diff -r 000000000000 -r 02cd6b52f378 synch_hg_p4/synch_hg_p4.pl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/synch_hg_p4/synch_hg_p4.pl	Thu May 28 10:10:03 2009 +0100
@@ -0,0 +1,677 @@
+#! perl
+
+# sync_hg_p4.pl
+
+use strict;
+use Getopt::Long;
+use File::Temp qw/ tempfile tempdir /;	# for tempfile()
+
+my $verbose;
+my $debug = 0;
+my $rootdir;
+my $help;
+my $remoterepo;
+my $hgbranch;
+my $sync_prefix = "sync_";
+
+# abandon_sync, all ye who enter here
+# This should send a notification to someone, as it will probably mean manual repair
+#
+sub abandon_sync(@)
+	{
+	print "ERROR - synchronisation of $rootdir abandoned\n\n";
+	print @_;
+	print "\n\n";
+	exit(1);
+	}
+	
+# utility to run an external command
+#
+sub run_cmd($;$)
+	{
+	my ($cmd,$failurematch) = @_;
+	print "--- $cmd\n" if ($verbose || $debug);
+	my @output = `$cmd`;
+	print @output,"\n---\n" if ($debug);
+	
+	if (defined $failurematch)
+		{
+		if (grep /$failurematch/, @output)
+			{
+			abandon_sync("COMMAND FAILED: $cmd\n", @output,"\n\n",
+				"Output matched $failurematch\n");
+			}
+		else
+			{
+			print "CMD OK - Didn't match /$failurematch/\n" if ($debug);
+			}
+		}
+	if ($?)
+		{
+		print @output,"\n---\n" if ($verbose);
+		abandon_sync("COMMAND FAILED: exit status = $?\n",$cmd,"\n");
+		}
+	
+	return @output;
+	}
+	
+
+# -------------- hg section -------------
+#
+# Code relating to other SCM system is abstracted into 
+# functions to do relatively simple actions. This section
+# contains the driving logic for the script, and all of the
+# manipulations of Mercurial
+#
+
+sub scm_usage();		# forward declarations
+sub scm_options();
+sub scm_init($@);
+sub scm_checkout($);	# non-destructive, i.e. leave untouched any workspace files not managed in SCM
+sub scm_checkin($$$$$$);
+
+sub Usage(;$)
+	{
+	my ($errmsg) = @_;
+	print "\nERROR: $errmsg\n" if (defined $errmsg);
+	scm_usage();
+	print <<'EOF';
+
+General options:
+
+-root rootdir       root of the Mercurial gateway repository
+-v                  verbose
+-h                  print this usage information
+
+Setting up a new synchronisation:
+
+-clone remoterepo   clones gateway from remote repository 
+-branch hgbranch    Mercurial branch name (if needed)
+
+EOF
+	exit 1;
+	}
+
+Usage() if !GetOptions(
+	'root=s' => \$rootdir,
+	'h' => \$help,
+	'v' => \$verbose,
+	'debug' => \$debug,
+	'clone=s' => \$remoterepo,
+	'branch=s' => \$hgbranch,
+	scm_options()
+	);
+
+Usage() if ($help);
+
+Usage("Must specify root directory for Mercurial gateway") if (!defined $rootdir);
+Usage("-branch is only used with -clone") if (defined $hgbranch && !defined $remoterepo);
+
+if ($verbose)
+	{
+	my @hgversion = run_cmd("hg --version");
+	print @hgversion;
+	}
+
+# utility to return the heads descended from a particular point
+#
+sub hg_heads($)
+	{
+	my ($rev_on_branch) = @_;
+	my @heads = run_cmd("hg heads --template {rev}\\t{tags}\\n $rev_on_branch");
+	return @heads;
+	}
+
+# return an unsorted list of synchronisation points, identified by
+# tags beginning with "sync_"
+# 
+sub hg_syncpoints(;$)
+	{
+	my ($tip_rev) = @_;
+	my @tags = run_cmd("hg tags");
+	my @syncpoints;
+	foreach my $tag (@tags)
+		{
+		if ($tag =~ /^tip\s+(\d+):\S+$/)
+			{
+			$$tip_rev = $1 if (defined $tip_rev);
+			next;
+			}
+		if ($tag =~ /^$sync_prefix(.*\S)\s+\S+$/)
+			{
+			push @syncpoints, $1;
+			next
+			}
+		}
+	if ($debug)
+		{
+		printf "Found %d syncpoints in %d tags:", scalar @syncpoints, scalar @tags;
