mpd/src/output/plugins/SolarisOutputPlugin.cxx

/*
 * Copyright 2003-2017 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 "SolarisOutputPlugin.hxx"
#include "../OutputAPI.hxx"
#include "../Wrapper.hxx"
#include "system/fd_util.h"
#include "system/Error.hxx"

#include <sys/stropts.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

#ifdef __sun
#include <sys/audio.h>
#else

/* some fake declarations that allow build this plugin on systems
   other than Solaris, just to see if it compiles */

#define AUDIO_GETINFO 0
#define AUDIO_SETINFO 0
#define AUDIO_ENCODING_LINEAR 0

struct audio_info {
	struct {
		unsigned sample_rate, channels, precision, encoding;
	} play;
};

#endif

class SolarisOutput {
	friend struct AudioOutputWrapper<SolarisOutput>;

	AudioOutput base;

	/* configuration */
	const char *const device;

	int fd;

	explicit SolarisOutput(const ConfigBlock &block)
		:base(solaris_output_plugin),
		 device(block.GetBlockValue("device", "/dev/audio")) {}

public:
	static SolarisOutput *Create(EventLoop &, const ConfigBlock &block) {
		return new SolarisOutput(block);
	}

	void Open(AudioFormat &audio_format);
	void Close();

	size_t Play(const void *chunk, size_t size);
	void Cancel();
};

static bool
solaris_output_test_default_device(void)
{
	struct stat st;

	return stat("/dev/audio", &st) == 0 && S_ISCHR(st.st_mode) &&
		access("/dev/audio", W_OK) == 0;
}

void
SolarisOutput::Open(AudioFormat &audio_format)
{
	struct audio_info info;
	int ret, flags;

	/* support only 16 bit mono/stereo for now; nothing else has
	   been tested */
	audio_format.format = SampleFormat::S16;

	/* open the device in non-blocking mode */

	fd = open_cloexec(device, O_WRONLY|O_NONBLOCK, 0);
	if (fd < 0)
		throw FormatErrno("Failed to open %s",
				  device);

	/* restore blocking mode */

	flags = fcntl(fd, F_GETFL);
	if (flags > 0 && (flags & O_NONBLOCK) != 0)
		fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);

	/* configure the audio device */

	ret = ioctl(fd, AUDIO_GETINFO, &info);
	if (ret < 0) {
		const int e = errno;
		close(fd);
		throw MakeErrno(e, "AUDIO_GETINFO failed");
	}

	info.play.sample_rate = audio_format.sample_rate;
	info.play.channels = audio_format.channels;
	info.play.precision = 16;
	info.play.encoding = AUDIO_ENCODING_LINEAR;

	ret = ioctl(fd, AUDIO_SETINFO, &info);
	if (ret < 0) {
		const int e = errno;
		close(fd);
		throw MakeErrno(e, "AUDIO_SETINFO failed");
	}
}

void
SolarisOutput::Close()
{
	close(fd);
}

size_t
SolarisOutput::Play(const void *chunk, size_t size)
{
	ssize_t nbytes = write(fd, chunk, size);
	if (nbytes <= 0)
		throw MakeErrno("Write failed");

	return nbytes;
}

void
SolarisOutput::Cancel()
{
	ioctl(fd, I_FLUSH);
}

typedef AudioOutputWrapper<SolarisOutput> Wrapper;

const struct AudioOutputPlugin solaris_output_plugin = {
	"solaris",
	solaris_output_test_default_device,
	&Wrapper::Init,
	&Wrapper::Finish,
	nullptr,
	nullptr,
	&Wrapper::Open,
	&Wrapper::Close,
	nullptr,
	nullptr,
	&Wrapper::Play,
	nullptr,
	&Wrapper::Cancel,
	nullptr,
	nullptr,
};