Johannes Schindelin[PATCH] git-fetch: Avoid reading packed refs over and over again
When checking which tags to fetch, the old code used to call git-show-ref --verify for _each_ remote tag. Since reading even packed refs is not a cheap operation when there are a lot of local refs, the code became quite slow.
This fixes it by teaching git-show-ref to filter out valid (i.e. locally stored) refs from stdin, when passing the parameter --filter-invalid to git-show-ref, and feeding it lines in the form 'sha1 refname'.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> --- Since this option is purely for use in git-fetch, I did not even bother documenting it.
This patch would have been so much cleaner if git-fetch was written in C... But since it accumulated so many functions by now, I see not much chance for that (at least in the near future).
In very unscientific tests, a single read_packed_refs() in the lilypond repo took 0.1 seconds. Yep, that's 1/10th second. So, the while loop in git-fetch took more than 10 seconds for 107 tags.
builtin-show-ref.c | 28 +++++++++++++++++++++++++++- git-fetch.sh | 2 +- 2 files changed, 28 insertions(+), 2 deletions(-)
Show changes to 2 files +28 −2
builtin-show-ref.c, git-fetch.sh
diff --git a/builtin-show-ref.c b/builtin-show-ref.c index f6929d9..c0b55c1 100644 --- a/builtin-show-ref.c +++ b/builtin-show-ref.c @@ -2,8 +2,9 @@ #include "refs.h" #include "object.h" #include "tag.h" +#include "path-list.h" -static const char show_ref_usage[] = "git show-ref [-q|--quiet] [--verify] [-h|--head] [-d|--dereference] [-s|--hash[=<length>]] [--abbrev[=<length>]] [--tags] [--heads] [--] [pattern*]"; +static const char show_ref_usage[] = "git show-ref [-q|--quiet] [--verify] [-h|--head] [-d|--dereference] [-s|--hash[=<length>]] [--abbrev[=<length>]] [--tags] [--heads] [--] [pattern*] | --filter-invalid < ref-list"; static int deref_tags = 0, show_head = 0, tags_only = 0, heads_only = 0, found_match = 0, verify = 0, quiet = 0, hash_only = 0, abbrev = 0; @@ -86,6 +87,29 @@ match: return 0; } +static int add_valid(const char *refname, const unsigned char *sha1, int flag, void *cbdata) +{ + struct path_list *list = (struct path_list *)cbdata; + path_list_insert(refname, list); + return 0; +} + +static int filter_invalid() +{ + static struct path_list valid_refs = { NULL, 0, 0, 0 }; + char buf[1024]; + + for_each_ref(add_valid, &valid_refs); + while (fgets(buf, sizeof(buf), stdin)) { + int len = strlen(buf); + if (len > 0 && buf[len - 1] == '\n') + buf[--len] = '\0'; + if (len < 41 || !path_list_has_path(&valid_refs, buf + 41)) + printf("%s\n", buf); + } + return 0; +} + int cmd_show_ref(int argc, const char **argv, const char *prefix) { int i; @@ -153,6 +177,8 @@ int cmd_show_ref(int argc, const char **argv, const char *prefix) heads_only = 1; continue; } + if (!strcmp(arg, "--filter-invalid")) + return filter_invalid(); usage(show_ref_usage); } if (verify) { diff --git a/git-fetch.sh b/git-fetch.sh index 3feba32..d1c00db 100755 --- a/git-fetch.sh +++ b/git-fetch.sh @@ -474,9 +474,9 @@ case "$no_tags$tags" in echo "$ls_remote_result" | sed -n -e 's|^\('"$_x40"'\) \(refs/tags/.*\)^{}$|\1 \2|p' \ -e 's|^\('"$_x40"'\) \(refs/tags/.*\)$|\1 \2|p' | + git-show-ref --filter-invalid | while read sha1 name do - git-show-ref --verify --quiet -- "$name" && continue git-check-ref-format "$name" || { echo >&2 "warning: tag ${name} ignored" continue
-- 1.4.4.1.g3c2a-dirty
