52 lines
1.1 KiB
C
52 lines
1.1 KiB
C
#include "gen_queue.h"
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#include <memory.h>
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#include <stdbool.h>
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Queue *q_create(uint32_t length, uint32_t elemSize, uint8_t *mem) {
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Queue *q = (Queue *)mem;
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q->length = length;
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q->elemSize = elemSize;
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q->readIdx = 0;
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q->writeIdx = 0;
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memset(q->elements, 0, length * elemSize);
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return q;
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}
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void q_clear(Queue *q) {
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q->readIdx = 0;
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q->writeIdx = 0;
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memset(q->elements, 0, q->length * q->elemSize);
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}
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uint32_t q_avail(const Queue *q) {
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return q->writeIdx - q->readIdx;
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}
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#define MQ_NEXT(size, current) (((current) + 1) % (size))
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bool q_push(Queue *q, const void *src) {
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if (MQ_NEXT(q->length, q->writeIdx) == q->readIdx) { // cannot push, queue is full
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return false;
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}
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// can push
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memcpy(q->elements + q->writeIdx * q->elemSize, src, q->elemSize);
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// advance write pointer
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q->writeIdx = MQ_NEXT(q->length, q->writeIdx);
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return true;
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}
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void q_top(Queue *q, void *dest) {
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memcpy(dest, q->elements + q->readIdx, q->elemSize);
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}
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void q_pop(Queue *q) {
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if (q_avail(q) > 0) { // if there's something to pop
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q->readIdx = MQ_NEXT(q->length, q->readIdx);
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}
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}
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