nodeca
pako
zlib port to javascript, very fast!
Why pako is cool:
- Results are binary equal to well known zlib (now contains ported zlib v1.2.8).
- Almost as fast in modern JS engines as C implementation (see benchmarks).
- Works in browsers, you can browserify any separate component.
This project was done to understand how fast JS can be and is it necessary to develop native C modules for CPU-intensive tasks. Enjoy the result!
Benchmarks:
node v12.16.3 (zlib 1.2.9), 1mb input sample:
deflate-imaya x 4.75 ops/sec ±4.93% (15 runs sampled)
deflate-pako x 10.38 ops/sec ±0.37% (29 runs sampled)
deflate-zlib x 17.74 ops/sec ±0.77% (46 runs sampled)
gzip-pako x 8.86 ops/sec ±1.41% (29 runs sampled)
inflate-imaya x 107 ops/sec ±0.69% (77 runs sampled)
inflate-pako x 131 ops/sec ±1.74% (82 runs sampled)
inflate-zlib x 258 ops/sec ±0.66% (88 runs sampled)
ungzip-pako x 115 ops/sec ±1.92% (80 runs sampled)node v14.15.0 (google's zlib), 1mb output sample:
deflate-imaya x 4.93 ops/sec ±3.09% (16 runs sampled)
deflate-pako x 10.22 ops/sec ±0.33% (29 runs sampled)
deflate-zlib x 18.48 ops/sec ±0.24% (48 runs sampled)
gzip-pako x 10.16 ops/sec ±0.25% (28 runs sampled)
inflate-imaya x 110 ops/sec ±0.41% (77 runs sampled)
inflate-pako x 134 ops/sec ±0.66% (83 runs sampled)
inflate-zlib x 402 ops/sec ±0.74% (87 runs sampled)
ungzip-pako x 113 ops/sec ±0.62% (80 runs sampled)zlib's test is partially affected by marshalling (that make sense for inflate only). You can change deflate level to 0 in benchmark source, to investigate details. For deflate level 6 results can be considered as correct.
Install:
npm install pakoExamples / API
Full docs - http://nodeca.github.io/pako/
const pako = require('pako');
// Deflate
//
const input = new Uint8Array();
//... fill input data here
const output = pako.deflate(input);
// Inflate (simple wrapper can throw exception on broken stream)
//
const compressed = new Uint8Array();
//... fill data to uncompress here
try {
const result = pako.inflate(compressed);
// ... continue processing
} catch (err) {
console.log(err);
}
//
// Alternate interface for chunking & without exceptions
//
const deflator = new pako.Deflate();
deflator.push(chunk1, false);
deflator.push(chunk2); // second param is false by default.
...
deflator.push(chunk_last, true); // `true` says this chunk is last
if (deflator.err) {
console.log(deflator.msg);
}
const output = deflator.result;
const inflator = new pako.Inflate();
inflator.push(chunk1);
inflator.push(chunk2);
...
inflator.push(chunk_last); // no second param because end is auto-detected
if (inflator.err) {
console.log(inflator.msg);
}
const output = inflator.result;Sometime you can wish to work with strings. For example, to send stringified objects to server. Pako's deflate detects input data type, and automatically recode strings to utf-8 prior to compress. Inflate has special option, to say compressed data has utf-8 encoding and should be recoded to javascript's utf-16.
const pako = require('pako');
const test = { my: 'super', puper: [456, 567], awesome: 'pako' };
const compressed = pako.deflate(JSON.stringify(test));
const restored = JSON.parse(pako.inflate(compressed, { to: 'string' }));Notes
Pako does not contain some specific zlib functions:
- deflate - methods
deflateCopy,deflateBound,deflateParams,deflatePending,deflatePrime,deflateTune. - inflate - methods
inflateCopy,inflateMark,inflatePrime,inflateGetDictionary,inflateSync,inflateSyncPoint,inflateUndermine. - High level inflate/deflate wrappers (classes) may not support some flush modes.
pako for enterprise
Available as part of the Tidelift Subscription
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Authors
Personal thanks to:
- Vyacheslav Egorov (@mraleph) for his awesome tutorials about optimising JS code for v8, IRHydra tool and his advices.
- David Duponchel (@dduponchel) for help with testing.
Original implementation (in C):
- zlib by Jean-loup Gailly and Mark Adler.
License
- MIT - all files, except
/lib/zlibfolder - ZLIB -
/lib/zlibcontent