/*
 * Copyright (C) 2009-2012 Thomas Preud'homme <thomas.preud-homme@lip6.fr>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdint.h>

/* Non standard include */
#include <commtech.h>
#include <specific_comm.h>


void *create_comm_channel(void)
{
	struct channel *channel;
	int flags;

	channel = malloc(sizeof(channel));
	if (channel != NULL)
	{
		if (!pipe(channel->pipefd))
		{
			flags = fcntl(channel->pipefd[READ_IDX], F_GETFL);
			fcntl(channel->pipefd[READ_IDX], F_SETFL, flags | O_NONBLOCK);
			return channel;
		}
		else
			free(channel);
	}
	return NULL;
}

int end_producer(void *unused __attribute__ ((unused)))
{
	return 0;
}

int destroy_comm_channel(void *channel)
{
	free(channel);
	return 0;
}

void *recv_one_data(struct channel *channel)
{
	void *result, **res_ptr;
	int n;
	unsigned int nb_read;

	nb_read = 0;
	res_ptr = &result;
	do
	{
		n = read(channel->pipefd[READ_IDX], res_ptr, sizeof(void *));
		if (n > 0)
		{
			nb_read += n;
			res_ptr = (void **) ((uintptr_t) res_ptr + n);
		}
	} while (nb_read < sizeof(void *));
	return result;
}

ssize_t recv_some_data(struct channel *channel, void **buf, size_t count)
{
	int n, nb_read, nb_bytes;

	nb_bytes = count * sizeof(void *);
	nb_read = read(channel->pipefd[READ_IDX], buf, nb_bytes);
	if (nb_read <= 0)
		return 0;
	buf = (void **) ((uintptr_t) buf + nb_read);
	while (nb_read % sizeof(void *))
	{
		n = read(channel->pipefd[READ_IDX], buf, sizeof(void *) - (nb_read % sizeof(void *)));
		if (n > 0)
		{
			nb_read += n;
			buf = (void **) ((uintptr_t) buf + n);
		}
	}
	return nb_read / sizeof(void *);
}