From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Wed, 1 Feb 2012 18:33:33 +0000 (+0000)
Subject: update wip - source sorting and selection done
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=topbloke.git;a=commitdiff_plain;h=0c4e7252eb9a9be00a1124a7d246434290bc73aa

update wip - source sorting and selection done
---

diff --git a/tb-update.pl b/tb-update.pl
index 9cae816..767dcf8 100755
--- a/tb-update.pl
+++ b/tb-update.pl
@@ -14,6 +14,28 @@ die "bad usage\n" if @ARGV;
 check_clean_tree();
 
 
+sub memo ($$$) { 
+    my ($memos,$key,$code) = @_;
+    return $memos->{$key} if exists $memos->{$key};
+    debug("----- $key");
+    $memos->{$key} = $code->();
+}
+
+sub merge_base ($$) {
+    my ($r,$s) = @_; # refs, ideally
+    our %memos;
+    return memo(\%memos, "$r $s", sub {
+	run_git_1line(qw(merge-base), $r, $s);
+		});
+}
+
+sub committ_date ($) {
+    my ($ref) = @_;
+    my $l = run_git_1line(qw(git-log --date=raw -n1 --pretty=format:%cd), $ref);
+    $l =~ m/^(\d+)\s/ or die;
+    return $l;
+}
+
 sub update_base ($) {
     my ($patch) = @_;
 
@@ -54,7 +76,11 @@ sub update_base ($) {
 	    } elsif ($depline =~ m/^-/) {
 		die "$depline ?"; # should have failed earlier
 	    } else {
-		push @sources, { Ref => "$tiprefs/$depline", Kind => 'tb' };
+		push @sources, { 
+		    Name => $depline,
+		    Ref => "$tiprefs/$depline", 
+		    Kind => 'tb',
+		};
 	    }
 	}
 
@@ -62,7 +88,11 @@ sub update_base ($) {
 	if ($obk ne 'missing') {
 	    $obj eq 'blob' or die "$patch $obk ??";
 	    chomp $tg or die "$patch ??";
-	    push @sources, { Ref => "refs/top-bases/$tg", Kind => 'topgit' };
+	    push @sources, {
+		Name => "-topgit $tg",
+		Ref => "refs/top-bases/$tg", 
+		Kind => 'topgit',
+	    };
 	}
 
 	# This bit involves rather too much history walking
@@ -71,14 +101,25 @@ sub update_base ($) {
 	# Find the merge base for each source
 	foreach my $source (@sources) {
 	    $source->{Head} = run_git_1line(qw(rev-parse), $source->{Ref});
-	    $source->{MergeBase} = 
-		run_git_1line(qw(merge-base), $head, "$baserefs/$patch");
+	    $source->{MergeBase} = merge_base($head, "$baserefs/$patch");
 	}
 	# The merge base is contained in $head, so if it is equal
 	# to the source's head, the source is contained in $head -
 	# ie we are ahead of the source.  Skip those sources.
 	@sources = grep { $source->{MergeBase} ne $source->{Head} } @sources;
 
+	our %cmp_memos;
+	@sources = sort { 
+	    memo(\%cmp_memos, "$a->{Name} $b->{Name}", sub {
+		my $mb = merge_base($a->{Ref}, $b->{Ref});
+		return -($mb eq $a->{Ref}) cmp ($mb eq $b->{Ref})
+		    # if merge base is $a then $a must be before $b
+		    # ie the commit equal to the merge base is earlier
+		    or (committ_date($a->{Ref}) cmp committ_date($b->{Ref}));
+	    })
+	} @sources;
+
+
 	# Now we run git-rev-list to walk the graph back to those
 	# sources so we can tell which is the most recent.
 	foreach my $source (@sources) {