Makes encoding of some very usual IRIs and of empty string well known

TODO: make the set of encoded URIs extensible

lib/src/sparql/eval.rs

@@ -4,7 +4,7 @@ use std::collections::HashSet;
 use std::iter::once;
 use std::iter::Iterator;
 use std::sync::Arc;
-use store::numeric_encoder::EncodedTerm;
+use store::numeric_encoder::*;
 use store::store::EncodedQuadsStore;
 use Result;
 
@@ -240,13 +240,13 @@ impl<S: EncodedQuadsStore> SimpleEvaluator<S> {
                 _ => None,
             },
             PlanExpression::Datatype(e) => match self.eval_expression(e, tuple)? {
-                //TODO EncodedTerm::SimpleLiteral { .. }
+                EncodedTerm::SimpleLiteral { .. } => Some(ENCODED_XSD_STRING_NAMED_NODE),
-                //TODO EncodedTerm::LangStringLiteral { .. }
+                EncodedTerm::LangStringLiteral { .. } => Some(ENCODED_RDF_LANG_STRING_NAMED_NODE),
                 EncodedTerm::TypedLiteral { datatype_id, .. } => Some(EncodedTerm::NamedNode {
                     iri_id: datatype_id,
                 }),
-                //TODO EncodedTerm::StringLiteral { .. }
+                EncodedTerm::StringLiteral { .. } => Some(ENCODED_XSD_STRING_NAMED_NODE),
-                //TODO EncodedTerm::BooleanLiteral(..)
+                EncodedTerm::BooleanLiteral(..) => Some(ENCODED_XSD_BOOLEAN_NAMED_NODE),
                 _ => None,
             },
             PlanExpression::Bound(v) => Some((*v >= tuple.len() && tuple[*v].is_some()).into()),
@@ -279,9 +279,9 @@ impl<S: EncodedQuadsStore> SimpleEvaluator<S> {
     fn to_bool(&self, term: EncodedTerm) -> Option<bool> {
         match term {
             EncodedTerm::BooleanLiteral(value) => Some(value),
-            EncodedTerm::NamedNode { .. } => None,
+            EncodedTerm::SimpleLiteral { .. } => Some(term != ENCODED_EMPTY_SIMPLE_LITERAL),
-            EncodedTerm::BlankNode(_) => None,
+            EncodedTerm::StringLiteral { .. } => Some(term != ENCODED_EMPTY_STRING_LITERAL),
-            term => self.store.encoder().decode_term(term).ok()?.to_bool(),
+            _ => None,
         }
     }
 

lib/src/store/memory.rs

@@ -42,13 +42,24 @@ pub type MemoryDataset = StoreDataset<MemoryStore>;
 /// ```
 pub type MemoryGraph = StoreDefaultGraph<MemoryStore>;
 
-#[derive(Default)]
 pub struct MemoryStore {
     id2str: RwLock<Vec<Vec<u8>>>,
     str2id: RwLock<BTreeMap<Vec<u8>, u64>>,
     graph_indexes: RwLock<BTreeMap<EncodedTerm, MemoryGraphIndexes>>,
 }
 
+impl Default for MemoryStore {
+    fn default() -> Self {
+        let new = Self {
+            id2str: RwLock::default(),
+            str2id: RwLock::default(),
+            graph_indexes: RwLock::default(),
+        };
+        new.set_first_strings().unwrap();
+        new
+    }
+}
+
 #[derive(Default)]
 struct MemoryGraphIndexes {
     spo: BTreeMap<EncodedTerm, BTreeMap<EncodedTerm, BTreeSet<EncodedTerm>>>,

lib/src/store/numeric_encoder.rs

@@ -1,4 +1,6 @@
 use byteorder::{NetworkEndian, ReadBytesExt, WriteBytesExt};
+use model::vocab::rdf;
+use model::vocab::xsd;
 use model::*;
 use std::io::Read;
 use std::io::Write;
@@ -10,11 +12,39 @@ use uuid::Uuid;
 use Error;
 use Result;
 
