solutions(QuerySolutionIter),
+    /// Result of a [ASK](https://www.w3.org/TR/sparql11-query/#ask) query.
+    Boolean(bool),
+    /// Results of a [CONSTRUCT](https://www.w3.org/TR/sparql11-query/#construct) or [DESCRIBE](https://www.w3.org/TR/sparql11-query/#describe) query.
+    Graph(QueryTripleIter),
+}
+
+impl QueryResults {
+    /// Reads a SPARQL query results serialization.
+    pub fn read(
+        read: impl Read + 'static,
+        format: QueryResultsFormat,
+    ) -> Result<Self, QueryResultsParseError> {
+        Ok(QueryResultsParser::from_format(format)
+            .parse_read(read)?
+            .into())
+    }
+
+    /// Writes the query results (solutions or boolean).
+    ///
+    /// This method fails if it is called on the `Graph` results.
+    ///
+    /// ```
+    /// use oxigraph::store::Store;
+    /// use oxigraph::model::*;
+    /// use oxigraph::sparql::results::QueryResultsFormat;
+    ///
+    /// let store = Store::new()?;
+    /// let ex = NamedNodeRef::new("http://example.com")?;
+    /// store.insert(QuadRef::new(ex, ex, ex, GraphNameRef::DefaultGraph))?;
+    ///
+    /// let results = store.query("SELECT ?s WHERE { ?s ?p ?o }")?;
+    /// assert_eq!(
+    ///     results.write(Vec::new(), QueryResultsFormat::Json)?,
+    ///     r#"{"head":{"vars":["s"]},"results":{"bindings":[{"s":{"type":"uri","value":"http://example.com"}}]}}"#.as_bytes()
+    /// );
+    /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+    /// ```
+    pub fn write<W: Write>(
+        self,
+        write: W,
+        format: QueryResultsFormat,
+    ) -> Result<W, EvaluationError> {
+        let serializer = QueryResultsSerializer::from_format(format);
+        match self {
+            Self::Boolean(value) => serializer.serialize_boolean_to_write(write, value),
+            Self::Solutions(solutions) => {
+                let mut writer = serializer
+                    .serialize_solutions_to_write(write, solutions.variables().to_vec())
+                    .map_err(EvaluationError::ResultsSerialization)?;
+                for solution in solutions {
+                    writer
+                        .write(&solution?)
+                        .map_err(EvaluationError::ResultsSerialization)?;
+                }
+                writer.finish()
+            }
+            Self::Graph(triples) => {
+                let s = VariableRef::new_unchecked("subject");
+                let p = VariableRef::new_unchecked("predicate");
+                let o = VariableRef::new_unchecked("object");
+                let mut writer = serializer
+                    .serialize_solutions_to_write(
+                        write,
+                        vec![s.into_owned(), p.into_owned(), o.into_owned()],
+                    )
+                    .map_err(EvaluationError::ResultsSerialization)?;
+                for triple in triples {
+                    let triple = triple?;
+                    writer
+                        .write([
+                            (s, &triple.subject.into()),
+                            (p, &triple.predicate.into()),
+                            (o, &triple.object),
+                        ])
+                        .map_err(EvaluationError::ResultsSerialization)?;
+                }
+                writer.finish()
+            }
+        }
+        .map_err(EvaluationError::ResultsSerialization)
+    }
+
+    /// Writes the graph query results.
+    ///
+    /// This method fails if it is called on the `Solution` or `Boolean` results.
+    ///
+    /// ```
+    /// use oxigraph::io::RdfFormat;
+    /// use oxigraph::model::*;
+    /// use oxigraph::store::Store;
+    ///
+    /// let graph = "<http://example.com> <http://example.com> <http://example.com> .\n";
+    ///
+    /// let store = Store::new()?;
+    /// store.load_graph(
+    ///     graph.as_bytes(),
+    ///     RdfFormat::NTriples,
+    ///     GraphName::DefaultGraph,
+    ///     None,
+    /// )?;
+    ///
+    /// let results = store.query("CONSTRUCT WHERE { ?s ?p ?o }")?;
+    /// assert_eq!(
+    ///     results.write_graph(Vec::new(), RdfFormat::NTriples)?,
+    ///     graph.as_bytes()
+    /// );
+    /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+    /// ```
+    pub fn write_graph<W: Write>(
+        self,
+        write: W,
+        format: impl Into<RdfFormat>,
+    ) -> Result<W, EvaluationError> {
+        if let Self::Graph(triples) = self {
+            let mut writer = RdfSerializer::from_format(format.into()).serialize_to_write(write);
+            for triple in triples {
+                writer
+                    .write_triple(&triple?)
+                    .map_err(EvaluationError::ResultsSerialization)?;
+            }
+            writer
+                .finish()
+                .map_err(EvaluationError::ResultsSerialization)
+        } else {
+            Err(EvaluationError::NotAGraph)
+        }
+    }
+}
+
+impl From<QuerySolutionIter> for QueryResults {
+    #[inline]
+    fn from(value: QuerySolutionIter) -> Self {
+        Self::Solutions(value)
+    }
+}
+
+impl<R: Read + 'static> From<FromReadQueryResultsReader<R>> for QueryResults {
+    fn from(reader: FromReadQueryResultsReader<R>) -> Self {
+        match reader {
+            FromReadQueryResultsReader::Solutions(s) => Self::Solutions(s.into()),
+            FromReadQueryResultsReader::Boolean(v) => Self::Boolean(v),
+        }
+    }
+}
+
+/// An iterator over [`QuerySolution`]s.
+///
+/// ```
+/// use oxigraph::sparql::QueryResults;
+/// use oxigraph::store::Store;
+///
+/// let store = Store::new()?;
+/// if let QueryResults::Solutions(solutions) = store.query("SELECT ?s WHERE { ?s ?p ?o }")? {
+///     for solution in solutions {
+///         println!("{:?}", solution?.get("s"));
+///     }
+/// }
+/// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+/// ```
+pub struct QuerySolutionIter {
+    variables: Arc<[Variable]>,
+    iter: Box<dyn Iterator<Item = Result<QuerySolution, EvaluationError>>>,
+}
+
+impl QuerySolutionIter {
+    /// Construct a new iterator of solution from an ordered list of solution variables and an iterator of solution tuples
+    /// (each tuple using the same ordering as the variable list such that tuple element 0 is the value for the variable 0...)
+    pub fn new(
+        variables: Arc<[Variable]>,
+        iter: impl Iterator<Item = Result<Vec<Option<Term>>, EvaluationError>> + 'static,
+    ) -> Self {
+        Self {
+            variables: Arc::clone(&variables),
+            iter: Box::new(
+                iter.map(move |t| t.map(|values| (Arc::clone(&variables), values).into())),
+            ),
+        }
+    }
+
+    /// The variables used in the solutions.
+    ///
+    /// ```
+    /// use oxigraph::sparql::{QueryResults, Variable};
+    /// use oxigraph::store::Store;
+    ///
+    /// let store = Store::new()?;
+    /// if let QueryResults::Solutions(solutions) = store.query("SELECT ?s ?o WHERE { ?s ?p ?o }")? {
+    ///     assert_eq!(
+    ///         solutions.variables(),
+    ///         &[Variable::new("s")?, Variable::new("o")?]
+    ///     );
+    /// }
+    /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+    /// ```
+    #[inline]
+    pub fn variables(&self) -> &[Variable] {
+        &self.variables
+    }
+}
+
+impl<R: Read + 'static> From<FromReadSolutionsReader<R>> for QuerySolutionIter {
+    fn from(reader: FromReadSolutionsReader<R>) -> Self {
+        Self {
+            variables: reader.variables().into(),
+            iter: Box::new(reader.map(|t| t.map_err(EvaluationError::from))),
+        }
+    }
+}
+
+impl Iterator for QuerySolutionIter {
+    type Item = Result<QuerySolution, EvaluationError>;
+
+    #[inline]
+    fn next(&mut self) -> Option<Self::Item> {
+        self.iter.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.iter.size_hint()
+    }
+}
+
+/// An iterator over the triples that compose a graph solution.
+///
+/// ```
+/// use oxigraph::sparql::QueryResults;
+/// use oxigraph::store::Store;
+///
+/// let store = Store::new()?;
+/// if let QueryResults::Graph(triples) = store.query("CONSTRUCT WHERE { ?s ?p ?o }")? {
+///     for triple in triples {
+///         println!("{}", triple?);
+///     }
+/// }
+/// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+/// ```
+pub struct QueryTripleIter {
+    pub(crate) iter: Box<dyn Iterator<Item = Result<Triple, EvaluationError>>>,
+}
+
+impl Iterator for QueryTripleIter {
+    type Item = Result<Triple, EvaluationError>;
+
+    #[inline]
+    fn next(&mut self) -> Option<Self::Item> {
+        self.iter.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.iter.size_hint()
+    }
+
+    #[inline]
+    fn fold<Acc, G>(self, init: Acc, g: G) -> Acc
+    where
+        G: FnMut(Acc, Self::Item) -> Acc,
+    {
+        self.iter.fold(init, g)
+    }
+}
+
+#[cfg(test)]
+#[allow(clippy::panic_in_result_fn)]
+mod tests {
+    use super::*;
+    use std::io::Cursor;
+
+    #[test]
+    fn test_serialization_roundtrip() -> Result<(), EvaluationError> {
+        use std::str;
+
+        for format in [
+            QueryResultsFormat::Json,
+            QueryResultsFormat::Xml,
+            QueryResultsFormat::Tsv,
+        ] {
+            let results = vec![
+                QueryResults::Boolean(true),
+                QueryResults::Boolean(false),
+                QueryResults::Solutions(QuerySolutionIter::new(
+                    [
+                        Variable::new_unchecked("foo"),
+                        Variable::new_unchecked("bar"),
+                    ]
+                    .as_ref()
+                    .into(),
+                    Box::new(
+                        vec![
+                            Ok(vec![None, None]),
+                            Ok(vec![
+                                Some(NamedNode::new_unchecked("http://example.com").into()),
+                                None,
+                            ]),
+                            Ok(vec![
+                                None,
+                                Some(NamedNode::new_unchecked("http://example.com").into()),
+                            ]),
+                            Ok(vec![
+                                Some(BlankNode::new_unchecked("foo").into()),
+                                Some(BlankNode::new_unchecked("bar").into()),
+                            ]),
+                            Ok(vec![Some(Literal::new_simple_literal("foo").into()), None]),
+                            Ok(vec![
+                                Some(
+                                    Literal::new_language_tagged_literal_unchecked("foo", "fr")
+                                        .into(),
+                                ),
+                                None,
+                            ]),
+                            Ok(vec![
+                                Some(Literal::from(1).into()),
+                                Some(Literal::from(true).into()),
+                            ]),
+                            Ok(vec![
+                                Some(Literal::from(1.33).into()),
+                                Some(Literal::from(false).into()),
+                            ]),
+                            Ok(vec![
+                                Some(
+                                    Triple::new(
+                                        NamedNode::new_unchecked("http://example.com/s"),
+                                        NamedNode::new_unchecked("http://example.com/p"),
+                                        Triple::new(
+                                            NamedNode::new_unchecked("http://example.com/os"),
+                                            NamedNode::new_unchecked("http://example.com/op"),
+                                            NamedNode::new_unchecked("http://example.com/oo"),
+                                        ),
+                                    )
+                                    .into(),
+                                ),
+                                None,
+                            ]),
+                        ]
+                        .into_iter(),
+                    ),
+                )),
+            ];
+
+            for ex in results {
+                let mut buffer = Vec::new();
+                ex.write(&mut buffer, format)?;
+                let ex2 = QueryResults::read(Cursor::new(buffer.clone()), format)?;
+                let mut buffer2 = Vec::new();
+                ex2.write(&mut buffer2, format)?;
+                assert_eq!(
+                    str::from_utf8(&buffer).unwrap(),
+                    str::from_utf8(&buffer2).unwrap()
+                );
+            }
+        }
+
+        Ok(())
+    }
+}

src/sparql/results.rs

@@ -0,0 +1,44 @@
+//! Utilities to read and write RDF results formats  using [sparesults](https://crates.io/crates/sparesults).
+//!
+//! It supports [SPARQL Query Results XML Format (Second Edition)](https://www.w3.org/TR/rdf-sparql-XMLres/), [SPARQL 1.1 Query Results JSON Format](https://www.w3.org/TR/sparql11-results-json/) and [SPARQL 1.1 Query Results CSV and TSV Formats](https://www.w3.org/TR/sparql11-results-csv-tsv/).
+//!
+//! Usage example converting a JSON result file into a TSV result file:
+//!
+//! ```
+//! use oxigraph::sparql::results::{QueryResultsFormat, QueryResultsParser, FromReadQueryResultsReader, QueryResultsSerializer};
+//! use std::io::Result;
+//!
+//! fn convert_json_to_tsv(json_file: &[u8]) -> Result<Vec<u8>> {
+//!     let json_parser = QueryResultsParser::from_format(QueryResultsFormat::Json);
+//!     let tsv_serializer = QueryResultsSerializer::from_format(QueryResultsFormat::Tsv);
+//!     // We start to read the JSON file and see which kind of results it is
+//!     match json_parser.parse_read(json_file)? {
+//!         FromReadQueryResultsReader::Boolean(value) => {
+//!             // it's a boolean result, we copy it in TSV to the output buffer
+//!             tsv_serializer.serialize_boolean_to_write(Vec::new(), value)
+//!         }
+//!         FromReadQueryResultsReader::Solutions(solutions_reader) => {
+//!             // it's a set of solutions, we create a writer and we write to it while reading in streaming from the JSON file
+//!             let mut serialize_solutions_to_write = tsv_serializer.serialize_solutions_to_write(Vec::new(), solutions_reader.variables().to_vec())?;
+//!             for solution in solutions_reader {
+//!                 serialize_solutions_to_write.write(&solution?)?;
+//!             }
+//!             serialize_solutions_to_write.finish()
+//!         }
+//!     }
+//! }
+//!
+//! // Let's test with a boolean
+//! assert_eq!(
+//!     convert_json_to_tsv(br#"{"boolean":true}"#.as_slice()).unwrap(),
+//!     b"true"
+//! );
+//!
+//! // And with a set of solutions
+//! assert_eq!(
+//!     convert_json_to_tsv(br#"{"head":{"vars":["foo","bar"]},"results":{"bindings":[{"foo":{"type":"literal","value":"test"}}]}}"#.as_slice()).unwrap(),
+//!     b"?foo\t?bar\n\"test\"\t\n"
+//! );
+//! ```
+
+pub use sparesults::*;

src/sparql/service.rs

@@ -0,0 +1,124 @@
+use crate::model::NamedNode;
+use crate::sparql::algebra::Query;
+use crate::sparql::error::EvaluationError;
+use crate::sparql::http::Client;
+use crate::sparql::model::QueryResults;
+use crate::sparql::results::QueryResultsFormat;
+use std::error::Error;
+use std::time::Duration;
+
+/// Handler for [SPARQL 1.1 Federated Query](https://www.w3.org/TR/sparql11-federated-query/) SERVICE.
+///
+/// Should be given to [`QueryOptions`](super::QueryOptions::with_service_handler())
+/// before evaluating a SPARQL query that uses SERVICE calls.
+///
+/// ```
+/// use oxigraph::model::*;
+/// use oxigraph::sparql::{EvaluationError, Query, QueryOptions, QueryResults, ServiceHandler};
+/// use oxigraph::store::Store;
+///
+/// struct TestServiceHandler {
+///     store: Store,
+/// }
+///
+/// impl ServiceHandler for TestServiceHandler {
+///     type Error = EvaluationError;
+///
+///     fn handle(
+///         &self,
+///         service_name: NamedNode,
+///         query: Query,
+///     ) -> Result<QueryResults, Self::Error> {
+///         if service_name == "http://example.com/service" {
+///             self.store.query(query)
+///         } else {
+///             panic!()
+///         }
+///     }
+/// }
+///
+/// let store = Store::new()?;
+/// let service = TestServiceHandler {
+///     store: Store::new()?,
+/// };
+/// let ex = NamedNodeRef::new("http://example.com")?;
+/// service
+///     .store
+///     .insert(QuadRef::new(ex, ex, ex, GraphNameRef::DefaultGraph))?;
+///
+/// if let QueryResults::Solutions(mut solutions) = store.query_opt(
+///     "SELECT ?s WHERE { SERVICE <http://example.com/service> { ?s ?p ?o } }",
+///     QueryOptions::default().with_service_handler(service),
+/// )? {
+///     assert_eq!(solutions.next().unwrap()?.get("s"), Some(&ex.into()));
+/// }
+/// # Result::<_,Box<dyn std::error::Error>>::Ok(())
+/// ```
+pub trait ServiceHandler: Send + Sync {
+    /// The service evaluation error.
+    type Error: Error + Send + Sync + 'static;
+
+    /// Evaluates a [`Query`] against a given service identified by a [`NamedNode`].
+    fn handle(&self, service_name: NamedNode, query: Query) -> Result<QueryResults, Self::Error>;
+}
+
+pub struct EmptyServiceHandler;
+
+impl ServiceHandler for EmptyServiceHandler {
+    type Error = EvaluationError;
+
+    fn handle(&self, name: NamedNode, _: Query) -> Result<QueryResults, Self::Error> {
+        Err(EvaluationError::UnsupportedService(name))
+    }
+}
+
+pub struct ErrorConversionServiceHandler<S: ServiceHandler> {
+    handler: S,
+}
+
+impl<S: ServiceHandler> ErrorConversionServiceHandler<S> {
+    pub fn wrap(handler: S) -> Self {
+        Self { handler }
+    }
+}
+
+impl<S: ServiceHandler> ServiceHandler for ErrorConversionServiceHandler<S> {
+    type Error = EvaluationError;
+
+    fn handle(&self, service_name: NamedNode, query: Query) -> Result<QueryResults, Self::Error> {
+        self.handler
+            .handle(service_name, query)
+            .map_err(|e| EvaluationError::Service(Box::new(e)))
+    }
+}
+
+pub struct SimpleServiceHandler {
+    client: Client,
+}
+
+impl SimpleServiceHandler {
+    pub fn new(http_timeout: Option<Duration>, http_redirection_limit: usize) -> Self {
+        Self {
+            client: Client::new(http_timeout, http_redirection_limit),
+        }
+    }
+}
+
+impl ServiceHandler for SimpleServiceHandler {
+    type Error = EvaluationError;
+
+    fn handle(&self, service_name: NamedNode, query: Query) -> Result<QueryResults, Self::Error> {
+        let (content_type, body) = self
+            .client
+            .post(
+                service_name.as_str(),
+                query.to_string().into_bytes(),
+                "application/sparql-query",
+                "application/sparql-results+json, application/sparql-results+xml",
+            )
+            .map_err(|e| EvaluationError::Service(Box::new(e)))?;
+        let format = QueryResultsFormat::from_media_type(&content_type)
+            .ok_or_else(|| EvaluationError::UnsupportedContentType(content_type))?;
+        Ok(QueryResults::read(body, format)?)
+    }
+}

