use crate::model::{PyQuad, PyTriple}; use oxigraph::io::read::{QuadReader, TripleReader}; use oxigraph::io::{ DatasetFormat, DatasetParser, DatasetSerializer, GraphFormat, GraphParser, GraphSerializer, }; use pyo3::exceptions::{PyIOError, PySyntaxError, PyValueError}; use pyo3::prelude::*; use pyo3::types::PyBytes; use pyo3::wrap_pyfunction; use pyo3::PyIterProtocol; use std::io; use std::io::{BufReader, Read, Write}; pub fn add_to_module(module: &PyModule) -> PyResult<()> { module.add_wrapped(wrap_pyfunction!(parse))?; module.add_wrapped(wrap_pyfunction!(serialize)) } /// Parses RDF graph and dataset serialization formats /// /// It currently supports the following formats: /// /// * `N-Triples `_ (``application/n-triples``) /// * `N-Quads `_ (``application/n-quads``) /// * `Turtle `_ (``text/turtle``) /// * `TriG `_ (``application/trig``) /// * `RDF/XML `_ (``application/rdf+xml``) /// /// It supports also some MIME type aliases. /// For example ``application/turtle`` could also be used for `Turtle `_ /// and ``application/xml`` for `RDF/XML `_. /// /// :param input: The binary I/O object to read from. For example, it could be a file opened in binary mode with ``open('my_file.ttl', 'rb')``. /// :type input: io.RawIOBase or io.BufferedIOBase /// :param mime_type: the MIME type of the RDF serialization /// :type mime_type: str /// :param base_iri: the base IRI used to resolve the relative IRIs in the file or :py:const:`None` if relative IRI resolution should not be done /// :type base_iri: str or None, optional /// :return: an iterator of RDF triples or quads depending on the format /// :rtype: iter(Triple) or iter(Quad) /// :raises ValueError: if the MIME type is not supported /// :raises SyntaxError: if the provided data is invalid /// /// >>> input = io.BytesIO(b'

"1" .') /// >>> list(parse(input, "text/turtle", base_iri="http://example.com/")) /// [ predicate= object=>>] #[pyfunction] #[text_signature = "(input, /, mime_type, *, base_iri = None)"] pub fn parse( input: PyObject, mime_type: &str, base_iri: Option<&str>, py: Python<'_>, ) -> PyResult { let input = BufReader::new(PyFileLike::new(input)); if let Some(graph_format) = GraphFormat::from_media_type(mime_type) { let mut parser = GraphParser::from_format(graph_format); if let Some(base_iri) = base_iri { parser = parser .with_base_iri(base_iri) .map_err(|e| PyValueError::new_err(e.to_string()))?; } Ok(PyTripleReader { inner: parser.read_triples(input).map_err(map_io_err)?, } .into_py(py)) } else if let Some(dataset_format) = DatasetFormat::from_media_type(mime_type) { let mut parser = DatasetParser::from_format(dataset_format); if let Some(base_iri) = base_iri { parser = parser .with_base_iri(base_iri) .map_err(|e| PyValueError::new_err(e.to_string()))?; } Ok(PyQuadReader { inner: parser.read_quads(input).map_err(map_io_err)?, } .into_py(py)) } else { Err(PyValueError::new_err(format!( "Not supported MIME type: {}", mime_type ))) } } /// Serializes an RDF graph or dataset /// /// It currently supports the following formats: /// /// * `N-Triples `_ (``application/n-triples``) /// * `N-Quads `_ (``application/n-quads``) /// * `Turtle `_ (``text/turtle``) /// * `TriG `_ (``application/trig``) /// * `RDF/XML `_ (``application/rdf+xml``) /// /// It supports also some MIME type aliases. /// For example ``application/turtle`` could also be used for `Turtle `_ /// and ``application/xml`` for `RDF/XML `_. /// /// :param input: the RDF triples and quads to serialize /// :type input: iter(Triple) or iter(Quad) /// :param output: The binary I/O object to write to. For example, it could be a file opened in binary mode with ``open('my_file.ttl', 'wb')``. /// :type output: io.RawIOBase or io.BufferedIOBase /// :param mime_type: the MIME type of the RDF serialization /// :type mime_type: str /// :raises ValueError: if the MIME type is not supported /// :raises TypeError: if a triple is given during a quad format serialization or reverse /// /// >>> output = io.BytesIO() /// >>> serialize([Triple(NamedNode('http://example.com'), NamedNode('http://example.com/p'), Literal('1'))], output, "text/turtle") /// >>> output.getvalue() /// b' "1" .