On Thu, 14 Jan 2021 09:31:19 GMT, Сергей Цыпанов <github.com+10835776+stsypa...@openjdk.org> wrote:
>> Looks good. >> >> I wonder... `CharArrayWriter` is an old and synchronized data structure, and >> since the instance used here isn't shared that synchronization seem useless. >> And since you're now bypassing the `char[]` and going straight for a >> `String` you might get better performance with a `StringBuilder` here? >> (`setLength(0)` instead of `reset()`...) > > @cl4es SB brings pessimization both for time and memory, try > `org.openjdk.bench.java.net.URLEncodeDecode`: > master > (count) (maxLength) > (mySeed) Mode Cnt Score Error Units > testEncodeUTF8 1024 1024 > 3 avgt 25 8.573 ? 0.023 ms/op > testEncodeUTF8:?gc.alloc.rate 1024 1024 > 3 avgt 25 1202.896 ? 3.225 MB/sec > testEncodeUTF8:?gc.alloc.rate.norm 1024 1024 > 3 avgt 25 11355727.904 ? 196.249 B/op > testEncodeUTF8:?gc.churn.G1_Eden_Space 1024 1024 > 3 avgt 25 1203.785 ? 6.240 MB/sec > testEncodeUTF8:?gc.churn.G1_Eden_Space.norm 1024 1024 > 3 avgt 25 11364143.637 ? 52830.222 B/op > testEncodeUTF8:?gc.churn.G1_Survivor_Space 1024 1024 > 3 avgt 25 0.008 ? 0.001 MB/sec > testEncodeUTF8:?gc.churn.G1_Survivor_Space.norm 1024 1024 > 3 avgt 25 77.088 ? 9.303 B/op > testEncodeUTF8:?gc.count 1024 1024 > 3 avgt 25 1973.000 counts > testEncodeUTF8:?gc.time 1024 1024 > 3 avgt 25 996.000 ms > > enc > (count) (maxLength) > (mySeed) Mode Cnt Score Error Units > testEncodeUTF8 1024 1024 > 3 avgt 25 7.931 ? 0.006 ms/op > testEncodeUTF8:?gc.alloc.rate 1024 1024 > 3 avgt 25 965.347 ? 0.736 MB/sec > testEncodeUTF8:?gc.alloc.rate.norm 1024 1024 > 3 avgt 25 8430590.163 ? 7.213 B/op > testEncodeUTF8:?gc.churn.G1_Eden_Space 1024 1024 > 3 avgt 25 966.373 ? 5.248 MB/sec > testEncodeUTF8:?gc.churn.G1_Eden_Space.norm 1024 1024 > 3 avgt 25 8439563.689 ? 47282.178 B/op > testEncodeUTF8:?gc.churn.G1_Survivor_Space 1024 1024 > 3 avgt 25 0.007 ? 0.001 MB/sec > testEncodeUTF8:?gc.churn.G1_Survivor_Space.norm 1024 1024 > 3 avgt 25 60.949 ? 8.405 B/op > testEncodeUTF8:?gc.count 1024 1024 > 3 avgt 25 1715.000 counts > testEncodeUTF8:?gc.time 1024 1024 > 3 avgt 25 888.000 ms > > stringBuilder > (count) (maxLength) > (mySeed) Mode Cnt Score Error Units > testEncodeUTF8 1024 1024 > 3 avgt 25 8.115 ? 0.110 ms/op > testEncodeUTF8:?gc.alloc.rate 1024 1024 > 3 avgt 25 1259.267 ? 16.716 MB/sec > testEncodeUTF8:?gc.alloc.rate.norm 1024 1024 > 3 avgt 25 11249391.875 ? 6.552 B/op > testEncodeUTF8:?gc.churn.G1_Eden_Space 1024 1024 > 3 avgt 25 1259.937 ? 17.232 MB/sec > testEncodeUTF8:?gc.churn.G1_Eden_Space.norm 1024 1024 > 3 avgt 25 11255413.875 ? 43636.143 B/op > testEncodeUTF8:?gc.churn.G1_Survivor_Space 1024 1024 > 3 avgt 25 0.007 ? 0.001 MB/sec > testEncodeUTF8:?gc.churn.G1_Survivor_Space.norm 1024 1024 > 3 avgt 25 59.461 ? 9.087 B/op > testEncodeUTF8:?gc.count 1024 1024 > 3 avgt 25 2236.000 counts > testEncodeUTF8:?gc.time 1024 1024 > 3 avgt 25 1089.000 ms > The reason seems to be single char `StringBuilder.append()` that apart from > range check does encoding check and stores `char` as two bytes in `byte[]` in > ASB Surprising, but thanks for checking! ------------- PR: https://git.openjdk.java.net/jdk/pull/1598