src/sparql/update.rs

@@ -0,0 +1,565 @@
+use crate::io::{RdfFormat, RdfParser};
+use crate::model::{GraphName as OxGraphName, GraphNameRef, Quad as OxQuad};
+use crate::sparql::algebra::QueryDataset;
+use crate::sparql::dataset::DatasetView;
+use crate::sparql::eval::{EncodedTuple, SimpleEvaluator};
+use crate::sparql::http::Client;
+use crate::sparql::{EvaluationError, Update, UpdateOptions};
+use crate::storage::numeric_encoder::{Decoder, EncodedTerm};
+use crate::storage::StorageWriter;
+use oxiri::Iri;
+use spargebra::algebra::{GraphPattern, GraphTarget};
+use spargebra::term::{
+    BlankNode, GraphName, GraphNamePattern, GroundQuad, GroundQuadPattern, GroundSubject,
+    GroundTerm, GroundTermPattern, GroundTriple, GroundTriplePattern, NamedNode, NamedNodePattern,
+    Quad, QuadPattern, Subject, Term, TermPattern, Triple, TriplePattern, Variable,
+};
+use spargebra::GraphUpdateOperation;
+use sparopt::Optimizer;
+use std::collections::HashMap;
+use std::io;
+use std::rc::Rc;
+use std::sync::Arc;
+
+pub fn evaluate_update<'a, 'b: 'a>(
+    transaction: &'a mut StorageWriter<'b>,
+    update: &Update,
+    options: &UpdateOptions,
+) -> Result<(), EvaluationError> {
+    SimpleUpdateEvaluator {
+        transaction,
+        base_iri: update.inner.base_iri.clone().map(Rc::new),
+        options: options.clone(),
+        client: Client::new(
+            options.query_options.http_timeout,
+            options.query_options.http_redirection_limit,
+        ),
+    }
+    .eval_all(&update.inner.operations, &update.using_datasets)
+}
+
+struct SimpleUpdateEvaluator<'a, 'b> {
+    transaction: &'a mut StorageWriter<'b>,
+    base_iri: Option<Rc<Iri<String>>>,
+    options: UpdateOptions,
+    client: Client,
+}
+
+impl<'a, 'b: 'a> SimpleUpdateEvaluator<'a, 'b> {
+    fn eval_all(
+        &mut self,
+        updates: &[GraphUpdateOperation],
+        using_datasets: &[Option<QueryDataset>],
+    ) -> Result<(), EvaluationError> {
+        for (update, using_dataset) in updates.iter().zip(using_datasets) {
+            self.eval(update, using_dataset)?;
+        }
+        Ok(())
+    }
+
+    fn eval(
+        &mut self,
+        update: &GraphUpdateOperation,
+        using_dataset: &Option<QueryDataset>,
+    ) -> Result<(), EvaluationError> {
+        match update {
+            GraphUpdateOperation::InsertData { data } => self.eval_insert_data(data),
+            GraphUpdateOperation::DeleteData { data } => self.eval_delete_data(data),
+            GraphUpdateOperation::DeleteInsert {
+                delete,
+                insert,
+                pattern,
+                ..
+            } => self.eval_delete_insert(
+                delete,
+                insert,
+                using_dataset.as_ref().unwrap_or(&QueryDataset::new()),
+                pattern,
+            ),
+            GraphUpdateOperation::Load {
+                silent,
+                source,
+                destination,
+            } => {
+                if let Err(error) = self.eval_load(source, destination) {
+                    if *silent {
+                        Ok(())
+                    } else {
+                        Err(error)
+                    }
+                } else {
+                    Ok(())
+                }
+            }
+            GraphUpdateOperation::Clear { graph, silent } => self.eval_clear(graph, *silent),
+            GraphUpdateOperation::Create { graph, silent } => self.eval_create(graph, *silent),
+            GraphUpdateOperation::Drop { graph, silent } => self.eval_drop(graph, *silent),
+        }
+    }
+
+    fn eval_insert_data(&mut self, data: &[Quad]) -> Result<(), EvaluationError> {
+        let mut bnodes = HashMap::new();
+        for quad in data {
+            let quad = Self::convert_quad(quad, &mut bnodes);
+            self.transaction.insert(quad.as_ref())?;
+        }
+        Ok(())
+    }
+
+    fn eval_delete_data(&mut self, data: &[GroundQuad]) -> Result<(), EvaluationError> {
+        for quad in data {
+            let quad = Self::convert_ground_quad(quad);
+            self.transaction.remove(quad.as_ref())?;
+        }
+        Ok(())
+    }
+
+    fn eval_delete_insert(
+        &mut self,
+        delete: &[GroundQuadPattern],
+        insert: &[QuadPattern],
+        using: &QueryDataset,
+        algebra: &GraphPattern,
+    ) -> Result<(), EvaluationError> {
+        let dataset = Rc::new(DatasetView::new(self.transaction.reader(), using));
+        let mut pattern = sparopt::algebra::GraphPattern::from(algebra);
+        if !self.options.query_options.without_optimizations {
+            pattern = Optimizer::optimize_graph_pattern(sparopt::algebra::GraphPattern::Reduced {
+                inner: Box::new(pattern),
+            });
+        }
+        let evaluator = SimpleEvaluator::new(
+            Rc::clone(&dataset),
+            self.base_iri.clone(),
+            self.options.query_options.service_handler(),
+            Arc::new(self.options.query_options.custom_functions.clone()),
+            false,
+        );
+        let mut variables = Vec::new();
+        let mut bnodes = HashMap::new();
+        let (eval, _) = evaluator.graph_pattern_evaluator(&pattern, &mut variables);
+        let tuples =
+            eval(EncodedTuple::with_capacity(variables.len())).collect::<Result<Vec<_>, _>>()?; // TODO: would be much better to stream
+        for tuple in tuples {
+            for quad in delete {
+                if let Some(quad) =
+                    Self::convert_ground_quad_pattern(quad, &variables, &tuple, &dataset)?
+                {
+                    self.transaction.remove(quad.as_ref())?;
+                }
+            }
+            for quad in insert {
+                if let Some(quad) =
+                    Self::convert_quad_pattern(quad, &variables, &tuple, &dataset, &mut bnodes)?
+                {
+                    self.transaction.insert(quad.as_ref())?;
+                }
+            }
+            bnodes.clear();
+        }
+        Ok(())
+    }
+
+    fn eval_load(&mut self, from: &NamedNode, to: &GraphName) -> Result<(), EvaluationError> {
+        let (content_type, body) = self
+            .client
+            .get(
+                from.as_str(),
+                "application/n-triples, text/turtle, application/rdf+xml",
+            )
+            .map_err(|e| EvaluationError::Service(Box::new(e)))?;
+        let format = RdfFormat::from_media_type(&content_type)
+            .ok_or_else(|| EvaluationError::UnsupportedContentType(content_type))?;
+        let to_graph_name = match to {
+            GraphName::NamedNode(graph_name) => graph_name.into(),
+            GraphName::DefaultGraph => GraphNameRef::DefaultGraph,
+        };
+        let mut parser = RdfParser::from_format(format)
+            .rename_blank_nodes()
+            .without_named_graphs()
+            .with_default_graph(to_graph_name);
+        parser = parser.with_base_iri(from.as_str()).map_err(|e| {
+            EvaluationError::Service(Box::new(io::Error::new(
+                io::ErrorKind::InvalidInput,
+                format!("Invalid URL: {from}: {e}"),
+            )))
+        })?;
+        for q in parser.parse_read(body) {
+            self.transaction.insert(q?.as_ref())?;
+        }
+        Ok(())
+    }
+
+    fn eval_create(&mut self, graph_name: &NamedNode, silent: bool) -> Result<(), EvaluationError> {
+        if self.transaction.insert_named_graph(graph_name.into())? || silent {
+            Ok(())
+        } else {
+            Err(EvaluationError::GraphAlreadyExists(graph_name.clone()))
+        }
+    }
+
+    fn eval_clear(&mut self, graph: &GraphTarget, silent: bool) -> Result<(), EvaluationError> {
+        match graph {
+            GraphTarget::NamedNode(graph_name) => {
+                if self
+                    .transaction
+                    .reader()
+                    .contains_named_graph(&graph_name.as_ref().into())?
+                {
+                    Ok(self.transaction.clear_graph(graph_name.into())?)
+                } else if silent {
+                    Ok(())
+                } else {
+                    Err(EvaluationError::GraphDoesNotExist(graph_name.clone()))
+                }
+            }
+            GraphTarget::DefaultGraph => {
+                self.transaction.clear_graph(GraphNameRef::DefaultGraph)?;
+                Ok(())
+            }
+            GraphTarget::NamedGraphs => Ok(self.transaction.clear_all_named_graphs()?),
+            GraphTarget::AllGraphs => Ok(self.transaction.clear_all_graphs()?),
+        }
+    }
+
+    fn eval_drop(&mut self, graph: &GraphTarget, silent: bool) -> Result<(), EvaluationError> {
+        match graph {
+            GraphTarget::NamedNode(graph_name) => {
+                if self.transaction.remove_named_graph(graph_name.into())? || silent {
+                    Ok(())
+                } else {
+                    Err(EvaluationError::GraphDoesNotExist(graph_name.clone()))
+                }
+            }
+            GraphTarget::DefaultGraph => {
+                Ok(self.transaction.clear_graph(GraphNameRef::DefaultGraph)?)
+            }
+            GraphTarget::NamedGraphs => Ok(self.transaction.remove_all_named_graphs()?),
+            GraphTarget::AllGraphs => Ok(self.transaction.clear()?),
+        }
+    }
+
+    fn convert_quad(quad: &Quad, bnodes: &mut HashMap<BlankNode, BlankNode>) -> OxQuad {
+        OxQuad {
+            subject: match &quad.subject {
+                Subject::NamedNode(subject) => subject.clone().into(),
+                Subject::BlankNode(subject) => Self::convert_blank_node(subject, bnodes).into(),
+                Subject::Triple(subject) => Self::convert_triple(subject, bnodes).into(),
+            },
+            predicate: quad.predicate.clone(),
+            object: match &quad.object {
+                Term::NamedNode(object) => object.clone().into(),
+                Term::BlankNode(object) => Self::convert_blank_node(object, bnodes).into(),
+                Term::Literal(object) => object.clone().into(),
+                Term::Triple(subject) => Self::convert_triple(subject, bnodes).into(),
+            },
+            graph_name: match &quad.graph_name {
+                GraphName::NamedNode(graph_name) => graph_name.clone().into(),
+                GraphName::DefaultGraph => OxGraphName::DefaultGraph,
+            },
+        }
+    }
+
+    fn convert_triple(triple: &Triple, bnodes: &mut HashMap<BlankNode, BlankNode>) -> Triple {
+        Triple {
+            subject: match &triple.subject {
+                Subject::NamedNode(subject) => subject.clone().into(),
+                Subject::BlankNode(subject) => Self::convert_blank_node(subject, bnodes).into(),
+                Subject::Triple(subject) => Self::convert_triple(subject, bnodes).into(),
+            },
+            predicate: triple.predicate.clone(),
+            object: match &triple.object {
+                Term::NamedNode(object) => object.clone().into(),
+                Term::BlankNode(object) => Self::convert_blank_node(object, bnodes).into(),
+                Term::Literal(object) => object.clone().into(),
+                Term::Triple(subject) => Self::convert_triple(subject, bnodes).into(),
+            },
+        }
+    }
+
+    fn convert_blank_node(
+        node: &BlankNode,
+        bnodes: &mut HashMap<BlankNode, BlankNode>,
+    ) -> BlankNode {
+        bnodes.entry(node.clone()).or_default().clone()
+    }
+
+    fn convert_ground_quad(quad: &GroundQuad) -> OxQuad {
+        OxQuad {
+            subject: match &quad.subject {
+                GroundSubject::NamedNode(subject) => subject.clone().into(),
+                GroundSubject::Triple(subject) => Self::convert_ground_triple(subject).into(),
+            },
+            predicate: quad.predicate.clone(),
+            object: match &quad.object {
+                GroundTerm::NamedNode(object) => object.clone().into(),
+                GroundTerm::Literal(object) => object.clone().into(),
+                GroundTerm::Triple(subject) => Self::convert_ground_triple(subject).into(),
+            },
+            graph_name: match &quad.graph_name {
+                GraphName::NamedNode(graph_name) => graph_name.clone().into(),
+                GraphName::DefaultGraph => OxGraphName::DefaultGraph,
+            },
+        }
+    }
+
+    fn convert_ground_triple(triple: &GroundTriple) -> Triple {
+        Triple {
+            subject: match &triple.subject {
+                GroundSubject::NamedNode(subject) => subject.clone().into(),
+                GroundSubject::Triple(subject) => Self::convert_ground_triple(subject).into(),
+            },
+            predicate: triple.predicate.clone(),
+            object: match &triple.object {
+                GroundTerm::NamedNode(object) => object.clone().into(),
+                GroundTerm::Literal(object) => object.clone().into(),
+                GroundTerm::Triple(subject) => Self::convert_ground_triple(subject).into(),
+            },
+        }
+    }
+
+    fn convert_quad_pattern(
+        quad: &QuadPattern,
+        variables: &[Variable],
+        values: &EncodedTuple,
+        dataset: &DatasetView,
+        bnodes: &mut HashMap<BlankNode, BlankNode>,
+    ) -> Result<Option<OxQuad>, EvaluationError> {
+        Ok(Some(OxQuad {
+            subject: match Self::convert_term_or_var(
+                &quad.subject,
+                variables,
+                values,
+                dataset,
+                bnodes,
+            )? {
+                Some(Term::NamedNode(node)) => node.into(),
+                Some(Term::BlankNode(node)) => node.into(),
+                Some(Term::Triple(triple)) => triple.into(),
+                Some(Term::Literal(_)) | None => return Ok(None),
+            },
+            predicate: if let Some(predicate) =
+                Self::convert_named_node_or_var(&quad.predicate, variables, values, dataset)?
+            {
+                predicate
+            } else {
+                return Ok(None);
+            },
+            object: if let Some(object) =
+                Self::convert_term_or_var(&quad.object, variables, values, dataset, bnodes)?
+            {
+                object
+            } else {
+                return Ok(None);
+            },
+            graph_name: if let Some(graph_name) =
+                Self::convert_graph_name_or_var(&quad.graph_name, variables, values, dataset)?
+            {
+                graph_name
+            } else {
+                return Ok(None);
+            },
+        }))
+    }
+
+    fn convert_term_or_var(
+        term: &TermPattern,
+        variables: &[Variable],
+        values: &EncodedTuple,
+        dataset: &DatasetView,
+        bnodes: &mut HashMap<BlankNode, BlankNode>,
+    ) -> Result<Option<Term>, EvaluationError> {
+        Ok(match term {
+            TermPattern::NamedNode(term) => Some(term.clone().into()),
+            TermPattern::BlankNode(bnode) => Some(Self::convert_blank_node(bnode, bnodes).into()),
+            TermPattern::Literal(term) => Some(term.clone().into()),
+            TermPattern::Triple(triple) => {
+                Self::convert_triple_pattern(triple, variables, values, dataset, bnodes)?
+                    .map(Into::into)
+            }
+            TermPattern::Variable(v) => Self::lookup_variable(v, variables, values)
+                .map(|node| dataset.decode_term(&node))
+                .transpose()?,
+        })
+    }
+
+    fn convert_named_node_or_var(
+        term: &NamedNodePattern,
+        variables: &[Variable],
+        values: &EncodedTuple,
+        dataset: &DatasetView,
+    ) -> Result<Option<NamedNode>, EvaluationError> {
+        Ok(match term {
+            NamedNodePattern::NamedNode(term) => Some(term.clone()),
+            NamedNodePattern::Variable(v) => Self::lookup_variable(v, variables, values)
+                .map(|node| dataset.decode_named_node(&node))
+                .transpose()?,
+        })
+    }
+
+    fn convert_graph_name_or_var(
+        term: &GraphNamePattern,
+        variables: &[Variable],
+        values: &EncodedTuple,
+        dataset: &DatasetView,
+    ) -> Result<Option<OxGraphName>, EvaluationError> {
+        match term {
+            GraphNamePattern::NamedNode(term) => Ok(Some(term.clone().into())),
+            GraphNamePattern::DefaultGraph => Ok(Some(OxGraphName::DefaultGraph)),
+            GraphNamePattern::Variable(v) => Self::lookup_variable(v, variables, values)
+                .map(|node| {
+                    Ok(if node == EncodedTerm::DefaultGraph {
+                        OxGraphName::DefaultGraph
+                    } else {
+                        dataset.decode_named_node(&node)?.into()
+                    })
+                })
+                .transpose(),
+        }
+    }
+
+    fn convert_triple_pattern(
+        triple: &TriplePattern,
+        variables: &[Variable],
+        values: &EncodedTuple,
+        dataset: &DatasetView,
+        bnodes: &mut HashMap<BlankNode, BlankNode>,
+    ) -> Result<Option<Triple>, EvaluationError> {
+        Ok(Some(Triple {
+            subject: match Self::convert_term_or_var(
+                &triple.subject,
+                variables,
+                values,
+                dataset,
+                bnodes,
+            )? {
+                Some(Term::NamedNode(node)) => node.into(),
+                Some(Term::BlankNode(node)) => node.into(),
+                Some(Term::Triple(triple)) => triple.into(),
+                Some(Term::Literal(_)) | None => return Ok(None),
+            },
+            predicate: if let Some(predicate) =
+                Self::convert_named_node_or_var(&triple.predicate, variables, values, dataset)?
+            {
+                predicate
+            } else {
+                return Ok(None);
+            },
+            object: if let Some(object) =
+                Self::convert_term_or_var(&triple.object, variables, values, dataset, bnodes)?
+            {
+                object
+            } else {
+                return Ok(None);
+            },
+        }))
+    }
+
+    fn convert_ground_quad_pattern(
+        quad: &GroundQuadPattern,
+        variables: &[Variable],
+        values: &EncodedTuple,
+        dataset: &DatasetView,
+    ) -> Result<Option<OxQuad>, EvaluationError> {
+        Ok(Some(OxQuad {
+            subject: match Self::convert_ground_term_or_var(
+                &quad.subject,
+                variables,
+                values,
+                dataset,
+            )? {
+                Some(Term::NamedNode(node)) => node.into(),
+                Some(Term::BlankNode(node)) => node.into(),
+                Some(Term::Triple(triple)) => triple.into(),
+                Some(Term::Literal(_)) | None => return Ok(None),
+            },
+            predicate: if let Some(predicate) =
+                Self::convert_named_node_or_var(&quad.predicate, variables, values, dataset)?
+            {
+                predicate
+            } else {
+                return Ok(None);
+            },
+            object: if let Some(object) =
+                Self::convert_ground_term_or_var(&quad.object, variables, values, dataset)?
+            {
+                object
+            } else {
+                return Ok(None);
+            },
+            graph_name: if let Some(graph_name) =
+                Self::convert_graph_name_or_var(&quad.graph_name, variables, values, dataset)?
+            {
+                graph_name
+            } else {
+                return Ok(None);
+            },
+        }))
+    }
+
+    fn convert_ground_term_or_var(
+        term: &GroundTermPattern,
+        variables: &[Variable],
+        values: &EncodedTuple,
+        dataset: &DatasetView,
+    ) -> Result<Option<Term>, EvaluationError> {
+        Ok(match term {
+            GroundTermPattern::NamedNode(term) => Some(term.clone().into()),
+            GroundTermPattern::Literal(term) => Some(term.clone().into()),
+            GroundTermPattern::Triple(triple) => {
+                Self::convert_ground_triple_pattern(triple, variables, values, dataset)?
+                    .map(Into::into)
+            }
+            GroundTermPattern::Variable(v) => Self::lookup_variable(v, variables, values)
+                .map(|node| dataset.decode_term(&node))
+                .transpose()?,
+        })
+    }
+
+    fn convert_ground_triple_pattern(
+        triple: &GroundTriplePattern,
+        variables: &[Variable],
+        values: &EncodedTuple,
+        dataset: &DatasetView,
+    ) -> Result<Option<Triple>, EvaluationError> {
+        Ok(Some(Triple {
+            subject: match Self::convert_ground_term_or_var(
+                &triple.subject,
+                variables,
+                values,
+                dataset,
+            )? {
+                Some(Term::NamedNode(node)) => node.into(),
+                Some(Term::BlankNode(node)) => node.into(),
+                Some(Term::Triple(triple)) => triple.into(),
+                Some(Term::Literal(_)) | None => return Ok(None),
+            },
+            predicate: if let Some(predicate) =
+                Self::convert_named_node_or_var(&triple.predicate, variables, values, dataset)?
+            {
+                predicate
+            } else {
+                return Ok(None);
+            },
+            object: if let Some(object) =
+                Self::convert_ground_term_or_var(&triple.object, variables, values, dataset)?
+            {
+                object
+            } else {
+                return Ok(None);
+            },
+        }))
+    }
+
+    fn lookup_variable(
+        v: &Variable,
+        variables: &[Variable],
+        values: &EncodedTuple,
+    ) -> Option<EncodedTerm> {
+        variables
+            .iter()
+            .position(|v2| v == v2)
+            .and_then(|i| values.get(i))
+            .cloned()
+    }
+}

