/*
* 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 "fifo_output_plugin.h"
#include "output_api.h"
#include "utils.h"
#include "timer.h"
#include "fd_util.h"
#include "open.h"
#include <glib.h>
#include <sys/types.h>
#include <sys/stat.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;
struct 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|O_BINARY, 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|O_BINARY, 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_r)
{
struct fifo_data *fd;
GError *error = NULL;
char *path = config_dup_block_path(param, "path", &error);
if (!path) {
if (error != NULL)
g_propagate_error(error_r, error);
else
g_set_error(error_r, fifo_output_quark(), 0,
"No \"path\" parameter specified");
return NULL;
}
fd = fifo_data_new();
fd->path = path;
if (!fifo_open(fd, error_r)) {
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,
};
