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#include <rtthread.h>
#include <rtdevice.h>
void rt_ringbuffer_init(struct rt_ringbuffer* rb, rt_uint8_t *pool, rt_uint16_t size)
{
RT_ASSERT(rb != RT_NULL);
/* initialize read and write index */
rb->read_index = rb->write_index = 0;
/* set buffer pool and size */
rb->buffer_ptr = pool;
rb->buffer_size = size;
}
rt_size_t rt_ringbuffer_put(struct rt_ringbuffer* rb, const rt_uint8_t *ptr, rt_uint16_t length)
{
rt_size_t size;
RT_ASSERT(rb != RT_NULL);
/* whether has enough space */
if (rb->read_index > rb->write_index)
size = rb->read_index - rb->write_index;
else
size = rb->buffer_size - rb->write_index + rb->read_index;
/* no space */
if (size == 0) return 0;
/* drop some data */
if (size < length) length = size;
if (rb->read_index > rb->write_index)
{
/* read_index - write_index = empty space */
rt_memcpy(&rb->buffer_ptr[rb->write_index], ptr, length);
rb->write_index += length;
}
else
{
if (rb->buffer_size - rb->write_index > length)
{
/* there is enough space after write_index */
rt_memcpy(&rb->buffer_ptr[rb->write_index], ptr, length);
rb->write_index += length;
}
else
{
rt_memcpy(&rb->buffer_ptr[rb->write_index], ptr,
rb->buffer_size - rb->write_index);
rt_memcpy(&rb->buffer_ptr[0], &ptr[rb->buffer_size - rb->write_index],
length - (rb->buffer_size - rb->write_index));
rb->write_index = length - (rb->buffer_size - rb->write_index);
}
}
return length;
}
/**
* put a character into ring buffer
*/
rt_size_t rt_ringbuffer_putchar(struct rt_ringbuffer* rb, const rt_uint8_t ch)
{
rt_uint16_t next;
RT_ASSERT(rb != RT_NULL);
/* whether has enough space */
next = rb->write_index + 1;
if (next >= rb->buffer_size) next = 0;
if (next == rb->read_index) return 0;
/* put character */
rb->buffer_ptr[rb->write_index] = ch;
rb->write_index = next;
return 1;
}
/**
* get data from ring buffer
*/
rt_size_t rt_ringbuffer_get(struct rt_ringbuffer* rb, rt_uint8_t *ptr, rt_uint16_t length)
{
rt_size_t size;
RT_ASSERT(rb != RT_NULL);
/* whether has enough data */
if (rb->read_index > rb->write_index)
size = rb->buffer_size - rb->read_index + rb->write_index;
else
size = rb->write_index - rb->read_index;
/* no data */
if (size == 0) return 0;
/* less data */
if (size < length) length = size;
if (rb->read_index > rb->write_index)
{
if (rb->buffer_size - rb->read_index > length)
{
/* copy directly */
rt_memcpy(ptr, &rb->buffer_ptr[rb->read_index], length);
rb->read_index += length;
}
else
{
/* copy first and second */
rt_memcpy(ptr, &rb->buffer_ptr[rb->read_index],
rb->buffer_size - rb->read_index);
rt_memcpy(&ptr[rb->buffer_size - rb->read_index], &rb->buffer_ptr[0],
length - rb->buffer_size + rb->read_index);
rb->read_index = length - rb->buffer_size + rb->read_index;
}
}
else
{
rt_memcpy(ptr, &rb->buffer_ptr[rb->read_index], length);
rb->read_index += length;
}
return length;
}
/**
* get available data size
*/
rt_size_t rt_ringbuffer_available_size(struct rt_ringbuffer* rb)
{
rt_size_t size;
RT_ASSERT(rb != RT_NULL);
if (rb->read_index > rb->write_index)
size = rb->buffer_size - rb->read_index + rb->write_index;
else
size = rb->write_index - rb->read_index;
/* return the available size */
return size;
}
/**
* get empty space size
*/
rt_size_t rt_ringbuffer_emptry_size(struct rt_ringbuffer* rb)
{
RT_ASSERT(rb != RT_NULL);
return rb->buffer_size - rt_ringbuffer_available_size(rb);
}
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