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authorMax Kellermann <max@duempel.org>2009-03-06 00:42:03 +0100
committerMax Kellermann <max@duempel.org>2009-03-06 00:42:03 +0100
commit01cf7feac7bef8b28605b98ef1e7438a995fc554 (patch)
treee1c4b7f5d0550d60d7fda8b4909353a47490fa4e /src/buffer.c
parent000b2d4f3a9c4f761ab918aaff4705621bb8559f (diff)
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pipe: added music_buffer, rewrite music_pipe
Turn the music_pipe into a simple music_chunk queue. The music_chunk allocation code is moved to music_buffer, and is now managed with a linked list instead of a ring buffer. Two separate music_pipe objects are used by the decoder for the "current" and the "next" song, which greatly simplifies the cross-fading code.
Diffstat (limited to '')
-rw-r--r--src/buffer.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/src/buffer.c b/src/buffer.c
new file mode 100644
index 000000000..1b300887f
--- /dev/null
+++ b/src/buffer.c
@@ -0,0 +1,127 @@
+/*
+ * 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 "buffer.h"
+#include "chunk.h"
+
+#include <glib.h>
+
+#include <assert.h>
+
+struct music_buffer {
+ struct music_chunk *chunks;
+ unsigned num_chunks;
+
+ struct music_chunk *available;
+
+ /** a mutex which protects #available */
+ GMutex *mutex;
+
+#ifndef NDEBUG
+ unsigned num_allocated;
+#endif
+};
+
+struct music_buffer *
+music_buffer_new(unsigned num_chunks)
+{
+ struct music_buffer *buffer;
+ struct music_chunk *chunk;
+
+ assert(num_chunks > 0);
+
+ buffer = g_new(struct music_buffer, 1);
+
+ buffer->chunks = g_new(struct music_chunk, num_chunks);
+ buffer->num_chunks = num_chunks;
+
+ chunk = buffer->available = buffer->chunks;
+
+ for (unsigned i = 1; i < num_chunks; ++i) {
+ chunk->next = &buffer->chunks[i];
+ chunk = chunk->next;
+ }
+
+ chunk->next = NULL;
+
+ buffer->mutex = g_mutex_new();
+
+#ifndef NDEBUG
+ buffer->num_allocated = 0;
+#endif
+
+ return buffer;
+}
+
+void
+music_buffer_free(struct music_buffer *buffer)
+{
+ assert(buffer->chunks != NULL);
+ assert(buffer->num_chunks > 0);
+ assert(buffer->num_allocated == 0);
+
+ g_mutex_free(buffer->mutex);
+ g_free(buffer->chunks);
+ g_free(buffer);
+}
+
+unsigned
+music_buffer_size(const struct music_buffer *buffer)
+{
+ return buffer->num_chunks;
+}
+
+struct music_chunk *
+music_buffer_allocate(struct music_buffer *buffer)
+{
+ struct music_chunk *chunk;
+
+ g_mutex_lock(buffer->mutex);
+
+ chunk = buffer->available;
+ if (chunk != NULL) {
+ buffer->available = chunk->next;
+ music_chunk_init(chunk);
+
+#ifndef NDEBUG
+ ++buffer->num_allocated;
+#endif
+ }
+
+ g_mutex_unlock(buffer->mutex);
+ return chunk;
+}
+
+void
+music_buffer_return(struct music_buffer *buffer, struct music_chunk *chunk)
+{
+ assert(buffer != NULL);
+ assert(chunk != NULL);
+
+ g_mutex_lock(buffer->mutex);
+
+ music_chunk_free(chunk);
+ chunk->next = buffer->available;
+ buffer->available = chunk;
+
+#ifndef NDEBUG
+ --buffer->num_allocated;
+#endif
+
+ g_mutex_unlock(buffer->mutex);
+}