src/storage/backend/fallback.rs

@@ -0,0 +1,310 @@
+//! TODO: This storage is dramatically naive.
+
+use crate::storage::StorageError;
+use crate::store::CorruptionError;
+use std::cell::RefCell;
+use std::collections::{BTreeMap, HashMap};
+use std::error::Error;
+use std::mem::transmute;
+use std::rc::{Rc, Weak};
+use std::sync::{Arc, RwLock, RwLockWriteGuard};
+
+pub struct ColumnFamilyDefinition {
+    pub name: &'static str,
+    pub use_iter: bool,
+    pub min_prefix_size: usize,
+    pub unordered_writes: bool,
+}
+
+#[derive(Clone)]
+pub struct Db(Arc<RwLock<HashMap<ColumnFamily, BTreeMap<Vec<u8>, Vec<u8>>>>>);
+
+impl Db {
+    #[allow(clippy::unnecessary_wraps)]
+    pub fn new(column_families: Vec<ColumnFamilyDefinition>) -> Result<Self, StorageError> {
+        let mut trees = HashMap::new();
+        for cf in column_families {
+            trees.insert(ColumnFamily(cf.name), BTreeMap::default());
+        }
+        trees.entry(ColumnFamily("default")).or_default(); // We make sure that "default" key exists.
+        Ok(Self(Arc::new(RwLock::new(trees))))
+    }
+
+    #[allow(clippy::unwrap_in_result)]
+    pub fn column_family(&self, name: &'static str) -> Result<ColumnFamily, StorageError> {
+        let column_family = ColumnFamily(name);
+        if self.0.read().unwrap().contains_key(&column_family) {
+            Ok(column_family)
+        } else {
+            Err(CorruptionError::from_missing_column_family_name(name).into())
+        }
+    }
+
+    #[must_use]
+    pub fn snapshot(&self) -> Reader {
+        Reader(InnerReader::Simple(Arc::clone(&self.0)))
+    }
+
+    #[allow(clippy::unwrap_in_result)]
+    pub fn transaction<'a, 'b: 'a, T, E: Error + 'static + From<StorageError>>(
+        &'b self,
+        f: impl Fn(Transaction<'a>) -> Result<T, E>,
+    ) -> Result<T, E> {
+        f(Transaction(Rc::new(RefCell::new(self.0.write().unwrap()))))
+    }
+}
+
+#[derive(Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
+pub struct ColumnFamily(&'static str);
+
+pub struct Reader(InnerReader);
+
+enum InnerReader {
+    Simple(Arc<RwLock<HashMap<ColumnFamily, BTreeMap<Vec<u8>, Vec<u8>>>>>),
+    Transaction(
+        Weak<RefCell<RwLockWriteGuard<'static, HashMap<ColumnFamily, BTreeMap<Vec<u8>, Vec<u8>>>>>>,
+    ),
+}
+
+impl Reader {
+    #[allow(clippy::unwrap_in_result)]
+    pub fn get(
+        &self,
+        column_family: &ColumnFamily,
+        key: &[u8],
+    ) -> Result<Option<Vec<u8>>, StorageError> {
+        match &self.0 {
+            InnerReader::Simple(reader) => Ok(reader
+                .read()
+                .unwrap()
+                .get(column_family)
+                .and_then(|cf| cf.get(key).cloned())),
+            InnerReader::Transaction(reader) => {
+                if let Some(reader) = reader.upgrade() {
+                    Ok((*reader)
+                        .borrow()
+                        .get(column_family)
+                        .and_then(|cf| cf.get(key).cloned()))
+                } else {
+                    Err(StorageError::Other(
+                        "The transaction is already ended".into(),
+                    ))
+                }
+            }
+        }
+    }
+
+    #[allow(clippy::unwrap_in_result)]
+    pub fn contains_key(
+        &self,
+        column_family: &ColumnFamily,
+        key: &[u8],
+    ) -> Result<bool, StorageError> {
+        match &self.0 {
+            InnerReader::Simple(reader) => Ok(reader
+                .read()
+                .unwrap()
+                .get(column_family)
+                .map_or(false, |cf| cf.contains_key(key))),
+            InnerReader::Transaction(reader) => {
+                if let Some(reader) = reader.upgrade() {
+                    Ok((*reader)
+                        .borrow()
+                        .get(column_family)
+                        .map_or(false, |cf| cf.contains_key(key)))
+                } else {
+                    Err(StorageError::Other(
+                        "The transaction is already ended".into(),
+                    ))
+                }
+            }
+        }
+    }
+
+    #[allow(clippy::iter_not_returning_iterator)]
+    pub fn iter(&self, column_family: &ColumnFamily) -> Result<Iter, StorageError> {
+        self.scan_prefix(column_family, &[])
+    }
+
+    #[allow(clippy::unwrap_in_result)]
+    pub fn scan_prefix(
+        &self,
+        column_family: &ColumnFamily,
+        prefix: &[u8],
+    ) -> Result<Iter, StorageError> {
+        let data: Vec<_> = match &self.0 {
+            InnerReader::Simple(reader) => {
+                let trees = reader.read().unwrap();
+                let Some(tree) = trees.get(column_family) else {
+                    return Ok(Iter {
+                        iter: Vec::new().into_iter(),
+                        current: None,
+                    });
+                };
+                if prefix.is_empty() {
+                    tree.iter().map(|(k, v)| (k.clone(), v.clone())).collect()
+                } else {
+                    tree.range(prefix.to_vec()..)
+                        .take_while(|(k, _)| k.starts_with(prefix))
+                        .map(|(k, v)| (k.clone(), v.clone()))
+                        .collect()
+                }
+            }
+            InnerReader::Transaction(reader) => {
+                let Some(reader) = reader.upgrade() else {
+                    return Err(StorageError::Other(
+                        "The transaction is already ended".into(),
+                    ));
+                };
+                let trees = (*reader).borrow();
+                let Some(tree) = trees.get(column_family) else {
+                    return Ok(Iter {
+                        iter: Vec::new().into_iter(),
+                        current: None,
+                    });
+                };
+                if prefix.is_empty() {
+                    tree.iter().map(|(k, v)| (k.clone(), v.clone())).collect()
+                } else {
+                    tree.range(prefix.to_vec()..)
+                        .take_while(|(k, _)| k.starts_with(prefix))
+                        .map(|(k, v)| (k.clone(), v.clone()))
+                        .collect()
+                }
+            }
+        };
+        let mut iter = data.into_iter();
+        let current = iter.next();
+        Ok(Iter { iter, current })
+    }
+
+    #[allow(clippy::unwrap_in_result)]
+    pub fn len(&self, column_family: &ColumnFamily) -> Result<usize, StorageError> {
+        match &self.0 {
+            InnerReader::Simple(reader) => Ok(reader
+                .read()
+                .unwrap()
+                .get(column_family)
+                .map_or(0, BTreeMap::len)),
+            InnerReader::Transaction(reader) => {
+                if let Some(reader) = reader.upgrade() {
+                    Ok((*reader)
+                        .borrow()
+                        .get(column_family)
+                        .map_or(0, BTreeMap::len))
+                } else {
+                    Err(StorageError::Other(
+                        "The transaction is already ended".into(),
+                    ))
+                }
+            }
+        }
+    }
+
+    #[allow(clippy::unwrap_in_result)]
+    pub fn is_empty(&self, column_family: &ColumnFamily) -> Result<bool, StorageError> {
+        match &self.0 {
+            InnerReader::Simple(reader) => Ok(reader
+                .read()
+                .unwrap()
+                .get(column_family)
+                .map_or(true, BTreeMap::is_empty)),
+            InnerReader::Transaction(reader) => {
+                if let Some(reader) = reader.upgrade() {
+                    Ok((*reader)
+                        .borrow()
+                        .get(column_family)
+                        .map_or(true, BTreeMap::is_empty))
+                } else {
+                    Err(StorageError::Other(
+                        "The transaction is already ended".into(),
+                    ))
+                }
+            }
+        }
+    }
+}
+
+pub struct Transaction<'a>(
+    Rc<RefCell<RwLockWriteGuard<'a, HashMap<ColumnFamily, BTreeMap<Vec<u8>, Vec<u8>>>>>>,
+);
+
+impl Transaction<'_> {
+    #[allow(unsafe_code, clippy::useless_transmute)]
+    pub fn reader(&self) -> Reader {
+        // SAFETY: This transmute is safe because we take a weak reference and the only Rc reference used is guarded by the lifetime.
+        Reader(InnerReader::Transaction(Rc::downgrade(unsafe {
+            transmute(&self.0)
+        })))
+    }
+
+    #[allow(clippy::unnecessary_wraps)]
+    pub fn contains_key_for_update(
+        &self,
+        column_family: &ColumnFamily,
+        key: &[u8],
+    ) -> Result<bool, StorageError> {
+        Ok((*self.0)
+            .borrow()
+            .get(column_family)
+            .map_or(false, |cf| cf.contains_key(key)))
+    }
+
+    #[allow(clippy::unnecessary_wraps, clippy::unwrap_in_result)]
+    pub fn insert(
+        &mut self,
+        column_family: &ColumnFamily,
+        key: &[u8],
+        value: &[u8],
+    ) -> Result<(), StorageError> {
+        self.0
+            .borrow_mut()
+            .get_mut(column_family)
+            .unwrap()
+            .insert(key.into(), value.into());
+        Ok(())
+    }
+
+    pub fn insert_empty(
+        &mut self,
+        column_family: &ColumnFamily,
+        key: &[u8],
+    ) -> Result<(), StorageError> {
+        self.insert(column_family, key, &[])
+    }
+
+    #[allow(clippy::unnecessary_wraps, clippy::unwrap_in_result)]
+    pub fn remove(&mut self, column_family: &ColumnFamily, key: &[u8]) -> Result<(), StorageError> {
+        self.0
+            .borrow_mut()
+            .get_mut(column_family)
+            .unwrap()
+            .remove(key);
+        Ok(())
+    }
+}
+
+pub struct Iter {
+    iter: std::vec::IntoIter<(Vec<u8>, Vec<u8>)>,
+    current: Option<(Vec<u8>, Vec<u8>)>,
+}
+
+impl Iter {
+    pub fn key(&self) -> Option<&[u8]> {
+        Some(&self.current.as_ref()?.0)
+    }
+
+    #[allow(dead_code)]
+    pub fn value(&self) -> Option<&[u8]> {
+        Some(&self.current.as_ref()?.1)
+    }
+
+    pub fn next(&mut self) {
+        self.current = self.iter.next();
+    }
+
+    #[allow(clippy::unnecessary_wraps, clippy::unused_self)]
+    pub fn status(&self) -> Result<(), StorageError> {
+        Ok(())
+    }
+}

src/storage/backend/mod.rs

@@ -0,0 +1,12 @@
+//! A storage backend
+//! RocksDB is available, if not in memory
+
+#[cfg(any(target_family = "wasm"))]
+pub use fallback::{ColumnFamily, ColumnFamilyDefinition, Db, Iter, Reader, Transaction};
+#[cfg(all(not(target_family = "wasm")))]
+pub use oxi_rocksdb::{ColumnFamily, ColumnFamilyDefinition, Db, Iter, Reader, Transaction};
+
+#[cfg(any(target_family = "wasm"))]
+mod fallback;
+#[cfg(all(not(target_family = "wasm")))]
+mod oxi_rocksdb;

