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authorMax Kellermann <max@duempel.org>2011-07-19 00:34:33 +0200
committerMax Kellermann <max@duempel.org>2011-07-19 00:34:33 +0200
commitb159bc0c5f64dd4030f18cfa38539c5851d5157d (patch)
tree452a1e9fc6d5949244dc5eca4ebc8b89e5225166 /src/queue.c
parenta222c4879cd7104bcd51011bc13d4a76ac3d7a96 (diff)
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queue: implement song "priorities"
Sorts remaining songs by priority. This can be used for the much-demanded "queue feature".
Diffstat (limited to 'src/queue.c')
-rw-r--r--src/queue.c274
1 files changed, 269 insertions, 5 deletions
diff --git a/src/queue.c b/src/queue.c
index 9225590fc..cd932875e 100644
--- a/src/queue.c
+++ b/src/queue.c
@@ -21,6 +21,8 @@
#include "queue.h"
#include "song.h"
+#include <stdlib.h>
+
/**
* Generate a non-existing id number.
*/
@@ -104,6 +106,7 @@ queue_append(struct queue *queue, struct song *song)
.song = song,
.id = id,
.version = queue->version,
+ .priority = 0,
};
queue->order[queue->length] = queue->length;
@@ -220,6 +223,30 @@ queue_move_range(struct queue *queue, unsigned start, unsigned end, unsigned to)
}
}
+/**
+ * Moves a song to a new position in the "order" list.
+ */
+static void
+queue_move_order(struct queue *queue, unsigned from_order, unsigned to_order)
+{
+ assert(queue != NULL);
+ assert(from_order < queue->length);
+ assert(to_order <= queue->length);
+
+ const unsigned from_position =
+ queue_order_to_position(queue, from_order);
+
+ if (from_order < to_order) {
+ for (unsigned i = from_order; i < to_order; ++i)
+ queue->order[i] = queue->order[i + 1];
+ } else {
+ for (unsigned i = from_order; i > to_order; --i)
+ queue->order[i] = queue->order[i - 1];
+ }
+
+ queue->order[to_order] = from_position;
+}
+
void
queue_delete(struct queue *queue, unsigned position)
{
@@ -308,15 +335,123 @@ queue_finish(struct queue *queue)
g_rand_free(queue->rand);
}
-void
-queue_shuffle_order(struct queue *queue)
+static const struct queue_item *
+queue_get_order_item_const(const struct queue *queue, unsigned order)
+{
+ assert(queue != NULL);
+ assert(order < queue->length);
+
+ return &queue->items[queue->order[order]];
+}
+
+static uint8_t
+queue_get_order_priority(const struct queue *queue, unsigned order)
+{
+ return queue_get_order_item_const(queue, order)->priority;
+}
+
+static gint
+queue_item_compare_order_priority(gconstpointer av, gconstpointer bv,
+ gpointer user_data)
+{
+ const struct queue *queue = user_data;
+ const unsigned *const ap = av;
+ const unsigned *const bp = bv;
+ assert(ap >= queue->order && ap < queue->order + queue->length);
+ assert(bp >= queue->order && bp < queue->order + queue->length);
+ uint8_t a = queue->items[*ap].priority;
+ uint8_t b = queue->items[*bp].priority;
+
+ if (G_LIKELY(a == b))
+ return 0;
+ else if (a > b)
+ return -1;
+ else
+ return 1;
+}
+
+static void
+queue_sort_order_by_priority(struct queue *queue, unsigned start, unsigned end)
{
+ assert(queue != NULL);
assert(queue->random);
+ assert(start <= end);
+ assert(end <= queue->length);
- for (unsigned i = 0; i < queue->length; i++)
+ g_qsort_with_data(&queue->order[start], end - start,
+ sizeof(queue->order[0]),
+ queue_item_compare_order_priority,
+ queue);
+}
+
+/**
+ * Shuffle the order of items in the specified range, ignoring their
+ * priorities.
+ */
+static void
+queue_shuffle_order_range(struct queue *queue, unsigned start, unsigned end)
+{
+ assert(queue != NULL);
+ assert(queue->random);
+ assert(start <= end);
+ assert(end <= queue->length);
+
+ for (unsigned i = start; i < end; ++i)
queue_swap_order(queue, i,
- g_rand_int_range(queue->rand, i,
- queue->length));
+ g_rand_int_range(queue->rand, i, end));
+}
+
+/**
+ * Sort the "order" of items by priority, and then shuffle each
+ * priority group.
