3 ms·
> ... for not much reason There's actually a good reason to do this, but it is an edge case. A timestamp-based build system can do a no-op check with very lit
by ycombobreaker 14y ago
> ... for not much reason
There's actually a good reason to do this, but it is an edge case. A timestamp-based build system can do a no-op check with very little I/O. A hash-based build system has to read all of the file contents in order to determine that nothing has changed. Depending on the latency and bandwidth of your storage, this can make a big difference in incremental builds.
- zwegner 14y agoI was more talking about the need to implement this layer yourself, when it should be taken care of by the build system (though I don't know of any build systems that can easily implement your suggestion, since it has to somehow redirect the output of a code-generation step to another file). Agreed that there are performance differences, though in my experience hashing is quite acceptable even for large projects if used reasonably (only hashing inputs to build steps if they are also outputs of another build step).