zstd-wasm
Zstandard for browser, Node.js and Deno.
For now support only simple API.
installation
npm install @bokuweb/zstd-wasm
examples
Node.js
Playground: https://runkit.com/bokuweb/60f1172a58aae5001aea2418
const { init, compress, decompress } = require('@bokuweb/zstd-wasm');
(async () => {
await init();
const compressed = compress(Buffer.from('Hello zstd!!'), 10);
const res = decompress(compressed);
Buffer.from(res).toString();
})();
Deno
See also, https://github.com/bokuweb/zstd-wasm/tree/master/examples/deno
import { init, decompress, compress } from 'https://deno.land/x/zstd_wasm/deno/zstd.ts';
await init();
const encoder = new TextEncoder();
const buffer = encoder.encode('Hello World');
const compressed = compress(buffer, 10);
const decompressed = decompress(compressed);
const decoder = new TextDecoder();
console.log(decoder.decode(decompressed));
without bundlers
import { init, compress, decompress } from '@bokuweb/zstd-wasm';
(async () => {
await init('./zstd.wasm');
const compressed = compress(Buffer.from('Hello zstd!!'), 10);
const res = decompress(compressed);
Buffer.from(res).toString();
})();
with webpack4
We need to use file-loader
with webpack4.
This is because, webpack doesn’t work well with wasm modules created with Emscripten.
See, https://github.com/webpack/webpack/issues/7352
import { init, compress, decompress } from '@bokuweb/zstd-wasm';
(async () => {
await init();
const compressed = compress(Buffer.from('Hello zstd!!'), 10);
const res = decompress(compressed);
Buffer.from(res).toString();
})();
In this case, please install file-loader
by yourself.
{
module: {
rules: [
{
test: /zstd\.wasm$/,
type: 'javascript/auto',
loader: 'file-loader',
},
],
},
}
with webpack5
We need to use Asset Modules
with webpack5.
This is because, webpack doesn’t work well with wasm modules created with Emscripten.
See, https://github.com/webpack/webpack/issues/7352
import { init, compress, decompress } from '@bokuweb/zstd-wasm';
(async () => {
await init();
const compressed = compress(Buffer.from('Hello zstd!!'), 10);
const res = decompress(compressed);
Buffer.from(res).toString();
})();
{
module: {
rules: [
{
test: /zstd\.wasm/,
type: 'asset/resource',
},
],
},
}
Using dictionary
- Create the dictionary
zstd --train FullPathToTrainingSet/* -o dictionaryName
- Compress with dictionary
const dict = readFileSync('./dict');
const compressed = compressUsingDict(createCCtx(), buffer, dict, 10);
- Decompress with dictionary
const dict = readFileSync('./dict');
const decompressed = decompressUsingDict(createDCtx(), buffer, dict);
See also example
API
async init(path?: string): Promise
Initialize module.
Please specify path to zstd.wasm
without bunders on browser.
compress(buffer: ArrayBuffer, compressionLevel?: number): ArrayBuffer
- buffer: data to compress.
- compressionLevel: (optional) compression level, default value is 3
Example:
const compressed = compress(buffer, 10);
decompress(buffer: ArrayBuffer): ArrayBuffer
- buffer: data to decompress.
Example:
const decompressed = decompress(buffer);
compressUsingDict(cctx: number, buffer: ArrayBuffer, dict: ArrayBuffer, compressionLevel?: number): ArrayBuffer
- cctx: a pointer to compress context. please create cctx with
createCCtx
. - buffer: data to compress.
- dict: dictionary data.
- compressionLevel: (optional) compression level, default value is 3
Example:
const dict = readFileSync('./dict');
const compressed = compressUsingDict(createCCtx(), buffer, dict, 10);
createCCtx(): number
- create a pointer to compress context.
decompressUsingDict(dctx: number, dict: ArrayBuffer): ArrayBuffer
- dctx: a pointer to decompress context. please create cctx with
createDCtx
. - buffer: data to decompress.
- dict: dictionary data.
Example:
const dict = readFileSync('./dict');
const decompressed = decompressUsingDict(createDCtx(), buffer, dict);
createDCtx(): number
- create a pointer to decompress context.
License
TypeScript glue is provided under the MIT License, and the zstd is provided by Facebook under the BSD 3-Clause License.