Rework charting cache fetcher for git repositories

charting/fetch.pl

@@ -6,23 +6,30 @@
 use File::stat;
 use Months;
 
-$fn = '../xml/ukfederation-metadata.xml';
-$fn2 = '../xml/ukfederation-stats.html';
+# Call git on the products directory
+my $git = "/usr/bin/env git -C ../../ukf-products";
+
+$fn1 = 'aggregates/ukfederation-metadata.xml';
+$fn2 = 'aggregates/ukfederation-stats.html';
 
 foreach $month (@months) {
 	print "Fetching $month...";
-
+
+	# Find the commit immediately prior to the start of that month.
+	my $instant = "$month-01T00:00:00Z";
+	my $commit = `$git rev-list -n 1 --before=$instant master`;
+	chomp $commit;
+	print "$commit";
+
 	my $dest1 = "cache/$month.xml";
 	if (!-e $dest1) {
-		system("/usr/bin/env svn update $fn --quiet --revision \\{$month-01T00:00:00Z\\}");
-		system("cp $fn $dest1");
+		system("$git show $commit:$fn1 >$dest1");
 	}
-	
+
 	my $dest2 = "cache/$month.html";
 	if (!-e $dest2) {
-		system("/usr/bin/env svn update $fn2 --quiet --revision \\{$month-01T00:00:00Z\\}");
-		system("cp $fn2 $dest2");
+		system("$git show $commit:$fn2 >$dest2");
 	}
-	
+
 	print "\n";
 }