mirror of
https://github.com/libretro/RetroArch.git
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125 lines
3.3 KiB
C
125 lines
3.3 KiB
C
/* Copyright (C) 2010-2016 The RetroArch team
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*
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* ---------------------------------------------------------------------------------------
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* The following license statement only applies to this file (fifo_queue.c).
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* ---------------------------------------------------------------------------------------
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*
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* Permission is hereby granted, free of charge,
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* to any person obtaining a copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
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* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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#include <stdlib.h>
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#include <string.h>
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#include <queues/fifo_queue.h>
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struct fifo_buffer
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{
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uint8_t *buffer;
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size_t size;
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size_t first;
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size_t end;
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};
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fifo_buffer_t *fifo_new(size_t size)
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{
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fifo_buffer_t *buf = (fifo_buffer_t*)calloc(1, sizeof(*buf));
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if (!buf)
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return NULL;
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buf->buffer = (uint8_t*)calloc(1, size + 1);
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if (!buf->buffer)
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{
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free(buf);
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return NULL;
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}
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buf->size = size + 1;
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return buf;
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}
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void fifo_clear(fifo_buffer_t *buffer)
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{
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buffer->first = 0;
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buffer->end = 0;
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}
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void fifo_free(fifo_buffer_t *buffer)
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{
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if (!buffer)
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return;
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free(buffer->buffer);
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free(buffer);
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}
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size_t fifo_read_avail(fifo_buffer_t *buffer)
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{
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size_t first = buffer->first;
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size_t end = buffer->end;
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if (end < first)
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end += buffer->size;
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return end - first;
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}
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size_t fifo_write_avail(fifo_buffer_t *buffer)
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{
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size_t first = buffer->first;
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size_t end = buffer->end;
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if (end < first)
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end += buffer->size;
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return (buffer->size - 1) - (end - first);
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}
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void fifo_write(fifo_buffer_t *buffer, const void *in_buf, size_t size)
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{
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size_t first_write = size;
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size_t rest_write = 0;
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if (buffer->end + size > buffer->size)
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{
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first_write = buffer->size - buffer->end;
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rest_write = size - first_write;
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}
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memcpy(buffer->buffer + buffer->end, in_buf, first_write);
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memcpy(buffer->buffer, (const uint8_t*)in_buf + first_write, rest_write);
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buffer->end = (buffer->end + size) % buffer->size;
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}
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void fifo_read(fifo_buffer_t *buffer, void *in_buf, size_t size)
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{
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size_t first_read = size;
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size_t rest_read = 0;
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if (buffer->first + size > buffer->size)
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{
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first_read = buffer->size - buffer->first;
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rest_read = size - first_read;
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}
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memcpy(in_buf, (const uint8_t*)buffer->buffer + buffer->first, first_read);
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memcpy((uint8_t*)in_buf + first_read, buffer->buffer, rest_read);
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buffer->first = (buffer->first + size) % buffer->size;
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}
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