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/* Copyright (C) 2010-2016 The RetroArch team
*
* ---------------------------------------------------------------------------------------
* The following license statement only applies to this file (fifo_queue.c).
* ---------------------------------------------------------------------------------------
*
* 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 <stdlib.h>
#include <string.h>
#include <queues/fifo_queue.h>
struct fifo_buffer
{
uint8_t *buffer;
size_t size;
size_t first;
size_t end;
};
fifo_buffer_t *fifo_new(size_t size)
{
fifo_buffer_t *buf = (fifo_buffer_t*)calloc(1, sizeof(*buf));
if (!buf)
return NULL;
buf->buffer = (uint8_t*)calloc(1, size + 1);
if (!buf->buffer)
{
free(buf);
return NULL;
}
buf->size = size + 1;
return buf;
}
void fifo_clear(fifo_buffer_t *buffer)
{
buffer->first = 0;
buffer->end = 0;
}
void fifo_free(fifo_buffer_t *buffer)
{
if (!buffer)
return;
free(buffer->buffer);
free(buffer);
}
size_t fifo_read_avail(fifo_buffer_t *buffer)
{
size_t first = buffer->first;
size_t end = buffer->end;
if (end < first)
end += buffer->size;
return end - first;
}
size_t fifo_write_avail(fifo_buffer_t *buffer)
{
size_t first = buffer->first;
size_t end = buffer->end;
if (end < first)
end += buffer->size;
return (buffer->size - 1) - (end - first);
}
void fifo_write(fifo_buffer_t *buffer, const void *in_buf, size_t size)
{
size_t first_write = size;
size_t rest_write = 0;
if (buffer->end + size > buffer->size)
{
first_write = buffer->size - buffer->end;
rest_write = size - first_write;
}
memcpy(buffer->buffer + buffer->end, in_buf, first_write);
memcpy(buffer->buffer, (const uint8_t*)in_buf + first_write, rest_write);
buffer->end = (buffer->end + size) % buffer->size;
}
void fifo_read(fifo_buffer_t *buffer, void *in_buf, size_t size)
{
size_t first_read = size;
size_t rest_read = 0;
if (buffer->first + size > buffer->size)
{
first_read = buffer->size - buffer->first;
rest_read = size - first_read;
}
memcpy(in_buf, (const uint8_t*)buffer->buffer + buffer->first, first_read);
memcpy((uint8_t*)in_buf + first_read, buffer->buffer, rest_read);
buffer->first = (buffer->first + size) % buffer->size;
}
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