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: about 1 month ago
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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 (over 4 years ago)
• Default Branch: main
• Last Pushed: 2023-10-28T04:38:58.000Z (about 1 year ago)
• Last Synced: 2024-10-05T11:57:31.353Z (about 2 months ago)
• Topics: compression, webassembly, zstandard, zstd
• Language: TypeScript
• Homepage:
• Size: 520 KB
• Stars: 58
• Watchers: 4
• Forks: 10
• Open Issues: 5
• Metadata Files:
  • Readme: README.md
  • Funding: .github/FUNDING.yml
  • License: LICENSE

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README

        
# zstddec

[![Latest NPM release](https://img.shields.io/npm/v/zstddec.svg)](https://www.npmjs.com/package/zstddec)

[![Minzipped size](https://badgen.net/bundlephobia/minzip/zstddec)](https://bundlephobia.com/result?p=zstddec)

[![Build Status](https://github.com/donmccurdy/zstddec/workflows/build/badge.svg?branch=main&event=push)](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:

```

npm install

npm run dist

```

To test changes:

```

npm test

```

## Building from source

Compiled from https://github.com/facebook/zstd/tree/dev/contrib/single_file_libs, with the

following steps:

```shell

./combine.sh -r ../../lib -o zstddeclib.c zstddeclib-in.c

emcc zstddeclib.c -Oz -s EXPORTED_FUNCTIONS="['_ZSTD_decompress', '_ZSTD_findDecompressedSize', '_ZSTD_isError', '_malloc', '_free']" -s ALLOW_MEMORY_GROWTH=1 -s MALLOC=emmalloc -o zstddec.wasm

base64 zstddec.wasm > zstddec.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.

## License

JavaScript wrapper is provided under the MIT License, and the WASM ZSTD decoder is provided by Facebook under the BSD 3-Clause License.