From 6a8f914beb77ec4cc36ed0aecb0e5da31a450418 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Tue, 14 Jul 2015 20:23:11 +0100
Subject: [PATCH] Memoise git config lookups (big speedup!)

---
 debian/changelog |  4 +++-
 dgit             | 37 ++++++++++++++++++++++++++-----------
 2 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/debian/changelog b/debian/changelog
index 67086e0f..a1f6ba11 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,5 +1,8 @@
 dgit (0.31~~) unstable; urgency=low
 
+  Improvements:
+  * Memoise git config lookups (big speedup!)
+
   Documentation:
   * dgit(1): Remove some obsolete caveats from BUGS.
   * dgit(1); Mention that -wgf can avoid need for build-deps.
@@ -14,7 +17,6 @@ dgit (0.31~~) unstable; urgency=low
   * Make dgit-ssh-dispatch not spew (harmless) warnings if caller
     tries for a shell session (ie SSH_ORIGINAL_COMMAND not set).
 
- --
 
 dgit (0.30) unstable; urgency=high
 
diff --git a/dgit b/dgit
index 1a2ee88f..a051622d 100755
--- a/dgit
+++ b/dgit
@@ -485,20 +485,35 @@ our %defcfg = ('dgit.default.distro' => 'debian',
 	       'dgit-distro.test-dummy.upload-host' => 'test-dummy',
                );
 
+sub git_get_config ($) {
+    my ($c) = @_;
+
+    our %git_get_config_memo;
+    if (exists $git_get_config_memo{$c}) {
+	return $git_get_config_memo{$c};
+    }
+
+    my $v;
+    my @cmd = (@git, qw(config --), $c);
+    {
+	local ($debuglevel) = $debuglevel-2;
+	$v = cmdoutput_errok @cmd;
+    };
+    if ($?==0) {
+    } elsif ($?==256) {
+	$v = undef;
+    } else {
+	failedcmd @cmd;
+    }
+    $git_get_config_memo{$c} = $v;
+    return $v;
+}
+
 sub cfg {
     foreach my $c (@_) {
 	return undef if $c =~ /RETURN-UNDEF/;
-	my @cmd = (@git, qw(config --), $c);
-	my $v;
-	{
-	    local ($debuglevel) = $debuglevel-2;
-	    $v = cmdoutput_errok @cmd;
-	};
-	if ($?==0) {
-	    return $v;
-	} elsif ($?!=256) {
-	    failedcmd @cmd;
-	}
+	my $v = git_get_config($c);
+	return $v if defined $v;
 	my $dv = $defcfg{$c};
 	return $dv if defined $dv;
     }
-- 
2.30.2