On Tue, 25 May 2021 09:04:07 GMT, Ambarish Rapte <[email protected]> wrote:
> `StyleManager.calculateCheckSum()` uses a raw InputStream as the input to a > `DigestInputStream` and reads one byte at a time. This is slower in > performance and should be changed, either to use `BufferedInputStream` or > read byte buffer of 4096 from the stream or use both. > > I have tried three approaches and tested with modena.css which is ~134 KB in > size. > Following are the approaches and time in milliseconds taken by the method > StyleManager.calculateCheckSum(), collected from 25 readings, > > 1. Use BufferedInputStream and read one byte at a time > [commit#1](https://github.com/openjdk/jfx/commit/6cd7d44d0ce1084c6cdb06a698c7aca127a615ef) > : > - Maximum: 53 ms, Minimum: 27 ms, Average: 39 ms > 2. Use BufferedInputStream and read buffer of 4096 at a time > [commit#1+2](https://github.com/openjdk/jfx/pull/518/files/6e0c621ea62691d5402b2bca5951d1012a5b1b91) > - Maximum: 17 ms, Minimum: 14 ms, Average: 15.58 ms > 3. Use raw InputStream(current implementation) and read buffer of 4096 at a > time > [commit#1+2+3](https://github.com/openjdk/jfx/pull/518/files/215e1a183cfb902247f0d48685f7a901cb5fb003), > which also similar to `NativeLibLoader.calculateCheckSum()` and looks faster > than previous two. > - Maximum: 16 ms, Minimum: 13 ms, Average: 14.25 ms > > > The time taken by `StyleManager.calculateCheckSum()` with current > implementation is, > - Maximum: 61 ms, Minimum: 38 ms, Average: 50.58 ms > > > Both approaches 2 & 3 show good improvement. I would prefer approach#3 as it > is similar to `NativeLibLoader.calculateCheckSum()`. > However we can choose approach#2 also. > If we choose approach#3 then bug summary should be changed accordingly. I also prefer approach 3, since the body of the try/finally loop is then identical to that of `NativeLibLoader::calculateCheckSum`. Can you add a unit test to validate the checksum method? It should be sufficient to do this by taking a file that is > 4096 bytes, but not a multiple of 4096, manually running `md5sum` on it to get its checksum that you can then use to compare with the computed one. ------------- PR: https://git.openjdk.java.net/jfx/pull/518