src/storage/binary_encoder.rs

@@ -0,0 +1,742 @@
+use crate::storage::error::{CorruptionError, StorageError};
+use crate::storage::numeric_encoder::{EncodedQuad, EncodedTerm, EncodedTriple, StrHash};
+use crate::storage::small_string::SmallString;
+use oxsdatatypes::*;
+use std::io::Read;
+use std::mem::size_of;
+
+#[cfg(all(not(target_family = "wasm")))]
+pub const LATEST_STORAGE_VERSION: u64 = 1;
+pub const WRITTEN_TERM_MAX_SIZE: usize = size_of::<u8>() + 2 * size_of::<StrHash>();
+
+// Encoded term type blocks
+// 1-7: usual named nodes (except prefixes c.f. later)
+// 8-15: blank nodes
+// 16-47: literals
+// 48-55: triples
+// 56-64: future use
+// 64-127: default named node prefixes
+// 128-255: custom named node prefixes
+const TYPE_NAMED_NODE_ID: u8 = 1;
+const TYPE_NUMERICAL_BLANK_NODE_ID: u8 = 8;
+const TYPE_SMALL_BLANK_NODE_ID: u8 = 9;
+const TYPE_BIG_BLANK_NODE_ID: u8 = 10;
+const TYPE_SMALL_STRING_LITERAL: u8 = 16;
+const TYPE_BIG_STRING_LITERAL: u8 = 17;
+const TYPE_SMALL_SMALL_LANG_STRING_LITERAL: u8 = 20;
+const TYPE_SMALL_BIG_LANG_STRING_LITERAL: u8 = 21;
+const TYPE_BIG_SMALL_LANG_STRING_LITERAL: u8 = 22;
+const TYPE_BIG_BIG_LANG_STRING_LITERAL: u8 = 23;
+const TYPE_SMALL_TYPED_LITERAL: u8 = 24;
+const TYPE_BIG_TYPED_LITERAL: u8 = 25;
+const TYPE_BOOLEAN_LITERAL_TRUE: u8 = 28;
+const TYPE_BOOLEAN_LITERAL_FALSE: u8 = 29;
+const TYPE_FLOAT_LITERAL: u8 = 30;
+const TYPE_DOUBLE_LITERAL: u8 = 31;
+const TYPE_INTEGER_LITERAL: u8 = 32;
+const TYPE_DECIMAL_LITERAL: u8 = 33;
+const TYPE_DATE_TIME_LITERAL: u8 = 34;
+const TYPE_TIME_LITERAL: u8 = 35;
+const TYPE_DATE_LITERAL: u8 = 36;
+const TYPE_G_YEAR_MONTH_LITERAL: u8 = 37;
+const TYPE_G_YEAR_LITERAL: u8 = 38;
+const TYPE_G_MONTH_DAY_LITERAL: u8 = 39;
+const TYPE_G_DAY_LITERAL: u8 = 40;
+const TYPE_G_MONTH_LITERAL: u8 = 41;
+const TYPE_DURATION_LITERAL: u8 = 42;
+const TYPE_YEAR_MONTH_DURATION_LITERAL: u8 = 43;
+const TYPE_DAY_TIME_DURATION_LITERAL: u8 = 44;
+const TYPE_TRIPLE: u8 = 48;
+
+#[derive(Clone, Copy)]
+pub enum QuadEncoding {
+    Spog,
+    Posg,
+    Ospg,
+    Gspo,
+    Gpos,
+    Gosp,
+    Dspo,
+    Dpos,
+    Dosp,
+}
+
+impl QuadEncoding {
+    pub fn decode(self, mut buffer: &[u8]) -> Result<EncodedQuad, StorageError> {
+        match self {
+            Self::Spog => buffer.read_spog_quad(),
+            Self::Posg => buffer.read_posg_quad(),
+            Self::Ospg => buffer.read_ospg_quad(),
+            Self::Gspo => buffer.read_gspo_quad(),
+            Self::Gpos => buffer.read_gpos_quad(),
+            Self::Gosp => buffer.read_gosp_quad(),
+            Self::Dspo => buffer.read_dspo_quad(),
+            Self::Dpos => buffer.read_dpos_quad(),
+            Self::Dosp => buffer.read_dosp_quad(),
+        }
+    }
+}
+
+pub fn decode_term(mut buffer: &[u8]) -> Result<EncodedTerm, StorageError> {
+    buffer.read_term()
+}
+
+pub trait TermReader {
+    fn read_term(&mut self) -> Result<EncodedTerm, StorageError>;
+
+    fn read_spog_quad(&mut self) -> Result<EncodedQuad, StorageError> {
+        let subject = self.read_term()?;
+        let predicate = self.read_term()?;
+        let object = self.read_term()?;
+        let graph_name = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name,
+        })
+    }
+
+    fn read_posg_quad(&mut self) -> Result<EncodedQuad, StorageError> {
+        let predicate = self.read_term()?;
+        let object = self.read_term()?;
+        let subject = self.read_term()?;
+        let graph_name = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name,
+        })
+    }
+
+    fn read_ospg_quad(&mut self) -> Result<EncodedQuad, StorageError> {
+        let object = self.read_term()?;
+        let subject = self.read_term()?;
+        let predicate = self.read_term()?;
+        let graph_name = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name,
+        })
+    }
+
+    fn read_gspo_quad(&mut self) -> Result<EncodedQuad, StorageError> {
+        let graph_name = self.read_term()?;
+        let subject = self.read_term()?;
+        let predicate = self.read_term()?;
+        let object = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name,
+        })
+    }
+
+    fn read_gpos_quad(&mut self) -> Result<EncodedQuad, StorageError> {
+        let graph_name = self.read_term()?;
+        let predicate = self.read_term()?;
+        let object = self.read_term()?;
+        let subject = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name,
+        })
+    }
+
+    fn read_gosp_quad(&mut self) -> Result<EncodedQuad, StorageError> {
+        let graph_name = self.read_term()?;
+        let object = self.read_term()?;
+        let subject = self.read_term()?;
+        let predicate = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name,
+        })
+    }
+
+    fn read_dspo_quad(&mut self) -> Result<EncodedQuad, StorageError> {
+        let subject = self.read_term()?;
+        let predicate = self.read_term()?;
+        let object = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name: EncodedTerm::DefaultGraph,
+        })
+    }
+
+    fn read_dpos_quad(&mut self) -> Result<EncodedQuad, StorageError> {
+        let predicate = self.read_term()?;
+        let object = self.read_term()?;
+        let subject = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name: EncodedTerm::DefaultGraph,
+        })
+    }
+
+    fn read_dosp_quad(&mut self) -> Result<EncodedQuad, StorageError> {
+        let object = self.read_term()?;
+        let subject = self.read_term()?;
+        let predicate = self.read_term()?;
+        Ok(EncodedQuad {
+            subject,
+            predicate,
+            object,
+            graph_name: EncodedTerm::DefaultGraph,
+        })
+    }
+}
+
+impl<R: Read> TermReader for R {
+    fn read_term(&mut self) -> Result<EncodedTerm, StorageError> {
+        let mut type_buffer = [0];
+        self.read_exact(&mut type_buffer)?;
+        match type_buffer[0] {
+            TYPE_NAMED_NODE_ID => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::NamedNode {
+                    iri_id: StrHash::from_be_bytes(buffer),
+                })
+            }
+            TYPE_NUMERICAL_BLANK_NODE_ID => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::NumericalBlankNode {
+                    id: u128::from_be_bytes(buffer),
+                })
+            }
+            TYPE_SMALL_BLANK_NODE_ID => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::SmallBlankNode(
+                    SmallString::from_be_bytes(buffer).map_err(CorruptionError::new)?,
+                ))
+            }
+            TYPE_BIG_BLANK_NODE_ID => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::BigBlankNode {
+                    id_id: StrHash::from_be_bytes(buffer),
+                })
+            }
+            TYPE_SMALL_SMALL_LANG_STRING_LITERAL => {
+                let mut language_buffer = [0; 16];
+                self.read_exact(&mut language_buffer)?;
+                let mut value_buffer = [0; 16];
+                self.read_exact(&mut value_buffer)?;
+                Ok(EncodedTerm::SmallSmallLangStringLiteral {
+                    value: SmallString::from_be_bytes(value_buffer)
+                        .map_err(CorruptionError::new)?,
+                    language: SmallString::from_be_bytes(language_buffer)
+                        .map_err(CorruptionError::new)?,
+                })
+            }
+            TYPE_SMALL_BIG_LANG_STRING_LITERAL => {
+                let mut language_buffer = [0; 16];
+                self.read_exact(&mut language_buffer)?;
+                let mut value_buffer = [0; 16];
+                self.read_exact(&mut value_buffer)?;
+                Ok(EncodedTerm::SmallBigLangStringLiteral {
+                    value: SmallString::from_be_bytes(value_buffer)
+                        .map_err(CorruptionError::new)?,
+                    language_id: StrHash::from_be_bytes(language_buffer),
+                })
+            }
+            TYPE_BIG_SMALL_LANG_STRING_LITERAL => {
+                let mut language_buffer = [0; 16];
+                self.read_exact(&mut language_buffer)?;
+                let mut value_buffer = [0; 16];
+                self.read_exact(&mut value_buffer)?;
+                Ok(EncodedTerm::BigSmallLangStringLiteral {
+                    value_id: StrHash::from_be_bytes(value_buffer),
+                    language: SmallString::from_be_bytes(language_buffer)
+                        .map_err(CorruptionError::new)?,
+                })
+            }
+            TYPE_BIG_BIG_LANG_STRING_LITERAL => {
+                let mut language_buffer = [0; 16];
+                self.read_exact(&mut language_buffer)?;
+                let mut value_buffer = [0; 16];
+                self.read_exact(&mut value_buffer)?;
+                Ok(EncodedTerm::BigBigLangStringLiteral {
+                    value_id: StrHash::from_be_bytes(value_buffer),
+                    language_id: StrHash::from_be_bytes(language_buffer),
+                })
+            }
+            TYPE_SMALL_TYPED_LITERAL => {
+                let mut datatype_buffer = [0; 16];
+                self.read_exact(&mut datatype_buffer)?;
+                let mut value_buffer = [0; 16];
+                self.read_exact(&mut value_buffer)?;
+                Ok(EncodedTerm::SmallTypedLiteral {
+                    datatype_id: StrHash::from_be_bytes(datatype_buffer),
+                    value: SmallString::from_be_bytes(value_buffer)
+                        .map_err(CorruptionError::new)?,
+                })
+            }
+            TYPE_BIG_TYPED_LITERAL => {
+                let mut datatype_buffer = [0; 16];
+                self.read_exact(&mut datatype_buffer)?;
+                let mut value_buffer = [0; 16];
+                self.read_exact(&mut value_buffer)?;
+                Ok(EncodedTerm::BigTypedLiteral {
+                    datatype_id: StrHash::from_be_bytes(datatype_buffer),
+                    value_id: StrHash::from_be_bytes(value_buffer),
+                })
+            }
+            TYPE_SMALL_STRING_LITERAL => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::SmallStringLiteral(
+                    SmallString::from_be_bytes(buffer).map_err(CorruptionError::new)?,
+                ))
+            }
+            TYPE_BIG_STRING_LITERAL => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(EncodedTerm::BigStringLiteral {
+                    value_id: StrHash::from_be_bytes(buffer),
+                })
+            }
+            TYPE_BOOLEAN_LITERAL_TRUE => Ok(true.into()),
+            TYPE_BOOLEAN_LITERAL_FALSE => Ok(false.into()),
+            TYPE_FLOAT_LITERAL => {
+                let mut buffer = [0; 4];
+                self.read_exact(&mut buffer)?;
+                Ok(Float::from_be_bytes(buffer).into())
+            }
+            TYPE_DOUBLE_LITERAL => {
+                let mut buffer = [0; 8];
+                self.read_exact(&mut buffer)?;
+                Ok(Double::from_be_bytes(buffer).into())
+            }
+            TYPE_INTEGER_LITERAL => {
+                let mut buffer = [0; 8];
+                self.read_exact(&mut buffer)?;
+                Ok(Integer::from_be_bytes(buffer).into())
+            }
+            TYPE_DECIMAL_LITERAL => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(Decimal::from_be_bytes(buffer).into())
+            }
+            TYPE_DATE_TIME_LITERAL => {
+                let mut buffer = [0; 18];
+                self.read_exact(&mut buffer)?;
+                Ok(DateTime::from_be_bytes(buffer).into())
+            }
+            TYPE_TIME_LITERAL => {
+                let mut buffer = [0; 18];
+                self.read_exact(&mut buffer)?;
+                Ok(Time::from_be_bytes(buffer).into())
+            }
+            TYPE_DATE_LITERAL => {
+                let mut buffer = [0; 18];
+                self.read_exact(&mut buffer)?;
+                Ok(Date::from_be_bytes(buffer).into())
+            }
+            TYPE_G_YEAR_MONTH_LITERAL => {
+                let mut buffer = [0; 18];
+                self.read_exact(&mut buffer)?;
+                Ok(GYearMonth::from_be_bytes(buffer).into())
+            }
+            TYPE_G_YEAR_LITERAL => {
+                let mut buffer = [0; 18];
+                self.read_exact(&mut buffer)?;
+                Ok(GYear::from_be_bytes(buffer).into())
+            }
+            TYPE_G_MONTH_DAY_LITERAL => {
+                let mut buffer = [0; 18];
+                self.read_exact(&mut buffer)?;
+                Ok(GMonthDay::from_be_bytes(buffer).into())
+            }
+            TYPE_G_DAY_LITERAL => {
+                let mut buffer = [0; 18];
+                self.read_exact(&mut buffer)?;
+                Ok(GDay::from_be_bytes(buffer).into())
+            }
+            TYPE_G_MONTH_LITERAL => {
+                let mut buffer = [0; 18];
+                self.read_exact(&mut buffer)?;
+                Ok(GMonth::from_be_bytes(buffer).into())
+            }
+            TYPE_DURATION_LITERAL => {
+                let mut buffer = [0; 24];
+                self.read_exact(&mut buffer)?;
+                Ok(Duration::from_be_bytes(buffer).into())
+            }
+            TYPE_YEAR_MONTH_DURATION_LITERAL => {
+                let mut buffer = [0; 8];
+                self.read_exact(&mut buffer)?;
+                Ok(YearMonthDuration::from_be_bytes(buffer).into())
+            }
+            TYPE_DAY_TIME_DURATION_LITERAL => {
+                let mut buffer = [0; 16];
+                self.read_exact(&mut buffer)?;
+                Ok(DayTimeDuration::from_be_bytes(buffer).into())
+            }
+            TYPE_TRIPLE => Ok(EncodedTriple {
+                subject: self.read_term()?,
+                predicate: self.read_term()?,
+                object: self.read_term()?,
+            }
+            .into()),
+            _ => Err(CorruptionError::msg("the term buffer has an invalid type id").into()),
+        }
+    }
+}
+
+pub fn write_spog_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, &quad.subject);
+    write_term(sink, &quad.predicate);
+    write_term(sink, &quad.object);
+    write_term(sink, &quad.graph_name);
+}
+
+pub fn write_posg_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, &quad.predicate);
+    write_term(sink, &quad.object);
+    write_term(sink, &quad.subject);
+    write_term(sink, &quad.graph_name);
+}
+
+pub fn write_ospg_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, &quad.object);
+    write_term(sink, &quad.subject);
+    write_term(sink, &quad.predicate);
+    write_term(sink, &quad.graph_name);
+}
+
+pub fn write_gspo_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, &quad.graph_name);
+    write_term(sink, &quad.subject);
+    write_term(sink, &quad.predicate);
+    write_term(sink, &quad.object);
+}
+
+pub fn write_gpos_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, &quad.graph_name);
+    write_term(sink, &quad.predicate);
+    write_term(sink, &quad.object);
+    write_term(sink, &quad.subject);
+}
+
+pub fn write_gosp_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, &quad.graph_name);
+    write_term(sink, &quad.object);
+    write_term(sink, &quad.subject);
+    write_term(sink, &quad.predicate);
+}
+
+pub fn write_spo_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, &quad.subject);
+    write_term(sink, &quad.predicate);
+    write_term(sink, &quad.object);
+}
+
+pub fn write_pos_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, &quad.predicate);
+    write_term(sink, &quad.object);
+    write_term(sink, &quad.subject);
+}
+
+pub fn write_osp_quad(sink: &mut Vec<u8>, quad: &EncodedQuad) {
+    write_term(sink, &quad.object);
+    write_term(sink, &quad.subject);
+    write_term(sink, &quad.predicate);
+}
+
+pub fn encode_term(t: &EncodedTerm) -> Vec<u8> {
+    let mut vec = Vec::with_capacity(WRITTEN_TERM_MAX_SIZE);
+    write_term(&mut vec, t);
+    vec
+}
+
+pub fn encode_term_pair(t1: &EncodedTerm, t2: &EncodedTerm) -> Vec<u8> {
+    let mut vec = Vec::with_capacity(2 * WRITTEN_TERM_MAX_SIZE);
+    write_term(&mut vec, t1);
+    write_term(&mut vec, t2);
+    vec
+}
+
+pub fn encode_term_triple(t1: &EncodedTerm, t2: &EncodedTerm, t3: &EncodedTerm) -> Vec<u8> {
+    let mut vec = Vec::with_capacity(3 * WRITTEN_TERM_MAX_SIZE);
+    write_term(&mut vec, t1);
+    write_term(&mut vec, t2);
+    write_term(&mut vec, t3);
+    vec
+}
+
+pub fn encode_term_quad(
+    t1: &EncodedTerm,
+    t2: &EncodedTerm,
+    t3: &EncodedTerm,
+    t4: &EncodedTerm,
+) -> Vec<u8> {
+    let mut vec = Vec::with_capacity(4 * WRITTEN_TERM_MAX_SIZE);
+    write_term(&mut vec, t1);
+    write_term(&mut vec, t2);
+    write_term(&mut vec, t3);
+    write_term(&mut vec, t4);
+    vec
+}
+
+pub fn write_term(sink: &mut Vec<u8>, term: &EncodedTerm) {
+    match term {
+        EncodedTerm::DefaultGraph => (),
+        EncodedTerm::NamedNode { iri_id } => {
+            sink.push(TYPE_NAMED_NODE_ID);
+            sink.extend_from_slice(&iri_id.to_be_bytes());
+        }
+        EncodedTerm::NumericalBlankNode { id } => {
+            sink.push(TYPE_NUMERICAL_BLANK_NODE_ID);
+            sink.extend_from_slice(&id.to_be_bytes())
+        }
+        EncodedTerm::SmallBlankNode(id) => {
+            sink.push(TYPE_SMALL_BLANK_NODE_ID);
+            sink.extend_from_slice(&id.to_be_bytes())
+        }
+        EncodedTerm::BigBlankNode { id_id } => {
+            sink.push(TYPE_BIG_BLANK_NODE_ID);
+            sink.extend_from_slice(&id_id.to_be_bytes());
+        }
+        EncodedTerm::SmallStringLiteral(value) => {
+            sink.push(TYPE_SMALL_STRING_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::BigStringLiteral { value_id } => {
+            sink.push(TYPE_BIG_STRING_LITERAL);
+            sink.extend_from_slice(&value_id.to_be_bytes());
+        }
+        EncodedTerm::SmallSmallLangStringLiteral { value, language } => {
+            sink.push(TYPE_SMALL_SMALL_LANG_STRING_LITERAL);
+            sink.extend_from_slice(&language.to_be_bytes());
+            sink.extend_from_slice(&value.to_be_bytes());
+        }
+        EncodedTerm::SmallBigLangStringLiteral { value, language_id } => {
+            sink.push(TYPE_SMALL_BIG_LANG_STRING_LITERAL);
+            sink.extend_from_slice(&language_id.to_be_bytes());
+            sink.extend_from_slice(&value.to_be_bytes());
+        }
+        EncodedTerm::BigSmallLangStringLiteral { value_id, language } => {
+            sink.push(TYPE_BIG_SMALL_LANG_STRING_LITERAL);
+            sink.extend_from_slice(&language.to_be_bytes());
+            sink.extend_from_slice(&value_id.to_be_bytes());
+        }
+        EncodedTerm::BigBigLangStringLiteral {
+            value_id,
+            language_id,
+        } => {
+            sink.push(TYPE_BIG_BIG_LANG_STRING_LITERAL);
+            sink.extend_from_slice(&language_id.to_be_bytes());
+            sink.extend_from_slice(&value_id.to_be_bytes());
+        }
+        EncodedTerm::SmallTypedLiteral { value, datatype_id } => {
+            sink.push(TYPE_SMALL_TYPED_LITERAL);
+            sink.extend_from_slice(&datatype_id.to_be_bytes());
+            sink.extend_from_slice(&value.to_be_bytes());
+        }
+        EncodedTerm::BigTypedLiteral {
+            value_id,
+            datatype_id,
+        } => {
+            sink.push(TYPE_BIG_TYPED_LITERAL);
+            sink.extend_from_slice(&datatype_id.to_be_bytes());
+            sink.extend_from_slice(&value_id.to_be_bytes());
+        }
+        EncodedTerm::BooleanLiteral(value) => sink.push(if bool::from(*value) {
+            TYPE_BOOLEAN_LITERAL_TRUE
+        } else {
+            TYPE_BOOLEAN_LITERAL_FALSE
+        }),
+        EncodedTerm::FloatLiteral(value) => {
+            sink.push(TYPE_FLOAT_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::DoubleLiteral(value) => {
+            sink.push(TYPE_DOUBLE_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::IntegerLiteral(value) => {
+            sink.push(TYPE_INTEGER_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::DecimalLiteral(value) => {
+            sink.push(TYPE_DECIMAL_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::DateTimeLiteral(value) => {
+            sink.push(TYPE_DATE_TIME_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::TimeLiteral(value) => {
+            sink.push(TYPE_TIME_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::DurationLiteral(value) => {
+            sink.push(TYPE_DURATION_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::DateLiteral(value) => {
+            sink.push(TYPE_DATE_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::GYearMonthLiteral(value) => {
+            sink.push(TYPE_G_YEAR_MONTH_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::GYearLiteral(value) => {
+            sink.push(TYPE_G_YEAR_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::GMonthDayLiteral(value) => {
+            sink.push(TYPE_G_MONTH_DAY_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::GDayLiteral(value) => {
+            sink.push(TYPE_G_DAY_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::GMonthLiteral(value) => {
+            sink.push(TYPE_G_MONTH_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::YearMonthDurationLiteral(value) => {
+            sink.push(TYPE_YEAR_MONTH_DURATION_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::DayTimeDurationLiteral(value) => {
+            sink.push(TYPE_DAY_TIME_DURATION_LITERAL);
+            sink.extend_from_slice(&value.to_be_bytes())
+        }
+        EncodedTerm::Triple(value) => {
+            sink.push(TYPE_TRIPLE);
+            write_term(sink, &value.subject);
+            write_term(sink, &value.predicate);
+            write_term(sink, &value.object);
+        }
+    }
+}
+
+#[cfg(test)]
+#[allow(clippy::panic_in_result_fn)]
+mod tests {
+    use super::*;
+    use crate::model::TermRef;
+    use crate::storage::numeric_encoder::*;
+    use std::cell::RefCell;
+    use std::collections::HashMap;
+
+    #[derive(Default)]
+    struct MemoryStrStore {
+        id2str: RefCell<HashMap<StrHash, String>>,
+    }
+
+    impl StrLookup for MemoryStrStore {
+        fn get_str(&self, key: &StrHash) -> Result<Option<String>, StorageError> {
+            Ok(self.id2str.borrow().get(key).cloned())
+        }
+    }
+
+    impl MemoryStrStore {
+        fn insert_term(&self, term: TermRef<'_>, encoded: &EncodedTerm) {
+            insert_term(term, encoded, &mut |h, v| {
+                self.insert_str(h, v);
+                Ok(())
+            })
+            .unwrap();
+        }
+
+        fn insert_str(&self, key: &StrHash, value: &str) {
+            self.id2str
+                .borrow_mut()
+                .entry(*key)
+                .or_insert_with(|| value.to_owned());
+        }
+    }
+
+    #[test]
+    fn test_encoding() {
+        use crate::model::vocab::xsd;
+        use crate::model::*;
+
+        let store = MemoryStrStore::default();
+        let terms: Vec<Term> = vec![
+            NamedNode::new_unchecked("http://foo.com").into(),
+            NamedNode::new_unchecked("http://bar.com").into(),
+            NamedNode::new_unchecked("http://foo.com").into(),
+            BlankNode::default().into(),
+            BlankNode::new_unchecked("bnode").into(),
+            BlankNode::new_unchecked("foo-bnode-thisisaverylargeblanknode").into(),
+            Literal::new_simple_literal("literal").into(),
+            BlankNode::new_unchecked("foo-literal-thisisaverylargestringliteral").into(),
+            Literal::from(true).into(),
+            Literal::from(1.2).into(),
+            Literal::from(1).into(),
+            Literal::from("foo-string").into(),
+            Literal::new_language_tagged_literal_unchecked("foo-fr", "fr").into(),
+            Literal::new_language_tagged_literal_unchecked(
+                "foo-fr-literal-thisisaverylargelanguagetaggedstringliteral",
+                "fr",
+            )
+            .into(),
+            Literal::new_language_tagged_literal_unchecked(
+                "foo-big",
+                "fr-FR-Latn-x-foo-bar-baz-bat-aaaa-bbbb-cccc",
+            )
+            .into(),
+            Literal::new_language_tagged_literal_unchecked(
+                "foo-big-literal-thisisaverylargelanguagetaggedstringliteral",
+                "fr-FR-Latn-x-foo-bar-baz-bat-aaaa-bbbb-cccc",
+            )
+            .into(),
+            Literal::new_typed_literal("-1.32", xsd::DECIMAL).into(),
+            Literal::new_typed_literal("2020-01-01T01:01:01Z", xsd::DATE_TIME).into(),
+            Literal::new_typed_literal("2020-01-01", xsd::DATE).into(),
+            Literal::new_typed_literal("01:01:01Z", xsd::TIME).into(),
+            Literal::new_typed_literal("2020-01", xsd::G_YEAR_MONTH).into(),
+            Literal::new_typed_literal("2020", xsd::G_YEAR).into(),
+            Literal::new_typed_literal("--01-01", xsd::G_MONTH_DAY).into(),
+            Literal::new_typed_literal("--01", xsd::G_MONTH).into(),
+            Literal::new_typed_literal("---01", xsd::G_DAY).into(),
+            Literal::new_typed_literal("PT1S", xsd::DURATION).into(),
+            Literal::new_typed_literal("PT1S", xsd::DAY_TIME_DURATION).into(),
+            Literal::new_typed_literal("P1Y", xsd::YEAR_MONTH_DURATION).into(),
+            Literal::new_typed_literal("-foo", NamedNode::new_unchecked("http://foo.com")).into(),
+            Literal::new_typed_literal(
+                "-foo-thisisaverybigtypedliteralwiththefoodatatype",
+                NamedNode::new_unchecked("http://foo.com"),
+            )
+            .into(),
+            Triple::new(
+                NamedNode::new_unchecked("http://foo.com"),
+                NamedNode::new_unchecked("http://bar.com"),
+                Literal::from(true),
+            )
+            .into(),
+        ];
+        for term in terms {
+            let encoded = term.as_ref().into();
+            store.insert_term(term.as_ref(), &encoded);
+            assert_eq!(encoded, term.as_ref().into());
+            assert_eq!(term, store.decode_term(&encoded).unwrap());
+
+            let mut buffer = Vec::new();
+            write_term(&mut buffer, &encoded);
+            assert_eq!(encoded, buffer.as_slice().read_term().unwrap());
+        }
+    }
+}

