From 1d9ee468725b3689a20128ddcb19fb70294b340f Mon Sep 17 00:00:00 2001
From: Eric Wong <normalperson@yhbt.net>
Date: Sun, 20 Apr 2014 19:18:19 +0000
Subject: [PATCH] use Git.pm for efficient cat_blob if available

This reduces the amount of fork+exec and should improve performance
for large imports.
---
 lib/Ssoma/Extractor.pm |  6 ++++--
 lib/Ssoma/Git.pm       | 27 +++++++++++++++++++++++----
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/lib/Ssoma/Extractor.pm b/lib/Ssoma/Extractor.pm
index 2589adb..9c93b43 100644
--- a/lib/Ssoma/Extractor.pm
+++ b/lib/Ssoma/Extractor.pm
@@ -96,8 +96,9 @@ sub _extract {
 sub _deliver_each_msg {
 	my ($self, $dest, $tip, $new) = @_;
 	my $git = $self->{git};
+	my $git_pm = $git->try_git_pm;
 	foreach my $path (@$new) {
-		_deliver_die($git->cat_blob("$tip:$path"), $dest);
+		_deliver_die($git->cat_blob("$tip:$path", $git_pm), $dest);
 	}
 }
 
@@ -118,8 +119,9 @@ sub _imap_deliver_each_msg {
 	my $git = $self->{git};
 	require Ssoma::IMAP;
 	my $imap = Ssoma::IMAP->new($git);
+	my $git_pm = $git->try_git_pm;
 	foreach my $path (@$new) {
-		$imap->imap_deliver($git->cat_blob("$tip:$path"));
+		$imap->imap_deliver($git->cat_blob("$tip:$path", $git_pm));
 	}
 	$imap->quit;
 }
diff --git a/lib/Ssoma/Git.pm b/lib/Ssoma/Git.pm
index 5cec7fb..5f5702b 100644
--- a/lib/Ssoma/Git.pm
+++ b/lib/Ssoma/Git.pm
@@ -199,10 +199,20 @@ sub mid2path {
 }
 
 sub cat_blob {
-	my ($self, $blob_id) = @_;
-	my $cmd = "git cat-file blob $blob_id";
-	my $str = `$cmd`;
-	die "$cmd failed: $?\n" if $?;
+	my ($self, $blob_id, $git_pm) = @_;
+	my $str;
+	if ($git_pm) {
+		open my $fh, '>', \$str or
+				die "failed to setup string handle: $!\n";
+		binmode $fh;
+		my $bytes = $git_pm->cat_blob($blob_id, $fh);
+		close $fh or die "failed to close string handle: $!\n";
+		die "$blob_id invalid\n" if $bytes <= 0;
+	} else {
+		my $cmd = "git cat-file blob $blob_id";
+		$str = `$cmd`;
+		die "$cmd failed: $?\n" if $?;
+	}
 	$str;
 }
 
@@ -268,4 +278,13 @@ sub commit_index {
 	system(@cmd) == 0 or die "command: ". join(' ', @cmd) . ": $?\n";
 }
 
+# keep Git.pm optional, not all installations of git have it
+sub try_git_pm {
+	my ($self) = @_;
+	eval {
+		require Git;
+		Git->repository(Directory => $self->{git_dir});
+	};
+}
+
 1;
-- 
2.26.2