Merge pull request #34 from pmyteh/ttlogmerge

ttlogmerge: A new helper script for the Unison file synchroniser

script/ttlogmerge.pl

@@ -0,0 +1,122 @@
+#!/usr/bin/perl
+
+# Syntax: ttlogmerge.pl logfile1 logfile2 outputlogfile
+#
+# A helper script for the Unison file synchroniser. One option for Unison is to
+# use an external program to merge two files which have been change in both
+# roots. This script uses this feature to merge two TagTime log files which
+# have been created on different machines.
+#
+# In principle, this allows you to run TagTime on multiple computers and, as
+# long as they have the same period and random seeds, create a merged file
+# which tracks what you were doing on all your machines.
+#
+# If a ping only exists in one file, use it.
+# If a ping exists in both files but one is tagged "RETRO", use the other.
+# If a ping exists in both files and both or neither are tagged "RETRO",
+#    then use the one with the most tags entered.
+# Note that it is assumed that both files have timestamps in ascending order.
+#
+# This is best used by adding something like the following to your Unison
+# preferences file:
+#
+# merge = Path path/to/tagtime/*.log -> /path/to/ttlogmerge.pl CURRENT1 CURRENT2 NEW
+
+use strict;
+use warnings;
+
+sub longer
+{
+	(length($_[0]) >= length($_[1])) ? $_[0] : $_[1];
+}
+
+sub parse
+# Returns the initial timestamp and tag set
+{
+	my $s = $_[0];
+	my @tokens = split(/\s+/, $s);
+	for my $i (1..3) { pop(@tokens) } # Discard date string
+#	print "parse: ", $_[0], @tokens;
+	return @tokens;
+}
+
+sub parse_timestamp
+# Returns just the initial timestamp from a line
+{
+	my $s = $_[0];
+	my @tokens = split(/\s+/, $s);
+	print "parse_timestamp: ", $tokens[0];
+	return $tokens[0];
+}
+
+open(my $f1, "<", $ARGV[0]) or die;
+open(my $f2, "<", $ARGV[1]) or die;
+open(my $fo, ">", $ARGV[2]) or die;
+
+# Read initial lines from files
+my $l1 = <$f1>;
+my $l2 = <$f2>;
+
+# If one file is present but empty, this will be skipped, and the other file
+# will be copied into the output file by the second loop.
+while (defined $l1 and defined $l2) {
+	my @l1a = &parse($l1);
+	my @l2a = &parse($l2);
+	if (not defined $l1a[0] or not defined $l2a[0])
+	{
+		last; # Spurious blank line
+	}
+	if ($l1a[0] < $l2a[0]) {
+		# f1 has ping not in f2
+		print $fo $l1;
+		$l1 = <$f1>;
+	} elsif ($l1a[0] > $l2a[0]) {
+		# f2 has ping not in f1
+		print $fo $l2;
+		$l2 = <$f2>;
+	} else {
+		# both f1 and f2 have a ping
+		if ($l1 eq $l2) {
+			# Identical. Print one copy and get new data
+			print $fo $l1;
+			$l1 = <$f1>;
+			$l2 = <$f2>;
+		} else {
+			# Different content.
+			if (index($l1, " RETRO ") != -1) {
+				if (index($l2, " RETRO ") != -1) {
+					# Both RETRO - print longer
+					print $fo &longer($l1, $l2);
+				} else {
+					# 1 RETRO, 2 not
+					print $fo $l2;
+				} 
+			} elsif (index($l2, "RETRO") != -1) {
+				# 2 RETRO, 1 not
+				print $fo $l1;
+			} else {
+				 # Both non-RETRO (shouldn't really happen)
+				print $fo &longer($l1, $l2);
+			}
+			# Get new lines from both files
+			$l1 = <$f1>;
+			$l2 = <$f2>;
+		}
+	}
+} 
+
+# One or both of the files is exhausted and its line undefined.
+# Any non-undefined files have unprocessed data in $lx
+if (defined $l1) {
+	do {
+#		print "Extra line in f1. Writing.\n", $l1; 
+		print $fo $l1
+	} while ($l1 = <$f1>);
+} elsif (defined $l2) {
+	do {
+#		print "Extra line in f2. Writing.\n", $l2; 
+		print $fo $l2
+	} while ($l2 = <$f2>);
+}			
+
+exit(0);