aboutsummaryrefslogtreecommitdiffstats
path: root/src
diff options
context:
space:
mode:
authorMax Kellermann <max@duempel.org>2009-01-22 23:40:11 +0100
committerMax Kellermann <max@duempel.org>2009-01-22 23:40:11 +0100
commitf78cddb407dbd8c3f5a1860ca5052d6a5984b734 (patch)
treef859388102e3fabea31ae5c3567fb04b5188d7f4 /src
parentd5dcd0ed668781b311375715f761f67c07442291 (diff)
downloadmpd-f78cddb407dbd8c3f5a1860ca5052d6a5984b734.tar.gz
mpd-f78cddb407dbd8c3f5a1860ca5052d6a5984b734.tar.xz
mpd-f78cddb407dbd8c3f5a1860ca5052d6a5984b734.zip
playlist: moved code to queue.c
Attempt to untie the playlist.c knot: moved the playlist storage code to queue.c, struct queue.
Diffstat (limited to '')
-rw-r--r--src/Makefile.am2
-rw-r--r--src/playlist.c538
-rw-r--r--src/playlist.h13
-rw-r--r--src/queue.c267
-rw-r--r--src/queue.h314
5 files changed, 777 insertions, 357 deletions
diff --git a/src/Makefile.am b/src/Makefile.am
index b1ebe1320..704e2a6a0 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -92,6 +92,7 @@ mpd_headers = \
player_control.h \
playlist.h \
playlist_save.h \
+ queue.h \
replay_gain.h \
sig_handlers.h \
song.h \
@@ -175,6 +176,7 @@ mpd_SOURCES = \
player_control.c \
playlist.c \
playlist_save.c \
+ queue.c \
replay_gain.c \
sig_handlers.c \
song.c \
diff --git a/src/playlist.c b/src/playlist.c
index fbb959fed..fd46d0fa9 100644
--- a/src/playlist.c
+++ b/src/playlist.c
@@ -78,30 +78,20 @@ static int playlist_noGoToNext;
bool playlist_saveAbsolutePaths = DEFAULT_PLAYLIST_SAVE_ABSOLUTE_PATHS;
-static void swapOrder(int a, int b);
static void playPlaylistOrderNumber(int orderNum);
static void randomizeOrder(int start, int end);
static void incrPlaylistVersion(void)
{
- static unsigned long max = ((uint32_t) 1 << 31) - 1;
- playlist.version++;
- if (playlist.version >= max) {
- for (unsigned i = 0; i < playlist.length; i++)
- playlist.songMod[i] = 0;
-
- playlist.version = 1;
- }
+ queue_increment_version(&playlist.queue);
idle_add(IDLE_PLAYLIST);
}
void playlistVersionChange(void)
{
- for (unsigned i = 0; i < playlist.length; i++)
- playlist.songMod[i] = playlist.version;
-
- incrPlaylistVersion();
+ queue_modify_all(&playlist.queue);
+ idle_add(IDLE_PLAYLIST);
}
static void incrPlaylistCurrent(void)
@@ -109,98 +99,42 @@ static void incrPlaylistCurrent(void)
if (playlist.current < 0)
return;
- if (playlist.current >= (int)playlist.length - 1) {
- if (playlist.repeat)
- playlist.current = 0;
- else
- playlist.current = -1;
- } else
- playlist.current++;
+ playlist.current = queue_next_order(&playlist.queue, playlist.current);
}
static void
playlist_tag_event(void)
{
- unsigned song;
-
if (playlist_state != PLAYLIST_STATE_PLAY ||
playlist.current < 0)
return;
- assert((unsigned)playlist.current < playlist.length);
-
- song = playlist.order[playlist.current];
- playlist.songMod[song] = playlist.version;
- incrPlaylistVersion();
+ queue_modify(&playlist.queue, playlist.current);
+ idle_add(IDLE_PLAYLIST);
}
void initPlaylist(void)
{
g_rand = g_rand_new();
- playlist.length = 0;
- playlist.repeat = false;
- playlist.version = 1;
- playlist.random = false;
- playlist.queued = -1;
- playlist.current = -1;
-
playlist_max_length = config_get_positive(CONF_MAX_PLAYLIST_LENGTH,
DEFAULT_PLAYLIST_MAX_LENGTH);
+ queue_init(&playlist.queue, playlist_max_length);
+
+ playlist.queued = -1;
+ playlist.current = -1;
+
playlist_saveAbsolutePaths =
config_get_bool(CONF_SAVE_ABSOLUTE_PATHS,
DEFAULT_PLAYLIST_SAVE_ABSOLUTE_PATHS);
- playlist.songs = g_malloc(sizeof(playlist.songs[0]) *
- playlist_max_length);
- playlist.songMod = g_malloc(sizeof(playlist.songMod[0]) *
- playlist_max_length);
- playlist.order = g_malloc(sizeof(playlist.order[0]) *
- playlist_max_length);
- playlist.idToPosition = g_malloc(sizeof(playlist.idToPosition[0]) *
- playlist_max_length *
- PLAYLIST_HASH_MULT);
- playlist.positionToId = g_malloc(sizeof(playlist.positionToId[0]) *
- playlist_max_length);
-
- memset(playlist.songs, 0, sizeof(char *) * playlist_max_length);
-
- for (unsigned i = 0; i < playlist_max_length * PLAYLIST_HASH_MULT;
- i++) {
- playlist.idToPosition[i] = -1;
- }
-
event_pipe_register(PIPE_EVENT_TAG, playlist_tag_event);
}
-static unsigned getNextId(void)
-{
- static unsigned cur = (unsigned)-1;
-
- do {
- cur++;
- if (cur >= playlist_max_length * PLAYLIST_HASH_MULT) {
- cur = 0;
- }
- } while (playlist.idToPosition[cur] != -1);
-
- return cur;
-}
-
void finishPlaylist(void)
{
- for (unsigned i = 0; i < playlist.length; i++)
- if (!song_in_database(playlist.songs[i]))
- song_free(playlist.songs[i]);
-
- playlist.length = 0;
-
- g_free(playlist.songs);
- g_free(playlist.songMod);
- g_free(playlist.order);
