On Wed, Sep 21, 2016 at 08:24:14PM +0200, Johannes Schindelin wrote: > The new regexec_buf() function operates on buffers with an explicitly > specified length, rather than NUL-terminated strings. > > We need to use this function whenever the buffer we want to pass to > regexec() may have been mmap()ed (and is hence not NUL-terminated). > > Note: the original motivation for this patch was to fix a bug where > `git diff -G <regex>` would crash. This patch converts more callers, > though, some of which explicitly allocated and constructed > NUL-terminated strings (or worse: modified read-only buffers to insert > NULs).
Nice. I probably would have split these into their own patch, but I think it is OK here. > @@ -228,18 +227,16 @@ static long ff_regexp(const char *line, long len, > len--; > } > > - line_buffer = xstrndup(line, len); /* make NUL terminated */ > - Nice to see this one going away in particular, since it's called quite a lot. According to perf, "git log -p" on git.git drops about 1.5 million malloc calls (about 9% of the total). And here are best-of-five results for that same command: [before] real 0m14.676s user 0m13.988s sys 0m0.676s [after] real 0m14.394s user 0m13.624s sys 0m0.760s Not a _huge_ improvement, but more significant than the run-to-run noise. -Peff
