https://github.com/donmccurdy/zstddec-wasm
ZSTD (Zstandard) decoder for Web and Node.js, using WebAssembly.
https://github.com/donmccurdy/zstddec-wasm
compression webassembly zstandard zstd
Last synced: 7 months ago
JSON representation
ZSTD (Zstandard) decoder for Web and Node.js, using WebAssembly.
- Host: GitHub
- URL: https://github.com/donmccurdy/zstddec-wasm
- Owner: donmccurdy
- License: other
- Created: 2020-07-27T04:27:03.000Z (almost 6 years ago)
- Default Branch: main
- Last Pushed: 2023-10-28T04:38:58.000Z (over 2 years ago)
- Last Synced: 2025-04-15T01:14:17.950Z (about 1 year ago)
- Topics: compression, webassembly, zstandard, zstd
- Language: TypeScript
- Homepage:
- Size: 520 KB
- Stars: 59
- Watchers: 3
- Forks: 11
- Open Issues: 6
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE
Awesome Lists containing this project
README
# zstddec
[](https://www.npmjs.com/package/zstddec)
[](https://bundlephobia.com/result?p=zstddec)
[](https://github.com/donmccurdy/zstddec/actions?query=workflow%3Abuild)
[ZSTD (Zstandard)](https://github.com/facebook/zstd) decoder for Web and Node.js, using WebAssembly.
## Installation
```shell
npm install --save zstddec
```
## API
```javascript
import { ZSTDDecoder } from 'zstddec';
const decoder = new ZSTDDecoder();
await decoder.init();
const decompressedArray = decoder.decode( compressedArray, uncompressedSize );
```
> **Limitations:** The decoder may fail with the error `wasm function signature contains illegal type` when the `uncompressedSize` is not known in advance and given to the `decode()` method. This is presumably a bug in the WASM bindings, which I am not yet sure how to fix.
## Contributing
To build the project locally, run:
```
yarn install
yarn build
```
To test changes:
```
yarn test
```
## Building from source
Compiled from https://github.com/facebook/zstd/tree/dev/build/single_file_libs, with the
following steps:
```shell
# build zstd
make
cd build/single_file_libs
./create_single_file_decoder.sh
# build wasm
emcc zstddeclib.c -s EXPORTED_FUNCTIONS="['_ZSTD_decompress', '_ZSTD_findDecompressedSize', '_ZSTD_isError', '_malloc', '_free']" -Wl,--no-entry -s WASM=1 -Oz -g0 -flto -s ALLOW_MEMORY_GROWTH=1 -s FILESYSTEM=0 -s STANDALONE_WASM=1 -DNDEBUG=1 -s PURE_WASI=0 -o zstddec.wasm
# build streaming wasm
emcc zstddeclib.c -s EXPORTED_FUNCTIONS="['_ZSTD_decompress', '_ZSTD_findDecompressedSize', '_ZSTD_createDCtx', '_ZSTD_decompressStream', '_ZSTD_freeDCtx', '_ZSTD_DStreamInSize', '_ZSTD_DStreamOutSize', '_malloc', '_free']" -Wl,--no-entry -s WASM=1 -Oz -g0 -flto -s ALLOW_MEMORY_GROWTH=1 -s FILESYSTEM=0 -s STANDALONE_WASM=1 -DNDEBUG=1 -s PURE_WASI=0 -o zstddec-stream.wasm
# encode WASM to base64
base64 -i zstddec.wasm > zstddec.txt
base64 -i zstddec-stream.wasm > zstddec-stream.txt
```
The base64 string written to `zstddec.txt` is embedded as the `wasm` variable at the bottom
of the source file. The rest of the file is written by hand, in order to avoid an additional JS
wrapper generated by Emscripten.
_Last built June 2025, zstd v1.5.7 (`f8745da6`), emscc v4.0.10_.
## License
JavaScript wrapper is provided under the MIT License, and the WASM ZSTD decoder is provided by Facebook under the BSD 3-Clause License.