- g_free(playlist.idToPosition);
- g_free(playlist.positionToId);
+ queue_finish(&playlist.queue);
g_rand_free(g_rand);
g_rand = NULL;
@@ -210,16 +144,14 @@ void clearPlaylist(void)
{
stopPlaylist();
- for (unsigned i = 0; i < playlist.length; i++) {
- if (!song_in_database(playlist.songs[i])) {
- pc_song_deleted(playlist.songs[i]);
- song_free(playlist.songs[i]);
- }
-
- playlist.idToPosition[playlist.positionToId[i]] = -1;
- playlist.songs[i] = NULL;
+ for (unsigned i = 0; i < queue_length(&playlist.queue); i++) {
+ const struct song *song = queue_get(&playlist.queue, i);
+ if (!song_in_database(song))
+ pc_song_deleted(song);
}
- playlist.length = 0;
+
+ queue_clear(&playlist.queue);
+
playlist.current = -1;
incrPlaylistVersion();
@@ -227,8 +159,9 @@ void clearPlaylist(void)
void showPlaylist(struct client *client)
{
- for (unsigned i = 0; i < playlist.length; i++) {
- char *uri = song_get_uri(playlist.songs[i]);
+ for (unsigned i = 0; i < queue_length(&playlist.queue); i++) {
+ const struct song *song = queue_get(&playlist.queue, i);
+ char *uri = song_get_uri(song);
client_printf(client, "%i:%s\n", i, uri);
g_free(uri);
}
@@ -236,8 +169,9 @@ void showPlaylist(struct client *client)
static void playlist_save(FILE *fp)
{
- for (unsigned i = 0; i < playlist.length; i++) {
- char *uri = song_get_uri(playlist.songs[i]);
+ for (unsigned i = 0; i < queue_length(&playlist.queue); i++) {
+ const struct song *song = queue_get(&playlist.queue, i);
+ char *uri = song_get_uri(song);
fprintf(fp, "%i:%s\n", i, uri);
g_free(uri);
}
@@ -256,7 +190,8 @@ void savePlaylistState(FILE *fp)
fprintf(fp, "%s\n", PLAYLIST_STATE_FILE_STATE_PLAY);
}
fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_CURRENT,
- playlist.order[playlist.current]);
+ queue_order_to_position(&playlist.queue,
+ playlist.current));
fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_TIME,
getPlayerElapsedTime());
break;
@@ -264,8 +199,10 @@ void savePlaylistState(FILE *fp)
fprintf(fp, "%s\n", PLAYLIST_STATE_FILE_STATE_STOP);
break;
}
- fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_RANDOM, playlist.random);
- fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_REPEAT, playlist.repeat);
+ fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_RANDOM,
+ playlist.queue.random);
+ fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_REPEAT,
+ playlist.queue.repeat);
fprintf(fp, "%s%i\n", PLAYLIST_STATE_FILE_CROSSFADE,
(int)(getPlayerCrossFade()));
fprintf(fp, "%s\n", PLAYLIST_STATE_FILE_PLAYLIST_BEGIN);
@@ -302,13 +239,13 @@ static void loadPlaylistFromStateFile(FILE *fp, char *buffer,
if (addToPlaylist(temp, NULL) == PLAYLIST_RESULT_SUCCESS
&& current == song) {
if (state != PLAYER_STATE_STOP) {
- playPlaylist(playlist.length - 1, 0);
+ playPlaylist(queue_length(&playlist.queue) - 1, 0);
}
if (state == PLAYER_STATE_PAUSE) {
playerPause();
}
if (state != PLAYER_STATE_STOP) {
- seekSongInPlaylist(playlist.length - 1,
+ seekSongInPlaylist(queue_length(&playlist.queue) - 1,
seek_time);
}
}
@@ -384,19 +321,16 @@ void readPlaylistState(FILE *fp)
static void printPlaylistSongInfo(struct client *client, unsigned song)
{
- song_print_info(client, playlist.songs[song]);
+ song_print_info(client, queue_get(&playlist.queue, song));
client_printf(client, "Pos: %u\nId: %u\n",
- song, playlist.positionToId[song]);
+ song, queue_position_to_id(&playlist.queue, song));
}
int playlistChanges(struct client *client, uint32_t version)
{
- for (unsigned i = 0; i < playlist.length; i++) {
- if (version > playlist.version ||
- playlist.songMod[i] >= version ||
- playlist.songMod[i] == 0) {
+ for (unsigned i = 0; i < queue_length(&playlist.queue); i++) {
+ if (queue_song_newer(&playlist.queue, i, version))
printPlaylistSongInfo(client, i);
- }
}
return 0;
@@ -404,13 +338,10 @@ int playlistChanges(struct client *client, uint32_t version)
int playlistChangesPosId(struct client *client, uint32_t version)
{
- for (unsigned i = 0; i < playlist.length; i++) {
- if (version > playlist.version ||
- playlist.songMod[i] >= version ||
- playlist.songMod[i] == 0) {
+ for (unsigned i = 0; i < queue_length(&playlist.queue); i++) {
+ if (queue_song_newer(&playlist.queue, i, version))
client_printf(client, "cpos: %i\nId: %i\n",
- i, playlist.positionToId[i]);
- }
+ i, queue_position_to_id(&playlist.queue, i));
}
return 0;
@@ -419,8 +350,8 @@ int playlistChangesPosId(struct client *client, uint32_t version)
enum playlist_result
playlistInfo(struct client *client, unsigned start, unsigned end)
{
- if (end > playlist.length)
- end = playlist.length;
+ if (end > queue_length(&playlist.queue))
+ end = queue_length(&playlist.queue);
if (start > end)
