77 lines
1.3 KiB
C
77 lines
1.3 KiB
C
#include "ringbuffer.h"
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#include <stdlib.h>
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ringbuffer_t
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ringbuffer_new(size_t size)
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{
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ringbuffer_t buffer = malloc(sizeof(struct ringbuffer_s));
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if(!buffer)
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{
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return NULL;
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}
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buffer->buffer = malloc(sizeof(char) * size);
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if(!buffer->buffer)
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{
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free(buffer);
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return NULL;
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}
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buffer->length = size;
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buffer->head = 0;
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buffer->tail = 0;
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buffer->ovf = 0;
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return buffer;
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}
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int
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ringbuffer_nonempty(ringbuffer_t buffer)
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{
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return (buffer->head != buffer->tail) || buffer->ovf;
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}
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unsigned char
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ringbuffer_get_char(ringbuffer_t buffer)
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{
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unsigned char result;
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if((buffer->head == buffer->tail) && !buffer->ovf)
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{
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return 0;
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}
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buffer->ovf = 0;
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result = buffer->buffer[buffer->tail];
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buffer->tail = (buffer->tail + 1) % buffer->length;
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return result;
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}
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int
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ringbuffer_put_char(ringbuffer_t buffer
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, unsigned char c)
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{
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if(buffer->ovf)
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{
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return 1;
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}
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buffer->buffer[buffer->head] = c;
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buffer->head = (buffer->head + 1) % buffer->length;
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if(buffer->head == buffer->tail)
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{
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buffer->ovf = 1;
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}
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return 0;
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}
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size_t ringbuffer_empty_bytes(ringbuffer_t buffer)
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{
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if(buffer->ovf)
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{
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return 0;
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}
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int raw_empty = buffer->length - (buffer->head - buffer->tail);
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if(raw_empty > buffer->length)
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{
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return raw_empty - buffer->length;
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}
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return raw_empty;
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}
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