rust: upgrade PyO3 0.22 -> 0.23

I implemented `Sync` without actually verifying the underlying types
are thread safe. I could have introduced major bugs in free-threaded
builds! We don't yet support free-threaded builds and we can't not
implement `Sync`. So I'm fine deferring the hard work of doing this
audit.

There were some compiler errors related to type coercion. So those were
fixed too.

Not fixed are a ton of new warnings we get with the upgrade.

Author: indygreg

Cargo.lock

@@ -26,5 +26,5 @@ version = "2.0.10+zstd.1.5.6"
 features = ["experimental", "legacy", "zstdmt"]
 
 [dependencies.pyo3]
-version = "0.22.6"
+version = "0.23.5"
 features = ["extension-module"]

Cargo.toml

@@ -59,7 +59,7 @@ Changes
   and we didn't run tests on this platform.
 * We now `collections.abs.Buffer` on Python 3.12+ instead of `typing.ByteString`,
   as `typing.ByteString` was deprecated and later removed. (#238, #262)
-* PyO3 Rust crate upgraded from 0.21 to 0.22. (#257)
+* PyO3 Rust crate upgraded from 0.21 to 0.22 (#257) and later to 0.23.
 
 Backwards Compatibility Notes
 -----------------------------

docs/news.rst

@@ -34,6 +34,8 @@ pub struct ZstdBufferSegment {
     len: usize,
 }
 
+unsafe impl Sync for ZstdBufferSegment {}
+
 impl ZstdBufferSegment {
     pub fn as_slice(&self) -> &[u8] {
         unsafe {
@@ -90,6 +92,8 @@ pub struct ZstdBufferSegments {
     parent: PyObject,
 }
 
+unsafe impl Sync for ZstdBufferSegments {}
+
 #[pymethods]
 impl ZstdBufferSegments {
     // PyBufferProtocol.
@@ -126,6 +130,8 @@ pub struct ZstdBufferWithSegments {
     pub(crate) segments: Vec<BufferSegment>,
 }
 
+unsafe impl Sync for ZstdBufferWithSegments {}
+
 impl ZstdBufferWithSegments {
     fn as_slice(&self) -> &[u8] {
         unsafe {
@@ -269,6 +275,8 @@ pub struct ZstdBufferWithSegmentsCollection {
     first_elements: Vec<usize>,
 }
 
+unsafe impl Sync for ZstdBufferWithSegmentsCollection {}
+
 #[pymethods]
 impl ZstdBufferWithSegmentsCollection {
     // PySequenceProtocol.

rust-ext/src/buffers.rs

@@ -23,6 +23,8 @@ pub struct ZstdCompressionChunker {
     partial_buffer: Option<Vec<u8>>,
 }
 
+unsafe impl Sync for ZstdCompressionChunker {}
+
 impl ZstdCompressionChunker {
     pub fn new(cctx: Arc<CCtx<'static>>, chunk_size: usize) -> PyResult<Self> {
         Ok(Self {
@@ -186,6 +188,8 @@ struct ZstdCompressionChunkerIterator {
     finished: bool,
 }
 
+unsafe impl Sync for ZstdCompressionChunkerIterator {}
+
 #[pymethods]
 impl ZstdCompressionChunkerIterator {
     // PyIterProtocol.

rust-ext/src/compression_chunker.rs

@@ -44,6 +44,8 @@ pub struct ZstdCompressionDict {
     ddict: Option<DDict<'static>>,
 }
 
+unsafe impl Sync for ZstdCompressionDict {}
+
 impl ZstdCompressionDict {
     pub(crate) fn load_into_cctx(&self, cctx: &CCtx) -> PyResult<()> {
         if let Some(cdict) = &self.cdict {

rust-ext/src/compression_dict.rs

@@ -207,6 +207,8 @@ pub struct ZstdCompressionParameters {
     pub(crate) params: *mut zstd_sys::ZSTD_CCtx_params,
 }
 
+unsafe impl Sync for ZstdCompressionParameters {}
+
 impl Drop for ZstdCompressionParameters {
     fn drop(&mut self) {
         unsafe {

rust-ext/src/compression_parameters.rs

@@ -30,6 +30,8 @@ pub struct ZstdCompressionReader {
     finished_output: bool,
 }
 
+unsafe impl Sync for ZstdCompressionReader {}
+
 impl ZstdCompressionReader {
     pub fn new(
         py: Python,

rust-ext/src/compression_reader.rs

@@ -31,6 +31,8 @@ pub struct ZstdCompressionWriter {
     dest_buffer: Vec<u8>,
 }
 
+unsafe impl Sync for ZstdCompressionWriter {}
+
 impl ZstdCompressionWriter {
     pub fn new(
         py: Python,

rust-ext/src/compression_writer.rs

@@ -20,6 +20,8 @@ pub struct ZstdCompressionObj {
     finished: bool,
 }
 
+unsafe impl Sync for ZstdCompressionObj {}
+
 impl ZstdCompressionObj {
     pub fn new(cctx: Arc<CCtx<'static>>) -> PyResult<Self> {
         Ok(ZstdCompressionObj {