return PLAYLIST_RESULT_BAD_RANGE;
@@ -433,19 +364,13 @@ playlistInfo(struct client *client, unsigned start, unsigned end)
static int song_id_to_position(unsigned id)
{
- if (id >= PLAYLIST_HASH_MULT*playlist_max_length)
- return -1;
-
- assert(playlist.idToPosition[id] >= -1);
- assert(playlist.idToPosition[id] < (int)playlist.length);
-
- return playlist.idToPosition[id];
+ return queue_id_to_position(&playlist.queue, id);
}
enum playlist_result playlistId(struct client *client, int id)
{
int begin = 0;
- unsigned end = playlist.length;
+ unsigned end = queue_length(&playlist.queue);
if (id >= 0) {
begin = song_id_to_position(id);
@@ -463,51 +388,40 @@ enum playlist_result playlistId(struct client *client, int id)
static void swapSongs(unsigned song1, unsigned song2)
{
- struct song *sTemp;
- unsigned iTemp;
-
- sTemp = playlist.songs[song1];
- playlist.songs[song1] = playlist.songs[song2];
- playlist.songs[song2] = sTemp;
-
- playlist.songMod[song1] = playlist.version;
- playlist.songMod[song2] = playlist.version;
-
- playlist.idToPosition[playlist.positionToId[song1]] = song2;
- playlist.idToPosition[playlist.positionToId[song2]] = song1;
-
- iTemp = playlist.positionToId[song1];
- playlist.positionToId[song1] = playlist.positionToId[song2];
- playlist.positionToId[song2] = iTemp;
+ queue_swap(&playlist.queue, song1, song2);
}
static void queueNextSongInPlaylist(void)
{
- if (playlist.current < (int)playlist.length - 1) {
+ if (playlist.current + 1 < (int)queue_length(&playlist.queue)) {
+ struct song *song;
char *uri;
playlist.queued = playlist.current + 1;
- uri = song_get_uri(playlist. songs[playlist.order[playlist.queued]]);
+ song = queue_get_order(&playlist.queue, playlist.queued);
+ uri = song_get_uri(song);
g_debug("playlist: queue song %i:\"%s\"",
playlist.queued, uri);
g_free(uri);
- queueSong(playlist.songs[playlist.order[playlist.queued]]);
- } else if (playlist.length && playlist.repeat) {
+ queueSong(song);
+ } else if (!queue_is_empty(&playlist.queue) && playlist.queue.repeat) {
+ struct song *song;
char *uri;
- if (playlist.length > 1 && playlist.random) {
- randomizeOrder(0, playlist.length - 1);
- }
+ if (queue_length(&playlist.queue) > 1 && playlist.queue.random)
+ randomizeOrder(0, queue_length(&playlist.queue) - 1);
+
playlist.queued = 0;
- uri = song_get_uri(playlist. songs[playlist.order[playlist.queued]]);
+ song = queue_get_order(&playlist.queue, playlist.queued);
+ uri = song_get_uri(song);
g_debug("playlist: queue song %i:\"%s\"",
playlist.queued, uri);
g_free(uri);
- queueSong(playlist.songs[playlist.order[playlist.queued]]);
+ queueSong(song);
}
}
@@ -591,34 +505,27 @@ addSongToPlaylist(struct song *song, unsigned *added_id)
{
unsigned id;
- if (playlist.length == playlist_max_length)
+ if (queue_is_full(&playlist.queue))
return PLAYLIST_RESULT_TOO_LARGE;
if (playlist_state == PLAYLIST_STATE_PLAY && playlist.queued >= 0 &&
- playlist.current == (int)playlist.length - 1)
+ playlist.current == (int)queue_length(&playlist.queue) - 1)
clearPlayerQueue();
- id = getNextId();
+ id = queue_append(&playlist.queue, song);
- playlist.songs[playlist.length] = song;
- playlist.songMod[playlist.length] = playlist.version;
- playlist.order[playlist.length] = playlist.length;
- playlist.positionToId[playlist.length] = id;
- playlist.idToPosition[playlist.positionToId[playlist.length]] =
- playlist.length;
- playlist.length++;
-
- if (playlist.random) {
+ if (playlist.queue.random) {
unsigned start;
/*if(playlist_state==PLAYLIST_STATE_STOP) start = 0;
else */ if (playlist.queued >= 0)
start = playlist.queued + 1;
else
start = playlist.current + 1;
- if (start < playlist.length) {
+ if (start < queue_length(&playlist.queue)) {
unsigned swap = g_rand_int_range(g_rand, start,
- playlist.length);
- swapOrder(playlist.length - 1, swap);
+ queue_length(&playlist.queue));
+ queue_swap_order(&playlist.queue,
+ queue_length(&playlist.queue) - 1, swap);
}
}
@@ -632,12 +539,15 @@ addSongToPlaylist(struct song *song, unsigned *added_id)
enum playlist_result swapSongsInPlaylist(unsigned song1, unsigned song2)
{
- if (song1 >= playlist.length || song2 >= playlist.length)
+ if (!queue_valid_position(&playlist.queue, song1) ||
+ !queue_valid_position(&playlist.queue, song2))
return PLAYLIST_RESULT_BAD_RANGE;
if (playlist_state == PLAYLIST_STATE_PLAY && playlist.queued >= 0) {
- unsigned queuedSong = playlist.order[playlist.queued];
- unsigned currentSong = playlist.order[playlist.current];
+ unsigned queuedSong = queue_order_to_position(&playlist.queue,
+ playlist.queued);
+ unsigned currentSong = queue_order_to_position(&playlist.queue,
+ playlist.current);
