Re: RFR: 8264777: Overload optimized FileInputStream::readAllBytes [v5]
On Tue, 4 May 2021 20:13:20 GMT, Brian Burkhalter wrote: >> On `/proc/cpuinfo` for example, `fstat()` succeeds but `st_size` in `struct >> stat` is zero. The correct position is however returned by `lseek()`. >> Apparently this proposal needs to be reworked to expect size zero when the >> size is in fact non-zero. > > Updated to handle `length() == 0` case. Not sure however whether for this > case it might not be better just to fall back to `super.readXBytes()` instead. Can you rename the native length and position methods to length0 and position0 as we will need to wrap these methods later. Also it will keep them consistent with RAF. - PR: https://git.openjdk.java.net/jdk/pull/3845
Re: RFR: 8264777: Overload optimized FileInputStream::readAllBytes [v5]
> Please consider this request to override the `java.io.InputStream` methods > `readAllBytes()` and `readNBytes(int)` in `FileInputStream` with more > performant implementations. The method overrides attempt to read all > requested bytes into a single array of the required size rather than > composing the result from a sequence of smaller arrays. An example of the > performance improvements is as follows. > > **readAllBytes** > Before > > Benchmark(length) Mode Cnt Score >Error Units > ReadAllBytes.readAllBytesFileInputStream 100 thrpt 20 2412.031 > ± 7.309 ops/s > ReadAllBytes.readAllBytesFileInputStream 1000 thrpt 20212.181 > ± 0.369 ops/s > ReadAllBytes.readAllBytesFileInputStream1 thrpt 20 19.860 > ± 0.048 ops/s > ReadAllBytes.readAllBytesFileInputStream 10 thrpt 20 1.298 > ± 0.183 ops/s > > After > > Benchmark(length) Mode Cnt Score >Error Units > ReadAllBytes.readAllBytesFileInputStream 100 thrpt 20 8218.473 > ± 43.425 ops/s > ReadAllBytes.readAllBytesFileInputStream 1000 thrpt 20302.781 > ± 1.273 ops/s > ReadAllBytes.readAllBytesFileInputStream1 thrpt 20 22.461 > ± 0.084 ops/s > ReadAllBytes.readAllBytesFileInputStream 10 thrpt 20 1.502 > ± 0.003 ops/s > > > **readNBytes** > > `N = file_size / 2` > > Before > > Benchmark(length) Mode Cnt Score >Error Units > ReadAllBytes.readHalfBytesFileInputStream 100 thrpt 20 5585.500 > ± 153.353 ops/s > ReadAllBytes.readHalfBytesFileInputStream1000 thrpt 20436.164 > ± 1.104 ops/s > ReadAllBytes.readHalfBytesFileInputStream 1 thrpt 20 40.167 > ± 0.141 ops/s > ReadAllBytes.readHalfBytesFileInputStream 10 thrpt 20 3.291 > ± 0.211 ops/s > > > After > > Benchmark(length) Mode Cnt Score >Error Units > ReadAllBytes.readHalfBytesFileInputStream 100 thrpt 20 15463.210 > ± 66.045 ops/s > ReadAllBytes.readHalfBytesFileInputStream1000 thrpt 20561.752 > ± 0.951 ops/s > ReadAllBytes.readHalfBytesFileInputStream 1 thrpt 20 45.043 > ± 0.102 ops/s > ReadAllBytes.readHalfBytesFileInputStream 10 thrpt 20 4.629 > ± 0.035 ops/s Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision: 8264777: Improve handling of position, length, and size checks - Changes: - all: https://git.openjdk.java.net/jdk/pull/3845/files - new: https://git.openjdk.java.net/jdk/pull/3845/files/5a4d9114..0e476822 Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jdk=3845=04 - incr: https://webrevs.openjdk.java.net/?repo=jdk=3845=03-04 Stats: 16 lines in 1 file changed: 5 ins; 4 del; 7 mod Patch: https://git.openjdk.java.net/jdk/pull/3845.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/3845/head:pull/3845 PR: https://git.openjdk.java.net/jdk/pull/3845
