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#include "ring_queue.h"
#include <stdlib.h>
#include <string.h>
#include "defines.h"
ring_queue* ring_queue_new(size_t type_size, size_t capacity, void* memory) {
ring_queue* q = malloc(sizeof(ring_queue));
q->len = 0;
q->capacity = capacity;
q->type_size = type_size;
q->head = 0;
q->tail = -1;
if (memory) {
// caller owns the memory
q->owns_memory = false;
q->data = memory;
} else {
// ring queue should own the memory
q->owns_memory = true;
q->data = malloc(capacity * type_size);
}
return q;
}
void ring_queue_free(ring_queue* queue) {
if (queue) {
if (queue->owns_memory) {
free(queue->data);
}
free(queue);
}
}
bool ring_queue_enqueue(ring_queue* queue, const void* value) {
if (queue->len == queue->capacity) {
return false;
}
queue->tail = (queue->tail + 1) % queue->capacity;
memcpy(queue->data + (queue->tail * queue->type_size), value, queue->type_size);
queue->len++;
return true;
}
bool ring_queue_dequeue(ring_queue* queue, void* out_value) {
if (queue->len == 0) {
// queue is empty
return false;
}
memcpy(out_value, queue->data + (queue->head * queue->type_size), queue->type_size);
queue->head = (queue->head + 1) % queue->capacity;
queue->len--;
return true;
}
bool ring_queue_peek(const ring_queue* queue, void* out_value) {
if (queue->len == 0) {
// queue is empty
return false;
}
memcpy(out_value, queue->data + (queue->head * queue->type_size), queue->type_size);
return true;
}
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