if (queuedSong == song1 || queuedSong == song2
|| currentSong == song1 || currentSong == song2)
@@ -645,18 +555,12 @@ enum playlist_result swapSongsInPlaylist(unsigned song1, unsigned song2)
}
swapSongs(song1, song2);
- if (playlist.random) {
- unsigned i, k;
- int j = -1;
- for (i = 0; playlist.order[i] != song1; i++) {
- if (playlist.order[i] == song2)
- j = i;
- }
- k = i;
- for (; j == -1; i++)
- if (playlist.order[i] == song2)
- j = i;
- swapOrder(k, j);
+ if (playlist.queue.random) {
+ queue_swap_order(&playlist.queue,
+ queue_position_to_order(&playlist.queue,
+ song1),
+ queue_position_to_order(&playlist.queue,
+ song2));
} else {
if (playlist.current == (int)song1)
playlist.current = song2;
@@ -680,57 +584,20 @@ enum playlist_result swapSongsInPlaylistById(unsigned id1, unsigned id2)
return swapSongsInPlaylist(song1, song2);
}
-#define moveSongFromTo(from, to) { \
- playlist.idToPosition[playlist.positionToId[from]] = to; \
- playlist.positionToId[to] = playlist.positionToId[from]; \
- playlist.songs[to] = playlist.songs[from]; \
- playlist.songMod[to] = playlist.version; \
-}
-
enum playlist_result deleteFromPlaylist(unsigned song)
{
- unsigned i;
unsigned songOrder;
- if (song >= playlist.length)
+ if (song >= queue_length(&playlist.queue))
return PLAYLIST_RESULT_BAD_RANGE;
+ songOrder = queue_position_to_order(&playlist.queue, song);
+
if (playlist_state == PLAYLIST_STATE_PLAY && playlist.queued >= 0
- && (playlist.order[playlist.queued] == song
- || playlist.order[playlist.current] == song))
+ && (playlist.queued == (int)songOrder ||
+ playlist.current == (int)songOrder))
clearPlayerQueue();
- if (!song_in_database(playlist.songs[song])) {
- pc_song_deleted(playlist.songs[song]);
- song_free(playlist.songs[song]);
- }
-
- playlist.idToPosition[playlist.positionToId[song]] = -1;
-
- /* delete song from songs array */
- for (i = song; i < playlist.length - 1; i++) {
- moveSongFromTo(i + 1, i);
- }
- /* now find it in the order array */
- for (i = 0; i < playlist.length - 1; i++) {
- if (playlist.order[i] == song)
- break;
- }
- songOrder = i;
- /* delete the entry from the order array */
- for (; i < playlist.length - 1; i++)
- playlist.order[i] = playlist.order[i + 1];
- /* readjust values in the order array */
- for (i = 0; i < playlist.length - 1; i++) {
- if (playlist.order[i] > song)
- playlist.order[i]--;
- }
- /* now take care of other misc stuff */
- playlist.songs[playlist.length - 1] = NULL;
- playlist.length--;
-
- incrPlaylistVersion();
-
if (playlist_state != PLAYLIST_STATE_STOP
&& playlist.current == (int)songOrder) {
/*if(playlist.current>=playlist.length) return playerStop(fd);
@@ -739,9 +606,17 @@ enum playlist_result deleteFromPlaylist(unsigned song)
playlist_noGoToNext = 1;
}
+ if (!song_in_database(queue_get(&playlist.queue, song)))
+ pc_song_deleted(queue_get(&playlist.queue, song));
+
+ queue_delete(&playlist.queue, song);
+
+ incrPlaylistVersion();
+
if (playlist.current > (int)songOrder) {
playlist.current--;
- } else if (playlist.current >= (int)playlist.length) {
+ } else if (playlist.current >= (int)queue_length(&playlist.queue)) {
+ --playlist.current;
incrPlaylistCurrent();
}
@@ -764,11 +639,8 @@ enum playlist_result deleteFromPlaylistById(unsigned id)
void
deleteASongFromPlaylist(const struct song *song)
{
- if (NULL == playlist.songs)
- return;
-
- for (int i = playlist.length - 1; i >= 0; --i)
- if (song == playlist.songs[i])
+ for (int i = queue_length(&playlist.queue) - 1; i >= 0; --i)
+ if (song == queue_get(&playlist.queue, i))
deleteFromPlaylist(i);
pc_song_deleted(song);
@@ -781,23 +653,26 @@ void stopPlaylist(void)
playlist.queued = -1;
playlist_state = PLAYLIST_STATE_STOP;
playlist_noGoToNext = 0;
- if (playlist.random)
- randomizeOrder(0, playlist.length - 1);
+ if (playlist.queue.random)
+ randomizeOrder(0, queue_length(&playlist.queue) - 1);
}
static void playPlaylistOrderNumber(int orderNum)
{
+ struct song *song;
char *uri;
playlist_state = PLAYLIST_STATE_PLAY;
playlist_noGoToNext = 0;
playlist.queued = -1;
- uri = song_get_uri(playlist.songs[playlist.order[orderNum]]);
+ song = queue_get_order(&playlist.queue, orderNum);
+
+ uri = song_get_uri(song);
g_debug("playlist: play %i:\"%s\"", orderNum, uri);
g_free(uri);
- playerPlay(playlist.songs[playlist.order[orderNum]]);
+ playerPlay(song);
playlist.current = orderNum;
}
@@ -808,34 +683,33 @@ enum playlist_result playPlaylist(int song, int stopOnError)
clearPlayerError();
if (song == -1) {
- if (playlist.length == 0)
+ if (queue_is_empty(&playlist.queue))
return PLAYLIST_RESULT_SUCCESS;
if (playlist_state == PLAYLIST_STATE_PLAY) {
playerSetPause(0);
return PLAYLIST_RESULT_SUCCESS;
}