+		print join("\n * ", "",@syncpoints), "\n";
+		}
+	return @syncpoints;
+	}
+
+my $hg_updated = 0;
+
+# Update the Mercurial workspace to a given sync point
+#
+sub hg_checkout($)
+	{
+	my ($scmref) = @_;
+	
+	my $tag = $sync_prefix.$scmref;
+	my @output = run_cmd("hg update --clean --rev $tag", "^abort:");
+	$hg_updated = 1;	# could check the output in case it didn't change anything
+	}
+
+# 0. Create the gateway repository, if -clone is specified
+
+if (defined $remoterepo)
+	{
+	Usage("Cannot create gateway because $rootdir already exists") if (-d $rootdir);
+
+	my $clonecmd = "clone";
+	$clonecmd .= " --rev $hgbranch" if (defined $hgbranch);
+	my @output = run_cmd("hg $clonecmd $remoterepo $rootdir");
+	$hg_updated = 1;
+	}
+
+chdir $rootdir;
+Usage("$rootdir is not a Mercurial repository") if (!-d ".hg");
+
+my $something_to_push = 0;
+
+# 1. Prime the SCM system, and get the ordered list of changes available to 
+# convert into Mercurial commits
+
+my $first_sync;		# is this the first synchronisation?
+my $scm_tip_only;	# can we process a series of changes in the SCM system?
+
+my $tip_rev = -1;
+my @syncpoints = hg_syncpoints(\$tip_rev);
+
+if (scalar @syncpoints != 0)
+	{
+	$first_sync = 0;	# no - it's already synchronised
+	$scm_tip_only = 0;	# so can allow sequence of SCM changes
+	}
+else
+	{
+	print "First synchronisation through this gateway\n" if ($verbose);
+ 	$first_sync = 1;
+	if ($tip_rev != -1)
+		{
+ 		$scm_tip_only = 1;	# because there's already something in the repository
+ 		}
+ 	else
+ 		{
+		print "Mercurial repository is empty\n" if ($verbose);
+		$scm_tip_only = 0;	# allow multiple SCM changes, because there's nothing to merge with
+		}
+	}
+
+my $opening_scmtag;	# ancestor by which we judge the headcount of the result
+my $latest_scmtag;
+
+my @scmrefs = scm_init($scm_tip_only, @syncpoints);
+
+if (scalar @scmrefs == 0)
+	{
+	print "No changes to process in local SCM\n";
+	$opening_scmtag = $tip_rev;
+	}
+else
+	{
+	$opening_scmtag = $sync_prefix.$scmrefs[0];
+	}
+$latest_scmtag = $opening_scmtag;
+
+if ($scm_tip_only && scalar @scmrefs > 1)
+	{
+	print "ERROR - cannot handle multiple SCM changes in this situation\n";
+	exit(1);
+	}
+
+# 2. Process the SCM changes, turning them into Mercurial commits and marking with tags
+# - we guarantee that there is at most one change, if this is the first synchronisation
+
+foreach my $scmref (@scmrefs)
+	{
+	my ($user,$date,@description) = scm_checkout($scmref);
+	
+	# commit the result
+
+	my ($fh,$filename) = tempfile();
+	print $fh join("\n",@description), "\n";
+	close $fh;
+	
+	run_cmd("hg commit --addremove --date \"$date\" --user \"$user\" --logfile  $filename", "^abort\:");
+	$something_to_push = 1;
+	
+	unlink($filename);	# remove temporary file
+
+	my $tag = $sync_prefix.$scmref;
+	run_cmd("hg tag --local $tag");
+	$latest_scmtag = $tag;
+	print "Synchronised $scmref into Mercurial gateway repository\n";
+	}
+
+# 3. Put the full Mercurial state into the SCM, if this is the first synchronisation
+
+if ($first_sync)
+	{
+	my @traceback = run_cmd("hg log --limit 1 --template {rev}\\t{node}\\t{tags}\\n");
+	my $line = shift @traceback;
+
+	chomp $line;
+	my ($rev,$node,$tags) = split /\t/,$line;
+	
+	if ($rev != 0)
+		{
+		# repository was not empty, so need to commit the current state back into Perforce
+	
+		my @description = run_cmd("hg log --rev $rev --template \"{author}\\n{date|isodate}\\n{desc}\"");
+		chomp @description;
+		my $author = shift @description;