\n' #[pyfunction] #[text_signature = "(input, output, /, mime_type, *, base_iri = None)"] pub fn serialize(input: &PyAny, output: PyObject, mime_type: &str) -> PyResult<()> { let output = PyFileLike::new(output); if let Some(graph_format) = GraphFormat::from_media_type(mime_type) { let mut writer = GraphSerializer::from_format(graph_format) .triple_writer(output) .map_err(map_io_err)?; for i in input.iter()? { writer .write(&*i?.downcast::>()?.borrow()) .map_err(map_io_err)?; } writer.finish().map_err(map_io_err)?; Ok(()) } else if let Some(dataset_format) = DatasetFormat::from_media_type(mime_type) { let mut writer = DatasetSerializer::from_format(dataset_format) .quad_writer(output) .map_err(map_io_err)?; for i in input.iter()? { writer .write(&*i?.downcast::>()?.borrow()) .map_err(map_io_err)?; } writer.finish().map_err(map_io_err)?; Ok(()) } else { Err(PyValueError::new_err(format!( "Not supported MIME type: {}", mime_type ))) } } #[pyclass(name = "TripleReader", module = "oxigraph")] pub struct PyTripleReader { inner: TripleReader>, } #[pyproto] impl PyIterProtocol for PyTripleReader { fn __iter__(slf: PyRefMut) -> Py { slf.into() } fn __next__(mut slf: PyRefMut) -> PyResult> { slf.inner .next() .map(|q| Ok(q.map_err(map_io_err)?.into())) .transpose() } } #[pyclass(name = "QuadReader", module = "oxigraph")] pub struct PyQuadReader { inner: QuadReader>, } #[pyproto] impl PyIterProtocol for PyQuadReader { fn __iter__(slf: PyRefMut) -> Py { slf.into() } fn __next__(mut slf: PyRefMut) -> PyResult> { slf.inner .next() .map(|q| Ok(q.map_err(map_io_err)?.into())) .transpose() } } pub struct PyFileLike { inner: PyObject, } impl PyFileLike { pub fn new(inner: PyObject) -> Self { Self { inner } } } impl Read for PyFileLike { fn read(&mut self, mut buf: &mut [u8]) -> io::Result { let gil = Python::acquire_gil(); let py = gil.python(); let read = self .inner .call_method(py, "read", (buf.len(),), None) .map_err(|e| to_io_err(e, py))?; let bytes: &PyBytes = read.cast_as(py).map_err(|e| to_io_err(e, py))?; buf.write_all(bytes.as_bytes())?; Ok(bytes.len()?) } } impl Write for PyFileLike { fn write(&mut self, buf: &[u8]) -> io::Result { let gil = Python::acquire_gil(); let py = gil.python(); usize::extract( self.inner .call_method(py, "write", (PyBytes::new(py, buf),), None) .map_err(|e| to_io_err(e, py))? .as_ref(py), ) .map_err(|e| to_io_err(e, py)) } fn flush(&mut self) -> io::Result<()> { let gil = Python::acquire_gil(); let py = gil.python(); self.inner.call_method(py, "flush", (), None)?; Ok(()) } } fn to_io_err(error: impl Into, py: Python<'_>) -> io::Error { if let Ok(message) = error .into() .to_object(py) .call_method(py, "__str__", (), None) { if let Ok(message) = message.extract::(py) { io::Error::new(io::ErrorKind::Other, message) } else { io::Error::new(io::ErrorKind::Other, "An unknown error has occurred") } } else { io::Error::new(io::ErrorKind::Other, "An unknown error has occurred") } } pub fn map_io_err(error: io::Error) -> PyErr { match error.kind() { io::ErrorKind::InvalidInput => PyValueError::new_err(error.to_string()), io::ErrorKind::InvalidData | io::ErrorKind::UnexpectedEof => { PySyntaxError::new_err(error.to_string()) } _ => PyIOError::new_err(error.to_string()), } }