- if (playlist.current >= 0 &&
- playlist.current < (int)playlist.length) {
- i = playlist.current;
- } else {
- i = 0;
- }
- } else if (song < 0 || song >= (int)playlist.length) {
+
+ i = playlist.current >= 0
+ ? playlist.current
+ : 0;
+ } else if (!queue_valid_position(&playlist.queue, song))
return PLAYLIST_RESULT_BAD_RANGE;
- }
- if (playlist.random) {
+ if (playlist.queue.random) {
if (song == -1 && playlist_state == PLAYLIST_STATE_PLAY) {
- randomizeOrder(0, playlist.length - 1);
+ randomizeOrder(0, queue_length(&playlist.queue) - 1);
} else {
if (song >= 0)
- for (i = 0; song != (int)playlist.order[i];
- i++) ;
+ i = queue_position_to_order(&playlist.queue, song);
+
if (playlist_state == PLAYLIST_STATE_STOP) {
playlist.current = 0;
}
- swapOrder(i, playlist.current);
+
+ queue_swap_order(&playlist.queue,
+ i, playlist.current);
i = playlist.current;
}
}
@@ -887,7 +761,7 @@ static void currentSongInPlaylist(void)
syncPlaylistWithQueue();
- if (playlist.current >= 0 && playlist.current < (int)playlist.length)
+ if (playlist.current >= 0)
playPlaylistOrderNumber(playlist.current);
else
stopPlaylist();
@@ -895,23 +769,31 @@ static void currentSongInPlaylist(void)
void nextSongInPlaylist(void)
{
+ int next_order;
+
if (playlist_state != PLAYLIST_STATE_PLAY)
return;
+ assert(!queue_is_empty(&playlist.queue));
+ assert(queue_valid_order(&playlist.queue, playlist.current));
+
syncPlaylistWithQueue();
playlist_stopOnError = 0;
- if (playlist.current < (int)playlist.length - 1) {
- playPlaylistOrderNumber(playlist.current + 1);
- } else if (playlist.length && playlist.repeat) {
- if (playlist.random)
- randomizeOrder(0, playlist.length - 1);
- playPlaylistOrderNumber(0);
- } else {
- incrPlaylistCurrent();
+ next_order = queue_next_order(&playlist.queue, playlist.current);
+ if (next_order < 0) {
stopPlaylist();
+ return;
+ }
+
+ if (next_order == 0) {
+ assert(playlist.queue.repeat);
+
+ randomizeOrder(0, queue_length(&playlist.queue) - 1);
}
+
+ playPlaylistOrderNumber(next_order);
}
static void playPlaylistIfPlayerStopped(void)
@@ -928,7 +810,7 @@ static void playPlaylistIfPlayerStopped(void)
&& ((playlist_stopOnError && error != PLAYER_ERROR_NOERROR)
|| error == PLAYER_ERROR_AUDIO
|| error == PLAYER_ERROR_SYSTEM
- || playlist_errorCount >= playlist.length)) {
+ || playlist_errorCount >= queue_length(&playlist.queue))) {
stopPlaylist();
} else if (playlist_noGoToNext)
currentSongInPlaylist();
@@ -939,37 +821,34 @@ static void playPlaylistIfPlayerStopped(void)
bool getPlaylistRepeatStatus(void)
{
- return playlist.repeat;
+ return playlist.queue.repeat;
}
bool getPlaylistRandomStatus(void)
{
- return playlist.random;
+ return playlist.queue.random;
}
void setPlaylistRepeatStatus(bool status)
{
if (playlist_state == PLAYLIST_STATE_PLAY &&
- playlist.repeat && !status && playlist.queued == 0)
+ playlist.queue.repeat && !status && playlist.queued == 0)
clearPlayerQueue();
- playlist.repeat = status;
+ playlist.queue.repeat = status;
idle_add(IDLE_OPTIONS);
}
enum playlist_result moveSongInPlaylist(unsigned from, int to)
{
- unsigned i;
- struct song *tmpSong;
- unsigned tmpId;
int currentSong;
- if (from >= playlist.length)
+ if (!queue_valid_position(&playlist.queue, from))
return PLAYLIST_RESULT_BAD_RANGE;
- if ((to >= 0 && to >= (int)playlist.length) ||
- (to < 0 && abs(to) > (int)playlist.length))
+ if ((to >= 0 && to >= (int)queue_length(&playlist.queue)) ||
+ (to < 0 && abs(to) > (int)queue_length(&playlist.queue)))
return PLAYLIST_RESULT_BAD_RANGE;
if ((int)from == to) /* no-op */
@@ -980,52 +859,28 @@ enum playlist_result moveSongInPlaylist(unsigned from, int to)
* (-playlist.length == to) => move to position BEFORE current song
*/
currentSong = playlist.current >= 0
- ? (int)playlist.order[playlist.current] : -1;
+ ? (int)queue_order_to_position(&playlist.queue,
+ playlist.current)
+ : -1;
if (to < 0 && playlist.current >= 0) {
if ((unsigned)currentSong == from)
/* no-op, can't be moved to offset of itself */
return PLAYLIST_RESULT_SUCCESS;
- to = (currentSong + abs(to)) % playlist.length;
+ to = (currentSong + abs(to)) % queue_length(&playlist.queue);
}
if (playlist_state == PLAYLIST_STATE_PLAY && playlist.queued >= 0) {
- int queuedSong = playlist.order[playlist.queued];
+ int queuedSong = queue_order_to_position(&playlist.queue,
+ playlist.queued);
if (queuedSong == (int)from || queuedSong == to
|| currentSong == (int)from || currentSong == to)
clearPlayerQueue();
}
- tmpSong = playlist.songs[from];
- tmpId = playlist.positionToId[from];
- /* move songs to one less in from->to */
- for (i = from; (int)i < to; i++) {
- moveSongFromTo(i + 1, i);
- }
- /* move songs to one more in to->from */
