playlist: moved code to queue.c

Attempt to untie the playlist.c knot: moved the playlist storage code
to queue.c, struct queue.

1 files changed, 267 insertions, 0 deletions

diff --git a/src/queue.c b/src/queue.c
new file mode 100644
index 000000000..97379b68a
--- /dev/null
+++ b/src/queue.c
@@ -0,0 +1,267 @@
+/*
+ * Copyright (C) 2003-2009 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "queue.h"
+#include "song.h"
+
+unsigned
+queue_generate_id(const struct queue *queue)
+{
+	static unsigned cur = (unsigned)-1;
+
+	do {
+		cur++;
+
+		if (cur >= queue->max_length * QUEUE_HASH_MULT)
+			cur = 0;
+	} while (queue->idToPosition[cur] != -1);
+
+	return cur;
+}
+
+int
+queue_next_order(const struct queue *queue, unsigned order)
+{
+	assert(order < queue->length);
+
+	if (order + 1 < queue->length)
+		return order + 1;
+	else if (queue->repeat)
+		/* restart at first song */
+		return 0;
+	else
+		/* end of queue */
+		return -1;
+}
+
+void
+queue_increment_version(struct queue *queue)
+{
+	static unsigned long max = ((uint32_t) 1 << 31) - 1;
+
+	queue->version++;
+
+	if (queue->version >= max) {
+		for (unsigned i = 0; i < queue->length; i++)
+			queue->songMod[i] = 0;
+
+		queue->version = 1;
+	}
+}
+
+void
+queue_modify(struct queue *queue, unsigned order)
+{
+	unsigned position;
+
+	assert(order < queue->length);
+
+	position = queue->order[order];
+	queue->songMod[position] = queue->version;
+
+	queue_increment_version(queue);
+}
+
+void
+queue_modify_all(struct queue *queue)
+{
+	for (unsigned i = 0; i < queue->length; i++)
+		queue->songMod[i] = queue->version;
+
+	queue_increment_version(queue);
+}
+
+unsigned
+queue_append(struct queue *queue, struct song *song)
+{
+	unsigned id = queue_generate_id(queue);
+
+	assert(!queue_is_full(queue));
+
+	queue->songs[queue->length] = song;
+	queue->songMod[queue->length] = queue->version;
+	queue->order[queue->length] = queue->length;
+	queue->positionToId[queue->length] = id;
+	queue->idToPosition[queue->positionToId[queue->length]] =
+	    queue->length;
+
+	++queue->length;
+
+	return id;
+}
+
+void
+queue_swap(struct queue *queue, unsigned position1, unsigned position2)
+{
+	struct song *sTemp;
+	unsigned iTemp;
+
+	sTemp = queue->songs[position1];
+	queue->songs[position1] = queue->songs[position2];
+	queue->songs[position2] = sTemp;
+
+	queue->songMod[position1] = queue->version;
+	queue->songMod[position2] = queue->version;
+
+	queue->idToPosition[queue->positionToId[position1]] = position2;
+	queue->idToPosition[queue->positionToId[position2]] = position1;
+
+	iTemp = queue->positionToId[position1];
+	queue->positionToId[position1] = queue->positionToId[position2];
+	queue->positionToId[position2] = iTemp;
+}
+
+static void
+queue_move_song_to(struct queue *queue, unsigned from, unsigned to)
+{
+	unsigned from_id = queue->positionToId[from];
+
+	queue->idToPosition[from_id] = to;
+	queue->positionToId[to] = from_id;
+	queue->songs[to] = queue->songs[from];
+	queue->songMod[to] = queue->version;
+}
+
+void
+queue_move(struct queue *queue, unsigned from, unsigned to)
+{
+	struct song *song;
+	unsigned id;
+
+	song = queue_get(queue, from);
+	id = queue_position_to_id(queue, from);
+
+	/* move songs to one less in from->to */
+
+	for (unsigned i = from; i < to; i++)
+		queue_move_song_to(queue, i + 1, i);
+
+	/* move songs to one more in to->from */
+
+	for (unsigned i = from; i > to; i--)
+		queue_move_song_to(queue, i - 1, i);
+
+	/* put song at _to_ */
+
+	queue->idToPosition[id] = to;
+	queue->positionToId[to] = id;
+	queue->songs[to] = song;
+	queue->songMod[to] = queue->version;
+}
+
+void
+queue_delete(struct queue *queue, unsigned position)
+{
+	struct song *song;
+	unsigned id, order;
+
+	assert(position < queue->length);
+
+	song = queue_get(queue, position);
+	if (!song_in_database(song))
+		song_free(song);
+
+	id = queue_position_to_id(queue, position);
+	order = queue_position_to_order(queue, position);
+
+	--queue->length;
+
+	/* release the song id */
+
+	queue->idToPosition[id] = -1;
+
+	/* delete song from songs array */
+
+	for (unsigned i = position; i < queue->length; i++)
+		queue_move_song_to(queue, i + 1, i);
+
+	/* delete the entry from the order array */
+
+	for (unsigned i = order; i < queue->length; i++)
+		queue->order[i] = queue->order[i + 1];
+
+	/* readjust values in the order array */
+
+	for (unsigned i = 0; i < queue->length; i++)
+		if (queue->order[i] > position)
+			--queue->order[i];
+}
+
+void
+queue_clear(struct queue *queue)
+{
+	for (unsigned i = 0; i < queue->length; i++) {
+		if (!song_in_database(queue->songs[i]))
+			song_free(queue->songs[i]);
+
+		queue->idToPosition[queue->positionToId[i]] = -1;
+	}
+
+	queue->length = 0;
+}
+
+void
+queue_init(struct queue *queue, unsigned max_length)
+{
+	queue->max_length = max_length;
+	queue->length = 0;
+	queue->version = 1;
+	queue->repeat = false;
+	queue->random = false;
+
+	queue->songs = g_malloc(sizeof(queue->songs[0]) * max_length);
+	queue->songMod = g_malloc(sizeof(queue->songMod[0]) *
+				    max_length);
+	queue->order = g_malloc(sizeof(queue->order[0]) *
+				  max_length);
+	queue->idToPosition = g_malloc(sizeof(queue->idToPosition[0]) *
+				       max_length * QUEUE_HASH_MULT);
+	queue->positionToId = g_malloc(sizeof(queue->positionToId[0]) *
+				       max_length);
+
+	for (unsigned i = 0; i < max_length * QUEUE_HASH_MULT; ++i)
+		queue->idToPosition[i] = -1;
+
+	queue->rand = g_rand_new();
+}
+
+void
+queue_finish(struct queue *queue)
+{
+	queue_clear(queue);
+
+	g_free(queue->songs);
+	g_free(queue->songMod);
+	g_free(queue->order);
+	g_free(queue->idToPosition);
+	g_free(queue->positionToId);
+
+	g_rand_free(queue->rand);
+}
+
+void
+queue_shuffle_range(struct queue *queue, unsigned start, unsigned end)
+{
+	assert(start <= end);
+	assert(end <= queue->length);
+
+	for (unsigned i = start; i < end; i++) {
+		unsigned ri = g_rand_int_range(queue->rand, i, end);
+		queue_swap(queue, i, ri);
+	}
+}