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The buffer module from node.js, for the browser.
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README.md

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The buffer module from node.js, for the browser.

saucelabs

With browserify, simply require('buffer') or use the Buffer global and you will get this module.

The goal is to provide an API that is 100% identical to node's Buffer API. Read the official docs for the full list of properties, instance methods, and class methods that are supported.

features

  • Manipulate binary data like a boss, in all browsers -- even IE6!
  • Super fast. Backed by Typed Arrays (Uint8Array/ArrayBuffer, not Object)
  • Extremely small bundle size (5.04KB minified + gzipped, 35.5KB with comments)
  • Excellent browser support (IE 6+, Chrome 4+, Firefox 3+, Safari 5.1+, Opera 11+, iOS, etc.)
  • Preserves Node API exactly, with one important difference (see below)
  • .slice() returns instances of the same type (Buffer)
  • Square-bracket buf[4] notation works, even in old browsers like IE6!
  • Does not modify any browser prototypes or put anything on window
  • Comprehensive test suite (including all buffer tests from node.js core)

install

To use this module directly (without browserify), install it:

npm install buffer

This module was previously called native-buffer-browserify, but please use buffer from now on.

usage

The module's API is identical to node's Buffer API. Read the official docs for the full list of properties, instance methods, and class methods that are supported.

As mentioned above, require('buffer') or use the Buffer global with browserify and this module will automatically be included in your bundle. Almost any npm module will work in the browser, even if it assumes that the node Buffer API will be available.

To depend on this module explicitly (without browserify), require it like this:

var Buffer = require('buffer/').Buffer  // note: the trailing slash is important!

To require this module explicitly, use require('buffer/') which tells the node.js module lookup algorithm (also used by browserify) to use the npm module named buffer instead of the node.js core module named buffer!

how does it work?

The Buffer constructor returns instances of Uint8Array that are augmented with function properties for all the Buffer API functions. We use Uint8Array so that square bracket notation works as expected -- it returns a single octet. By augmenting the instances, we can avoid modifying the Uint8Array prototype.

differences

IMPORTANT: always use Buffer.isBuffer instead of instanceof Buffer

The Buffer constructor returns a Uint8Array (with all the Buffer methods added as properties on the instance) for performance reasons, so instanceof Buffer won't work. In node, you can use either Buffer.isBuffer or instanceof Buffer to check if an object is a Buffer. But, in the browser you must use Buffer.isBuffer to detect the special Uint8Array-based Buffers.

Minor: buf.slice() does not modify parent buffer's memory in old browsers

If you only support modern browsers (specifically, those with typed array support), then this issue does not affect you.

In node, the slice() method returns a new Buffer that shares underlying memory with the original Buffer. When you modify one buffer, you modify the other. Read more.

This works correctly in browsers with typed array support (* with the exception of Firefox older than version 30). Browsers that lack typed arrays get an alternate buffer implementation based on Object which has no mechanism to point separate Buffers to the same underlying slab of memory.

* Firefox older than version 30 gets the Object implementation -- not the typed arrays one -- because of this bug (now fixed!) that made it impossible to add properties to a typed array.

tracking the latest node api

This module tracks the Buffer API in the latest (unstable) version of node.js. The Buffer API is considered stable in the node stability index, so it is unlikely that there will ever be breaking changes. Nonetheless, when/if the Buffer API changes in node, this module's API will change accordingly.

performance

See perf tests in /perf.

BrowserBuffer is the browser buffer module (this repo). Uint8Array is included as a sanity check (since BrowserBuffer uses Uint8Array under the hood, Uint8Array will always be at least a bit faster). Finally, NodeBuffer is the node.js buffer module, which is included to compare against.