- for (i = from; (int)i > to; i--) {
- moveSongFromTo(i - 1, i);
- }
- /* put song at _to_ */
- playlist.idToPosition[tmpId] = to;
- playlist.positionToId[to] = tmpId;
- playlist.songs[to] = tmpSong;
- playlist.songMod[to] = playlist.version;
- /* now deal with order */
- if (playlist.random) {
- for (i = 0; i < playlist.length; i++) {
- if (playlist.order[i] > from &&
- (int)playlist.order[i] <= to) {
- playlist.order[i]--;
- } else if (playlist.order[i] < from &&
- (int)playlist.order[i] >= to) {
- playlist.order[i]++;
- } else if (from == playlist.order[i]) {
- playlist.order[i] = to;
- }
- }
- }
- else
- {
+ queue_move(&playlist.queue, from, to);
+
+ if (!playlist.queue.random) {
+ /* update current/queued */
if (playlist.current == (int)from)
playlist.current = to;
else if (playlist.current > (int)from &&
@@ -1063,25 +918,14 @@ enum playlist_result moveSongInPlaylistById(unsigned id1, int to)
static void orderPlaylist(void)
{
- unsigned i;
-
- if (playlist.current >= 0 && playlist.current < (int)playlist.length)
- playlist.current = playlist.order[playlist.current];
+ if (playlist.current >= 0)
+ playlist.current = queue_order_to_position(&playlist.queue,
+ playlist.current);
if (playlist_state == PLAYLIST_STATE_PLAY && playlist.queued >= 0)
clearPlayerQueue();
- for (i = 0; i < playlist.length; i++) {
- playlist.order[i] = i;
- }
-
-}
-
-static void swapOrder(int a, int b)
-{
- int bak = playlist.order[a];
- playlist.order[a] = playlist.order[b];
- playlist.order[b] = bak;
+ queue_restore_order(&playlist.queue);
}
static void randomizeOrder(int start, int end)
@@ -1101,26 +945,25 @@ static void randomizeOrder(int start, int end)
playlist.current = i;
else if (i == playlist.current)
playlist.current = ri;
- swapOrder(i, ri);
+ queue_swap_order(&playlist.queue, i, ri);
}
}
void setPlaylistRandomStatus(bool status)
{
- if (status == playlist.random)
+ if (status == playlist.queue.random)
return;
- playlist.random = status;
+ playlist.queue.random = status;
- if (playlist.random) {
+ if (playlist.queue.random) {
/*if(playlist_state==PLAYLIST_STATE_PLAY) {
randomizeOrder(playlist.current+1,
playlist.length-1);
}
- else */ randomizeOrder(0, playlist.length - 1);
- if (playlist.current >= 0 &&
- playlist.current < (int)playlist.length) {
- swapOrder(playlist.current, 0);
+ else */ randomizeOrder(0, queue_length(&playlist.queue) - 1);
+ if (playlist.current >= 0) {
+ queue_swap_order(&playlist.queue, playlist.current, 0);
playlist.current = 0;
}
} else
@@ -1146,8 +989,8 @@ void previousSongInPlaylist(void)
} else {
if (playlist.current > 0) {
playPlaylistOrderNumber(playlist.current - 1);
- } else if (playlist.repeat) {
- playPlaylistOrderNumber(playlist.length - 1);
+ } else if (playlist.queue.repeat) {
+ playPlaylistOrderNumber(queue_length(&playlist.queue) - 1);
} else {
playPlaylistOrderNumber(playlist.current);
}
@@ -1157,21 +1000,20 @@ void previousSongInPlaylist(void)
void shufflePlaylist(void)
{
unsigned i;
- int ri;
- if (playlist.length > 1) {
+ if (queue_length(&playlist.queue) > 1) {
if (playlist_state == PLAYLIST_STATE_PLAY) {
if (playlist.queued >= 0)
clearPlayerQueue();
if (playlist.current >= 0)
/* put current playing song first */
- swapSongs(0, playlist.order[playlist.current]);
+ swapSongs(0, queue_order_to_position(&playlist.queue,
+ playlist.current));
- if (playlist.random) {
- int j;
- for (j = 0; 0 != playlist.order[j]; j++) ;
- playlist.current = j;
+ if (playlist.queue.random) {
+ playlist.current =
+ queue_position_to_order(&playlist.queue, 0);
} else
playlist.current = 0;
i = 1;
@@ -1179,11 +1021,10 @@ void shufflePlaylist(void)
i = 0;
playlist.current = -1;
}
+
/* shuffle the rest of the list */
- for (; i < playlist.length; i++) {
- ri = g_rand_int_range(g_rand, i, playlist.length);
- swapSongs(i, ri);
- }
+ queue_shuffle_range(&playlist.queue, i,
+ queue_length(&playlist.queue));
incrPlaylistVersion();
}
@@ -1212,8 +1053,8 @@ enum playlist_result savePlaylist(const char *utf8file)
if (fp == NULL)
return PLAYLIST_RESULT_ERRNO;
- for (unsigned i = 0; i < playlist.length; i++)
- playlist_print_song(fp, playlist.songs[i]);
+ for (unsigned i = 0; i < queue_length(&playlist.queue); i++)
+ playlist_print_song(fp, queue_get(&playlist.queue, i));
while (fclose(fp) && errno == EINTR) ;
@@ -1223,22 +1064,21 @@ enum playlist_result savePlaylist(const char *utf8file)
int getPlaylistCurrentSong(void)
{
- if (playlist.current >= 0 &&
- playlist.current < (int)playlist.length) {
- return playlist.order[playlist.current];
- }
+ if (playlist.current >= 0)
+ return queue_order_to_position(&playlist.queue,
+ playlist.current);
return -1;
}