+		my $date = shift @description;
+		my @changes = run_cmd("hg status --clean");	# include info on unmodified files
+		@changes = sort @changes;
+
+		# Deliver changes to SCM
+		my $scmref = scm_checkin($node,$author,$date,\@changes,\@description,$tags);
+		
+		my $tag = $sync_prefix.$scmref;
+		run_cmd("hg tag --local $tag");
+		$latest_scmtag = $tag;
+		print "Synchronised $scmref from Mercurial gateway, to initialise the synchronisation\n";
+		}
+	
+	$opening_scmtag = $latest_scmtag;	# don't consider history before this point
+	}
+
+
+# 3. pull from Mercurial default path, deal with new stuff
+
+my @pull_output = run_cmd("hg pull --update");
+$hg_updated = 1;
+
+my @heads = hg_heads($opening_scmtag);
+
+if (scalar @heads > 1)
+	{
+	# more than one head - try a safe merge
+	print "WARNING: multiple heads\n",@heads,"\nMerge is needed\n\n\n" if ($verbose);
+	
+	my @merge_output = run_cmd("hg --config \"ui.merge=internal:fail\" merge");	# which head?
+	if ($merge_output[0] =~ / 0 files unresolved/)
+		{
+		# successful merge - commit it.
+		run_cmd("hg commit --message \"Automatic merge\"");
+		$something_to_push = 1;
+		}
+	else
+		{
+		# clean up any partially merged files
+		run_cmd("hg update -C");
+		}
+	}
+
+# 4. Identify the sequence of Mercurial changes on the trunk and put them into the SCM
+# - Do only the head revision if this is the first synchronisation, to avoid copying ancient history
+
+my $options = "--follow-first";
+$options .= " --prune $latest_scmtag";
+
+my @traceback = run_cmd("hg log $options --template {rev}\\t{node}\\t{tags}\\n");
+foreach my $line (reverse @traceback)
+	{
+	chomp $line;
+	my ($rev,$node,$tags) = split /\t/,$line;
+	if ($tags =~ /$sync_prefix/)
+		{
+		# shouldn't happen - it would mean that tip goes back to an ancestor
+		# of the latest sync point
+		abandon_sync("Cannot handle this structure\n",@traceback);
+		}
+	
+	# Read commit information and update workspace from Mercurial
+	
+	my @description = run_cmd("hg log --rev $rev --template \"{author}\\n{date|isodate}\\n{desc}\"");
+	chomp @description;
+	my $author = shift @description;
+	my $date = shift @description;
+	my @changes = run_cmd("hg status --rev $latest_scmtag --rev $rev");
+	@changes = sort @changes;
+
+	run_cmd("hg update -C --rev $rev");
+	$hg_updated = 1;
+	
+	# Deliver changes to SCM
+	my $scmref = scm_checkin($node,$author,$date,\@changes,\@description,$tags);
+	
+	# Tag as the latest sync point
+	my $tag = $sync_prefix.$scmref;
+	run_cmd("hg tag --local $tag");
+	$latest_scmtag = $tag;
+	print "Synchronised $scmref from Mercurial gateway\n";
+	}
+
+# 3. push changes to the destination gateway
+
+if ($something_to_push)
+	{
+	my @output = run_cmd("hg -v push --force --rev $latest_scmtag");
+	print "\n",@output,"\n" if ($verbose);
+	print "Destination Mercurial repository has been updated\n"; 
+	}
+else
+	{
+	print "Nothing to push to destination Mercurial repository\n";
+	}
+
+# 4. Check to see if we are in a clean state
+
+@heads = hg_heads($opening_scmtag);
+if (scalar @heads > 1)
+	{
+	print "\n------------------\n";
+	print "WARNING: Mercurial repository has multiple heads - manual merge recommended\n";
+	}
+
+exit(0);
+
+
+# -------------- SCM section -------------
+#
+# Code relating to non-Mercurial SCM system.
+# This version implements the sync with Perforce
+#
+
+sub scm_usage()
+	{
+	print <<'EOF';
+
+perl sync_hg_p4.pl -root rootdir [options]
+version 0.7
+ 
+Synchronise a branch in Perforce with a branch in Mercurial.
