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zlib port to javascript, very fast!

Why pako is cool:

• Results are binary equal to well knownzlib (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 todevelop 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 pako

Full docs -http://nodeca.github.io/pako/

constpako=require('pako');// Deflate//constinput=newUint8Array();//... fill input data hereconstoutput=pako.deflate(input);// Inflate (simple wrapper can throw exception on broken stream)//constcompressed=newUint8Array();//... fill data to uncompress heretry{constresult=pako.inflate(compressed);// ... continue processing}catch(err){console.log(err);}//// Alternate interface for chunking & without exceptions//constdeflator=newpako.Deflate();deflator.push(chunk1,false);deflator.push(chunk2);// second param is false by default....deflator.push(chunk_last,true);// `true` says this chunk is lastif(deflator.err){console.log(deflator.msg);}constoutput=deflator.result;constinflator=newpako.Inflate();inflator.push(chunk1);inflator.push(chunk2);...inflator.push(chunk_last);// no second param because end is auto-detectedif(inflator.err){console.log(inflator.msg);}constoutput=inflator.result;

Sometime you can wish to work with strings. For example, to sendstringified objects to server. Pako's deflate detects input data type, andautomatically recode strings to utf-8 prior to compress. Inflate has specialoption, to say compressed data has utf-8 encoding and should be recoded tojavascript's utf-16.

constpako=require('pako');consttest={my:'super',puper:[456,567],awesome:'pako'};constcompressed=pako.deflate(JSON.stringify(test));constrestored=JSON.parse(pako.inflate(compressed,{to:'string'}));

Pako does not contain some specific zlib functions:

• deflate - methodsdeflateCopy,deflateBound,deflateParams,deflatePending,deflatePrime,deflateTune.
• inflate - methodsinflateCopy,inflateMark,inflatePrime,inflateGetDictionary,inflateSync,inflateSyncPoint,inflateUndermine.
• High level inflate/deflate wrappers (classes) may not support some flushmodes.

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• Andrey Tupitsin@anrd83
• Vitaly Puzrin@puzrin

Personal thanks to:

• Vyacheslav Egorov (@mraleph) for his awesometutorials about optimising JS code for v8,IRHydratool and his advices.
• David Duponchel (@dduponchel) for help withtesting.

Original implementation (in C):

• zlib by Jean-loup Gailly and Mark Adler.

• MIT - all files, except/lib/zlib folder
• ZLIB -/lib/zlib content