Merge branch 'feat/p2b-blosc2' into feat/p2b-scale

# Conflicts:
#	CHANGELOG.md

crates/clawhdf5-format/src/filter_registry.rs

@@ -5,7 +5,8 @@
 //! * **Built-in filters** — a static table of the filters compiled into this
 //!   build: the HDF5 standard filters (deflate, shuffle, Fletcher32, szip,
 //!   N-Bit, scale-offset) and the plugin filters whose cargo features are
-//!   enabled (LZ4, Zstandard, pcodec, LZF, bitshuffle, bzip2, blosc).
+//!   enabled (LZ4, Zstandard, pcodec, LZF, bitshuffle, bzip2, blosc,
+//!   blosc2).
 //!   [`builtin_filters`] lists them.
 //! * **Registered filters** (`std` only) — codecs the application supplies
 //!   for any other ID with [`register_filter`] (a [`FilterCodec`], or just a
@@ -166,7 +167,7 @@ pub fn known_filter(id: u16) -> Option<(&'static str, Option<&'static str>)> {
         32019 => ("JPEG", None),
         32022 => ("BitGroom", None),
         32023 => ("Granular BitRound", None),
-        32026 => ("Blosc2", None),
+        32026 => ("Blosc2", Some("blosc2")),
         _ => return None,
     })
 }
@@ -452,12 +453,12 @@ pub(crate) mod tests {
     #[test]
     fn unsupported_filter_error_names_the_filter() {
         let msg = FormatError::UnsupportedFilter(32026).to_string();
+        assert!(msg.contains("Blosc2") && msg.contains("`blosc2`"), "{msg}");
+        let msg = FormatError::UnsupportedFilter(32013).to_string();
         assert!(
-            msg.contains("Blosc2") && msg.contains("not implemented"),
+            msg.contains("ZFP") && msg.contains("not implemented"),
             "{msg}"
         );
-        let msg = FormatError::UnsupportedFilter(32013).to_string();
-        assert!(msg.contains("ZFP"), "{msg}");
         let msg = FormatError::UnsupportedFilter(32000).to_string();
         assert!(msg.contains("LZF") && msg.contains("`lzf`"), "{msg}");
         assert_eq!(

crates/clawhdf5-format/src/filters.rs

@@ -455,6 +455,13 @@ pub(crate) static BUILTIN_FILTERS: &[BuiltinFilter] = &[
         },
         encode: None,
     },
+    #[cfg(feature = "blosc2")]
+    BuiltinFilter {
+        id: crate::filter_pipeline::FILTER_BLOSC2,
+        name: "blosc2",
+        decode: crate::filters_blosc2::blosc2_decode,
+        encode: None,
+    },
 ];
 
 /// Decode the HDF5 scale-offset filter (id 6).

crates/clawhdf5-format/src/filters_bitshuffle.rs

@@ -218,12 +218,20 @@ pub(crate) fn bitshuffle_decode(
 }
 
 /// Decode Zstandard frames into exactly `dst`, failing if they hold more.
+///
+/// ruzstd reserves a frame's declared window (by default up to 100 MiB)
+/// before decoding it, so the window is capped at what the output could
+/// need: twice `dst` (window sizes are rounded up), and at least 128 KiB.
+/// The encoders behind these filters (c-blosc, c-blosc2, bitshuffle)
+/// compress each block in one call with its size known, so libzstd's
+/// window never exceeds the block.
 #[cfg(any(feature = "bitshuffle", feature = "blosc"))]
 pub(crate) fn zstd_decode_into(
     decoder: &mut ruzstd::decoding::FrameDecoder,
     frames: &[u8],
     dst: &mut [u8],
 ) -> Result<usize, FormatError> {
+    decoder.set_max_window_size((2 * dst.len()).max(1 << 17) as u64);
     decoder
         .decode_all(frames, dst)
         .map_err(|e| FormatError::DecompressionError(format!("zstd: {e}")))

crates/clawhdf5-format/src/filters_blosc.rs

@@ -49,7 +49,7 @@ fn le32(b: &[u8], at: usize) -> Result<usize, FormatError> {
 
 /// The codec inside a Blosc frame (flags bits 5-7).
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
-enum Codec {
+pub(crate) enum Codec {
     BloscLz,
     Lz4,
     Snappy,
@@ -58,7 +58,7 @@ enum Codec {
 }
 
 impl Codec {
-    fn from_flags(flags: u8) -> Result<Codec, FormatError> {
+    pub(crate) fn from_flags(flags: u8) -> Result<Codec, FormatError> {
         match flags >> 5 {
             0 => Ok(Codec::BloscLz),
             1 => Ok(Codec::Lz4),
@@ -71,7 +71,7 @@ impl Codec {
 }
 
 /// Decode one codec stream into exactly `dst`.
-fn decode_stream(
+pub(crate) fn decode_stream(
     codec: Codec,
     src: &[u8],
     dst: &mut [u8],

crates/clawhdf5-format/src/lib.rs

@@ -87,6 +87,8 @@ pub mod filters;
 mod filters_bitshuffle;
 #[cfg(feature = "blosc")]
 pub mod filters_blosc;
+#[cfg(feature = "blosc2")]
+pub mod filters_blosc2;
 #[cfg(feature = "bzip2")]
 mod filters_bzip2;
 #[cfg(feature = "lzf")]