X-Git-Url: https://git.draconx.ca/gitweb/mpdhacks.git/blobdiff_plain/8a39a0fd4ed8d545759e07937fa4c66f5d324987..HEAD:/mpdreload.pl

diff --git a/mpdreload.pl b/mpdreload.pl
index c852a2b..8cf010d 100755
--- a/mpdreload.pl
+++ b/mpdreload.pl
@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright © 2019-2020 Nick Bowler
+# Copyright © 2019-2021 Nick Bowler
 #
 # Replace the current MPD play queue with a saved playlist, by rearranging
 # existing queue entries when possible.  This avoids losing the current
@@ -26,11 +26,13 @@ use MPDHacks;
 
 my $sock;
 
-# Returns a hash reference containing all tracks in the current play queue.
-# The hash keys are filenames.
+my $pl_current_length;
+
+# Returns a hash reference mapping filenames to an array reference listing
+# the queue IDs for that file in the current play queue.
 sub get_tracks_in_play_queue {
-	my %matches;
-	my $entry;
+	my (%matches, %idmap, $entry);
+	my $pos = -1;
 
 	MPD::exec("playlistinfo");
 	while (<$sock>) {
@@ -39,23 +41,18 @@ sub get_tracks_in_play_queue {
 
 		if (/^(\w+): (.*)$/) {
 			if ($1 eq "file") {
-				if (exists($matches{$2})) {
-					$entry = $matches{$2};
-				} else {
-					$entry = {};
-					$matches{$2} = $entry;
-				}
-			}
-
-			if (exists($entry->{$1})) {
-				$entry->{$1}->{$2} = 1;
-			} else {
-				$entry->{$1} = { $2 => 1 }
+				$entry = $matches{$2} //= [];
+				$pos++;
+			} elsif ($1 eq "Id") {
+				push @$entry, $2;
+				$idmap{$2} = $pos;
 			}
 		}
 	}
 
-	return \%matches;
+	$pl_current_length = $pos+1;
+
+	return (\%matches, \%idmap);
 }
 
 # Given an MPD playlist name, returns a reference to an array containing
@@ -129,37 +126,78 @@ if (@ARGV != 1) {
 $sock = MPD::connect();
 
 # Retrieve the current play queue and target play queue.
-my $current = get_tracks_in_play_queue();
+MPD::run("tagtypes", "clear");
+my ($current, $idmap) = get_tracks_in_play_queue();
 my $target = get_playlist_files($ARGV[0]);
 
+my $add_start;
+
+sub load_tracks($$) {
+	my ($seq, $dst) = @_;
+	my ($newlen, $count);
+
+	my $start = $add_start // $seq;
+	my $add_position = $pl_current_length;
+	my $end = $seq+1;
+
+	$dst //= $start;
+
+	MPD::exec("load", $ARGV[0], "$start:$end");
+	MPD::exec("status");
+	MPD::exec("command_list_end");
+
+	while (<$sock>) {
+		last if (/^OK/);
+		die($_) if (/^ACK/);
+
+		if (/^(\w+): (.*)$/) {
+			if ($1 eq "playlistlength") {
+				$newlen = int($2);
+			}
+		}
+	}
+
+	$count = $newlen - $pl_current_length;
+
+	MPD::exec("command_list_begin");
+	if ($newlen > $pl_current_length) {
+		MPD::exec("move", "$add_position:$newlen", $dst)
+			if ($add_position != $dst);
+	}
+
+	$pl_current_length = $newlen;
+	undef $add_start;
+
+	return $count;
+}
+
 MPD::exec("command_list_begin");
+my ($num_added, $num_failed) = (0, 0);
 for (my $i = 0; $i < @$target; $i++) {
 	my $f = $target->[$i];
-	my $ids = $current->{$f}->{Id};
+	my $id = shift @{ $current->{$f} };
 
-	my $id = (keys %$ids)[0];
-	delete $ids->{$id};
+	if (defined $id and defined $add_start) {
+		my $n = $i - $add_start;
+		my $m = load_tracks($i-1, $add_start - $num_failed);
 
-	# Remove tracks with no unused queue IDs
-	delete $current->{$f} unless (keys %$ids > 0);
+		$num_added += $m;
+		$num_failed += $n - $m;
+	}
 
 	if (defined $id) {
-		MPD::exec("moveid", $id, $i);
+		# Try not to move tracks already in the right place.
+		MPD::exec("moveid", $id, $i - $num_failed)
+			if ($i - $num_failed != $idmap->{$id} + $num_added);
 	} else {
-		MPD::exec("addid", $f, $i);
+		$add_start //= $i;
 	}
 }
 
-# Remove any tracks left from the old play queue.
-foreach (keys %$current) {
-	my $ids = $current->{$_}->{Id};
-	foreach (keys %$ids) {
-		MPD::exec("deleteid", $_);
-	}
-}
+# Now all unwanted tracks from the original playqueue have been moved to the
+# end and can be deleted all at once.
 
-MPD::exec("command_list_end");
-while (<$sock>) {
-	last if /^OK$/;
-	die($_) if /^ACK/;
-}
+my $pos = ($add_start // @$target) - $num_failed;
+MPD::exec("delete", $pos . ":") if map { @$_ } values %$current;
+MPD::exec("load", $ARGV[0], "$add_start:") if defined $add_start;
+MPD::run("command_list_end");