unsigned long getPlaylistVersion(void)
{
- return playlist.version;
+ return playlist.queue.version;
}
int getPlaylistLength(void)
{
- return playlist.length;
+ return queue_length(&playlist.queue);
}
enum playlist_result seekSongInPlaylist(unsigned song, float seek_time)
@@ -1246,11 +1086,11 @@ enum playlist_result seekSongInPlaylist(unsigned song, float seek_time)
unsigned i;
int ret;
- if (song >= playlist.length)
+ if (!queue_valid_position(&playlist.queue, song))
return PLAYLIST_RESULT_BAD_RANGE;
- if (playlist.random)
- for (i = 0; song != playlist.order[i]; i++) ;
+ if (playlist.queue.random)
+ i = queue_position_to_order(&playlist.queue, song);
else
i = song;
@@ -1268,7 +1108,7 @@ enum playlist_result seekSongInPlaylist(unsigned song, float seek_time)
playPlaylistOrderNumber(i);
}
- ret = playerSeek(playlist.songs[playlist.order[i]], seek_time);
+ ret = playerSeek(queue_get_order(&playlist.queue, i), seek_time);
if (ret < 0)
return PLAYLIST_RESULT_NOT_PLAYING;
@@ -1286,7 +1126,7 @@ enum playlist_result seekSongInPlaylistById(unsigned id, float seek_time)
unsigned getPlaylistSongId(unsigned song)
{
- return playlist.positionToId[song];
+ return queue_position_to_id(&playlist.queue, song);
}
int PlaylistInfo(struct client *client, const char *utf8file, int detail)
@@ -1357,8 +1197,10 @@ void searchForSongsInPlaylist(struct client *client,
items[i].needle = g_utf8_casefold(originalNeedles[i], -1);
}
- for (i = 0; i < playlist.length; i++) {
- if (strstrSearchTags(playlist.songs[i], numItems, items))
+ for (i = 0; i < queue_length(&playlist.queue); i++) {
+ const struct song *song = queue_get(&playlist.queue, i);
+
+ if (strstrSearchTags(song, numItems, items))
printPlaylistSongInfo(client, i);
}
@@ -1373,8 +1215,10 @@ void searchForSongsInPlaylist(struct client *client,
void findSongsInPlaylist(struct client *client,
unsigned numItems, LocateTagItem * items)
{
- for (unsigned i = 0; i < playlist.length; i++) {
- if (tagItemsFoundAndMatches(playlist.songs[i], numItems, items))
+ for (unsigned i = 0; i < queue_length(&playlist.queue); i++) {
+ const struct song *song = queue_get(&playlist.queue, i);
+
+ if (tagItemsFoundAndMatches(song, numItems, items))
printPlaylistSongInfo(client, i);
}
}
diff --git a/src/playlist.h b/src/playlist.h
index a2531963b..443f4222d 100644
--- a/src/playlist.h
+++ b/src/playlist.h
@@ -20,6 +20,7 @@
#define MPD_PLAYLIST_H
#include "locate.h"
+#include "queue.h"
#include <stdbool.h>
#include <stdio.h>
@@ -43,18 +44,10 @@ enum playlist_result {
};
typedef struct _Playlist {
- struct song **songs;
- /* holds version a song was modified on */
- uint32_t *songMod;
- unsigned *order;
- unsigned *positionToId;
- int *idToPosition;
- unsigned length;
+ struct queue queue;
+
int current;
int queued;
- bool repeat;
- bool random;
- uint32_t version;
} Playlist;
extern bool playlist_saveAbsolutePaths;
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);
+ }
+}
diff --git a/src/queue.h b/src/queue.h
new file mode 100644
index 000000000..098424cdd
--- /dev/null
+++ b/src/queue.h
@@ -0,0 +1,314 @@
+/*
+ * 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
+ */
+
+#ifndef QUEUE_H
+#define QUEUE_H
+
+#include <glib.h>
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+enum {
+ /**
+ * reserve max_length * QUEUE_HASH_MULT elements in the id
+ * number space
+ */
+ QUEUE_HASH_MULT = 4,
+};
+
+/**
+ * A queue of songs. This is the backend of the playlist: it contains
+ * an ordered list of songs.
+ *
+ * Songs can be addressed in three possible ways:
+ *
+ * - the position in the queue
+ * - the unique id (which stays the same, regardless of moves)
+ * - the order number (which only differs from "position" in random mode)
+ */
+struct queue {
+ /** configured maximum length of the queue */
+ unsigned max_length;
+
+ /** number of songs in the queue */
+ unsigned length;
+
+ /** the current version number */
+ uint32_t version;
+
+ /** all songs in "position" order */
+ struct song **songs;
+
+ /** holds version a song was modified on */
+ uint32_t *songMod;
+
+ /** map order numbers to positions */
+ unsigned *order;
+
+ /** map positions to song ids */
+ unsigned *positionToId;
+
+ /** map song ids to posiitons */
+ int *idToPosition;
+
+ /** repeat playback when the end of the queue has been
+ reached? */
+ bool repeat;
+
+ /** play back songs in random order? */
+ bool random;
+
+ /** random number generator for shuffle and random mode */
+ GRand *rand;
+};
+
+static inline unsigned
+queue_length(const struct queue *queue)
+{
+ assert(queue->length <= queue->max_length);
+
+ return queue->length;
+}
+
+/**
+ * Determine if the queue is empty, i.e. there are no songs.