src/storage/error.rs

@@ -0,0 +1,139 @@
+use crate::io::{RdfFormat, RdfParseError};
+use crate::storage::numeric_encoder::EncodedTerm;
+use oxiri::IriParseError;
+use oxrdf::TermRef;
+use std::error::Error;
+use std::io;
+
+/// An error related to storage operations (reads, writes...).
+#[derive(Debug, thiserror::Error)]
+#[non_exhaustive]
+pub enum StorageError {
+    /// Error from the OS I/O layer.
+    #[error(transparent)]
+    Io(#[from] io::Error),
+    /// Error related to data corruption.
+    #[error(transparent)]
+    Corruption(#[from] CorruptionError),
+    #[doc(hidden)]
+    #[error("{0}")]
+    Other(#[source] Box<dyn Error + Send + Sync + 'static>),
+}
+
+impl From<StorageError> for io::Error {
+    #[inline]
+    fn from(error: StorageError) -> Self {
+        match error {
+            StorageError::Io(error) => error,
+            StorageError::Corruption(error) => error.into(),
+            StorageError::Other(error) => Self::new(io::ErrorKind::Other, error),
+        }
+    }
+}
+
+/// An error return if some content in the database is corrupted.
+#[derive(Debug, thiserror::Error)]
+#[error(transparent)]
+pub struct CorruptionError(#[from] CorruptionErrorKind);
+
+/// An error return if some content in the database is corrupted.
+#[derive(Debug, thiserror::Error)]
+enum CorruptionErrorKind {
+    #[error("{0}")]
+    Msg(String),
+    #[error("{0}")]
+    Other(#[source] Box<dyn Error + Send + Sync + 'static>),
+}
+
+impl CorruptionError {
+    /// Builds an error from a printable error message.
+    #[inline]
+    pub(crate) fn new(error: impl Into<Box<dyn Error + Send + Sync + 'static>>) -> Self {
+        Self(CorruptionErrorKind::Other(error.into()))
+    }
+
+    #[inline]
+    pub(crate) fn from_encoded_term(encoded: &EncodedTerm, term: &TermRef<'_>) -> Self {
+        // TODO: eventually use a dedicated error enum value
+        Self::msg(format!("Invalid term encoding {encoded:?} for {term}"))
+    }
+
+    #[inline]
+    pub(crate) fn from_missing_column_family_name(name: &'static str) -> Self {
+        // TODO: eventually use a dedicated error enum value
+        Self::msg(format!("Column family {name} does not exist"))
+    }
+
+    /// Builds an error from a printable error message.
+    #[inline]
+    pub(crate) fn msg(msg: impl Into<String>) -> Self {
+        Self(CorruptionErrorKind::Msg(msg.into()))
+    }
+}
+
+impl From<CorruptionError> for io::Error {
+    #[inline]
+    fn from(error: CorruptionError) -> Self {
+        Self::new(io::ErrorKind::InvalidData, error)
+    }
+}
+
+/// An error raised while loading a file into a [`Store`](crate::store::Store).
+#[derive(Debug, thiserror::Error)]
+pub enum LoaderError {
+    /// An error raised while reading the file.
+    #[error(transparent)]
+    Parsing(#[from] RdfParseError),
+    /// An error raised during the insertion in the store.
+    #[error(transparent)]
+    Storage(#[from] StorageError),
+    /// The base IRI is invalid.
+    #[error("Invalid base IRI '{iri}': {error}")]
+    InvalidBaseIri {
+        /// The IRI itself.
+        iri: String,
+        /// The parsing error.
+        #[source]
+        error: IriParseError,
+    },
+}
+
+impl From<LoaderError> for io::Error {
+    #[inline]
+    fn from(error: LoaderError) -> Self {
+        match error {
+            LoaderError::Storage(error) => error.into(),
+            LoaderError::Parsing(error) => error.into(),
+            LoaderError::InvalidBaseIri { .. } => {
+                Self::new(io::ErrorKind::InvalidInput, error.to_string())
+            }
+        }
+    }
+}
+
+/// An error raised while writing a file from a [`Store`](crate::store::Store).
+#[derive(Debug, thiserror::Error)]
+pub enum SerializerError {
+    /// An error raised while writing the content.
+    #[error(transparent)]
+    Io(#[from] io::Error),
+    /// An error raised during the lookup in the store.
+    #[error(transparent)]
+    Storage(#[from] StorageError),
+    /// A format compatible with [RDF dataset](https://www.w3.org/TR/rdf11-concepts/#dfn-rdf-dataset) is required.
+    #[error("A RDF format supporting datasets was expected, {0} found")]
+    DatasetFormatExpected(RdfFormat),
+}
+
+impl From<SerializerError> for io::Error {
+    #[inline]
+    fn from(error: SerializerError) -> Self {
+        match error {
+            SerializerError::Storage(error) => error.into(),
+            SerializerError::Io(error) => error,
+            SerializerError::DatasetFormatExpected(_) => {
+                Self::new(io::ErrorKind::InvalidInput, error.to_string())
+            }
+        }
+    }
+}

src/storage/small_string.rs

@@ -0,0 +1,177 @@
+use std::borrow::Borrow;
+use std::cmp::Ordering;
+use std::hash::{Hash, Hasher};
+use std::ops::Deref;
+use std::str::{FromStr, Utf8Error};
+use std::{fmt, str};
+
+/// A small inline string
+#[derive(Clone, Copy, Default)]
+#[repr(transparent)]
+pub struct SmallString {
+    inner: [u8; 16],
+}
+
+impl SmallString {
+    #[inline]
+    pub const fn new() -> Self {
+        Self { inner: [0; 16] }
+    }
+
+    #[inline]
+    pub fn from_utf8(bytes: &[u8]) -> Result<Self, BadSmallStringError> {
+        Self::from_str(str::from_utf8(bytes).map_err(BadSmallStringError::BadUtf8)?)
+    }
+
+    #[inline]
+    pub fn from_be_bytes(bytes: [u8; 16]) -> Result<Self, BadSmallStringError> {
+        // We check that it is valid UTF-8
+        str::from_utf8(&bytes.as_ref()[..bytes[15].into()])
+            .map_err(BadSmallStringError::BadUtf8)?;
+        Ok(Self { inner: bytes })
+    }
+
+    #[inline]
+    pub fn len(&self) -> usize {
+        self.inner[15].into()
+    }
+
+    #[inline]
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
+    #[inline]
+    #[allow(unsafe_code)]
+    pub fn as_str(&self) -> &str {
+        // SAFETY: safe because we ensured it in constructors
+        unsafe { str::from_utf8_unchecked(self.as_bytes()) }
+    }
+
+    #[inline]
+    pub fn as_bytes(&self) -> &[u8] {
+        &self.inner[..self.len()]
+    }
+
+    #[inline]
+    pub fn to_be_bytes(self) -> [u8; 16] {
+        self.inner
+    }
+}
+
+impl Deref for SmallString {
+    type Target = str;
+
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        self.as_str()
+    }
+}
+
+impl AsRef<str> for SmallString {
+    #[inline]
+    fn as_ref(&self) -> &str {
+        self.as_str()
+    }
+}
+
+impl Borrow<str> for SmallString {
+    #[inline]
+    fn borrow(&self) -> &str {
+        self.as_str()
+    }
+}
+
+impl fmt::Debug for SmallString {
+    #[inline]
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.as_str().fmt(f)
+    }
+}
+
+impl fmt::Display for SmallString {
+    #[inline]
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.as_str().fmt(f)
+    }
+}
+
+impl PartialEq for SmallString {
+    #[inline]
+    fn eq(&self, other: &Self) -> bool {
+        self.as_str() == other.as_str()
+    }
+}
+
+impl Eq for SmallString {}
+
+impl PartialOrd for SmallString {
+    #[inline]
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for SmallString {
+    #[inline]
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.as_str().cmp(other.as_str())
+    }
+}
+
+impl Hash for SmallString {
+    #[inline]
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.as_str().hash(state)
+    }
+}
+
+impl From<SmallString> for String {
+    #[inline]
+    fn from(value: SmallString) -> Self {
+        value.as_str().into()
+    }
+}
+
+impl<'a> From<&'a SmallString> for &'a str {
+    #[inline]
+    fn from(value: &'a SmallString) -> Self {
+        value.as_str()
+    }
+}
+
+impl FromStr for SmallString {
+    type Err = BadSmallStringError;
+
+    #[inline]
+    fn from_str(value: &str) -> Result<Self, Self::Err> {
+        if value.len() <= 15 {
+            let mut inner = [0; 16];
+            inner[..value.len()].copy_from_slice(value.as_bytes());
+            inner[15] = value
+                .len()
+                .try_into()
+                .map_err(|_| Self::Err::TooLong(value.len()))?;
+            Ok(Self { inner })
+        } else {
+            Err(Self::Err::TooLong(value.len()))
+        }
+    }
+}
+
+impl<'a> TryFrom<&'a str> for SmallString {
+    type Error = BadSmallStringError;
+
+    #[inline]
+    fn try_from(value: &'a str) -> Result<Self, Self::Error> {
+        Self::from_str(value)
+    }
+}
+
+#[derive(Debug, Clone, Copy, thiserror::Error)]
+pub enum BadSmallStringError {
+    #[error("small strings could only contain at most 15 characters, found {0}")]
+    TooLong(usize),
+    #[error(transparent)]
+    BadUtf8(#[from] Utf8Error),
+}

