git-svn: cache max revision in rev_db databases

Cache the maximum revision for each rev_db URL rather than looking it
up each time.  This saves a lot of time when rebuilding indexes on a
freshly cloned repository.

Signed-off-by: Sam Vilain <sam.vilain@catalyst.net.nz>
Acked-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-svn.perl b/git-svn.perl
index d111dc1442096a30431731b45aa0666604f07921..d5088eab9cacccb9bef2bd26acc65365ebe2f785 100755 (executable)
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -806,6 +806,7 @@ sub working_head_info {
        my ($head, $refs) = @_;
        my ($fh, $ctx) = command_output_pipe('log', $head);
        my $hash;
+       my %max;
        while (<$fh>) {
                if ( m{^commit ($::sha1)$} ) {
                        unshift @$refs, $hash if $hash and $refs;
@@ -815,11 +816,14 @@ sub working_head_info {
                next unless s{^\s*(git-svn-id:)}{$1};
                my ($url, $rev, $uuid) = extract_metadata($_);
                if (defined $url && defined $rev) {
+                       next if $max{$url} and $max{$url} < $rev;
                        if (my $gs = Git::SVN->find_by_url($url)) {
                                my $c = $gs->rev_db_get($rev);
                                if ($c && $c eq $hash) {
                                        close $fh; # break the pipe
                                        return ($url, $rev, $uuid, $gs);
+                               } else {
+                                       $max{$url} ||= $gs->rev_db_max;
                                }
                        }
                }