!Build Status12 !dependency status34 !dev dependency status56
A very fast standards-compliant ES2015 Promise library for node.
There are several fast promise implementations out there, like
bluebird, but they all add a bunch of stuff that's not in the ES2015 Promise spec. Further, as they've added more and more features they've grown so complex that they can't be easily audited against the ES2015 spec (or the official
babybirdlibrary is a stripped-down "just ES2015" Promise implementation, which passes the Promises/A+ and
test262test suites. It is very competitive with the performance of
bluebird, without having to give us standards compliance. On the doxbee benchmark running under node 5.1.0,
babybirdis 2.4 times faster than native Promises, 4 times faster than the Promise implementation in
core-js, and almost 9 times faster than the Promise implementation in
es6-shim. The performance improvement is even greater when running under node 0.10.
babybirdsupports subclassing (as all ES2015 Promise implementations ought). This means that if you'd like additional bells and whistles on your Promises, you can add then via subclassing and without stomping on the global Promise. In fact, the
prfunlibrary provides much the same feature set as
bluebird, but with a clean separation of concerns. Further,
prfunruns on top of any ES2015-compliant Promise implementation, so if
babybirdis someday supplanted, you can just swap out the core Promise implementation underneath
prfunwithout having to update any of your uses of the core ES2015 or extended
npm install babybird
var Promise = require('babybird');
babybirdlibrary plays very nicely with
prfun, if you'd like a few bells and whistles with your library. I recommend creating a new module, named (say)
promise.js, with the contents:
and then using the wrapped promises this way:
module.exports = require('prfun/wrap')(require('babybird'));
var Promise = require('./promise.js');
BenchmarksThese benchmarks are derived from the benchmarks included with
bluebird. A few of the bluebird test cases have been forked to add "fair" versions, since bluebird obtained some of its speed by using a faster
promisifymethod than that provided to other promise implementations, and by using a few
bluebird-specific APIs which appeared to be tuned for the benchmark.
You can reproduce these results using
npm run bench.
results for 20000 parallel executions, 1 ms per I/O op file time(ms) slowdown memory(MB) callbacks-baseline.js 819 0.48 32.99 promises-bluebird.js 1383 0.81 50.59 promises-bluebird-fair.js 1715 1.00 39.02 promises-cscott-babybird-noall.js 1870 1.09 41.19 promises-cscott-babybird.js 1925 1.12 61.81 promises-cscott-babybird-prfun.js 1991 1.16 48.60 promises-then-promise-es6.js 3084 1.80 64.54 promises-then-promise.js 3112 1.81 64.39 promises-paulmillr-es6shim.js 12475 7.27 94.20 promises-zloirock-corejs.js 18695 10.90 94.11 Platform info: Linux 4.2.0-1-amd64 ia32 Node.JS 0.10.40 V8 22.214.171.124 Intel(R) Core(TM) i7 CPU L 640 @ 2.13GHz × 4
results for 20000 parallel executions, 1 ms per I/O op file time(ms) slowdown memory(MB) callbacks-baseline.js 826 0.53 29.29 promises-bluebird-generator.js 1105 0.71 25.49 promises-bluebird-generator-fair.js 1113 0.72 28.27 promises-cscott-babybird-prfun-generator.js 1202 0.77 33.68 promises-bluebird-fair.js 1553 1.00 51.38 promises-cscott-babybird-noall.js 1623 1.05 65.25 promises-bluebird.js 1643 1.06 43.66 promises-cscott-babybird-prfun.js 1707 1.10 72.33 promises-cscott-babybird.js 1724 1.11 72.82 promises-then-promise-es6.js 2985 1.92 106.96 promises-then-promise.js 3004 1.93 106.69 promises-ecmascript6-native.js 3770 2.43 176.96 promises-zloirock-corejs.js 6298 4.06 155.89 promises-paulmillr-es6shim.js 13892 8.95 227.61 Platform info: Linux 4.2.0-1-amd64 ia32 Node.JS 5.1.0 V8 126.96.36.199 Intel(R) Core(TM) i7 CPU L 640 @ 2.13GHz × 4
LicenseCopyright (c) 2015 C. Scott Ananian
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.