补充 ringbufer 接口

Signed-off-by: a1012112796 <1012112796@qq.com>

rt-thread/components/drivers/ipc/ringbuffer.c

@@ -464,4 +464,84 @@ void rt_ringbuffer_destroy(struct rt_ringbuffer *rb)
 }
 RTM_EXPORT(rt_ringbuffer_destroy);
 
+/**
+ *  copy data from ring buffer
+ */
+rt_size_t rt_ringbuffer_cpy(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  */
+    size = rt_ringbuffer_data_len(rb);
+
+    /* no data */
+    if (size == 0)
+        return 0;
+
+    /* less data */
+    if (size < length)
+        length = size;
+
+    if (rb->buffer_size - rb->read_index > length)
+    {
+        /* copy all of data */
+        memcpy(ptr, &rb->buffer_ptr[rb->read_index], length);
+        /* this should not cause overflow because there is enough space for
+         * length of data in current mirror */
+        //rb->read_index += length;
+        return length;
+    }
+
+    memcpy(&ptr[0],
+           &rb->buffer_ptr[rb->read_index],
+           rb->buffer_size - rb->read_index);
+    memcpy(&ptr[rb->buffer_size - rb->read_index],
+           &rb->buffer_ptr[0],
+           length - (rb->buffer_size - rb->read_index));
+
+    /* we are going into the other side of the mirror */
+    //rb->read_mirror = ~rb->read_mirror;
+    //rb->read_index = length - (rb->buffer_size - rb->read_index);
+
+    return length;
+}
+RTM_EXPORT(rt_ringbuffer_copy);
+
+/**
+ *  del data from ring buffer
+ */
+rt_size_t rt_ringbuffer_del(struct rt_ringbuffer *rb,
+                            rt_uint16_t           length)
+{
+    rt_size_t size;
+
+    RT_ASSERT(rb != RT_NULL);
+
+    /* whether has enough data  */
+    size = rt_ringbuffer_data_len(rb);
+
+    /* no data */
+    if (size == 0)
+        return 0;
+
+    /* less data */
+    if (size < length)
+        length = size;
+
+    if (rb->buffer_size - rb->read_index > length)
+    {
+        rb->read_index += length;
+        return length;
+    }
+    rb->read_mirror = ~rb->read_mirror;
+    rb->read_index = length - (rb->buffer_size - rb->read_index);
+
+    return length;
+}
+RTM_EXPORT(rt_ringbuffer_del);
+
 #endif