"1" .')
/// >>> list(parse(input, "text/turtle", base_iri="http://example.com/"))
/// [ predicate= object=>>]
#[pyfunction]
#[pyo3(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 = PyFileLike::open(input, py).map_err(map_io_err)?;
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: py.allow_threads(|| parser.read_triples(input).map_err(map_parse_error))?,
}
.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: py.allow_threads(|| parser.read_quads(input).map_err(map_parse_error))?,
}
.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 or file path to write to. For example, it could be a file path as a string or a file writer opened in binary mode with ``open('my_file.ttl', 'wb')``.
/// :type output: io.RawIOBase or io.BufferedIOBase or str
/// :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]
#[pyo3(text_signature = "(input, output, /, mime_type, *, base_iri = None)")]
pub fn serialize(input: &PyAny, output: PyObject, mime_type: &str, py: Python<'_>) -> PyResult<()> {
let output = PyFileLike::create(output, py).map_err(map_io_err)?;
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>,
}
#[pymethods]
impl PyTripleReader {
fn __iter__(slf: PyRef<'_, Self>) -> Py {
slf.into()
}
fn __next__(&mut self, py: Python<'_>) -> PyResult> {
py.allow_threads(|| {
self.inner
.next()
.map(|q| Ok(q.map_err(map_parse_error)?.into()))
.transpose()
})
}
}
#[pyclass(name = "QuadReader", module = "oxigraph")]
pub struct PyQuadReader {
inner: QuadReader>,
}
#[pymethods]
impl PyQuadReader {
fn __iter__(slf: PyRef<'_, Self>) -> Py {
slf.into()
}
fn __next__(&mut self, py: Python<'_>) -> PyResult> {
py.allow_threads(|| {
self.inner
.next()
.map(|q| Ok(q.map_err(map_parse_error)?.into()))
.transpose()
})
}
}
pub(crate) enum PyFileLike {
Io(PyObject),
File(File),
}
impl PyFileLike {
pub fn open(inner: PyObject, py: Python<'_>) -> io::Result> {
Ok(BufReader::new(match inner.extract::<&str>(py) {
Ok(path) => Self::File(py.allow_threads(|| File::open(path))?),
Err(_) => Self::Io(inner),
}))
}
pub fn create(inner: PyObject, py: Python<'_>) -> io::Result> {
Ok(BufWriter::new(match inner.extract::<&str>(py) {
Ok(path) => Self::File(py.allow_threads(|| File::create(path))?),
Err(_) => Self::Io(inner),
}))
}
}
impl Read for PyFileLike {
fn read(&mut self, mut buf: &mut [u8]) -> io::Result {
match self {
Self::Io(io) => {
let gil = Python::acquire_gil();
let py = gil.python();
let read = io
.call_method(py, "read", (buf.len(),), None)
.map_err(to_io_err)?;
let bytes: &[u8] = read.extract(py).map_err(to_io_err)?;
buf.write_all(bytes)?;
Ok(bytes.len())
}
Self::File(file) => file.read(buf),
}
}
}
impl Write for PyFileLike {
fn write(&mut self, buf: &[u8]) -> io::Result {
match self {
Self::Io(io) => {
let gil = Python::acquire_gil();
let py = gil.python();
usize::extract(
io.call_method(py, "write", (PyBytes::new(py, buf),), None)
.map_err(to_io_err)?
.as_ref(py),
)
.map_err(to_io_err)
}
Self::File(file) => file.write(buf),
}
}
fn flush(&mut self) -> io::Result<()> {
match self {
Self::Io(io) => {
let gil = Python::acquire_gil();
let py = gil.python();
io.call_method(py, "flush", (), None)?;
Ok(())
}
Self::File(file) => file.flush(),
}
}
}
fn to_io_err(error: impl Into) -> io::Error {
io::Error::new(io::ErrorKind::Other, error.into())
}
pub(crate) fn map_io_err(error: io::Error) -> PyErr {
if error.get_ref().map_or(false, |s| s.is::()) {
*error.into_inner().unwrap().downcast().unwrap()
} else {
PyIOError::new_err(error.to_string())
}
}
pub(crate) fn map_parse_error(error: ParseError) -> PyErr {
match error {
ParseError::Syntax(error) => PySyntaxError::new_err(error.to_string()),
ParseError::Io(error) => map_io_err(error),
}
}
/// Release the GIL
/// There should not be ANY use of pyo3 code inside of this method!!!
///
/// Code from pyo3: https://github.com/PyO3/pyo3/blob/a67180c8a42a0bc0fdc45b651b62c0644130cf47/src/python.rs#L366
#[allow(unsafe_code)]
pub(crate) fn allow_threads_unsafe(f: impl FnOnce() -> T) -> T {
struct RestoreGuard {
tstate: *mut pyo3::ffi::PyThreadState,
}
impl Drop for RestoreGuard {
fn drop(&mut self) {
unsafe {
pyo3::ffi::PyEval_RestoreThread(self.tstate);
}
}
}
let _guard = RestoreGuard {
tstate: unsafe { pyo3::ffi::PyEval_SaveThread() },
};
f()
}