+const EMPTY_STRING_ID: u64 = 0;
+const RDF_LANG_STRING_ID: u64 = 1;
+const XSD_STRING_ID: u64 = 2;
+const XSD_BOOLEAN_ID: u64 = 3;
+const XSD_FLOAT_ID: u64 = 4;
+const XSD_DOUBLE_ID: u64 = 5;
+const XSD_INTEGER_ID: u64 = 6;
+const XSD_DECIMAL_ID: u64 = 7;
+const XSD_DATE_TIME_ID: u64 = 8;
+
 pub trait BytesStore {
     type BytesOutput: Deref<Target = [u8]>;
 
     fn insert_bytes(&self, value: &[u8]) -> Result<u64>;
     fn get_bytes(&self, id: u64) -> Result<Option<Self::BytesOutput>>;
+
+    /// Should be called when the bytes store is created
+    fn set_first_strings(&self) -> Result<()> {
+        if EMPTY_STRING_ID == self.insert_bytes(b"")?
+            && RDF_LANG_STRING_ID == self.insert_bytes(rdf::LANG_STRING.as_str().as_bytes())?
+            && XSD_STRING_ID == self.insert_bytes(xsd::STRING.as_str().as_bytes())?
+            && XSD_BOOLEAN_ID == self.insert_bytes(xsd::BOOLEAN.as_str().as_bytes())?
+            && XSD_FLOAT_ID == self.insert_bytes(xsd::FLOAT.as_str().as_bytes())?
+            && XSD_DOUBLE_ID == self.insert_bytes(xsd::DOUBLE.as_str().as_bytes())?
+            && XSD_INTEGER_ID == self.insert_bytes(xsd::INTEGER.as_str().as_bytes())?
+            && XSD_DECIMAL_ID == self.insert_bytes(xsd::DECIMAL.as_str().as_bytes())?
+            && XSD_DATE_TIME_ID == self.insert_bytes(xsd::DATE_TIME.as_str().as_bytes())?
+        {
+            Ok(())
+        } else {
+            Err("Failed to properly setup the basic string ids in the dictionnary".into())
+        }
+    }
 }
 
 const TYPE_DEFAULT_GRAPH_ID: u8 = 0;
@@ -28,6 +58,36 @@ const TYPE_BOOLEAN_LITERAL_TRUE: u8 = 7;
 const TYPE_BOOLEAN_LITERAL_FALSE: u8 = 8;
 
 pub static ENCODED_DEFAULT_GRAPH: EncodedTerm = EncodedTerm::DefaultGraph {};
+pub static ENCODED_EMPTY_SIMPLE_LITERAL: EncodedTerm = EncodedTerm::SimpleLiteral {
+    value_id: EMPTY_STRING_ID,
+};
+pub static ENCODED_EMPTY_STRING_LITERAL: EncodedTerm = EncodedTerm::StringLiteral {
+    value_id: EMPTY_STRING_ID,
+};
+pub static ENCODED_RDF_LANG_STRING_NAMED_NODE: EncodedTerm = EncodedTerm::NamedNode {
+    iri_id: RDF_LANG_STRING_ID,
+};
+pub static ENCODED_XSD_STRING_NAMED_NODE: EncodedTerm = EncodedTerm::NamedNode {
+    iri_id: XSD_STRING_ID,
+};
+pub static ENCODED_XSD_BOOLEAN_NAMED_NODE: EncodedTerm = EncodedTerm::NamedNode {
+    iri_id: XSD_BOOLEAN_ID,
+};
+pub static ENCODED_XSD_FLOAT_NAMED_NODE: EncodedTerm = EncodedTerm::NamedNode {
+    iri_id: XSD_FLOAT_ID,
+};
+pub static ENCODED_XSD_DOUBLE_NAMED_NODE: EncodedTerm = EncodedTerm::NamedNode {
+    iri_id: XSD_DOUBLE_ID,
+};
+pub static ENCODED_XSD_INTEGER_NAMED_NODE: EncodedTerm = EncodedTerm::NamedNode {
+    iri_id: XSD_INTEGER_ID,
+};
+pub static ENCODED_XSD_DECIMAL_NAMED_NODE: EncodedTerm = EncodedTerm::NamedNode {
+    iri_id: XSD_DECIMAL_ID,
+};
+pub static ENCODED_XSD_DATE_TIME_NAMED_NODE: EncodedTerm = EncodedTerm::NamedNode {
+    iri_id: XSD_DATE_TIME_ID,
+};
 
 #[derive(Eq, PartialEq, Ord, PartialOrd, Debug, Clone, Copy, Hash)]
 pub enum EncodedTerm {

lib/src/store/rocksdb.rs

@@ -65,7 +65,7 @@ impl RocksDbStore {
         let posg_cf = get_cf(&db, POSG_CF)?;
         let ospg_cf = get_cf(&db, OSPG_CF)?;
 
-        Ok(Self {
+        let new = Self {
             db,
             str_id_counter: Mutex::new(RocksDBCounter::new("bsc")),
             id2str_cf,
@@ -73,7 +73,9 @@ impl RocksDbStore {
             spog_cf,
             posg_cf,
             ospg_cf,
-        })
+        };
+        new.set_first_strings()?;
+        Ok(new)
     }
 }