I slightly disagree with your analysis. If the file has been written with a different encoding, the result string will be corrupted when read and unmappable chars replaced as indicated by [1], but then, the consequence is that the two strings will differ and the file will be overwritten anyway. So I don't think any failure can happen and the result should be the same, whether we do the comparison on the bytes or on the string.
That said, I agree this will avoid an unnecessary decoding of the existing file and an optimization by checking the file length as you said. I've raised a PR for that [2]. Cheers, Guillaume Nodet [1] https://docs.oracle.com/javase/7/docs/api/java/lang/String.html#String(byte[],%20java.nio.charset.Charset) [2] https://github.com/codehaus-plexus/modello/pull/186 Le lun. 14 févr. 2022 à 08:41, Vladimir Sitnikov < sitnikov.vladi...@gmail.com> a écrit : > I believe the added CachingWriter is might become a cause of silent > failures. > > What CachingWriter does is an attempt to read the file and decode it with > the provided encoding. > Apparently, the decoding might fail since the file might be written in > another encoding or it might be corrupted. > > A better approach would be to convert the created String into `byte[]`, and > then compare the bytes with file contents. > Then you never really need to decode the file > > Could someone with commit privileges just fix it? > The fix is just to remove readString and writeString methods, and use > Arrays.equals to compare the contents. > Then, you can compare file contents and avoid reading the file if you know > the length differs (it optimizes the "file differs" case). > > ---- > > I remember I faced "Maven recompiling everything" issue multiple times, so > I wonder if Maven itself has a solution for that. > I understand tracking inputs and outputs might take a while to implement, > so > what if Maven had a solid API for generating files that skips overwriting > if the contents are the same? > > Sample issues on the top of my head: > https://issues.apache.org/jira/browse/MRRESOURCES-91 > https://github.com/freemarker/fmpp/issues/11 > https://github.com/julianhyde/hydromatic-resource/pull/4 > > Why does every plugin have to reinvent a half-broken caching wheel? > > Vladimir > -- ------------------------ Guillaume Nodet
