circularbuffer_C_API/circular_buffer.c at master · vinitjames/circularbuffer_C_API · GitHub

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#include "circular_buffer.h"
#include <stdlib.h>
#include <string.h>

struct CircularBuffer {
	void* buffer;
	size_t head;
	size_t tail;
	size_t length;
	size_t unitsize;
	bool full;
};

CircularBufferHandle CircularBufInit(void* buffer, size_t length, size_t unitsize){
	if ((buffer == NULL)||(length == 0)||(unitsize == 0)){
		return NULL;
	}


	CircularBufferHandle c_buf = (CircularBuffer*) malloc(sizeof(CircularBuffer));

	if (c_buf == NULL){
		return NULL;
	}
	c_buf->buffer = buffer;
	CircularBufReset(c_buf);
	c_buf->unitsize = unitsize;
	c_buf->length = length;
	return c_buf;
}

C_Buffer_Status CircularBufReset(CircularBufferHandle c_buf){
	if(c_buf == NULL)
		return ERR_HANDLE_NULL;
	c_buf->head = 0;
	c_buf->tail = 0;
	c_buf->full = false;
	return SUCC_BUF_RESET;
}

C_Buffer_Status CircularBufFree(CircularBufferHandle c_buf){
	if(c_buf == NULL)
		return ERR_HANDLE_NULL;
	free(c_buf);
	return SUCC_BUF_FREE;
}

bool CircularBufFull(CircularBufferHandle c_buf){
	return c_buf->full;
}

bool CircularBufEmpty(CircularBufferHandle c_buf){
	return (!c_buf->full)&&(c_buf->tail==c_buf->head);
}

size_t CircularBufCapacity(CircularBufferHandle c_buf){
	return c_buf->length;
}

size_t CircularBufUnitSize(CircularBufferHandle c_buf){
	return c_buf->unitsize;
}

size_t CircularBufSize(CircularBufferHandle c_buf){
	if(c_buf->full)
		return c_buf->length;
	if(c_buf->head >= c_buf->tail)
		return c_buf->head-c_buf->tail;
	return c_buf->length + c_buf->head - c_buf->tail;
}

static void _advancepointer(CircularBufferHandle c_buf){
	if(c_buf->full)
		c_buf->tail = (c_buf->tail + c_buf->unitsize)%c_buf->length;
	c_buf->head = (c_buf->head + c_buf->unitsize)%c_buf->length;
	c_buf->full = (c_buf->head == c_buf->tail);
}

static void _recedepointer(CircularBufferHandle c_buf){
	c_buf->full = false;
	c_buf->tail = (c_buf->tail + c_buf->unitsize)%c_buf->length;

}

C_Buffer_Status CircularBufInsert(CircularBufferHandle c_buf, void* data, size_t datasize){
	if(c_buf == NULL)
		return ERR_HANDLE_NULL;
	if (data == NULL)
		return ERR_DATA_NULL;
	if (datasize != c_buf->unitsize)
		return ERR_DATASIZE_UNEQ;
	memcpy((void*)((char*)c_buf->buffer+c_buf->head), data, c_buf->unitsize);
	_advancepointer(c_buf);
	return SUCC_BUF_INS;
}

C_Buffer_Status CircularBufInsert_V2(CircularBufferHandle c_buf, void* data, size_t datasize){
	if(c_buf == NULL)
		return ERR_HANDLE_NULL;
	if (data == NULL)
		return ERR_DATA_NULL;
	if(c_buf->full)
		return ERR_BUF_FULL;
	if (datasize != c_buf->unitsize)
		return ERR_DATASIZE_UNEQ;
	memcpy((void*)((char*)c_buf->buffer+c_buf->head), data, c_buf->unitsize);
	_advancepointer(c_buf);
	return SUCC_BUF_INS;
}

C_Buffer_Status CircularBufGet(CircularBufferHandle c_buf, void* data, size_t datasize){
	if(c_buf == NULL)
		return ERR_HANDLE_NULL;
	if (data == NULL)
		return ERR_DATA_NULL;
	if(CircularBufEmpty(c_buf))
		return ERR_BUF_EMPTY;
	if (datasize != c_buf->unitsize)
		return ERR_DATASIZE_UNEQ;
	memcpy(data, (void*)((char*)c_buf->buffer+c_buf->tail), c_buf->unitsize);
	_recedepointer(c_buf);
	return SUCC_BUF_INS;
}