/*

 *

 *  BlueZ - Bluetooth protocol stack for Linux

 *

 *  Copyright (C) 2012-2014  Intel Corporation. All rights reserved.

 *

 *

 *  This library is free software; you can redistribute it and/or

 *  modify it under the terms of the GNU Lesser General Public

 *  License as published by the Free Software Foundation; either

 *  version 2.1 of the License, or (at your option) any later version.

 *

 *  This library 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

 *  Lesser General Public License for more details.

 *

 *  You should have received a copy of the GNU Lesser General Public

 *  License along with this library; if not, write to the Free Software

 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 *

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <errno.h>

#include <glib.h>

#include "src/shared/io.h"

struct io_watch {

	struct io *io;

	guint id;

	io_callback_func_t callback;

	io_destroy_func_t destroy;

	void *user_data;

};

struct io {

	int ref_count;

	GIOChannel *channel;

	struct io_watch *read_watch;

	struct io_watch *write_watch;

	struct io_watch *disconnect_watch;

};

static struct io *io_ref(struct io *io)

{

	if (!io)

		return NULL;

	__sync_fetch_and_add(&io->ref_count, 1);

	return io;

}

static void io_unref(struct io *io)

{

	if (!io)

		return;

	if (__sync_sub_and_fetch(&io->ref_count, 1))

		return;

	g_free(io);

}

struct io *io_new(int fd)

{

	struct io *io;

	if (fd < 0)

		return NULL;

	io = g_try_new0(struct io, 1);

	if (!io)

		return NULL;

	io->channel = g_io_channel_unix_new(fd);

	g_io_channel_set_encoding(io->channel, NULL, NULL);

	g_io_channel_set_buffered(io->channel, FALSE);

	g_io_channel_set_close_on_unref(io->channel, FALSE);

	return io_ref(io);

}

static void watch_destroy(void *user_data)

{

	struct io_watch *watch = user_data;

	struct io *io = watch->io;

	if (watch == io->read_watch)

		io->read_watch = NULL;

	else if (watch == io->write_watch)

		io->write_watch = NULL;

	else if (watch == io->disconnect_watch)

		io->disconnect_watch = NULL;

	if (watch->destroy)

		watch->destroy(watch->user_data);

	io_unref(watch->io);

	g_free(watch);

}

void io_destroy(struct io *io)

{

	if (!io)

		return;

	if (io->read_watch) {

		g_source_remove(io->read_watch->id);

		io->read_watch = NULL;

	}

	if (io->write_watch) {

		g_source_remove(io->write_watch->id);

		io->write_watch = NULL;

	}

	if (io->disconnect_watch) {

		g_source_remove(io->disconnect_watch->id);

		io->disconnect_watch = NULL;

	}

	g_io_channel_unref(io->channel);

	io->channel = NULL;

	io_unref(io);

}

int io_get_fd(struct io *io)

{

	if (!io)

		return -ENOTCONN;

	return g_io_channel_unix_get_fd(io->channel);

}

bool io_set_close_on_destroy(struct io *io, bool do_close)

{

	if (!io)

		return false;

	if (do_close)

		g_io_channel_set_close_on_unref(io->channel, TRUE);

	else

		g_io_channel_set_close_on_unref(io->channel, FALSE);

	return true;

}

static gboolean watch_callback(GIOChannel *channel, GIOCondition cond,

							gpointer user_data)

{

	struct io_watch *watch = user_data;

	bool result, destroy;

	destroy = watch == watch->io->disconnect_watch;

	if (!destroy && (cond & (G_IO_ERR | G_IO_NVAL)))

		return FALSE;

	if (watch->callback)

		result = watch->callback(watch->io, watch->user_data);

	else

		result = false;

	return result ? TRUE : FALSE;

}

static struct io_watch *watch_new(struct io *io, GIOCondition cond,

				io_callback_func_t callback, void *user_data,

				io_destroy_func_t destroy)

{

	struct io_watch *watch;

	int prio;

	watch = g_try_new0(struct io_watch, 1);

	if (!watch)

		return NULL;

	watch->io = io_ref(io);

	watch->callback = callback;

	watch->destroy = destroy;

	watch->user_data = user_data;

	prio = cond == G_IO_HUP ? G_PRIORITY_DEFAULT_IDLE : G_PRIORITY_DEFAULT;

	watch->id = g_io_add_watch_full(io->channel, prio,

						cond | G_IO_ERR | G_IO_NVAL,

						watch_callback, watch,

						watch_destroy);

	if (watch->id == 0) {

		watch_destroy(watch);

		return NULL;

	}

	return watch;

}

static bool io_set_handler(struct io *io, GIOCondition cond,

				io_callback_func_t callback, void *user_data,

				io_destroy_func_t destroy)

{

	struct io_watch **watch;

	if (!io)

		return false;

	switch (cond) {

	case G_IO_IN:

		watch = &io->read_watch;

		break;

	case G_IO_OUT:

		watch = &io->write_watch;

		break;

	case G_IO_HUP:

		watch = &io->disconnect_watch;

		break;

	case G_IO_PRI:

	case G_IO_ERR:

	case G_IO_NVAL:

	default:

		return false;

	}

	if (*watch) {

		g_source_remove((*watch)->id);

		*watch = NULL;

	}

	if (!callback)

		return true;

	*watch = watch_new(io, cond, callback, user_data, destroy);

	if (!*watch)

		return false;

	return true;

}

bool io_set_read_handler(struct io *io, io_callback_func_t callback,

				void *user_data, io_destroy_func_t destroy)

{

	return io_set_handler(io, G_IO_IN, callback, user_data, destroy);

}

bool io_set_write_handler(struct io *io, io_callback_func_t callback,

				void *user_data, io_destroy_func_t destroy)

{

	return io_set_handler(io, G_IO_OUT, callback, user_data, destroy);

}

bool io_set_disconnect_handler(struct io *io, io_callback_func_t callback,

				void *user_data, io_destroy_func_t destroy)

{

	return io_set_handler(io, G_IO_HUP, callback, user_data, destroy);

}

ssize_t io_send(struct io *io, const struct iovec *iov, int iovcnt)

{

	int fd;

	ssize_t ret;

	if (!io || !io->channel)

		return -ENOTCONN;

	fd = io_get_fd(io);

	do {

		ret = writev(fd, iov, iovcnt);

	} while (ret < 0 && errno == EINTR);

	if (ret < 0)

		return -errno;

	return ret;

}

bool io_shutdown(struct io *io)

{

	if (!io || !io->channel)

		return false;

	return g_io_channel_shutdown(io->channel, TRUE, NULL)

							== G_IO_STATUS_NORMAL;

}