Re: git-svn performance

From

EWEric Wong <normalperson@yhbt.net>

Date

Oct 19, 2014, 02:29 UTC

Message-ID

<20141019022953.GA6537@dcvr.yhbt.net>

In-Reply-To

<20141019003256.GA18532@dcvr.yhbt.net>

Eric Wong <normalperson@yhbt.net> wrote:

> Hin-Tak (Cc-ed) reported good improvements with them, but also
> a large memory increase:

This might reduce the pathname and internal hash overheads:
------------------------8<-----------------------
From: Eric Wong <normalperson@yhbt.net>
Date: Sun, 19 Oct 2014 02:26:53 +0000
Subject: [PATCH] git-svn: simplify cached_mergeinfo layout

Signed-off-by: Eric Wong <normalperson@yhbt.net>
---
 perl/Git/SVN.pm | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/perl/Git/SVN.pm b/perl/Git/SVN.pm
index b1a84d0..25dbcd5 100644
--- a/perl/Git/SVN.pm
+++ b/perl/Git/SVN.pm
@@ -1708,15 +1708,17 @@ sub mergeinfo_changes {
 	my %minfo = map {split ":", $_ } split "\n", $mergeinfo_prop;
 	my $old_minfo = {};
 
+	# layout: $path => [ $rev, \%mergeinfo ]
+	my $cached_mergeinfo = $self->{cached_mergeinfo};
+
 	# Initialize cache on the first call.
-	unless (defined $self->{cached_mergeinfo_rev}) {
-		$self->{cached_mergeinfo_rev} = {};
-		$self->{cached_mergeinfo} = {};
+	unless (defined $cached_mergeinfo) {
+		$cached_mergeinfo = $self->{cached_mergeinfo} = {};
 	}
 
-	my $cached_rev = $self->{cached_mergeinfo_rev}{$old_path};
-	if (defined $cached_rev && $cached_rev == $old_rev) {
-		$old_minfo = $self->{cached_mergeinfo}{$old_path};
+	my $cached = $cached_mergeinfo->{$old_path};
+	if (defined $cached && $cached->[0] == $old_rev) {
+		$old_minfo = $cached->[1];
 	} else {
 		my $ra = $self->ra;
 		# Give up if $old_path isn't in the repo.
@@ -1733,13 +1735,11 @@ sub mergeinfo_changes {
 				$props->{"svn:mergeinfo"};
 			$old_minfo = \%omi;
 		}
-		$self->{cached_mergeinfo}{$old_path} = $old_minfo;
-		$self->{cached_mergeinfo_rev}{$old_path} = $old_rev;
+		$cached_mergeinfo->{$old_path} = [ $old_rev, $old_minfo ];
 	}
 
 	# Cache the new mergeinfo.
-	$self->{cached_mergeinfo}{$path} = \%minfo;
-	$self->{cached_mergeinfo_rev}{$path} = $rev;
+	$cached_mergeinfo->{$path} = [ $rev, \%minfo ];
 
 	my %changes = ();
 	foreach my $p (keys %minfo) {

-- 
EW