tests/rocksdb_bc_data/CURRENT

@@ -0,0 +1 @@
+MANIFEST-000004

tests/rocksdb_bc_data/IDENTITY

@@ -0,0 +1 @@
+f08a4c5b-0479-408c-80d3-7d4b10d7c7aa

tests/rocksdb_bc_data/OPTIONS-000026

@@ -0,0 +1,964 @@
+# This is a RocksDB option file.
+#
+# For detailed file format spec, please refer to the example file
+# in examples/rocksdb_option_file_example.ini
+#
+
+[Version]
+  rocksdb_version=6.7.3
+  options_file_version=1.1
+
+[DBOptions]
+  write_dbid_to_manifest=false
+  avoid_unnecessary_blocking_io=false
+  two_write_queues=false
+  allow_ingest_behind=false
+  writable_file_max_buffer_size=1048576
+  avoid_flush_during_shutdown=false
+  avoid_flush_during_recovery=false
+  info_log_level=INFO_LEVEL
+  access_hint_on_compaction_start=NORMAL
+  allow_concurrent_memtable_write=true
+  enable_pipelined_write=false
+  stats_dump_period_sec=600
+  stats_persist_period_sec=600
+  strict_bytes_per_sync=false
+  WAL_ttl_seconds=0
+  WAL_size_limit_MB=0
+  max_subcompactions=1
+  dump_malloc_stats=false
+  db_log_dir=
+  wal_recovery_mode=kPointInTimeRecovery
+  log_file_time_to_roll=0
+  enable_write_thread_adaptive_yield=true
+  recycle_log_file_num=0
+  table_cache_numshardbits=6
+  atomic_flush=false
+  preserve_deletes=false
+  stats_history_buffer_size=1048576
+  max_open_files=-1
+  max_file_opening_threads=16
+  delete_obsolete_files_period_micros=21600000000
+  max_background_flushes=-1
+  write_thread_slow_yield_usec=3
+  base_background_compactions=-1
+  manual_wal_flush=false
+  wal_dir=tests/rockdb_bc_data
+  max_background_compactions=-1
+  bytes_per_sync=0
+  max_background_jobs=2
+  use_fsync=false
+  unordered_write=false
+  fail_if_options_file_error=false
+  random_access_max_buffer_size=1048576
+  compaction_readahead_size=0
+  wal_bytes_per_sync=0
+  new_table_reader_for_compaction_inputs=false
+  skip_stats_update_on_db_open=false
+  persist_stats_to_disk=false
+  skip_log_error_on_recovery=false
+  log_readahead_size=0
+  is_fd_close_on_exec=true
+  use_adaptive_mutex=false
+  error_if_exists=false
+  write_thread_max_yield_usec=100
+  enable_thread_tracking=false
+  db_write_buffer_size=0
+  create_missing_column_families=true
+  paranoid_checks=true
+  create_if_missing=true
+  max_manifest_file_size=1073741824
+  allow_2pc=false
+  max_total_wal_size=0
+  use_direct_io_for_flush_and_compaction=false
+  manifest_preallocation_size=4194304
+  use_direct_reads=false
+  delayed_write_rate=16777216
+  allow_fallocate=true
+  max_write_batch_group_size_bytes=1048576
+  keep_log_file_num=1000
+  allow_mmap_reads=false
+  max_log_file_size=0
+  allow_mmap_writes=false
+  advise_random_on_open=true
+  
+
+[CFOptions "default"]
+  sample_for_compression=0
+  compaction_pri=kMinOverlappingRatio
+  merge_operator=nullptr
+  compaction_filter_factory=nullptr
+  memtable_factory=SkipListFactory
+  memtable_insert_with_hint_prefix_extractor=nullptr
+  comparator=leveldb.BytewiseComparator
+  target_file_size_base=67108864
+  max_sequential_skip_in_iterations=8
+  compaction_style=kCompactionStyleLevel
+  max_bytes_for_level_base=268435456
+  bloom_locality=0
+  write_buffer_size=67108864
+  compression_per_level=
+  memtable_huge_page_size=0
+  max_successive_merges=0
+  arena_block_size=8388608
+  memtable_whole_key_filtering=false
+  target_file_size_multiplier=1
+  max_bytes_for_level_multiplier_additional=1:1:1:1:1:1:1
+  num_levels=7
+  min_write_buffer_number_to_merge=1
+  max_write_buffer_number_to_maintain=0
+  max_write_buffer_number=2
+  compression=kSnappyCompression
+  level0_stop_writes_trigger=36
+  level0_slowdown_writes_trigger=20
+  compaction_filter=nullptr
+  level0_file_num_compaction_trigger=4
+  max_compaction_bytes=1677721600
+  compaction_options_universal={stop_style=kCompactionStopStyleTotalSize;compression_size_percent=-1;allow_trivial_move=false;max_merge_width=4294967295;max_size_amplification_percent=200;min_merge_width=2;size_ratio=1;}
+  memtable_prefix_bloom_size_ratio=0.000000
+  max_write_buffer_size_to_maintain=0
+  hard_pending_compaction_bytes_limit=274877906944
+  ttl=2592000
+  table_factory=BlockBasedTable
+  soft_pending_compaction_bytes_limit=68719476736
+  prefix_extractor=nullptr
+  bottommost_compression=kDisableCompressionOption
+  force_consistency_checks=false
+  paranoid_file_checks=false
+  compaction_options_fifo={allow_compaction=false;max_table_files_size=1073741824;}
+  max_bytes_for_level_multiplier=10.000000
+  optimize_filters_for_hits=false
+  level_compaction_dynamic_level_bytes=false
+  inplace_update_num_locks=10000
+  inplace_update_support=false
+  periodic_compaction_seconds=0
+  disable_auto_compactions=false
+  report_bg_io_stats=false
+  
+[TableOptions/BlockBasedTable "default"]
+  pin_top_level_index_and_filter=true
+  enable_index_compression=true
+  read_amp_bytes_per_bit=8589934592
+  format_version=2
+  block_align=false
+  metadata_block_size=4096
+  block_size_deviation=10
+  partition_filters=false
+  block_size=4096
+  index_block_restart_interval=1
+  no_block_cache=false
+  checksum=kCRC32c
+  whole_key_filtering=true
+  index_shortening=kShortenSeparators
+  data_block_index_type=kDataBlockBinarySearch
+  index_type=kBinarySearch
+  verify_compression=false
+  filter_policy=nullptr
+  data_block_hash_table_util_ratio=0.750000
+  pin_l0_filter_and_index_blocks_in_cache=false
+  block_restart_interval=16
+  cache_index_and_filter_blocks_with_high_priority=true
+  cache_index_and_filter_blocks=false
+  hash_index_allow_collision=true
+  flush_block_policy_factory=FlushBlockBySizePolicyFactory
+  
+
+[CFOptions "id2str"]
+  sample_for_compression=0
+  compaction_pri=kMinOverlappingRatio
+  merge_operator=nullptr
+  compaction_filter_factory=nullptr
+  memtable_factory=SkipListFactory
+  memtable_insert_with_hint_prefix_extractor=nullptr
+  comparator=leveldb.BytewiseComparator
+  target_file_size_base=67108864
+  max_sequential_skip_in_iterations=8
+  compaction_style=kCompactionStyleLevel
+  max_bytes_for_level_base=268435456
+  bloom_locality=0
+  write_buffer_size=67108864
+  compression_per_level=
+  memtable_huge_page_size=0
+  max_successive_merges=0
+  arena_block_size=8388608
+  memtable_whole_key_filtering=false
+  target_file_size_multiplier=1
+  max_bytes_for_level_multiplier_additional=1:1:1:1:1:1:1
+  num_levels=7
+  min_write_buffer_number_to_merge=1
+  max_write_buffer_number_to_maintain=0
+  max_write_buffer_number=2
+  compression=kSnappyCompression
+  level0_stop_writes_trigger=36
+  level0_slowdown_writes_trigger=20
+  compaction_filter=nullptr
+  level0_file_num_compaction_trigger=4
+  max_compaction_bytes=1677721600
+  compaction_options_universal={stop_style=kCompactionStopStyleTotalSize;compression_size_percent=-1;allow_trivial_move=false;max_merge_width=4294967295;max_size_amplification_percent=200;min_merge_width=2;size_ratio=1;}
+  memtable_prefix_bloom_size_ratio=0.000000
+  max_write_buffer_size_to_maintain=0
+  hard_pending_compaction_bytes_limit=274877906944
+  ttl=2592000
+  table_factory=BlockBasedTable
+  soft_pending_compaction_bytes_limit=68719476736
+  prefix_extractor=nullptr
+  bottommost_compression=kDisableCompressionOption
+  force_consistency_checks=false
+  paranoid_file_checks=false
+  compaction_options_fifo={allow_compaction=false;max_table_files_size=1073741824;}
+  max_bytes_for_level_multiplier=10.000000
+  optimize_filters_for_hits=false
+  level_compaction_dynamic_level_bytes=false
+  inplace_update_num_locks=10000
+  inplace_update_support=false
+  periodic_compaction_seconds=0
+  disable_auto_compactions=false
+  report_bg_io_stats=false
+  
+[TableOptions/BlockBasedTable "id2str"]
+  pin_top_level_index_and_filter=true
+  enable_index_compression=true
+  read_amp_bytes_per_bit=8589934592
+  format_version=2
+  block_align=false
+  metadata_block_size=4096
+  block_size_deviation=10
+  partition_filters=false
+  block_size=4096
+  index_block_restart_interval=1
+  no_block_cache=false
+  checksum=kCRC32c
+  whole_key_filtering=true
+  index_shortening=kShortenSeparators
+  data_block_index_type=kDataBlockBinarySearch
+  index_type=kBinarySearch
+  verify_compression=false
+  filter_policy=nullptr
+  data_block_hash_table_util_ratio=0.750000
+  pin_l0_filter_and_index_blocks_in_cache=false
+  block_restart_interval=16
+  cache_index_and_filter_blocks_with_high_priority=true
+  cache_index_and_filter_blocks=false
+  hash_index_allow_collision=true
+  flush_block_policy_factory=FlushBlockBySizePolicyFactory
+  
+
+[CFOptions "spog"]
+  sample_for_compression=0
+  compaction_pri=kMinOverlappingRatio
+  merge_operator=nullptr
+  compaction_filter_factory=nullptr
+  memtable_factory=SkipListFactory
+  memtable_insert_with_hint_prefix_extractor=nullptr
+  comparator=leveldb.BytewiseComparator
+  target_file_size_base=67108864
+  max_sequential_skip_in_iterations=8
+  compaction_style=kCompactionStyleLevel
+  max_bytes_for_level_base=268435456
+  bloom_locality=0
+  write_buffer_size=67108864
+  compression_per_level=
+  memtable_huge_page_size=0
+  max_successive_merges=0
+  arena_block_size=8388608
+  memtable_whole_key_filtering=false
+  target_file_size_multiplier=1
+  max_bytes_for_level_multiplier_additional=1:1:1:1:1:1:1
+  num_levels=7
+  min_write_buffer_number_to_merge=1
+  max_write_buffer_number_to_maintain=0
+  max_write_buffer_number=2
+  compression=kSnappyCompression
+  level0_stop_writes_trigger=36
+  level0_slowdown_writes_trigger=20
+  compaction_filter=nullptr
+  level0_file_num_compaction_trigger=4
+  max_compaction_bytes=1677721600
+  compaction_options_universal={stop_style=kCompactionStopStyleTotalSize;compression_size_percent=-1;allow_trivial_move=false;max_merge_width=4294967295;max_size_amplification_percent=200;min_merge_width=2;size_ratio=1;}
+  memtable_prefix_bloom_size_ratio=0.000000
+  max_write_buffer_size_to_maintain=0
+  hard_pending_compaction_bytes_limit=274877906944
+  ttl=2592000
+  table_factory=BlockBasedTable
+  soft_pending_compaction_bytes_limit=68719476736
+  prefix_extractor=nullptr
+  bottommost_compression=kDisableCompressionOption
+  force_consistency_checks=false
+  paranoid_file_checks=false
+  compaction_options_fifo={allow_compaction=false;max_table_files_size=1073741824;}
+  max_bytes_for_level_multiplier=10.000000
+  optimize_filters_for_hits=false
+  level_compaction_dynamic_level_bytes=false
+  inplace_update_num_locks=10000
+  inplace_update_support=false
+  periodic_compaction_seconds=0
+  disable_auto_compactions=false
+  report_bg_io_stats=false
+  
+[TableOptions/BlockBasedTable "spog"]
+  pin_top_level_index_and_filter=true
+  enable_index_compression=true
+  read_amp_bytes_per_bit=8589934592
+  format_version=2
+  block_align=false
+  metadata_block_size=4096
+  block_size_deviation=10
+  partition_filters=false
+  block_size=4096
+  index_block_restart_interval=1
+  no_block_cache=false
+  checksum=kCRC32c
+  whole_key_filtering=true
+  index_shortening=kShortenSeparators
+  data_block_index_type=kDataBlockBinarySearch
+  index_type=kBinarySearch
+  verify_compression=false
+  filter_policy=nullptr
+  data_block_hash_table_util_ratio=0.750000
+  pin_l0_filter_and_index_blocks_in_cache=false
+  block_restart_interval=16
+  cache_index_and_filter_blocks_with_high_priority=true
+  cache_index_and_filter_blocks=false
+  hash_index_allow_collision=true
+  flush_block_policy_factory=FlushBlockBySizePolicyFactory
+  
+
+[CFOptions "posg"]
+  sample_for_compression=0
+  compaction_pri=kMinOverlappingRatio
+  merge_operator=nullptr
+  compaction_filter_factory=nullptr
+  memtable_factory=SkipListFactory
+  memtable_insert_with_hint_prefix_extractor=nullptr
+  comparator=leveldb.BytewiseComparator
+  target_file_size_base=67108864
+  max_sequential_skip_in_iterations=8
+  compaction_style=kCompactionStyleLevel
+  max_bytes_for_level_base=268435456
+  bloom_locality=0
+  write_buffer_size=67108864
+  compression_per_level=
+  memtable_huge_page_size=0
+  max_successive_merges=0
+  arena_block_size=8388608
+  memtable_whole_key_filtering=false
+  target_file_size_multiplier=1
+  max_bytes_for_level_multiplier_additional=1:1:1:1:1:1:1
+  num_levels=7
+  min_write_buffer_number_to_merge=1
+  max_write_buffer_number_to_maintain=0
+  max_write_buffer_number=2
+  compression=kSnappyCompression
+  level0_stop_writes_trigger=36
+  level0_slowdown_writes_trigger=20
+  compaction_filter=nullptr
+  level0_file_num_compaction_trigger=4
+  max_compaction_bytes=1677721600
+  compaction_options_universal={stop_style=kCompactionStopStyleTotalSize;compression_size_percent=-1;allow_trivial_move=false;max_merge_width=4294967295;max_size_amplification_percent=200;min_merge_width=2;size_ratio=1;}
+  memtable_prefix_bloom_size_ratio=0.000000
+  max_write_buffer_size_to_maintain=0
+  hard_pending_compaction_bytes_limit=274877906944
+  ttl=2592000
+  table_factory=BlockBasedTable
+  soft_pending_compaction_bytes_limit=68719476736
+  prefix_extractor=nullptr
+  bottommost_compression=kDisableCompressionOption
+  force_consistency_checks=false
+  paranoid_file_checks=false
+  compaction_options_fifo={allow_compaction=false;max_table_files_size=1073741824;}
+  max_bytes_for_level_multiplier=10.000000
+  optimize_filters_for_hits=false
+  level_compaction_dynamic_level_bytes=false
+  inplace_update_num_locks=10000
+  inplace_update_support=false
+  periodic_compaction_seconds=0
+  disable_auto_compactions=false
+  report_bg_io_stats=false
+  
+[TableOptions/BlockBasedTable "posg"]
+  pin_top_level_index_and_filter=true
+  enable_index_compression=true
+  read_amp_bytes_per_bit=8589934592
+  format_version=2
+  block_align=false
+  metadata_block_size=4096
+  block_size_deviation=10
+  partition_filters=false
+  block_size=4096
+  index_block_restart_interval=1
+  no_block_cache=false
+  checksum=kCRC32c
+  whole_key_filtering=true
+  index_shortening=kShortenSeparators
+  data_block_index_type=kDataBlockBinarySearch
+  index_type=kBinarySearch
+  verify_compression=false
+  filter_policy=nullptr
+  data_block_hash_table_util_ratio=0.750000
+  pin_l0_filter_and_index_blocks_in_cache=false
+  block_restart_interval=16
+  cache_index_and_filter_blocks_with_high_priority=true
+  cache_index_and_filter_blocks=false
+  hash_index_allow_collision=true
+  flush_block_policy_factory=FlushBlockBySizePolicyFactory
+  
+
+[CFOptions "ospg"]
+  sample_for_compression=0
+  compaction_pri=kMinOverlappingRatio
+  merge_operator=nullptr
+  compaction_filter_factory=nullptr
+  memtable_factory=SkipListFactory
+  memtable_insert_with_hint_prefix_extractor=nullptr
+  comparator=leveldb.BytewiseComparator
+  target_file_size_base=67108864
+  max_sequential_skip_in_iterations=8
+  compaction_style=kCompactionStyleLevel
+  max_bytes_for_level_base=268435456
+  bloom_locality=0
+  write_buffer_size=67108864
+  compression_per_level=
+  memtable_huge_page_size=0
+  max_successive_merges=0
+  arena_block_size=8388608
+  memtable_whole_key_filtering=false
+  target_file_size_multiplier=1
+  max_bytes_for_level_multiplier_additional=1:1:1:1:1:1:1
+  num_levels=7
+  min_write_buffer_number_to_merge=1
+  max_write_buffer_number_to_maintain=0
+  max_write_buffer_number=2
+  compression=kSnappyCompression
+  level0_stop_writes_trigger=36
+  level0_slowdown_writes_trigger=20
+  compaction_filter=nullptr
+  level0_file_num_compaction_trigger=4
+  max_compaction_bytes=1677721600
+  compaction_options_universal={stop_style=kCompactionStopStyleTotalSize;compression_size_percent=-1;allow_trivial_move=false;max_merge_width=4294967295;max_size_amplification_percent=200;min_merge_width=2;size_ratio=1;}
+  memtable_prefix_bloom_size_ratio=0.000000
+  max_write_buffer_size_to_maintain=0
+  hard_pending_compaction_bytes_limit=274877906944
+  ttl=2592000
+  table_factory=BlockBasedTable
+  soft_pending_compaction_bytes_limit=68719476736
+  prefix_extractor=nullptr
+  bottommost_compression=kDisableCompressionOption
+  force_consistency_checks=false
+  paranoid_file_checks=false
+  compaction_options_fifo={allow_compaction=false;max_table_files_size=1073741824;}
+  max_bytes_for_level_multiplier=10.000000
+  optimize_filters_for_hits=false
+  level_compaction_dynamic_level_bytes=false
+  inplace_update_num_locks=10000
+  inplace_update_support=false
+  periodic_compaction_seconds=0
+  disable_auto_compactions=false
+  report_bg_io_stats=false
+  
+[TableOptions/BlockBasedTable "ospg"]
+  pin_top_level_index_and_filter=true
+  enable_index_compression=true
+  read_amp_bytes_per_bit=8589934592
+  format_version=2
+  block_align=false
+  metadata_block_size=4096
+  block_size_deviation=10
+  partition_filters=false
+  block_size=4096
+  index_block_restart_interval=1
+  no_block_cache=false
+  checksum=kCRC32c
+  whole_key_filtering=true
+  index_shortening=kShortenSeparators
+  data_block_index_type=kDataBlockBinarySearch
+  index_type=kBinarySearch
+  verify_compression=false
+  filter_policy=nullptr
+  data_block_hash_table_util_ratio=0.750000
+  pin_l0_filter_and_index_blocks_in_cache=false
+  block_restart_interval=16
+  cache_index_and_filter_blocks_with_high_priority=true
+  cache_index_and_filter_blocks=false
+  hash_index_allow_collision=true
+  flush_block_policy_factory=FlushBlockBySizePolicyFactory
+  
+
+[CFOptions "gspo"]
+  sample_for_compression=0
+  compaction_pri=kMinOverlappingRatio
+  merge_operator=nullptr
