buffer (native-buffer-browserify)
The buffer module from node.js, for the browser.
install
When you require('buffer')
or use the Buffer
global in browserify, this module will automatically load.
If you want to manually install it for some reason, do:
npm install buffer
features
- Backed by Typed Arrays (
Uint8Array
and ArrayBuffer
) (not Object
, so it's fast) - Small bundle size (35KB) (half the size of
buffer-browserify
) - Excellent browser support (IE 6+, Chrome 4+, Firefox 3+, Safari 5.1+, Opera 11+, iOS, etc.).
- Preserves Node API exactly.
- Faster pretty much across the board (see perf results 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.
- Comprehensive test suite.
usage
var buffer = require('buffer/').Buffer // use the npm module, not the core module!
The goal is to provide a Buffer API that is 100% identical to node's Buffer API. Read the official docs for a full list of supported methods.
important differences
use Buffer.isBuffer
instead of instanceof Buffer
The Buffer constructor returns a Uint8Array
(as discussed above) for performance reasons, so instanceof Buffer
won't work. In node Buffer.isBuffer
just does instanceof Buffer
, but in browserify we use a Buffer.isBuffer
shim that detects our special Uint8Array
-based Buffers.
don't rely on slice()
to modify the memory of the parent buffer
If the browser is using the Typed Array implementation then modifying a buffer created by slice()
will modify the original memory, just like in Node. But for the Object implementation (used in unsupported browsers), this is not possible. Therefore, do not rely on this behavior until browser support gets better. (Note: currently even Firefox isn't using the Typed Array implementation because of this bug.)
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.
performance
See perf tests in /perf
.
# Chrome 33
NewBuffer#bracket-notation x 11,194,815 ops/sec ±1.73% (64 runs sampled)
OldBuffer#bracket-notation x 9,546,694 ops/sec ±0.76% (67 runs sampled)
Fastest is NewBuffer#bracket-notation
NewBuffer#concat x 949,714 ops/sec ±2.48% (63 runs sampled)
OldBuffer#concat x 634,906 ops/sec ±0.42% (68 runs sampled)
Fastest is NewBuffer#concat
NewBuffer#copy x 15,436,458 ops/sec ±1.74% (67 runs sampled)
OldBuffer#copy x 3,990,346 ops/sec ±0.42% (68 runs sampled)
Fastest is NewBuffer#copy
NewBuffer#readDoubleBE x 1,132,954 ops/sec ±2.36% (65 runs sampled)
OldBuffer#readDoubleBE x 846,337 ops/sec ±0.58% (68 runs sampled)
Fastest is NewBuffer#readDoubleBE
NewBuffer#new x 1,419,300 ops/sec ±3.50% (66 runs sampled)
Uint8Array#new x 3,898,573 ops/sec ±0.88% (67 runs sampled) (used internally by NewBuffer)
OldBuffer#new x 2,284,568 ops/sec ±0.57% (67 runs sampled)
Fastest is Uint8Array#new
NewBuffer#readFloatBE x 1,203,763 ops/sec ±1.81% (68 runs sampled)
OldBuffer#readFloatBE x 954,923 ops/sec ±0.66% (70 runs sampled)
Fastest is NewBuffer#readFloatBE
NewBuffer#readUInt32LE x 750,341 ops/sec ±1.70% (66 runs sampled)
OldBuffer#readUInt32LE x 1,408,478 ops/sec ±0.60% (68 runs sampled)
Fastest is OldBuffer#readUInt32LE
NewBuffer#slice x 1,802,870 ops/sec ±1.87% (64 runs sampled)
OldBuffer#slice x 1,725,928 ops/sec ±0.74% (68 runs sampled)
Fastest is NewBuffer#slice
NewBuffer#writeFloatBE x 830,407 ops/sec ±3.09% (66 runs sampled)
OldBuffer#writeFloatBE x 508,446 ops/sec ±0.49% (69 runs sampled)
Fastest is NewBuffer#writeFloatBE
# Node 0.11
NewBuffer#bracket-notation x 10,912,085 ops/sec ±0.89% (92 runs sampled)
OldBuffer#bracket-notation x 9,051,638 ops/sec ±0.84% (92 runs sampled)
Buffer#bracket-notation x 10,721,608 ops/sec ±0.63% (91 runs sampled)
Fastest is NewBuffer#bracket-notation
NewBuffer#concat x 1,438,825 ops/sec ±1.80% (91 runs sampled)
OldBuffer#concat x 888,614 ops/sec ±2.09% (93 runs sampled)
Buffer#concat x 1,832,307 ops/sec ±1.20% (90 runs sampled)
Fastest is Buffer#concat
NewBuffer#copy x 5,987,167 ops/sec ±0.85% (94 runs sampled)
OldBuffer#copy x 3,892,165 ops/sec ±1.28% (93 runs sampled)
Buffer#copy x 11,208,889 ops/sec ±0.76% (91 runs sampled)
Fastest is Buffer#copy
NewBuffer#readDoubleBE x 1,057,233 ops/sec ±1.28% (88 runs sampled)
OldBuffer#readDoubleBE x 4,094 ops/sec ±1.09% (86 runs sampled)
Buffer#readDoubleBE x 1,587,308 ops/sec ±0.87% (84 runs sampled)
Fastest is Buffer#readDoubleBE
NewBuffer#new x 739,791 ops/sec ±0.89% (89 runs sampled)
Uint8Array#new x 2,745,243 ops/sec ±0.95% (91 runs sampled)
OldBuffer#new x 2,604,537 ops/sec ±0.93% (88 runs sampled)
Buffer#new x 1,836,218 ops/sec ±0.74% (92 runs sampled)
Fastest is Uint8Array#new
NewBuffer#readFloatBE x 1,111,263 ops/sec ±0.41% (97 runs sampled)
OldBuffer#readFloatBE x 4,026 ops/sec ±1.24% (90 runs sampled)
Buffer#readFloatBE x 1,611,800 ops/sec ±0.58% (96 runs sampled)
Fastest is Buffer#readFloatBE
NewBuffer#readUInt32LE x 502,024 ops/sec ±0.59% (94 runs sampled)
OldBuffer#readUInt32LE x 1,259,028 ops/sec ±0.79% (87 runs sampled)
Buffer#readUInt32LE x 2,778,635 ops/sec ±0.46% (97 runs sampled)
Fastest is Buffer#readUInt32LE
NewBuffer#slice x 1,174,908 ops/sec ±1.47% (89 runs sampled)
OldBuffer#slice x 2,396,302 ops/sec ±4.36% (86 runs sampled)
Buffer#slice x 2,994,029 ops/sec ±0.79% (89 runs sampled)
Fastest is Buffer#slice
NewBuffer#writeFloatBE x 721,081 ops/sec ±1.10% (86 runs sampled)
OldBuffer#writeFloatBE x 4,020 ops/sec ±1.04% (92 runs sampled)
Buffer#writeFloatBE x 1,811,134 ops/sec ±0.67% (91 runs sampled)
Fastest is Buffer#writeFloatBE
credit
This was originally forked from buffer-browserify.
license
MIT. Copyright (C) Feross Aboukhadijeh, Romain Beauxis, and other contributors.