1 files changed, 302 insertions, 0 deletions
diff --git a/src/output/fifo_output_plugin.c b/src/output/fifo_output_plugin.c
new file mode 100644
index 000000000..b5e6f5314
--- /dev/null
+++ b/src/output/fifo_output_plugin.c
@@ -0,0 +1,302 @@
+/*
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "output_api.h"
+#include "utils.h"
+#include "timer.h"
+#include "fd_util.h"
+
+#include <glib.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "fifo"
+
+#define FIFO_BUFFER_SIZE 65536 /* pipe capacity on Linux >= 2.6.11 */
+
+struct fifo_data {
+	char *path;
+	int input;
+	int output;
+	bool created;
+	Timer *timer;
+};
+
+/**
+ * The quark used for GError.domain.
+ */
+static inline GQuark
+fifo_output_quark(void)
+{
+	return g_quark_from_static_string("fifo_output");
+}
+
+static struct fifo_data *fifo_data_new(void)
+{
+	struct fifo_data *ret;
+
+	ret = g_new(struct fifo_data, 1);
+
+	ret->path = NULL;
+	ret->input = -1;
+	ret->output = -1;
+	ret->created = false;
+
+	return ret;
+}
+
+static void fifo_data_free(struct fifo_data *fd)
+{
+	g_free(fd->path);
+	g_free(fd);
+}
+
+static void fifo_delete(struct fifo_data *fd)
+{
+	g_debug("Removing FIFO \"%s\"", fd->path);
+
+	if (unlink(fd->path) < 0) {
+		g_warning("Could not remove FIFO \"%s\": %s",
+			  fd->path, strerror(errno));
+		return;
+	}
+
+	fd->created = false;
+}
+
+static void
+fifo_close(struct fifo_data *fd)
+{
+	struct stat st;
+
+	if (fd->input >= 0) {
+		close(fd->input);
+		fd->input = -1;
+	}
+
+	if (fd->output >= 0) {
+		close(fd->output);
+		fd->output = -1;
+	}
+
+	if (fd->created && (stat(fd->path, &st) == 0))
+		fifo_delete(fd);
+}
+
+static bool
+fifo_make(struct fifo_data *fd, GError **error)
+{
+	if (mkfifo(fd->path, 0666) < 0) {
+		g_set_error(error, fifo_output_quark(), errno,
+			    "Couldn't create FIFO \"%s\": %s",
+			    fd->path, strerror(errno));
+		return false;
+	}
+
+	fd->created = true;
+
+	return true;
+}
+
+static bool
+fifo_check(struct fifo_data *fd, GError **error)
+{
+	struct stat st;
+
+	if (stat(fd->path, &st) < 0) {
+		if (errno == ENOENT) {
+			/* Path doesn't exist */
+			return fifo_make(fd, error);
+		}
+
+		g_set_error(error, fifo_output_quark(), errno,
+			    "Failed to stat FIFO \"%s\": %s",
+			    fd->path, strerror(errno));
+		return false;
+	}
+
+	if (!S_ISFIFO(st.st_mode)) {
+		g_set_error(error, fifo_output_quark(), 0,
+			    "\"%s\" already exists, but is not a FIFO",
+			    fd->path);
+		return false;
+	}
+
+	return true;
+}
+
+static bool
+fifo_open(struct fifo_data *fd, GError **error)
+{
+	if (!fifo_check(fd, error))
+		return false;
+
+	fd->input = open_cloexec(fd->path, O_RDONLY|O_NONBLOCK, 0);
+	if (fd->input < 0) {
+		g_set_error(error, fifo_output_quark(), errno,
+			    "Could not open FIFO \"%s\" for reading: %s",
+			    fd->path, strerror(errno));
+		fifo_close(fd);
+		return false;
+	}
+
+	fd->output = open_cloexec(fd->path, O_WRONLY|O_NONBLOCK, 0);
+	if (fd->output < 0) {
+		g_set_error(error, fifo_output_quark(), errno,
+			    "Could not open FIFO \"%s\" for writing: %s",
+			    fd->path, strerror(errno));
+		fifo_close(fd);
+		return false;
+	}
+
+	return true;
+}
+
+static void *
+fifo_output_init(G_GNUC_UNUSED const struct audio_format *audio_format,
+		 const struct config_param *param,
+		 GError **error)
+{
+	struct fifo_data *fd;
+	char *value, *path;
+
+	value = config_dup_block_string(param, "path", NULL);
+	if (value == NULL) {
+		g_set_error(error, fifo_output_quark(), errno,
+			    "No \"path\" parameter specified");
+		return NULL;
+	}
+
+	path = parsePath(value);
+	g_free(value);
+	if (!path) {
+		g_set_error(error, fifo_output_quark(), errno,
+			    "Could not parse \"path\" parameter");
+		return NULL;
+	}
+
+	fd = fifo_data_new();
+	fd->path = path;
+
+	if (!fifo_open(fd, error)) {
+		fifo_data_free(fd);
+		return NULL;
+	}
+
+	return fd;
+}
+
+static void
+fifo_output_finish(void *data)
+{
+	struct fifo_data *fd = (struct fifo_data *)data;
+
+	fifo_close(fd);
+	fifo_data_free(fd);
+}
+
+static bool
+fifo_output_open(void *data, struct audio_format *audio_format,
+		 G_GNUC_UNUSED GError **error)
+{
+	struct fifo_data *fd = (struct fifo_data *)data;
+
+	fd->timer = timer_new(audio_format);
+
+	return true;
+}
+
+static void
+fifo_output_close(void *data)
+{
+	struct fifo_data *fd = (struct fifo_data *)data;
+
+	timer_free(fd->timer);
+}
+
+static void
+fifo_output_cancel(void *data)
+{
+	struct fifo_data *fd = (struct fifo_data *)data;
+	char buf[FIFO_BUFFER_SIZE];
+	int bytes = 1;
+
+	timer_reset(fd->timer);
+
+	while (bytes > 0 && errno != EINTR)
+		bytes = read(fd->input, buf, FIFO_BUFFER_SIZE);
+
+	if (bytes < 0 && errno != EAGAIN) {
+		g_warning("Flush of FIFO \"%s\" failed: %s",
+			  fd->path, strerror(errno));
+	}
+}
+
+static size_t
+fifo_output_play(void *data, const void *chunk, size_t size,
+		 GError **error)
+{
+	struct fifo_data *fd = (struct fifo_data *)data;
+	ssize_t bytes;
+
+	if (!fd->timer->started)
+		timer_start(fd->timer);
+	else
+		timer_sync(fd->timer);
+
+	timer_add(fd->timer, size);
+
+	while (true) {
+		bytes = write(fd->output, chunk, size);
+		if (bytes > 0)
+			return (size_t)bytes;
+
+		if (bytes < 0) {
+			switch (errno) {
+			case EAGAIN:
+				/* The pipe is full, so empty it */
+				fifo_output_cancel(fd);
+				continue;
+			case EINTR:
+				continue;
+			}
+
+			g_set_error(error, fifo_output_quark(), errno,
+				    "Failed to write to FIFO %s: %s",
+				    fd->path, g_strerror(errno));
+			return 0;
+		}
+	}
+}
+
+const struct audio_output_plugin fifo_output_plugin = {
+	.name = "fifo",
+	.init = fifo_output_init,
+	.finish = fifo_output_finish,
+	.open = fifo_output_open,
+	.close = fifo_output_close,
+	.play = fifo_output_play,
+	.cancel = fifo_output_cancel,
+};