+  compaction_filter_factory=nullptr
+  memtable_factory=SkipListFactory
+  memtable_insert_with_hint_prefix_extractor=nullptr
+  comparator=leveldb.BytewiseComparator
+  target_file_size_base=67108864
+  max_sequential_skip_in_iterations=8
+  compaction_style=kCompactionStyleLevel
+  max_bytes_for_level_base=268435456
+  bloom_locality=0
+  write_buffer_size=67108864
+  compression_per_level=
+  memtable_huge_page_size=0
+  max_successive_merges=0
+  arena_block_size=8388608
+  memtable_whole_key_filtering=false
+  target_file_size_multiplier=1
+  max_bytes_for_level_multiplier_additional=1:1:1:1:1:1:1
+  num_levels=7
+  min_write_buffer_number_to_merge=1
+  max_write_buffer_number_to_maintain=0
+  max_write_buffer_number=2
+  compression=kSnappyCompression
+  level0_stop_writes_trigger=36
+  level0_slowdown_writes_trigger=20
+  compaction_filter=nullptr
+  level0_file_num_compaction_trigger=4
+  max_compaction_bytes=1677721600
+  compaction_options_universal={stop_style=kCompactionStopStyleTotalSize;compression_size_percent=-1;allow_trivial_move=false;max_merge_width=4294967295;max_size_amplification_percent=200;min_merge_width=2;size_ratio=1;}
+  memtable_prefix_bloom_size_ratio=0.000000
+  max_write_buffer_size_to_maintain=0
+  hard_pending_compaction_bytes_limit=274877906944
+  ttl=2592000
+  table_factory=BlockBasedTable
+  soft_pending_compaction_bytes_limit=68719476736
+  prefix_extractor=nullptr
+  bottommost_compression=kDisableCompressionOption
+  force_consistency_checks=false
+  paranoid_file_checks=false
+  compaction_options_fifo={allow_compaction=false;max_table_files_size=1073741824;}
+  max_bytes_for_level_multiplier=10.000000
+  optimize_filters_for_hits=false
+  level_compaction_dynamic_level_bytes=false
+  inplace_update_num_locks=10000
+  inplace_update_support=false
+  periodic_compaction_seconds=0
+  disable_auto_compactions=false
+  report_bg_io_stats=false
+  
+[TableOptions/BlockBasedTable "gspo"]
+  pin_top_level_index_and_filter=true
+  enable_index_compression=true
+  read_amp_bytes_per_bit=8589934592
+  format_version=2
+  block_align=false
+  metadata_block_size=4096
+  block_size_deviation=10
+  partition_filters=false
+  block_size=4096
+  index_block_restart_interval=1
+  no_block_cache=false
+  checksum=kCRC32c
+  whole_key_filtering=true
+  index_shortening=kShortenSeparators
+  data_block_index_type=kDataBlockBinarySearch
+  index_type=kBinarySearch
+  verify_compression=false
+  filter_policy=nullptr
+  data_block_hash_table_util_ratio=0.750000
+  pin_l0_filter_and_index_blocks_in_cache=false
+  block_restart_interval=16
+  cache_index_and_filter_blocks_with_high_priority=true
+  cache_index_and_filter_blocks=false
+  hash_index_allow_collision=true
+  flush_block_policy_factory=FlushBlockBySizePolicyFactory
+  
+
+[CFOptions "gpos"]
+  sample_for_compression=0
+  compaction_pri=kMinOverlappingRatio
+  merge_operator=nullptr
+  compaction_filter_factory=nullptr
+  memtable_factory=SkipListFactory
+  memtable_insert_with_hint_prefix_extractor=nullptr
+  comparator=leveldb.BytewiseComparator
+  target_file_size_base=67108864
+  max_sequential_skip_in_iterations=8
+  compaction_style=kCompactionStyleLevel
+  max_bytes_for_level_base=268435456
+  bloom_locality=0
+  write_buffer_size=67108864
+  compression_per_level=
+  memtable_huge_page_size=0
+  max_successive_merges=0
+  arena_block_size=8388608
+  memtable_whole_key_filtering=false
+  target_file_size_multiplier=1
+  max_bytes_for_level_multiplier_additional=1:1:1:1:1:1:1
+  num_levels=7
+  min_write_buffer_number_to_merge=1
+  max_write_buffer_number_to_maintain=0
+  max_write_buffer_number=2
+  compression=kSnappyCompression
+  level0_stop_writes_trigger=36
+  level0_slowdown_writes_trigger=20
+  compaction_filter=nullptr
+  level0_file_num_compaction_trigger=4
+  max_compaction_bytes=1677721600
+  compaction_options_universal={stop_style=kCompactionStopStyleTotalSize;compression_size_percent=-1;allow_trivial_move=false;max_merge_width=4294967295;max_size_amplification_percent=200;min_merge_width=2;size_ratio=1;}
+  memtable_prefix_bloom_size_ratio=0.000000
+  max_write_buffer_size_to_maintain=0
+  hard_pending_compaction_bytes_limit=274877906944
+  ttl=2592000
+  table_factory=BlockBasedTable
+  soft_pending_compaction_bytes_limit=68719476736
+  prefix_extractor=nullptr
+  bottommost_compression=kDisableCompressionOption
+  force_consistency_checks=false
+  paranoid_file_checks=false
+  compaction_options_fifo={allow_compaction=false;max_table_files_size=1073741824;}
+  max_bytes_for_level_multiplier=10.000000
+  optimize_filters_for_hits=false
+  level_compaction_dynamic_level_bytes=false
+  inplace_update_num_locks=10000
+  inplace_update_support=false
+  periodic_compaction_seconds=0
+  disable_auto_compactions=false
+  report_bg_io_stats=false
+  
+[TableOptions/BlockBasedTable "gpos"]
+  pin_top_level_index_and_filter=true
+  enable_index_compression=true
+  read_amp_bytes_per_bit=8589934592
+  format_version=2
+  block_align=false
+  metadata_block_size=4096
+  block_size_deviation=10
+  partition_filters=false
+  block_size=4096
+  index_block_restart_interval=1
+  no_block_cache=false
+  checksum=kCRC32c
+  whole_key_filtering=true
+  index_shortening=kShortenSeparators
+  data_block_index_type=kDataBlockBinarySearch
+  index_type=kBinarySearch
+  verify_compression=false
+  filter_policy=nullptr
+  data_block_hash_table_util_ratio=0.750000
+  pin_l0_filter_and_index_blocks_in_cache=false
+  block_restart_interval=16
+  cache_index_and_filter_blocks_with_high_priority=true
+  cache_index_and_filter_blocks=false
+  hash_index_allow_collision=true
+  flush_block_policy_factory=FlushBlockBySizePolicyFactory
+  
+
+[CFOptions "gosp"]
+  sample_for_compression=0
+  compaction_pri=kMinOverlappingRatio
+  merge_operator=nullptr
+  compaction_filter_factory=nullptr
+  memtable_factory=SkipListFactory
+  memtable_insert_with_hint_prefix_extractor=nullptr
+  comparator=leveldb.BytewiseComparator
+  target_file_size_base=67108864
+  max_sequential_skip_in_iterations=8
+  compaction_style=kCompactionStyleLevel
+  max_bytes_for_level_base=268435456
+  bloom_locality=0
+  write_buffer_size=67108864
+  compression_per_level=
+  memtable_huge_page_size=0
+  max_successive_merges=0
+  arena_block_size=8388608
+  memtable_whole_key_filtering=false
+  target_file_size_multiplier=1
+  max_bytes_for_level_multiplier_additional=1:1:1:1:1:1:1
+  num_levels=7
+  min_write_buffer_number_to_merge=1
+  max_write_buffer_number_to_maintain=0
+  max_write_buffer_number=2
+  compression=kSnappyCompression
+  level0_stop_writes_trigger=36
+  level0_slowdown_writes_trigger=20
+  compaction_filter=nullptr
+  level0_file_num_compaction_trigger=4
+  max_compaction_bytes=1677721600
+  compaction_options_universal={stop_style=kCompactionStopStyleTotalSize;compression_size_percent=-1;allow_trivial_move=false;max_merge_width=4294967295;max_size_amplification_percent=200;min_merge_width=2;size_ratio=1;}
+  memtable_prefix_bloom_size_ratio=0.000000
+  max_write_buffer_size_to_maintain=0
+  hard_pending_compaction_bytes_limit=274877906944
+  ttl=2592000
+  table_factory=BlockBasedTable
+  soft_pending_compaction_bytes_limit=68719476736
+  prefix_extractor=nullptr
+  bottommost_compression=kDisableCompressionOption
+  force_consistency_checks=false
+  paranoid_file_checks=false
+  compaction_options_fifo={allow_compaction=false;max_table_files_size=1073741824;}
+  max_bytes_for_level_multiplier=10.000000
+  optimize_filters_for_hits=false
+  level_compaction_dynamic_level_bytes=false
+  inplace_update_num_locks=10000
+  inplace_update_support=false
+  periodic_compaction_seconds=0
+  disable_auto_compactions=false
+  report_bg_io_stats=false
+  
+[TableOptions/BlockBasedTable "gosp"]
+  pin_top_level_index_and_filter=true
+  enable_index_compression=true
+  read_amp_bytes_per_bit=8589934592
+  format_version=2
+  block_align=false
+  metadata_block_size=4096
+  block_size_deviation=10
+  partition_filters=false
+  block_size=4096
+  index_block_restart_interval=1
+  no_block_cache=false
+  checksum=kCRC32c
+  whole_key_filtering=true
+  index_shortening=kShortenSeparators
+  data_block_index_type=kDataBlockBinarySearch
+  index_type=kBinarySearch
+  verify_compression=false
+  filter_policy=nullptr
+  data_block_hash_table_util_ratio=0.750000
+  pin_l0_filter_and_index_blocks_in_cache=false
+  block_restart_interval=16
+  cache_index_and_filter_blocks_with_high_priority=true
+  cache_index_and_filter_blocks=false
+  hash_index_allow_collision=true
+  flush_block_policy_factory=FlushBlockBySizePolicyFactory
+  
+
+[CFOptions "dspo"]
+  sample_for_compression=0
+  compaction_pri=kMinOverlappingRatio
+  merge_operator=nullptr
+  compaction_filter_factory=nullptr
+  memtable_factory=SkipListFactory
+  memtable_insert_with_hint_prefix_extractor=nullptr
+  comparator=leveldb.BytewiseComparator
+  target_file_size_base=67108864
+  max_sequential_skip_in_iterations=8
+  compaction_style=kCompactionStyleLevel
+  max_bytes_for_level_base=268435456
+  bloom_locality=0
+  write_buffer_size=67108864
+  compression_per_level=
+  memtable_huge_page_size=0
+  max_successive_merges=0
+  arena_block_size=8388608
+  memtable_whole_key_filtering=false
+  target_file_size_multiplier=1
+  max_bytes_for_level_multiplier_additional=1:1:1:1:1:1:1
+  num_levels=7
+  min_write_buffer_number_to_merge=1
+  max_write_buffer_number_to_maintain=0
+  max_write_buffer_number=2
+  compression=kSnappyCompression
+  level0_stop_writes_trigger=36
+  level0_slowdown_writes_trigger=20
+  compaction_filter=nullptr
+  level0_file_num_compaction_trigger=4
+  max_compaction_bytes=1677721600
+  compaction_options_universal={stop_style=kCompactionStopStyleTotalSize;compression_size_percent=-1;allow_trivial_move=false;max_merge_width=4294967295;max_size_amplification_percent=200;min_merge_width=2;size_ratio=1;}
+  memtable_prefix_bloom_size_ratio=0.000000
+  max_write_buffer_size_to_maintain=0
+  hard_pending_compaction_bytes_limit=274877906944
+  ttl=2592000
+  table_factory=BlockBasedTable
+  soft_pending_compaction_bytes_limit=68719476736
+  prefix_extractor=nullptr
+  bottommost_compression=kDisableCompressionOption
+  force_consistency_checks=false
+  paranoid_file_checks=false
+  compaction_options_fifo={allow_compaction=false;max_table_files_size=1073741824;}
+  max_bytes_for_level_multiplier=10.000000
+  optimize_filters_for_hits=false
+  level_compaction_dynamic_level_bytes=false
+  inplace_update_num_locks=10000
+  inplace_update_support=false
+  periodic_compaction_seconds=0
+  disable_auto_compactions=false
+  report_bg_io_stats=false
+  
+[TableOptions/BlockBasedTable "dspo"]
+  pin_top_level_index_and_filter=true
+  enable_index_compression=true
+  read_amp_bytes_per_bit=8589934592
+  format_version=2
+  block_align=false
+  metadata_block_size=4096
+  block_size_deviation=10
+  partition_filters=false
+  block_size=4096
+  index_block_restart_interval=1
+  no_block_cache=false
+  checksum=kCRC32c
+  whole_key_filtering=true
+  index_shortening=kShortenSeparators
+  data_block_index_type=kDataBlockBinarySearch
+  index_type=kBinarySearch
+  verify_compression=false
+  filter_policy=nullptr
+  data_block_hash_table_util_ratio=0.750000
+  pin_l0_filter_and_index_blocks_in_cache=false
+  block_restart_interval=16
+  cache_index_and_filter_blocks_with_high_priority=true
+  cache_index_and_filter_blocks=false
+  hash_index_allow_collision=true
+  flush_block_policy_factory=FlushBlockBySizePolicyFactory
+  
+
+[CFOptions "dpos"]
+  sample_for_compression=0
+  compaction_pri=kMinOverlappingRatio
+  merge_operator=nullptr
+  compaction_filter_factory=nullptr
+  memtable_factory=SkipListFactory
+  memtable_insert_with_hint_prefix_extractor=nullptr
+  comparator=leveldb.BytewiseComparator
+  target_file_size_base=67108864
+  max_sequential_skip_in_iterations=8
+  compaction_style=kCompactionStyleLevel
+  max_bytes_for_level_base=268435456
+  bloom_locality=0
+  write_buffer_size=67108864
+  compression_per_level=
+  memtable_huge_page_size=0
+  max_successive_merges=0
+  arena_block_size=8388608
+  memtable_whole_key_filtering=false
+  target_file_size_multiplier=1
+  max_bytes_for_level_multiplier_additional=1:1:1:1:1:1:1
+  num_levels=7
+  min_write_buffer_number_to_merge=1
+  max_write_buffer_number_to_maintain=0
+  max_write_buffer_number=2
+  compression=kSnappyCompression
+  level0_stop_writes_trigger=36
+  level0_slowdown_writes_trigger=20
+  compaction_filter=nullptr
+  level0_file_num_compaction_trigger=4
+  max_compaction_bytes=1677721600
+  compaction_options_universal={stop_style=kCompactionStopStyleTotalSize;compression_size_percent=-1;allow_trivial_move=false;max_merge_width=4294967295;max_size_amplification_percent=200;min_merge_width=2;size_ratio=1;}
+  memtable_prefix_bloom_size_ratio=0.000000
+  max_write_buffer_size_to_maintain=0
+  hard_pending_compaction_bytes_limit=274877906944
+  ttl=2592000
+  table_factory=BlockBasedTable
+  soft_pending_compaction_bytes_limit=68719476736
+  prefix_extractor=nullptr
+  bottommost_compression=kDisableCompressionOption
+  force_consistency_checks=false
+  paranoid_file_checks=false
+  compaction_options_fifo={allow_compaction=false;max_table_files_size=1073741824;}
+  max_bytes_for_level_multiplier=10.000000
+  optimize_filters_for_hits=false
+  level_compaction_dynamic_level_bytes=false
+  inplace_update_num_locks=10000
+  inplace_update_support=false
+  periodic_compaction_seconds=0
+  disable_auto_compactions=false
+  report_bg_io_stats=false
+  
+[TableOptions/BlockBasedTable "dpos"]
+  pin_top_level_index_and_filter=true
+  enable_index_compression=true
+  read_amp_bytes_per_bit=8589934592
+  format_version=2
+  block_align=false
+  metadata_block_size=4096
+  block_size_deviation=10
+  partition_filters=false
+  block_size=4096
+  index_block_restart_interval=1
+  no_block_cache=false
+  checksum=kCRC32c
+  whole_key_filtering=true
+  index_shortening=kShortenSeparators
+  data_block_index_type=kDataBlockBinarySearch
+  index_type=kBinarySearch
+  verify_compression=false
+  filter_policy=nullptr
+  data_block_hash_table_util_ratio=0.750000
+  pin_l0_filter_and_index_blocks_in_cache=false
+  block_restart_interval=16
+  cache_index_and_filter_blocks_with_high_priority=true
+  cache_index_and_filter_blocks=false
+  hash_index_allow_collision=true
+  flush_block_policy_factory=FlushBlockBySizePolicyFactory
+  
+
+[CFOptions "dosp"]
+  sample_for_compression=0
+  compaction_pri=kMinOverlappingRatio
+  merge_operator=nullptr
+  compaction_filter_factory=nullptr
+  memtable_factory=SkipListFactory
+  memtable_insert_with_hint_prefix_extractor=nullptr
+  comparator=leveldb.BytewiseComparator
+  target_file_size_base=67108864
+  max_sequential_skip_in_iterations=8
+  compaction_style=kCompactionStyleLevel
+  max_bytes_for_level_base=268435456
+  bloom_locality=0
+  write_buffer_size=67108864
+  compression_per_level=
+  memtable_huge_page_size=0
+  max_successive_merges=0
+  arena_block_size=8388608
+  memtable_whole_key_filtering=false
+  target_file_size_multiplier=1
+  max_bytes_for_level_multiplier_additional=1:1:1:1:1:1:1
+  num_levels=7
+  min_write_buffer_number_to_merge=1
+  max_write_buffer_number_to_maintain=0
+  max_write_buffer_number=2
+  compression=kSnappyCompression
+  level0_stop_writes_trigger=36
+  level0_slowdown_writes_trigger=20
+  compaction_filter=nullptr
+  level0_file_num_compaction_trigger=4
+  max_compaction_bytes=1677721600
+  compaction_options_universal={stop_style=kCompactionStopStyleTotalSize;compression_size_percent=-1;allow_trivial_move=false;max_merge_width=4294967295;max_size_amplification_percent=200;min_merge_width=2;size_ratio=1;}
+  memtable_prefix_bloom_size_ratio=0.000000
+  max_write_buffer_size_to_maintain=0
+  hard_pending_compaction_bytes_limit=274877906944
+  ttl=2592000
+  table_factory=BlockBasedTable
+  soft_pending_compaction_bytes_limit=68719476736
+  prefix_extractor=nullptr
+  bottommost_compression=kDisableCompressionOption
+  force_consistency_checks=false
+  paranoid_file_checks=false
+  compaction_options_fifo={allow_compaction=false;max_table_files_size=1073741824;}
+  max_bytes_for_level_multiplier=10.000000
+  optimize_filters_for_hits=false
+  level_compaction_dynamic_level_bytes=false
+  inplace_update_num_locks=10000
+  inplace_update_support=false
+  periodic_compaction_seconds=0
+  disable_auto_compactions=false
+  report_bg_io_stats=false
+  
+[TableOptions/BlockBasedTable "dosp"]
+  pin_top_level_index_and_filter=true
+  enable_index_compression=true
+  read_amp_bytes_per_bit=8589934592
+  format_version=2
+  block_align=false
+  metadata_block_size=4096
+  block_size_deviation=10
+  partition_filters=false
+  block_size=4096
+  index_block_restart_interval=1
+  no_block_cache=false
+  checksum=kCRC32c
+  whole_key_filtering=true
+  index_shortening=kShortenSeparators
+  data_block_index_type=kDataBlockBinarySearch
+  index_type=kBinarySearch
+  verify_compression=false
+  filter_policy=nullptr
+  data_block_hash_table_util_ratio=0.750000
+  pin_l0_filter_and_index_blocks_in_cache=false
+  block_restart_interval=16
+  cache_index_and_filter_blocks_with_high_priority=true
+  cache_index_and_filter_blocks=false
+  hash_index_allow_collision=true
+  flush_block_policy_factory=FlushBlockBySizePolicyFactory
+  

