[pacman-dev] [PATCH] Database read optimizations
Hard to believe there was still more room to improve on this, but I found an easily correctable oversight tonight. Our databases (both sync and local) contain many blank lines, and we were not moving onto the next line right away in these cases; instead we would proceed through our strcmp() conditional checks as normal. Some local numbers follow to show the effects of this patch: Sync `-Ss foobarbaz`: 71,709 blank lines skipped early ~1,505,889 strcmp() calls avoided (21 per line) ~15% speed improvement (.210 --> .179 sec) Local `-Qs foobarbaz`: 6,823 blank lines skipped early 115,991 strcmp() calls avoided (17 per line) ~6% speed improvement (.080 -> .071 sec) Signed-off-by: Dan McGee <dan@archlinux.org> --- lib/libalpm/be_local.c | 8 +++++++- lib/libalpm/be_sync.c | 5 ++++- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/lib/libalpm/be_local.c b/lib/libalpm/be_local.c index 1a46dfd..be02bb5 100644 --- a/lib/libalpm/be_local.c +++ b/lib/libalpm/be_local.c @@ -580,7 +580,13 @@ static int local_db_read(alpm_pkg_t *info, alpm_dbinfrq_t inforeq) goto error; } while(!feof(fp)) { - READ_NEXT(); + if(fgets(line, sizeof(line), fp) == NULL && !feof(fp)) { + goto error; + } + if(_alpm_strip_newline(line) == 0) { + /* length of stripped line was zero */ + continue; + } if(strcmp(line, "%NAME%") == 0) { READ_NEXT(); if(strcmp(line, info->name) != 0) { diff --git a/lib/libalpm/be_sync.c b/lib/libalpm/be_sync.c index ac99e05..12d5b7f 100644 --- a/lib/libalpm/be_sync.c +++ b/lib/libalpm/be_sync.c @@ -526,7 +526,10 @@ static int sync_db_read(alpm_db_t *db, struct archive *archive, int ret; while((ret = _alpm_archive_fgets(archive, &buf)) == ARCHIVE_OK) { char *line = buf.line; - _alpm_strip_newline(line); + if(_alpm_strip_newline(line) == 0) { + /* length of stripped line was zero */ + continue; + } if(strcmp(line, "%NAME%") == 0) { READ_NEXT(); -- 1.7.6
participants (1)
-
Dan McGee