snappy

What is snappy?

The 'snappy' npm package is a Node.js binding for Google's Snappy compression library. It provides fast and efficient compression and decompression functionalities, making it suitable for applications that require high-speed data processing.

What are snappy's main functionalities?

Compression

This feature allows you to compress a given input buffer using Snappy's compression algorithm. The code sample demonstrates how to compress a simple 'Hello, world!' string.

const snappy = require('snappy');
const input = Buffer.from('Hello, world!');
snappy.compress(input, (err, compressed) => {
  if (err) throw err;
  console.log('Compressed:', compressed);
});

Decompression

This feature allows you to decompress a previously compressed buffer. The code sample shows how to uncompress data and convert it back to its original form.

const snappy = require('snappy');
const compressed = Buffer.from('compressed data here');
snappy.uncompress(compressed, { asBuffer: true }, (err, original) => {
  if (err) throw err;
  console.log('Decompressed:', original.toString());
});

Stream Compression

This feature provides stream-based compression, which is useful for handling large files or data streams. The code sample demonstrates how to compress a file using streams.

const snappy = require('snappy');
const fs = require('fs');
const input = fs.createReadStream('input.txt');
const output = fs.createWriteStream('output.snappy');
input.pipe(snappy.compressStream()).pipe(output);

Stream Decompression

This feature provides stream-based decompression. The code sample shows how to decompress a file using streams.

const snappy = require('snappy');
const fs = require('fs');
const input = fs.createReadStream('output.snappy');
const output = fs.createWriteStream('decompressed.txt');
input.pipe(snappy.uncompressStream()).pipe(output);

Other packages similar to snappy

lz4

The 'lz4' package provides bindings for the LZ4 compression algorithm, which is known for its high-speed compression and decompression. Compared to Snappy, LZ4 often offers better compression ratios but may be slightly slower in some scenarios.

zlib

The 'zlib' package is a core Node.js module that provides compression and decompression functionalities using the Deflate algorithm. While zlib offers good compression ratios, it is generally slower than Snappy and LZ4.

brotli

The 'brotli' package provides bindings for the Brotli compression algorithm, which is known for its high compression ratios and efficiency. Brotli is often used for web content compression but may be slower than Snappy in terms of speed.

README

snappy

Nodejs bindings to the snappy compression library

Installation

npm install snappy

Example

Input

var snappy = require('snappy')

snappy.compress('beep boop', function (err, compressed) {
  console.log('compressed is a Buffer', compressed)
  // return it as a string
  snappy.uncompress(compressed, { asBuffer: false }, function (err, original) {
    console.log('the original String', original)
  })
})

Output

compressed is a Buffer <SlowBuffer 09 20 62 65 65 70 20 62 6f 6f 70>
the original String beep boop

API

snappy.compress(input, callback)

Compress input, which can be a Buffer or a String.

The callback function will be called with a single error if the operation failed for any reason. If successful the first argument will be null and the second argument will be the value as a ``Buffer`.

snappy.compressSync(input)

The synchronous version of snappy.compress, returns the compressed value.

snappy.uncompress(compressed, [options,] callback)

Uncompress compressed and call callback with err and decompressed.

options

• 'asBuffer' (boolean, default: true): Used to determine whether to return the value of the entry as a String or a Node.js Buffer object. Note that converting from a Buffer to a String incurs a cost so if you need a String (and the value can legitimately become a UFT8 string) then you should fetch it as one with asBuffer: true and you'll avoid this conversion cost.

The callback function will be called with a single error if the operation failed for any reason. If successful the first argument will be null and the second argument will be the value as a String or Buffer depending on the asBuffer option.

snappy.uncompressSync(compressed, [options])

The synchronous version of snappy.uncompress, returns the uncompressed value.

snappy.isValidCompressed(input, callback)

Check is input is a valid compressed Buffer.

The callback function will be called with a single error if the operation failed for any reason and the second argument will be true if input is a valid snappy compressed Buffer, false otherwise.

snappy.isValidCompressedSync(input)

The synchronous version of snappy.isValidCompressed, returns a boolean indicating if input was correctly compressed or not.

stream

For a streaming interface to snappy, please take a look at snappy-stream

Benchmark

This is the result I'm seeing on my laptop (Macbook Air from 2012) running node benchmark

  snappy.compress() x 479 ops/sec ±0.99% (80 runs sampled)
  zlib.gzip() x 289 ops/sec ±1.66% (86 runs sampled)
  snappy.uncompress() x 652 ops/sec ±0.86% (43 runs sampled)
  zlib.gunzip() x 559 ops/sec ±1.65% (64 runs sampled)

License

Copyright (c) 2011 - 2015 David Björklund & contributors

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.