buffer, pipe: convert to C++

src/MusicPipe.cxx

@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) 2003-2011 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "MusicPipe.hxx"
+#include "MusicBuffer.hxx"
+#include "MusicChunk.hxx"
+
+#include <glib.h>
+
+#include <assert.h>
+
+struct music_pipe {
+	/** the first chunk */
+	struct music_chunk *head;
+
+	/** a pointer to the tail of the chunk */
+	struct music_chunk **tail_r;
+
+	/** the current number of chunks */
+	unsigned size;
+
+	/** a mutex which protects #head and #tail_r */
+	GMutex *mutex;
+
+#ifndef NDEBUG
+	struct audio_format audio_format;
+#endif
+};
+
+struct music_pipe *
+music_pipe_new(void)
+{
+	struct music_pipe *mp = g_new(struct music_pipe, 1);
+
+	mp->head = NULL;
+	mp->tail_r = &mp->head;
+	mp->size = 0;
+	mp->mutex = g_mutex_new();
+
+#ifndef NDEBUG
+	audio_format_clear(&mp->audio_format);
+#endif
+
+	return mp;
+}
+
+void
+music_pipe_free(struct music_pipe *mp)
+{
+	assert(mp->head == NULL);
+	assert(mp->tail_r == &mp->head);
+
+	g_mutex_free(mp->mutex);
+	g_free(mp);
+}
+
+#ifndef NDEBUG
+
+bool
+music_pipe_check_format(const struct music_pipe *pipe,
+			const struct audio_format *audio_format)
+{
+	assert(pipe != NULL);
+	assert(audio_format != NULL);
+
+	return !audio_format_defined(&pipe->audio_format) ||
+		audio_format_equals(&pipe->audio_format, audio_format);
+}
+
+bool
+music_pipe_contains(const struct music_pipe *mp,
+		    const struct music_chunk *chunk)
+{
+	g_mutex_lock(mp->mutex);
+
+	for (const struct music_chunk *i = mp->head;
+	     i != NULL; i = i->next) {
+		if (i == chunk) {
+			g_mutex_unlock(mp->mutex);
+			return true;
+		}
+	}
+
+	g_mutex_unlock(mp->mutex);
+
+	return false;
+}
+
+#endif
+
+const struct music_chunk *
+music_pipe_peek(const struct music_pipe *mp)
+{
+	return mp->head;
+}
+
+struct music_chunk *
+music_pipe_shift(struct music_pipe *mp)
+{
+	struct music_chunk *chunk;
+
+	g_mutex_lock(mp->mutex);
+
+	chunk = mp->head;
+	if (chunk != NULL) {
+		assert(!music_chunk_is_empty(chunk));
+
+		mp->head = chunk->next;
+		--mp->size;
+
+		if (mp->head == NULL) {
+			assert(mp->size == 0);
+			assert(mp->tail_r == &chunk->next);
+
+			mp->tail_r = &mp->head;
+		} else {
+			assert(mp->size > 0);
+			assert(mp->tail_r != &chunk->next);
+		}
+
+#ifndef NDEBUG
+		/* poison the "next" reference */
+		chunk->next = (struct music_chunk *)(void *)0x01010101;
+
+		if (mp->size == 0)
+			audio_format_clear(&mp->audio_format);
+#endif
+	}
+
+	g_mutex_unlock(mp->mutex);
+
+	return chunk;
+}
+
+void
+music_pipe_clear(struct music_pipe *mp, struct music_buffer *buffer)
+{
+	struct music_chunk *chunk;
+
+	while ((chunk = music_pipe_shift(mp)) != NULL)
+		music_buffer_return(buffer, chunk);
+}
+
+void
+music_pipe_push(struct music_pipe *mp, struct music_chunk *chunk)
+{
+	assert(!music_chunk_is_empty(chunk));
+	assert(chunk->length == 0 || audio_format_valid(&chunk->audio_format));
+
+	g_mutex_lock(mp->mutex);
+
+	assert(mp->size > 0 || !audio_format_defined(&mp->audio_format));
+	assert(!audio_format_defined(&mp->audio_format) ||
+	       music_chunk_check_format(chunk, &mp->audio_format));
+
+#ifndef NDEBUG
+	if (!audio_format_defined(&mp->audio_format) && chunk->length > 0)
+		mp->audio_format = chunk->audio_format;
+#endif
+
+	chunk->next = NULL;
+	*mp->tail_r = chunk;
+	mp->tail_r = &chunk->next;
+
+	++mp->size;
+
+	g_mutex_unlock(mp->mutex);
+}
+
+unsigned
+music_pipe_size(const struct music_pipe *mp)
+{
+	g_mutex_lock(mp->mutex);
+	unsigned size = mp->size;
+	g_mutex_unlock(mp->mutex);
+	return size;
+}