+
+The branch starts at rootdir, which is a local Mercurial repository.
+The Perforce clientspec is assumed to exist, to specify modtime & rmdir, 
+and to exclude the .hg directory from the rootdir.
+
+The tool will sync rootdir/... to the specified changelist, and
+then reflect all changes affecting this part of the directory tree into
+Mercurial.
+
+The -first option is used to specify the first sync point if the gateway
+has not been previously synchronised, e.g. when -clone is specified.
+
+Perforce-related options:
+
+-m maxchangelist    highest changelist to consider
+                    defaults to #head
+
+EOF
+	}
+
+my $max_changelist;
+
+sub scm_options()
+	{
+	# set defaults
+	
+	$max_changelist = "#head";
+	
+	# return the GetOpt specification
+	return (
+		'm|max=s' => \$max_changelist,
+		);
+	}
+
+sub p4_sync($)
+	{
+	my ($changelist)= @_;
+	
+	my $sync = $hg_updated? "sync -k":"sync";
+	my @sync_output = run_cmd("p4 $sync ...\@$changelist 2>&1");
+
+	$hg_updated = 0;	# avoid doing sync -f next time, if possible
+	return @sync_output;
+	}
+
+sub scm_init($@)
+	{
+	my ($tip_only, @syncpoints) = @_;
+	
+	my $first_changelist;
+	
+	# decide on the range of changelists to process
+	
+	if ($tip_only)
+		{
+		# Script says we must synchronise from the Perforce tip revision
+		my @changes = run_cmd("p4 changes -m2 ...");
+		foreach my $change (@changes)
+			{
+			if ($change =~ /^(Change (\d+) on (\S+) by (\S+)@\S+) /)
+				{
+				$first_changelist = $2;
+				last;
+				}
+			}
+		if (!defined $first_changelist)
+			{
+			print "Perforce branch contains no changes\n";
+			return ();
+			}
+		print "Synchronisation from tip ($first_changelist)\n" if ($verbose);
+		$max_changelist = "#head";
+		}
+	else
+		{
+		# deduce the last synchronisation point from the tags
+		@syncpoints = sort {$b <=> $a} @syncpoints;
+		$first_changelist = shift @syncpoints;
+		printf "%d changes previously synchronised, most recent is %s\n", 
+				1+scalar @syncpoints, $first_changelist;
+		
+		# Get Mercurial & Perforce into the synchronised state
+		run_cmd("p4 revert ... 2>&1");
+		hg_checkout($first_changelist);
+		p4_sync($first_changelist);
+		$first_changelist += 1;		# we've already synched that one
+		}
+	
+	# enumerate the changelists
+
+	my @changes = run_cmd("p4 changes ...\@$first_changelist,$max_changelist");
+
+	my @scmrefs;
+	foreach my $change (reverse @changes)
+		{
+		# Change 297463 on 2003/09/24 by ErnestoG@LON-ERNESTOG02 'Initial MRP files for Component
+		if ($change =~ /^(Change (\d+) on (\S+) by (\S+)@\S+) /)
+			{
+			my $scmref = $2;
+			push @scmrefs, $2;
+			}
+		}
+
+	if ($debug && scalar @scmrefs > 3)
+		{
+		print "DEBUG - Processing only the first 3 SCM changes\n";
+		@scmrefs = ($scmrefs[0],$scmrefs[1],$scmrefs[2]);
+		}
+
+	if ($verbose)
+		{
+		printf "Found %d new changelists to process (range %d to %s)\n",
+			scalar @scmrefs, $first_changelist, $max_changelist;
+		print join(", ", @scmrefs), "\n";
+		}
+	
+	return @scmrefs;
+	}
+
+# scm_checkout
+# Update the workspace to reflect the given SCM reference
+#
+sub scm_checkout($)
+	{
+	my ($scmref) = @_;
+	
+	my @changelist = run_cmd("p4 describe -s $scmref 2>&1", "$scmref - no such changelist");
+	
+	my @change_description;
+	my $change_date;
+	my $change_user;
+	
+	my $change_summary = shift @changelist;
+	if ($change_summary =~ /^Change (\d+) by (\S+)@\S+ on (\S+ \S+)/)
