[pacman-dev] [PATCH] repo-add: use bsdtar optimization for better performance

[Dan McGee]

When unzipping packages and the database archives, we don't need to look
through the entire archive to do what we need to do. For packages, .PKGINFO
should only be found once and should be the first file in the package. For
the database check, we only really need to look for one desc file.

The bsdtar -q option is very similar to the GNU tar --occurrence=1 option.

Example of speedup:

$ time repo-add junkdb.db.tar.gz *.pkg.tar.gz >/dev/null
real	0m16.159s
user	0m14.836s
sys	0m2.277s

$ time ./scripts/repo-add junkdb.db.tar.gz *.pkg.tar.gz >/dev/null
real	0m4.949s
user	0m3.730s
sys	0m2.093s

Signed-off-by: Dan McGee <dan at archlinux.org>
---
 scripts/repo-add.sh.in |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/scripts/repo-add.sh.in b/scripts/repo-add.sh.in
index 7c12aaf..5454fb0 100644
--- a/scripts/repo-add.sh.in
+++ b/scripts/repo-add.sh.in
@@ -193,7 +193,7 @@ db_write_entry()
 
 	# read info from the zipped package
 	local line var val
-	for line in $(bsdtar -xOf "$pkgfile" .PKGINFO |
+	for line in $(bsdtar -xOqf "$pkgfile" .PKGINFO |
 			grep -v '^#' | sed 's|\(\w*\)\s*=\s*\(.*\)|\1 \2|'); do
 		# bash awesomeness here- var is always one word, val is everything else
 		var=${line%% *}
@@ -305,7 +305,7 @@ check_repo_db()
 	fi
 
 	if [ -f "$REPO_DB_FILE" ]; then
-		if ! (bsdtar -tf "$REPO_DB_FILE" | grep -q "/desc"); then
+		if ! bsdtar -tqf "$REPO_DB_FILE" '*/desc' 2>&1 >/dev/null; then
 			error "$(gettext "Repository file '%s' is not a proper pacman database.")" "$REPO_DB_FILE"
 			exit 1
 		fi
@@ -351,7 +351,7 @@ add()
 	fi
 
 	pkgfile=$1
-	if ! bsdtar -tf "$pkgfile" .PKGINFO 2>&1 >/dev/null; then
+	if ! bsdtar -tqf "$pkgfile" .PKGINFO 2>&1 >/dev/null; then
 		error "$(gettext "'%s' is not a package file, skipping")" "$pkgfile"
 		return 1
 	fi
-- 
1.6.3.2