+ */
+void
+queue_shuffle_order_range_with_priority(struct queue *queue,
+ unsigned start, unsigned end)
+{
+ assert(queue != NULL);
+ assert(queue->random);
+ assert(start <= end);
+ assert(end <= queue->length);
+
+ if (start == end)
+ return;
+
+ /* first group the range by priority */
+ queue_sort_order_by_priority(queue, start, end);
+
+ /* now shuffle each priority group */
+ unsigned group_start = start;
+ uint8_t group_priority = queue_get_order_priority(queue, start);
+
+ for (unsigned i = start + 1; i < end; ++i) {
+ uint8_t priority = queue_get_order_priority(queue, i);
+ assert(priority <= group_priority);
+
+ if (priority != group_priority) {
+ /* start of a new group - shuffle the one that
+ has just ended */
+ queue_shuffle_order_range(queue, group_start, i);
+ group_start = i;
+ group_priority = priority;
+ }
+ }
+
+ /* shuffle the last group */
+ queue_shuffle_order_range(queue, group_start, end);
+}
+
+void
+queue_shuffle_order(struct queue *queue)
+{
+ queue_shuffle_order_range_with_priority(queue, 0, queue->length);
+}
+
+static void
+queue_shuffle_order_first(struct queue *queue, unsigned start, unsigned end)
+{
+ queue_swap_order(queue, start,
+ g_rand_int_range(queue->rand, start, end));
}
void
@@ -337,3 +472,132 @@ queue_shuffle_range(struct queue *queue, unsigned start, unsigned end)
queue_swap(queue, i, ri);
}
}
+
+/**
+ * Find the first item that has this specified priority or higher.
+ */
+G_GNUC_PURE
+static unsigned
+queue_find_priority_order(const struct queue *queue, unsigned start_order,
+ uint8_t priority, unsigned exclude_order)
+{
+ assert(queue != NULL);
+ assert(queue->random);
+ assert(start_order <= queue->length);
+
+ for (unsigned order = start_order; order < queue->length; ++order) {
+ const unsigned position = queue_order_to_position(queue, order);
+ const struct queue_item *item = &queue->items[position];
+ if (item->priority <= priority && order != exclude_order)
+ return order;
+ }
+
+ return queue->length;
+}
+
+G_GNUC_PURE
+static unsigned
+queue_count_same_priority(const struct queue *queue, unsigned start_order,
+ uint8_t priority)
+{
+ assert(queue != NULL);
+ assert(queue->random);
+ assert(start_order <= queue->length);
+
+ for (unsigned order = start_order; order < queue->length; ++order) {
+ const unsigned position = queue_order_to_position(queue, order);
+ const struct queue_item *item = &queue->items[position];
+ if (item->priority != priority)
+ return order - start_order;
+ }
+
+ return queue->length - start_order;
+}
+
+bool
+queue_set_priority(struct queue *queue, unsigned position, uint8_t priority,
+ int after_order)
+{
+ assert(queue != NULL);
+ assert(position < queue->length);
+
+ struct queue_item *item = &queue->items[position];
+ uint8_t old_priority = item->priority;
+ if (old_priority == priority)
+ return false;
+
+ item->version = queue->version;
+ item->priority = priority;
+
+ if (!queue->random)
+ /* don't reorder if not in random mode */
+ return true;
+
+ unsigned order = queue_position_to_order(queue, position);
+ if (after_order >= 0) {
+ if (order == (unsigned)after_order)
+ /* don't reorder the current song */
+ return true;
+
+ if (order < (unsigned)after_order) {
+ /* the specified song has been played already
+ - enqueue it only if its priority has just
+ become bigger than the current one's */
+
+ const unsigned after_position =
+ queue_order_to_position(queue, after_order);
+ const struct queue_item *after_item =
+ &queue->items[after_position];
+ if (old_priority > after_item->priority ||
+ priority <= after_item->priority)
+ /* priority hasn't become bigger */
+ return true;
+ }
+ }
+
+ /* move the item to the beginning of the priority group (or
+ create a new priority group) */
+
+ const unsigned before_order =
+ queue_find_priority_order(queue, after_order + 1, priority,
+ order);
+ const unsigned new_order = before_order > order
+ ? before_order - 1
+ : before_order;
+ queue_move_order(queue, order, new_order);
+
+ /* shuffle the song within that priority group */
+
+ const unsigned priority_count =
+ queue_count_same_priority(queue, new_order, priority);
+ assert(priority_count >= 1);
+ queue_shuffle_order_first(queue, new_order,
+ new_order + priority_count);
+
+ return true;
+}
+
+bool
+queue_set_priority_range(struct queue *queue,
+ unsigned start_position, unsigned end_position,
+ uint8_t priority, int after_order)
+{
+ assert(queue != NULL);
+ assert(start_position <= end_position);
+ assert(end_position <= queue->length);
+
+ bool modified = false;
+ int after_position = after_order >= 0
+ ? (int)queue_order_to_position(queue, after_order)
+ : -1;
+ for (unsigned i = start_position; i < end_position; ++i) {
+ after_order = after_position >= 0
+ ? (int)queue_position_to_order(queue, after_position)
+ : -1;
+
+ modified |= queue_set_priority(queue, i, priority,
+ after_order);
+ }
+
+ return modified;
+}