+ */
+static inline bool
+queue_is_empty(const struct queue *queue)
+{
+ return queue->length == 0;
+}
+
+/**
+ * Determine if the maximum number of songs has been reached.
+ */
+static inline bool
+queue_is_full(const struct queue *queue)
+{
+ assert(queue->length <= queue->max_length);
+
+ return queue->length >= queue->max_length;
+}
+
+/**
+ * Is that a valid position number?
+ */
+static inline bool
+queue_valid_position(const struct queue *queue, unsigned position)
+{
+ return position < queue->length;
+}
+
+/**
+ * Is that a valid order number?
+ */
+static inline bool
+queue_valid_order(const struct queue *queue, unsigned order)
+{
+ return order < queue->length;
+}
+
+static inline int
+queue_id_to_position(const struct queue *queue, unsigned id)
+{
+ if (id >= queue->max_length * QUEUE_HASH_MULT)
+ return -1;
+
+ assert(queue->idToPosition[id] >= -1);
+ assert(queue->idToPosition[id] < (int)queue->length);
+
+ return queue->idToPosition[id];
+}
+
+static inline int
+queue_position_to_id(const struct queue *queue, unsigned position)
+{
+ assert(position < queue->length);
+
+ return queue->positionToId[position];
+}
+
+static inline unsigned
+queue_order_to_position(const struct queue *queue, unsigned order)
+{
+ assert(order < queue->length);
+
+ return queue->order[order];
+}
+
+static inline unsigned
+queue_position_to_order(const struct queue *queue, unsigned position)
+{
+ assert(position < queue->length);
+
+ for (unsigned i = 0;; ++i) {
+ assert(i < queue->length);
+
+ if (queue->order[i] == position)
+ return i;
+ }
+}
+
+/**
+ * Returns the song at the specified position.
+ */
+static inline struct song *
+queue_get(const struct queue *queue, unsigned position)
+{
+ assert(position < queue->length);
+
+ return queue->songs[position];
+}
+
+/**
+ * Returns the song at the specified order number.
+ */
+static inline struct song *
+queue_get_order(const struct queue *queue, unsigned order)
+{
+ return queue_get(queue, queue_order_to_position(queue, order));
+}
+
+/**
+ * Is the song at the specified position newer than the specified
+ * version?
+ */
+static inline bool
+queue_song_newer(const struct queue *queue, unsigned position,
+ uint32_t version)
+{
+ assert(position < queue->length);
+
+ return version > queue->version ||
+ queue->songMod[position] >= version ||
+ queue->songMod[position] == 0;
+}
+
+/**
+ * Initialize a queue object.
+ */
+void
+queue_init(struct queue *queue, unsigned max_length);
+
+/**
+ * Deinitializes a queue object. It does not free the queue pointer
+ * itself.
+ */
+void
+queue_finish(struct queue *queue);
+
+/**
+ * Generate a non-existing id number.
+ */
+unsigned
+queue_generate_id(const struct queue *queue);
+
+/**
+ * Returns the order number following the specified one. This takes
+ * end of queue and "repeat" mode into account.
+ *
+ * @return the next order number, or -1 to stop playback
+ */
+int
+queue_next_order(const struct queue *queue, unsigned order);
+
+/**
+ * Increments the queue's version number. This handles integer
+ * overflow well.
+ */
+void
+queue_increment_version(struct queue *queue);
+
+/**
+ * Marks the specified song as "modified" and increments the version
+ * number.
+ */
+void
+queue_modify(struct queue *queue, unsigned order);
+
+/**
+ * Marks all songs as "modified" and increments the version number.
+ */
+void
+queue_modify_all(struct queue *queue);
+
+/**
+ * Appends a song to the queue and returns its position. Prior to
+ * that, the caller must check if the queue is already full.
+ *
+ * If a song is not in the database (determined by
+ * song_in_database()), it is freed when removed from the queue.
+ */
+unsigned
+queue_append(struct queue *queue, struct song *song);
+
+/**
+ * Swaps two songs, addressed by their position.
+ */
+void
+queue_swap(struct queue *queue, unsigned position1, unsigned position2);
+
+/**
+ * Swaps two songs, addressed by their order number.
+ */
+static inline void
+queue_swap_order(struct queue *queue, unsigned order1, unsigned order2)
+{
+ unsigned tmp = queue->order[order1];
+ queue->order[order1] = queue->order[order2];
+ queue->order[order2] = tmp;
+}
+
+/**
+ * Moves a song to a new position.
+ */
+void
+queue_move(struct queue *queue, unsigned from, unsigned to);
+
+/**
+ * Removes a song from the playlist.
+ */
+void
+queue_delete(struct queue *queue, unsigned position);
+
+/**
+ * Removes all songs from the playlist.
+ */
+void
+queue_clear(struct queue *queue);
+
+/**
+ * Initializes the "order" array, and restores "normal" order.
+ */
+static inline void
+queue_restore_order(struct queue *queue)
+{
+ for (unsigned i = 0; i < queue->length; ++i)
+ queue->order[i] = i;
+}
+
+/**
+ * Shuffles a (position) range in the queue. The songs are physically
+ * shuffled, not by using the "order" mapping.
+ */
+void
+queue_shuffle_range(struct queue *queue, unsigned start, unsigned end);
+
+#endif