java - 是否有任何基准比较 Java 8 Streams 和 Guava Iterables？

Question

我对 Java 8 上的 Guava 非常满意 - 迁移到 Streams 以获取顺序代码是否有任何性能优势或缺陷？

Answer 1

我已经开始了 a project on GitHub玩这个。

Streams 的初始结果令人惊讶地积极 - 对于字符串上的标识映射，Java HotSpot(TM) 64 位服务器 VM(构建 25.25-b02，混合模式)在 2014 MacBookAir 1.7Ghz i7 上，代码版本 https://github.com/dmcg/iterables-v-streams#ea8498ee0627fc59834001a837fa92fba4bcf47ebcf47e

Experiment selection:   Benchmark Methods:   [guava, iterate, streams]  Instruments:   [allocation, runtime]  User parameters:   {}  Virtual machines:  [default]  Selection type:    Full cartesian productThis selection yields 6 experiments.Trial Report (1 of 6):  Experiment {instrument=allocation, benchmarkMethod=iterate, vm=default, parameters={}}  Results:    bytes(B): min=4072.00, 1st qu.=4072.00, median=4072.00, mean=4072.00, 3rd qu.=4072.00, max=4072.00    objects: min=3.00, 1st qu.=3.00, median=3.00, mean=3.00, 3rd qu.=3.00, max=3.00Trial Report (2 of 6):  Experiment {instrument=allocation, benchmarkMethod=guava, vm=default, parameters={}}  Results:    bytes(B): min=15104.00, 1st qu.=15104.00, median=15104.00, mean=15104.00, 3rd qu.=15104.00, max=15104.00    objects: min=17.00, 1st qu.=17.00, median=17.00, mean=17.00, 3rd qu.=17.00, max=17.00Trial Report (3 of 6):  Experiment {instrument=allocation, benchmarkMethod=streams, vm=default, parameters={}}  Results:    bytes(B): min=15272.00, 1st qu.=15272.00, median=15272.00, mean=15527.64, 3rd qu.=15432.00, max=17252.80    objects: min=20.00, 1st qu.=20.00, median=20.00, mean=25.00, 3rd qu.=26.00, max=53.00Trial Report (4 of 6):  Experiment {instrument=runtime, benchmarkMethod=guava, vm=default, parameters={}}  Results:    runtime(ns): min=13365.32, 1st qu.=13660.61, median=13802.51, mean=13961.91, 3rd qu.=14445.46, max=14715.34Trial Report (5 of 6):  Experiment {instrument=runtime, benchmarkMethod=iterate, vm=default, parameters={}}  Results:    runtime(ns): min=9952.47, 1st qu.=10892.64, median=11372.35, mean=11243.07, 3rd qu.=11785.48, max=12024.76Trial Report (6 of 6):  Experiment {instrument=runtime, benchmarkMethod=streams, vm=default, parameters={}}  Results:    runtime(ns): min=10527.26, 1st qu.=11051.70, median=11747.29, mean=11631.15, 3rd qu.=12205.97, max=12581.39Collected 81 measurements from:  2 instrument(s)  2 virtual machine(s)  3 benchmark(s)Execution complete: 1.188 min.Results have been uploaded. View them at: https://microbenchmarks.appspot.com/runs/d2c7f83b-2cfa-4217-ab0b-e8d506eaa85c

我仍在研究 Google 卡尺，但它似乎表明 Streams 比 Guava 更快，而且并不比直接的 for 循环慢多少。