iltorb

iltorb is a Node.js package offering native bindings for the brotli compression library.

Install

This module uses node-pre-gyp to download a pre-compiled binary for your platform, if it exists. Otherwise, it will use node-gyp to build the module.

npm install iltorb

Prerequisites for Building

The following is required to build from source or when a pre-compiled binary does not exist.

• Python 2.7
• GCC 4.8+ (Unix) or windows-build-tools (Windows), see Node Building tools.

Methods

Async

compress(buffer[, brotliEncodeParams], callback)

const compress = require('iltorb').compress;

compress(input, function(err, output) {
  // ...
});

decompress(buffer[, brotliDecodeParams], callback)

const decompress = require('iltorb').decompress;

decompress(input, function(err, output) {
  // ...
});

Sync

compressSync(buffer[, brotliEncodeParams])

const compressSync = require('iltorb').compressSync;

try {
  var output = compressSync(input);
} catch(err) {
  // ...
}

decompressSync(buffer[, brotliDecodeParams])

const decompressSync = require('iltorb').decompressSync;

try {
  var output = decompressSync(input);
} catch(err) {
  // ...
}

Stream

compressStream([brotliEncodeParams])

const compressStream = require('iltorb').compressStream;
const fs = require('fs');

fs.createReadStream('path/to/input')
  .pipe(compressStream())
  .pipe(fs.createWriteStream('path/to/output'));

compressionStream.flush()

Call this method to flush pending data. Don't call this frivolously, premature flushes negatively impact the effectiveness of the compression algorithm.

decompressStream([brotliDecodeParams])

const decompressStream = require('iltorb').decompressStream;
const fs = require('fs');

fs.createReadStream('path/to/input')
  .pipe(decompressStream())
  .pipe(fs.createWriteStream('path/to/output'));

brotliEncodeParams

The compress, compressSync and compressStream methods may accept an optional brotliEncodeParams object to define some or all of brotli's compression parameters:

• type definition
• defaults
• explanations

const brotliEncodeParams = {
  mode: 0,
  quality: 11,
  lgwin: 22,
  lgblock: 0,
  size_hint: 0, // automatically set for `compress` and `compressSync`
  disable_literal_context_modeling: false,
  dictionary: Buffer
};

brotliDecodeParams

The decompress, decompressSync and decompressStream methods may accept an optional brotliDecodeParams object to provide a custom dictionary.

const brotliDecodeParams = {
  dictionary: Buffer
};

Troubleshooting

1. I am unable to install iltorb because the host (GitHub) that serves the binaries is blocked by my firewall.

   a) By default, if the binaries could not be downloaded for any reason, npm will attempt to compile the binaries locally on your machine. This requires having all of the build requirements fulfilled.

   b) You can override the binary.host value found in package.json with the following methods:

   • using the following ENV variable npm_config_iltorb_binary_host_mirror=url
   • as an additional argument with npm install --iltorb_binary_host_mirror=url