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`make all` exercises substantially more than the default zstd binary. It also builds compression-only and decompression-only archives, older contrib tools that compile program C shims directly, and the single-file amalgamations. The Rust migration had changed symbol ownership without updating every one of those feature and link boundaries. The first failure came from `fileio_asyncio`: it is always compiled, but its codec bindings unconditionally referenced both `zstd_compress` and `zstd_decompress`. A compression-only archive therefore required disabled decoder modules, and the decompression-only configuration had the symmetric problem. Gate the concrete codec imports, callback types, helpers, and exports with their Cargo features. Keep the format probe compilable without the legacy decoder predicate when decompression is disabled. Once that boundary compiled, the remaining `make all` paths exposed related integration gaps. Move the C decompression projection declarations out of the compression preprocessor block, while leaving destination callback types shared. Link the Rust CLI helpers archive into zlibWrapper, pzstd, and largeNbDicts, whose util/time/data-generator C files are now declaration shims rather than implementations. The generated single-file C sources also call Rust-owned symbols now. Build and link an appropriately featured Rust archive in their native smoke tests, and include the pool configuration shim in the decoder case. The full amalgamation combines `zstd_lazy.c` and `zstd_opt.c` into one translation unit, so guard their otherwise translation-unit-local dictionary mode enum against duplicate definition. A Rust-backed amalgamation is no longer a standalone Emscripten input. Remove the obsolete emcc/Docker path and report that limitation explicitly; restoring the WebAssembly smoke test requires a Rust WebAssembly archive and a defined cross-language amalgamation contract. Test Plan: - `cargo check --manifest-path rust/Cargo.toml --no-default-features --features compression` -- passed - `cargo check --manifest-path rust/Cargo.toml --no-default-features --features decompression` -- passed - `sh -n build/single_file_libs/build_decoder_test.sh build/single_file_libs/build_library_test.sh` -- passed - `make all` -- passed, including native single-file and seekable-format tests - `git diff --cached --check` -- passed
Parallel Zstandard (PZstandard)
Parallel Zstandard is a Pigz-like tool for Zstandard. It provides Zstandard format compatible compression and decompression that is able to utilize multiple cores. It breaks the input up into equal sized chunks and compresses each chunk independently into a Zstandard frame. It then concatenates the frames together to produce the final compressed output. Pzstandard will write a 12 byte header for each frame that is a skippable frame in the Zstandard format, which tells PZstandard the size of the next compressed frame. PZstandard supports parallel decompression of files compressed with PZstandard. When decompressing files compressed with Zstandard, PZstandard does IO in one thread, and decompression in another.
Usage
PZstandard supports the same command line interface as Zstandard, but also provides the -p option to specify the number of threads.
Dictionary mode is not currently supported.
Basic usage
pzstd input-file -o output-file -p num-threads -# # Compression
pzstd -d input-file -o output-file -p num-threads # Decompression
PZstandard also supports piping and fifo pipes
cat input-file | pzstd -p num-threads -# -c > /dev/null
For more options
pzstd --help
PZstandard tries to pick a smart default number of threads if not specified (displayed in pzstd --help).
If this number is not suitable, during compilation you can define PZSTD_NUM_THREADS to the number of threads you prefer.
Benchmarks
As a reference, PZstandard and Pigz were compared on an Intel Core i7 @ 3.1 GHz, each using 4 threads, with the Silesia compression corpus.
| Compression Speed vs Ratio with 4 Threads | Decompression Speed with 4 Threads |
|---|---|
 |
 |
The test procedure was to run each of the following commands 2 times for each compression level, and take the minimum time.
time pzstd -# -p 4 -c silesia.tar > silesia.tar.zst
time pzstd -d -p 4 -c silesia.tar.zst > /dev/null
time pigz -# -p 4 -k -c silesia.tar > silesia.tar.gz
time pigz -d -p 4 -k -c silesia.tar.gz > /dev/null
PZstandard was tested using compression levels 1-19, and Pigz was tested using compression levels 1-9. Pigz cannot do parallel decompression, it simply does each of reading, decompression, and writing on separate threads.
Tests
Tests require that you have gtest installed.
Set GTEST_INC and GTEST_LIB in Makefile to specify the location of the gtest headers and libraries.
Alternatively, run make googletest, which will clone googletest and build it.
Run make tests && make check to run tests.