Chrome 38

Method Operations Accuracy Sampled Fastest
BrowserBuffer#bracket-notation 11,457,464 ops/sec ±0.86% 66
Uint8Array#bracket-notation 10,824,332 ops/sec ±0.74% 65
BrowserBuffer#concat 450,532 ops/sec ±0.76% 68
Uint8Array#concat 1,368,911 ops/sec ±1.50% 62
BrowserBuffer#copy(16000) 903,001 ops/sec ±0.96% 67
Uint8Array#copy(16000) 1,422,441 ops/sec ±1.04% 66
BrowserBuffer#copy(16) 11,431,358 ops/sec ±0.46% 69
Uint8Array#copy(16) 13,944,163 ops/sec ±1.12% 68
BrowserBuffer#new(16000) 106,329 ops/sec ±6.70% 44
Uint8Array#new(16000) 131,001 ops/sec ±2.85% 31
BrowserBuffer#new(16) 1,554,491 ops/sec ±1.60% 65
Uint8Array#new(16) 6,623,930 ops/sec ±1.66% 65
BrowserBuffer#readDoubleBE 112,830 ops/sec ±0.51% 69
DataView#getFloat64 93,500 ops/sec ±0.57% 68
BrowserBuffer#readFloatBE 146,678 ops/sec ±0.95% 68
DataView#getFloat32 99,311 ops/sec ±0.41% 67
BrowserBuffer#readUInt32LE 843,214 ops/sec ±0.70% 69
DataView#getUint32 103,024 ops/sec ±0.64% 67
BrowserBuffer#slice 1,013,941 ops/sec ±0.75% 67
Uint8Array#subarray 1,903,928 ops/sec ±0.53% 67
BrowserBuffer#writeFloatBE 61,387 ops/sec ±0.90% 67
DataView#setFloat32 141,249 ops/sec ±0.40% 66

Firefox 33

Method Operations Accuracy Sampled Fastest
BrowserBuffer#bracket-notation 20,800,421 ops/sec ±1.84% 60
Uint8Array#bracket-notation 20,826,235 ops/sec ±2.02% 61
BrowserBuffer#concat 153,076 ops/sec ±2.32% 61
Uint8Array#concat 1,255,674 ops/sec ±8.65% 52
BrowserBuffer#copy(16000) 1,105,312 ops/sec ±1.16% 63
Uint8Array#copy(16000) 1,615,911 ops/sec ±0.55% 66
BrowserBuffer#copy(16) 16,357,599 ops/sec ±0.73% 68
Uint8Array#copy(16) 31,436,281 ops/sec ±1.05% 68
BrowserBuffer#new(16000) 52,995 ops/sec ±6.01% 35
Uint8Array#new(16000) 87,686 ops/sec ±5.68% 45
BrowserBuffer#new(16) 252,031 ops/sec ±1.61% 66
Uint8Array#new(16) 8,477,026 ops/sec ±0.49% 68
BrowserBuffer#readDoubleBE 99,871 ops/sec ±0.41% 69
DataView#getFloat64 285,663 ops/sec ±0.70% 68
BrowserBuffer#readFloatBE 115,540 ops/sec ±0.42% 69
DataView#getFloat32 288,722 ops/sec ±0.82% 68
BrowserBuffer#readUInt32LE 633,926 ops/sec ±1.08% 67
DataView#getUint32 294,808 ops/sec ±0.79% 64
BrowserBuffer#slice 349,425 ops/sec ±0.46% 69
Uint8Array#subarray 5,965,819 ops/sec ±0.60% 65
BrowserBuffer#writeFloatBE 59,980 ops/sec ±0.41% 67
DataView#setFloat32 317,634 ops/sec ±0.63% 68

