diff options
Diffstat (limited to 'components/drivers/src/ringbuffer.c')
| -rw-r--r-- | components/drivers/src/ringbuffer.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/components/drivers/src/ringbuffer.c b/components/drivers/src/ringbuffer.c new file mode 100644 index 0000000000..6872c19dc3 --- /dev/null +++ b/components/drivers/src/ringbuffer.c @@ -0,0 +1,154 @@ +#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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