1#![cfg(not(Py_LIMITED_API))]
2
3//! Support for the Python `marshal` format.
4
5use crate::ffi;
6use crate::types::{PyAny, PyBytes};
7use crate::{AsPyPointer, FromPyPointer, PyResult, Python};
8use std::os::raw::{c_char, c_int};
9
10/// The current version of the marshal binary format.
11pub const VERSION: i32 = 4;
12
13/// Serialize an object to bytes using the Python built-in marshal module.
14///
15/// The built-in marshalling only supports a limited range of objects.
16/// The exact types supported depend on the version argument.
17/// The [`VERSION`] constant holds the highest version currently supported.
18///
19/// See the [Python documentation](https://docs.python.org/3/library/marshal.html) for more details.
20///
21/// # Examples
22/// ```
23/// # use pyo3::{marshal, types::PyDict};
24/// # pyo3::Python::with_gil(|py| {
25/// let dict = PyDict::new(py);
26/// dict.set_item("aap", "noot").unwrap();
27/// dict.set_item("mies", "wim").unwrap();
28/// dict.set_item("zus", "jet").unwrap();
29///
30/// let bytes = marshal::dumps(py, dict, marshal::VERSION);
31/// # });
32/// ```
33pub fn dumps<'a>(py: Python<'a>, object: &impl AsPyPointer, version: i32) -> PyResult<&'a PyBytes> {
34 unsafe {
35 let bytes: *mut PyObject = ffi::PyMarshal_WriteObjectToString(object:object.as_ptr(), version as c_int);
36 FromPyPointer::from_owned_ptr_or_err(py, ptr:bytes)
37 }
38}
39
40/// Deserialize an object from bytes using the Python built-in marshal module.
41pub fn loads<'a, B>(py: Python<'a>, data: &B) -> PyResult<&'a PyAny>
42where
43 B: AsRef<[u8]> + ?Sized,
44{
45 let data: &[u8] = data.as_ref();
46 unsafe {
47 let c_str: *const i8 = data.as_ptr() as *const c_char;
48 let object: *mut PyObject = ffi::PyMarshal_ReadObjectFromString(data:c_str, data.len() as isize);
49 FromPyPointer::from_owned_ptr_or_err(py, ptr:object)
50 }
51}
52
53#[cfg(test)]
54mod tests {
55 use super::*;
56 use crate::types::PyDict;
57
58 #[test]
59 fn marshal_roundtrip() {
60 Python::with_gil(|py| {
61 let dict = PyDict::new(py);
62 dict.set_item("aap", "noot").unwrap();
63 dict.set_item("mies", "wim").unwrap();
64 dict.set_item("zus", "jet").unwrap();
65
66 let bytes = dumps(py, dict, VERSION)
67 .expect("marshalling failed")
68 .as_bytes();
69 let deserialized = loads(py, bytes).expect("unmarshalling failed");
70
71 assert!(equal(py, dict, deserialized));
72 });
73 }
74
75 fn equal(_py: Python<'_>, a: &impl AsPyPointer, b: &impl AsPyPointer) -> bool {
76 unsafe { ffi::PyObject_RichCompareBool(a.as_ptr(), b.as_ptr(), ffi::Py_EQ) != 0 }
77 }
78}
79