Safari 8

Method Operations Accuracy Sampled Fastest
BrowserBuffer#bracket-notation 10,279,729 ops/sec ±2.25% 56
Uint8Array#bracket-notation 10,030,767 ops/sec ±2.23% 59
BrowserBuffer#concat 144,138 ops/sec ±1.38% 65
Uint8Array#concat 4,950,764 ops/sec ±1.70% 63
BrowserBuffer#copy(16000) 1,058,548 ops/sec ±1.51% 64
Uint8Array#copy(16000) 1,409,666 ops/sec ±1.17% 65
BrowserBuffer#copy(16) 6,282,529 ops/sec ±1.88% 58
Uint8Array#copy(16) 11,907,128 ops/sec ±2.87% 58
BrowserBuffer#new(16000) 101,663 ops/sec ±3.89% 57
Uint8Array#new(16000) 22,050,818 ops/sec ±6.51% 46
BrowserBuffer#new(16) 176,072 ops/sec ±2.13% 64
Uint8Array#new(16) 24,385,731 ops/sec ±5.01% 51
BrowserBuffer#readDoubleBE 41,341 ops/sec ±1.06% 67
DataView#getFloat64 322,280 ops/sec ±0.84% 68
BrowserBuffer#readFloatBE 46,141 ops/sec ±1.06% 65
DataView#getFloat32 337,025 ops/sec ±0.43% 69
BrowserBuffer#readUInt32LE 151,551 ops/sec ±1.02% 66
DataView#getUint32 308,278 ops/sec ±0.94% 67
BrowserBuffer#slice 197,365 ops/sec ±0.95% 66
Uint8Array#subarray 9,558,024 ops/sec ±3.08% 58
BrowserBuffer#writeFloatBE 17,518 ops/sec ±1.03% 63
DataView#setFloat32 319,751 ops/sec ±0.48% 68

Node 0.11.14

Method Operations Accuracy Sampled Fastest
BrowserBuffer#bracket-notation 10,489,828 ops/sec ±3.25% 90
Uint8Array#bracket-notation 10,534,884 ops/sec ±0.81% 92
NodeBuffer#bracket-notation 10,389,910 ops/sec ±0.97% 87
BrowserBuffer#concat 487,830 ops/sec ±2.58% 88
Uint8Array#concat 1,814,327 ops/sec ±1.28% 88
NodeBuffer#concat 1,636,523 ops/sec ±1.88% 73
BrowserBuffer#copy(16000) 1,073,665 ops/sec ±0.77% 90
Uint8Array#copy(16000) 1,348,517 ops/sec ±0.84% 89
NodeBuffer#copy(16000) 1,289,533 ops/sec ±0.82% 93
BrowserBuffer#copy(16) 12,782,706 ops/sec ±0.74% 85
Uint8Array#copy(16) 14,180,427 ops/sec ±0.93% 92
NodeBuffer#copy(16) 11,083,134 ops/sec ±1.06% 89
BrowserBuffer#new(16000) 141,678 ops/sec ±3.30% 67
Uint8Array#new(16000) 161,491 ops/sec ±2.96% 60
NodeBuffer#new(16000) 292,699 ops/sec ±3.20% 55
BrowserBuffer#new(16) 1,655,466 ops/sec ±2.41% 82
Uint8Array#new(16) 14,399,926 ops/sec ±0.91% 94
NodeBuffer#new(16) 3,894,696 ops/sec ±0.88% 92
BrowserBuffer#readDoubleBE 109,582 ops/sec ±0.75% 93
DataView#getFloat64 91,235 ops/sec ±0.81% 90
NodeBuffer#readDoubleBE 88,593 ops/sec ±0.96% 81
BrowserBuffer#readFloatBE 139,854 ops/sec ±1.03% 85
DataView#getFloat32 98,744 ops/sec ±0.80% 89
NodeBuffer#readFloatBE 92,769 ops/sec ±0.94% 93
BrowserBuffer#readUInt32LE 710,861 ops/sec ±0.82% 92
DataView#getUint32 117,893 ops/sec ±0.84% 91
NodeBuffer#readUInt32LE 851,412 ops/sec ±0.72% 93
BrowserBuffer#slice 1,673,877 ops/sec ±0.73% 94
Uint8Array#subarray 6,919,243 ops/sec ±0.67% 90
NodeBuffer#slice 4,617,604 ops/sec ±0.79% 93
BrowserBuffer#writeFloatBE 66,011 ops/sec ±0.75% 93
DataView#setFloat32 127,760 ops/sec ±0.72% 93
NodeBuffer#writeFloatBE 103,352 ops/sec ±0.83% 93

JavaScript Standard Style

This module uses JavaScript Standard Style.

js-standard-style

credit

This was originally forked from buffer-browserify.

license

MIT. Copyright (C) Feross Aboukhadijeh, and other contributors. Originally forked from an MIT-licensed module by Romain Beauxis.

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