src/main/common/circular_queue.c

   1 /*
   2  * This file is part of INAV Project.
   3  *
   4  * This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   6  * You can obtain one at http://mozilla.org/MPL/2.0/.
   7  *
   8  * Alternatively, the contents of this file may be used under the terms
   9  * of the GNU General Public License Version 3, as described below:
  10  *
  11  * This file is free software: you may copy, redistribute and/or modify
  12  * it under the terms of the GNU General Public License as published by the
  13  * Free Software Foundation, either version 3 of the License, or (at your
  14  * option) any later version.
  15  *
  16  * This file is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  19  * Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program. If not, see http://www.gnu.org/licenses/.
  23  */
  24
  25 #include "circular_queue.h"
  26
  27 void circularBufferInit(circularBuffer_t *circular_buffer, uint8_t *buffer, size_t buffer_size,
  28                           size_t buffer_element_size) {
  29     circular_buffer->buffer = buffer;
  30     circular_buffer->bufferSize = buffer_size;
  31     circular_buffer->elementSize = buffer_element_size;
  32     circular_buffer->head = 0;
  33     circular_buffer->tail = 0;
  34     circular_buffer->size = 0;
  35 }
  36
  37 void circularBufferPushElement(circularBuffer_t *circularBuffer, uint8_t *element) {
  38     if (circularBufferIsFull(circularBuffer))
  39         return;
  40
  41     memcpy(circularBuffer->buffer + circularBuffer->tail, element, circularBuffer->elementSize);
  42
  43     circularBuffer->tail += circularBuffer->elementSize;
  44     circularBuffer->tail %= circularBuffer->bufferSize;
  45     circularBuffer->size += 1;
  46 }
  47
  48 void circularBufferPopHead(circularBuffer_t *circularBuffer, uint8_t *element) {
  49     memcpy(element, circularBuffer->buffer + circularBuffer->head, circularBuffer->elementSize);
  50
  51     circularBuffer->head += circularBuffer->elementSize;
  52     circularBuffer->head %= circularBuffer->bufferSize;
  53     circularBuffer->size -= 1;
  54 }
  55
  56 int circularBufferIsFull(circularBuffer_t *circularBuffer) {
  57     return circularBufferCountElements(circularBuffer) * circularBuffer->elementSize == circularBuffer->bufferSize;
  58 }
  59
  60 int circularBufferIsEmpty(circularBuffer_t *circularBuffer) {
  61     return circularBuffer==NULL || circularBufferCountElements(circularBuffer) == 0;
  62 }
  63
  64 size_t circularBufferCountElements(circularBuffer_t *circularBuffer) {
  65     return circularBuffer->size;
  66 }