On Thu, Jul 21, 2016 at 06:46:44PM +0200, René Scharfe wrote: > >> - strbuf_add(out, untracked->ident.buf, untracked->ident.len); > >> + strbuf_addbuf(out, &untracked->ident); > > > > This is actually slightly _less_ efficient, because we already are using > > the precomputed len, and the new code will call an extra strbuf_grow() > > to cover the case where the two arguments are the same. See 81d2cae > > (strbuf_addbuf(): allow passing the same buf to dst and src, > > 2010-01-12). > > Ah, I wasn't aware of that. Calling strbuf_grow() twice shouldn't be > thaaat bad. However, I wonder where we duplicate strbufs, or why we > would ever want to do so. Anyway, here's a patch for that: I don't think we do. Going back to the original discussion: http://thread.gmane.org/gmane.comp.version-control.git/136141/focus=136774 it was mostly just "hey, this would fail really confusingly if we ever did, so let's make it safe". The second strbuf_grow() is by definition a noop (which is why 81d2cae works at all), but we do pay the size-computation cost. > -- >8 -- > Subject: strbuf: avoid calling strbuf_grow() twice in strbuf_addbuf() > > Implement strbuf_addbuf() as a normal function in order to avoid calling > strbuf_grow() twice, with the second callinside strbud_add() being a > no-op. This is slightly faster and also reduces the text size a bit. Seems reasonable. IMHO the main advantage is that one does not have to reason about the double strbuf_grow() (i.e., that the strbuf_add() is safe because we know its grow is a noop). -Peff -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html