simple-promise

一个简单的promise实现

项目已通过promise a plus test

执行测试: npm test

执行bench: npm run bench

##Promise的重要特性

在如下时刻检查是否需要执行回调:

• promise状态改变
• promise.then被调用
• nextObject中的fn执行完毕，生成新的promise，将nextObject传递给新的promise

benchmark & memory

bluebird

--------start bluebird---------
Start benchmark!
Memory usage at start is
{ rss: 33701888, heapTotal: 16773120, heapUsed: 4861952 }
Memory usage at end is
{ rss: 33718272, heapTotal: 16773120, heapUsed: 4862200 }
Total time 386 ms!

promise

--------start then promise---------
Start benchmark!
Memory usage at start is
{ rss: 32088064, heapTotal: 15724544, heapUsed: 4077552 }
Memory usage at end is
{ rss: 57253888, heapTotal: 40890368, heapUsed: 4088480 }
Total time 371 ms!

simple-pormise(this repo)

--------start simple-promise---------
Start benchmark!
Memory usage at start is
{ rss: 60047360, heapTotal: 41938944, heapUsed: 7242584 }
Memory usage at end is
{ rss: 61419520, heapTotal: 44036096, heapUsed: 7222720 }
Total time 2172 ms!

es(es6)

--------start es---------

Start benchmark!
Memory usage at start is
{ rss: 152784896, heapTotal: 135262208, heapUsed: 97369552 }
Memory usage at end is
{ rss: 1006039040, heapTotal: 988803072, heapUsed: 939507128 }
Total time 9287 ms!

mimi-promise

--------start mimi-promise---------

Start benchmark!
Memory usage at start is
{ rss: 117932032, heapTotal: 99610624, heapUsed: 63493432 }
Memory usage at end is
{ rss: 656711680, heapTotal: 637530112, heapUsed: 574386816 }
Total time 4537 ms!