tests/store.rs

@@ -0,0 +1,542 @@
+#![cfg(test)]
+#![allow(clippy::panic_in_result_fn)]
+
+use oxigraph::io::RdfFormat;
+use oxigraph::model::vocab::{rdf, xsd};
+use oxigraph::model::*;
+use oxigraph::store::Store;
+#[cfg(all(not(target_family = "wasm")))]
+use rand::random;
+#[cfg(all(not(target_family = "wasm")))]
+use std::env::temp_dir;
+use std::error::Error;
+#[cfg(all(not(target_family = "wasm")))]
+use std::fs::{create_dir_all, remove_dir_all, File};
+#[cfg(all(not(target_family = "wasm")))]
+use std::io::Write;
+#[cfg(all(not(target_family = "wasm")))]
+use std::iter::empty;
+#[cfg(all(target_os = "linux"))]
+use std::iter::once;
+#[cfg(all(not(target_family = "wasm")))]
+use std::path::{Path, PathBuf};
+#[cfg(all(target_os = "linux"))]
+use std::process::Command;
+
+#[allow(clippy::non_ascii_literal)]
+const DATA: &str = r#"
+@prefix schema: <http://schema.org/> .
+@prefix wd: <http://www.wikidata.org/entity/> .
+@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
+
+wd:Q90 a schema:City ;
+    schema:name "Paris"@fr , "la ville lumière"@fr ;
+    schema:country wd:Q142 ;
+    schema:population 2000000 ;
+    schema:startDate "-300"^^xsd:gYear ;
+    schema:url "https://www.paris.fr/"^^xsd:anyURI ;
+    schema:postalCode "75001" .
+"#;
+
+#[allow(clippy::non_ascii_literal)]
+const GRAPH_DATA: &str = r#"
+@prefix schema: <http://schema.org/> .
+@prefix wd: <http://www.wikidata.org/entity/> .
+@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
+
+GRAPH <http://www.wikidata.org/wiki/Special:EntityData/Q90> {
+    wd:Q90 a schema:City ;
+        schema:name "Paris"@fr , "la ville lumière"@fr ;
+        schema:country wd:Q142 ;
+        schema:population 2000000 ;
+        schema:startDate "-300"^^xsd:gYear ;
+        schema:url "https://www.paris.fr/"^^xsd:anyURI ;
+        schema:postalCode "75001" .
+}
+"#;
+const NUMBER_OF_TRIPLES: usize = 8;
+
+fn quads(graph_name: impl Into<GraphNameRef<'static>>) -> Vec<QuadRef<'static>> {
+    let graph_name = graph_name.into();
+    let paris = NamedNodeRef::new_unchecked("http://www.wikidata.org/entity/Q90");
+    let france = NamedNodeRef::new_unchecked("http://www.wikidata.org/entity/Q142");
+    let city = NamedNodeRef::new_unchecked("http://schema.org/City");
+    let name = NamedNodeRef::new_unchecked("http://schema.org/name");
+    let country = NamedNodeRef::new_unchecked("http://schema.org/country");
+    let population = NamedNodeRef::new_unchecked("http://schema.org/population");
+    let start_date = NamedNodeRef::new_unchecked("http://schema.org/startDate");
+    let url = NamedNodeRef::new_unchecked("http://schema.org/url");
+    let postal_code = NamedNodeRef::new_unchecked("http://schema.org/postalCode");
+    vec![
+        QuadRef::new(paris, rdf::TYPE, city, graph_name),
+        QuadRef::new(
+            paris,
+            name,
+            LiteralRef::new_language_tagged_literal_unchecked("Paris", "fr"),
+            graph_name,
+        ),
+        QuadRef::new(
+            paris,
+            name,
+            LiteralRef::new_language_tagged_literal_unchecked("la ville lumi\u{E8}re", "fr"),
+            graph_name,
+        ),
+        QuadRef::new(paris, country, france, graph_name),
+        QuadRef::new(
+            paris,
+            population,
+            LiteralRef::new_typed_literal("2000000", xsd::INTEGER),
+            graph_name,
+        ),
+        QuadRef::new(
+            paris,
+            start_date,
+            LiteralRef::new_typed_literal("-300", xsd::G_YEAR),
+            graph_name,
+        ),
+        QuadRef::new(
+            paris,
+            url,
+            LiteralRef::new_typed_literal("https://www.paris.fr/", xsd::ANY_URI),
+            graph_name,
+        ),
+        QuadRef::new(
+            paris,
+            postal_code,
+            LiteralRef::new_simple_literal("75001"),
+            graph_name,
+        ),
+    ]
+}
+
+#[test]
+fn test_load_graph() -> Result<(), Box<dyn Error>> {
+    let store = Store::new()?;
+    store.load_from_read(RdfFormat::Turtle, DATA.as_bytes())?;
+    for q in quads(GraphNameRef::DefaultGraph) {
+        assert!(store.contains(q)?);
+    }
+    store.validate()?;
+    Ok(())
+}
+
+#[test]
+#[cfg(all(not(target_family = "wasm")))]
+fn test_bulk_load_graph() -> Result<(), Box<dyn Error>> {
+    let store = Store::new()?;
+    store
+        .bulk_loader()
+        .load_from_read(RdfFormat::Turtle, DATA.as_bytes())?;
+    for q in quads(GraphNameRef::DefaultGraph) {
+        assert!(store.contains(q)?);
+    }
+    store.validate()?;
+    Ok(())
+}
+
+#[test]
+#[cfg(all(not(target_family = "wasm")))]
+fn test_bulk_load_graph_lenient() -> Result<(), Box<dyn Error>> {
+    let store = Store::new()?;
+    store.bulk_loader().on_parse_error(|_| Ok(())).load_from_read(
+        RdfFormat::NTriples,
+        b"<http://example.com> <http://example.com> <http://example.com##> .\n<http://example.com> <http://example.com> <http://example.com> .".as_slice(),
+    )?;
+    assert_eq!(store.len()?, 1);
+    assert!(store.contains(QuadRef::new(
+        NamedNodeRef::new_unchecked("http://example.com"),
+        NamedNodeRef::new_unchecked("http://example.com"),
+        NamedNodeRef::new_unchecked("http://example.com"),
+        GraphNameRef::DefaultGraph
+    ))?);
+    store.validate()?;
+    Ok(())
+}
+
+#[test]
+#[cfg(all(not(target_family = "wasm")))]
+fn test_bulk_load_empty() -> Result<(), Box<dyn Error>> {
+    let store = Store::new()?;
+    store.bulk_loader().load_quads(empty::<Quad>())?;
+    assert!(store.is_empty()?);
+    store.validate()?;
+    Ok(())
+}
+
+#[test]
+fn test_load_dataset() -> Result<(), Box<dyn Error>> {
+    let store = Store::new()?;
+    store.load_from_read(RdfFormat::TriG, GRAPH_DATA.as_bytes())?;
+    for q in quads(NamedNodeRef::new_unchecked(
+        "http://www.wikidata.org/wiki/Special:EntityData/Q90",
+    )) {
+        assert!(store.contains(q)?);
+    }
+    store.validate()?;
+    Ok(())
+}
+
+#[test]
+#[cfg(all(not(target_family = "wasm")))]
+fn test_bulk_load_dataset() -> Result<(), Box<dyn Error>> {
+    let store = Store::new()?;
+    store
+        .bulk_loader()
+        .load_from_read(RdfFormat::TriG, GRAPH_DATA.as_bytes())?;
+    let graph_name =
+        NamedNodeRef::new_unchecked("http://www.wikidata.org/wiki/Special:EntityData/Q90");
+    for q in quads(graph_name) {
+        assert!(store.contains(q)?);
+    }
+    assert!(store.contains_named_graph(graph_name)?);
+    store.validate()?;
+    Ok(())
+}
+
+#[test]
+fn test_load_graph_generates_new_blank_nodes() -> Result<(), Box<dyn Error>> {
+    let store = Store::new()?;
+    for _ in 0..2 {
+        store.load_from_read(
+            RdfFormat::NTriples,
+            "_:a <http://example.com/p> <http://example.com/p> .".as_bytes(),
+        )?;
+    }
+    assert_eq!(store.len()?, 2);
+    Ok(())
+}
+
+#[test]
+fn test_dump_graph() -> Result<(), Box<dyn Error>> {
+    let store = Store::new()?;
+    for q in quads(GraphNameRef::DefaultGraph) {
+        store.insert(q)?;
+    }
+
+    let mut buffer = Vec::new();
+    store.dump_graph_to_write(GraphNameRef::DefaultGraph, RdfFormat::NTriples, &mut buffer)?;
+    assert_eq!(
+        buffer.into_iter().filter(|c| *c == b'\n').count(),
+        NUMBER_OF_TRIPLES
+    );
+    Ok(())
+}
+
+#[test]
+fn test_dump_dataset() -> Result<(), Box<dyn Error>> {
+    let store = Store::new()?;
+    for q in quads(GraphNameRef::DefaultGraph) {
+        store.insert(q)?;
+    }
+
+    let buffer = store.dump_to_write(RdfFormat::NQuads, Vec::new())?;
+    assert_eq!(
+        buffer.into_iter().filter(|c| *c == b'\n').count(),
+        NUMBER_OF_TRIPLES
+    );
+    Ok(())
+}
+
+#[test]
+fn test_snapshot_isolation_iterator() -> Result<(), Box<dyn Error>> {
+    let quad = QuadRef::new(
+        NamedNodeRef::new("http://example.com/s")?,
+        NamedNodeRef::new("http://example.com/p")?,
+        NamedNodeRef::new("http://example.com/o")?,
+        NamedNodeRef::new("http://www.wikidata.org/wiki/Special:EntityData/Q90")?,
+    );
+    let store = Store::new()?;
+    store.insert(quad)?;
+    let iter = store.iter();
+    store.remove(quad)?;
+    assert_eq!(
+        iter.collect::<Result<Vec<_>, _>>()?,
+        vec![quad.into_owned()]
+    );
+    store.validate()?;
+    Ok(())
+}
+
+#[test]
+#[cfg(all(not(target_family = "wasm")))]
+fn test_bulk_load_on_existing_delete_overrides_the_delete() -> Result<(), Box<dyn Error>> {
+    let quad = QuadRef::new(
+        NamedNodeRef::new_unchecked("http://example.com/s"),
+        NamedNodeRef::new_unchecked("http://example.com/p"),
+        NamedNodeRef::new_unchecked("http://example.com/o"),
+        NamedNodeRef::new_unchecked("http://www.wikidata.org/wiki/Special:EntityData/Q90"),
+    );
+    let store = Store::new()?;
+    store.remove(quad)?;
+    store.bulk_loader().load_quads([quad.into_owned()])?;
+    assert_eq!(store.len()?, 1);
+    Ok(())
+}
+
+#[test]
+#[cfg(all(not(target_family = "wasm")))]
+fn test_open_bad_dir() -> Result<(), Box<dyn Error>> {
+    let dir = TempDir::default();
+    create_dir_all(&dir.0)?;
+    {
+        File::create(dir.0.join("CURRENT"))?.write_all(b"foo")?;
+    }
+    assert!(Store::open(&dir.0).is_err());
+    Ok(())
+}
+
+#[test]
+#[cfg(all(target_os = "linux"))]
+fn test_bad_stt_open() -> Result<(), Box<dyn Error>> {
+    let dir = TempDir::default();
+    let store = Store::open(&dir.0)?;
+    remove_dir_all(&dir.0)?;
+    store
+        .bulk_loader()
+        .load_quads(once(Quad::new(
+            NamedNode::new_unchecked("http://example.com/s"),
+            NamedNode::new_unchecked("http://example.com/p"),
+            NamedNode::new_unchecked("http://example.com/o"),
+            GraphName::DefaultGraph,
+        )))
+        .unwrap_err();
+    Ok(())
+}
+
+// #[test]
+// #[cfg(all(not(target_family = "wasm")))]
+// fn test_backup() -> Result<(), Box<dyn Error>> {
+//     let quad = QuadRef::new(
+//         NamedNodeRef::new_unchecked("http://example.com/s"),
+//         NamedNodeRef::new_unchecked("http://example.com/p"),
+//         NamedNodeRef::new_unchecked("http://example.com/o"),
+//         GraphNameRef::DefaultGraph,
+//     );
+//     let store_dir = TempDir::default();
+//     let backup_from_rw_dir = TempDir::default();
+//     let backup_from_ro_dir = TempDir::default();
+//     let backup_from_secondary_dir = TempDir::default();
+
+//     let store = Store::open(&store_dir)?;
+//     store.insert(quad)?;
+//     let secondary_store = Store::open_secondary(&store_dir)?;
+//     store.flush()?;
+
+//     store.backup(&backup_from_rw_dir)?;
+//     secondary_store.backup(&backup_from_secondary_dir)?;
+//     store.remove(quad)?;
+//     assert!(!store.contains(quad)?);
+
+//     let backup_from_rw = Store::open_read_only(&backup_from_rw_dir.0)?;
+//     backup_from_rw.validate()?;
+//     assert!(backup_from_rw.contains(quad)?);
+//     backup_from_rw.backup(&backup_from_ro_dir)?;
+
+//     let backup_from_ro = Store::open_read_only(&backup_from_ro_dir.0)?;
+//     backup_from_ro.validate()?;
+//     assert!(backup_from_ro.contains(quad)?);
+
+//     let backup_from_secondary = Store::open_read_only(&backup_from_secondary_dir.0)?;
+//     backup_from_secondary.validate()?;
+//     assert!(backup_from_secondary.contains(quad)?);
+
+//     Ok(())
+// }
+
+#[test]
+#[cfg(all(not(target_family = "wasm")))]
+fn test_bad_backup() -> Result<(), Box<dyn Error>> {
+    let store_dir = TempDir::default();
+    let backup_dir = TempDir::default();
+
+    create_dir_all(&backup_dir.0)?;
+    Store::open(&store_dir)?.backup(&backup_dir.0).unwrap_err();
+    Ok(())
+}
+
+#[test]
+#[cfg(all(not(target_family = "wasm")))]
+fn test_backup_on_in_memory() -> Result<(), Box<dyn Error>> {
+    let backup_dir = TempDir::default();
+    Store::new()?.backup(&backup_dir).unwrap_err();
+    Ok(())
+}
+
+#[test]
+#[cfg(all(target_os = "linux"))]
+fn test_backward_compatibility() -> Result<(), Box<dyn Error>> {
+    // We run twice to check if data is properly saved and closed
+    for _ in 0..2 {
+        let store = Store::open("tests/rocksdb_bc_data")?;
+        for q in quads(GraphNameRef::DefaultGraph) {
+            assert!(store.contains(q)?);
+        }
+        let graph_name =
+            NamedNodeRef::new_unchecked("http://www.wikidata.org/wiki/Special:EntityData/Q90");
+        for q in quads(graph_name) {
+            assert!(store.contains(q)?);
+        }
+        assert!(store.contains_named_graph(graph_name)?);
+        assert_eq!(
+            vec![NamedOrBlankNode::from(graph_name)],
+            store.named_graphs().collect::<Result<Vec<_>, _>>()?
+        );
+    }
+    reset_dir("tests/rocksdb_bc_data")?;
+    Ok(())
+}
+
+// #[test]
+// #[cfg(all(not(target_family = "wasm")))]
+// fn test_secondary() -> Result<(), Box<dyn Error>> {
+//     let quad = QuadRef::new(
+//         NamedNodeRef::new_unchecked("http://example.com/s"),
+//         NamedNodeRef::new_unchecked("http://example.com/p"),
+//         NamedNodeRef::new_unchecked("http://example.com/o"),
+//         GraphNameRef::DefaultGraph,
+//     );
+//     let primary_dir = TempDir::default();
+
+//     // We open the store
+//     let primary = Store::open(&primary_dir)?;
+//     let secondary = Store::open_secondary(&primary_dir)?;
+
+//     // We insert a quad
+//     primary.insert(quad)?;
+//     primary.flush()?;
+
+//     // It is readable from both stores
+//     for store in &[&primary, &secondary] {
+//         assert!(store.contains(quad)?);
+//         assert_eq!(
+//             store.iter().collect::<Result<Vec<_>, _>>()?,
+//             vec![quad.into_owned()]
+//         );
+//     }
+
+//     // We validate the states
+//     primary.validate()?;
+//     secondary.validate()?;
+
+//     // We close the primary store and remove its content
+//     drop(primary);
+//     remove_dir_all(&primary_dir)?;
+
+//     // We secondary store is still readable
+//     assert!(secondary.contains(quad)?);
+//     secondary.validate()?;
+
+//     Ok(())
+// }
+
+// #[test]
+// #[cfg(all(not(target_family = "wasm")))]
+// fn test_open_secondary_bad_dir() -> Result<(), Box<dyn Error>> {
+//     let primary_dir = TempDir::default();
+//     create_dir_all(&primary_dir.0)?;
+//     {
+//         File::create(primary_dir.0.join("CURRENT"))?.write_all(b"foo")?;
+//     }
+//     assert!(Store::open_secondary(&primary_dir).is_err());
+//     Ok(())
+// }
+
+#[test]
+#[cfg(all(not(target_family = "wasm")))]
+fn test_read_only() -> Result<(), Box<dyn Error>> {
+    let s = NamedNodeRef::new_unchecked("http://example.com/s");
+    let p = NamedNodeRef::new_unchecked("http://example.com/p");
+    let first_quad = QuadRef::new(
+        s,
+        p,
+        NamedNodeRef::new_unchecked("http://example.com/o"),
+        GraphNameRef::DefaultGraph,
+    );
+    let second_quad = QuadRef::new(
+        s,
+        p,
+        NamedNodeRef::new_unchecked("http://example.com/o2"),
+        GraphNameRef::DefaultGraph,
+    );
+    let store_dir = TempDir::default();
+
+    // We write to the store and close it
+    {
+        let read_write = Store::open(&store_dir)?;
+        read_write.insert(first_quad)?;
+        read_write.flush()?;
+    }
+
+    // We open as read-only
+    let read_only = Store::open_read_only(&store_dir, None)?;
+    assert!(read_only.contains(first_quad)?);
+    assert_eq!(
+        read_only.iter().collect::<Result<Vec<_>, _>>()?,
+        vec![first_quad.into_owned()]
+    );
+    read_only.validate()?;
+
+    // We open as read-write again
+    let read_write = Store::open(&store_dir)?;
+    read_write.insert(second_quad)?;
+    read_write.flush()?;
+    read_write.optimize()?; // Makes sure it's well flushed
+
+    // The new quad is in the read-write instance but not the read-only instance
+    assert!(read_write.contains(second_quad)?);
+    assert!(!read_only.contains(second_quad)?);
+    read_only.validate()?;
+
+    Ok(())
+}
+
+#[test]
+#[cfg(all(not(target_family = "wasm")))]
+fn test_open_read_only_bad_dir() -> Result<(), Box<dyn Error>> {
+    let dir = TempDir::default();
+    create_dir_all(&dir.0)?;
+    {
+        File::create(dir.0.join("CURRENT"))?.write_all(b"foo")?;
+    }
+    assert!(Store::open_read_only(&dir, None).is_err());
+    Ok(())
+}
+
+#[cfg(all(target_os = "linux"))]
+fn reset_dir(dir: &str) -> Result<(), Box<dyn Error>> {
+    assert!(Command::new("git")
+        .args(["clean", "-fX", dir])
+        .status()?
+        .success());
+    assert!(Command::new("git")
+        .args(["checkout", "HEAD", "--", dir])
+        .status()?
+        .success());
+    Ok(())
+}
+
+#[cfg(all(not(target_family = "wasm")))]
+struct TempDir(PathBuf);
+
+#[cfg(all(not(target_family = "wasm")))]
+impl Default for TempDir {
+    fn default() -> Self {
+        Self(temp_dir().join(format!("oxigraph-test-{}", random::<u128>())))
+    }
+}
+
+#[cfg(all(not(target_family = "wasm")))]
+impl AsRef<Path> for TempDir {
+    fn as_ref(&self) -> &Path {
+        &self.0
+    }
+}
+
+#[cfg(all(not(target_family = "wasm")))]
+impl Drop for TempDir {
+    fn drop(&mut self) {
+        if self.0.is_dir() {
+            remove_dir_all(&self.0).unwrap();
+        }
+    }
+}