On 4/4/23 21:51, Alejandro Colomar wrote: > Hi, > > I've met some strange diff with the histogram algorithm. I know this > has a lot of magic in it, and it's probably not so trivial to improve, > and maybe my code base is so weird that it makes the histogram do crazy > stuff, but I wanted to show it to you in case there's anything that can > be improved. > > So, patience is showing a better diff than histogram, which shouldn't > happen usually, and less in this case, where p++ is such a common thing > to do (although maybe this nxt_slow_path() macro is called a lot in the > file and confuses the histogram?). > > Code base: <https://github.com/nginx/unit.git> > > Cheers, > Alex Now this has surprised me even more: alx@asus5775:~/src/nginx/unit/space$ git diff --diff-algorithm=histogram diff --git a/src/nxt_http_parse.c b/src/nxt_http_parse.c index 8646a6ce..3559f2e2 100644 --- a/src/nxt_http_parse.c +++ b/src/nxt_http_parse.c @@ -340,9 +340,9 @@ nxt_http_parse_request_line(nxt_http_request_parse_t *rp, u_char **pos, space_after_target: - if (nxt_slow_path(end - p < 10)) { + p++; - p++; + if (nxt_slow_path(end - p < 10)) { if (p == end) { return NXT_AGAIN; alx@asus5775:~/src/nginx/unit/space$ git diff --diff-algorithm=patience diff --git a/src/nxt_http_parse.c b/src/nxt_http_parse.c index 8646a6ce..3559f2e2 100644 --- a/src/nxt_http_parse.c +++ b/src/nxt_http_parse.c @@ -340,10 +340,10 @@ nxt_http_parse_request_line(nxt_http_request_parse_t *rp, u_char **pos, space_after_target: + p++; + if (nxt_slow_path(end - p < 10)) { - p++; - if (p == end) { return NXT_AGAIN; } -- <http://www.alejandro-colomar.es/> GPG key fingerprint: A9348594CE31283A826FBDD8D57633D441E25BB5
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