56 lines
1.2 KiB
C
56 lines
1.2 KiB
C
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#include "queue.h"
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#include "../runtime/stdio.h"
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void queue_InitBuffered(queue *q, void *buffer, uintptr_t size) {
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q->data = q->begin = q->end = buffer;
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q->size = size;
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q->count = 0;
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}
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void queue_PushByte(queue *q, const uint8_t b) {
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if (q->count == q->size) { // no more space
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io_Printf("queue_PushByte: full[%llu bytes], discarding byte 0x%x\n", q->size, b);
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return;
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}
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q->count++;
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*((uint8_t *)(q->end++)) = b;
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if (q->end == q->data + q->size)
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q->end = q->data; // out of the buffer: wrap around
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}
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uint8_t queue_PopByte(queue *q) {
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if (q->count == 0) {
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io_WriteConsoleASCII("queue_PopByte: poping an empty queue\n");
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return 0;
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}
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q->count--;
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uint8_t data = *((uint8_t *)(q->begin++));
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if (q->begin == q->data + q->size)
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q->begin = q->data; // wrap around
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return data;
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}
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uint8_t queue_TopByte(queue *q) {
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if (q->count == 0) {
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io_WriteConsoleASCII("queue_TopByte: accessing an empty queue\n");
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return 0;
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}
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return *((uint8_t *)q->begin);
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}
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bool queue_Empty(queue *q) {
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return q->count == 0;
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}
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uintptr_t queue_Size(queue *q) {
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return q->count;
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}
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uintptr_t queue_Space(queue *q) {
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return q->size - q->count;
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}
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