+		{
+		$change_user = $2;
+		$change_date = $3;
+		}
+	else
+		{
+		print "Failed to parse change summary => $change_summary\n";
+		exit(1);
+		}
+	
+	# Extract the descriptive part of the change description, watching for
+	# the Symbian XML format enforced by the submission checker
+	#
+	my $symbian_format = 0;
+	foreach my $line (@changelist)
+		{
+		last if ($line =~ /^(Affected files|Jobs fixed)/);
+
+		$line =~ s/^\t//;	# remove leading tab from description text
+		if ($line =~ /^<EXTERNAL>/)
+			{
+			$symbian_format = 1;
+			@change_description = ();
+			next;
+			}
+		if ($line =~ /^<\/EXTERNAL>/)
+			{
+			$symbian_format = 2;
+			next;
+			}
+		
+		chomp $line;
+		push @change_description, $line if ($symbian_format < 2);
+		
+		# <detail submitter=      "Sangamma VChandangoudar" />
+		if ($line =~ /detail submitter=\s*\"([^\"]+)\"/)	# name in " marks
+			{
+			$change_user = $1;
+			}
+		}
+	
+	$change_date =~ s/\//-/g;	# convert to yyyy-mm-dd hh:mm::ss"
+	
+	p4_sync($scmref);
+	
+	return ($change_user,$change_date,@change_description);
+	}
+
+# scm_checkin
+# Describe the changes to the workspace as an SCM change
+# Return the new SCM reference
+#
+sub scm_checkin($$$$$$)
+	{
+	my ($hgnode,$author,$date,$changes,$description,$tags) = @_;
+	
+	my @hg_tags = grep !/^tip$/, split /\s+/, $tags;
+	my @p4_edit;
+	my @p4_delete;
+	my @p4_add;
+	
+	foreach my $line (@$changes)
+		{
+		my $type = substr($line,0,2,"");	# removes type as well as extracting it
+		if ($type eq "M ")
+			{
+			push @p4_edit, $line;
+			next;
+			}
+		if ($type eq "A " || $type eq "C ")
+			{
+			push @p4_add, $line;
+			next;
+			}		
+		if ($type eq "R ")
+			{
+			push @p4_delete, $line;
+			next;
+			}
+		
+		abandon_sync("Unexpected hg status line: $type$line");
+		}
+	
+	if (scalar @p4_add)
+		{
+		open P4ADD, "|p4 -x - add";
+		print P4ADD @p4_add;
+		close P4ADD;
+		abandon_sync("Perforce error on p4 add: $?\n") if ($?);
+		}
+	
+	if (scalar @p4_edit)
+		{
+		open P4EDIT, "|p4 -x - edit";
+		print P4EDIT @p4_edit;
+		close P4EDIT;
+		abandon_sync("Perforce error on p4 edit: $?\n") if ($?);
+		}
+	if (scalar @p4_delete)
+		{
+		open P4DELETE, "|p4 -x - delete";
+		print P4DELETE @p4_delete;
+		close P4DELETE;
+		abandon_sync("Perforce error on p4 delete: $?\n") if ($?);
+		}
+	
+	my @pending_change = run_cmd("p4 change -o");
+	
+	# Can't do anything with the author or date information?
+	
+	my ($fh,$filename) = tempfile();
+
+	my $hasfiles = 0;
+	foreach my $line (@pending_change)
+		{
+		if ($line =~ /<enter description here>/)
+			{
+			print $fh "\t(Synchronised from Mercurial commit $hgnode: $date $author)";
+			print $fh "\t(Mercurial tags: ", join(", ",$tags),")" if (scalar @hg_tags != 0);
+			print $fh join("\n\t", "", @$description), "\n";
+			next;
+			}
+		$hasfiles = 1 if ($line =~/^Files:/);
+		print $fh $line;
+		}
+	
+	close $fh;
+	
+	abandon_sync("No files in Perforce submission? $filename\n", @pending_change) if (!$hasfiles);
+	
+	my @submission = run_cmd("p4 submit -i < $filename 2>&1");
+	
+	unlink($filename);	# remove temporary file
+	
+	# Change 1419488 renamed change 1419490 and submitted.
+	# Change 1419487 submitted.
+	foreach my $line (reverse @submission)
+		{
+		if ($line =~ /change (\d+)( and)? submitted/i)
+			{
+			return $1;
+			}
+		}
+	
+	abandon_sync("Failed to parse output of p4 submit:\n",@submission);
+	}