udp_send: Force chunk queuing.

[paraslash.git] / chunk_queue.c

diff --git a/chunk_queue.c b/chunk_queue.c
index ad28190a163d32c4731316a3bd609f626f7871ec..5b102f286641d7b93418f3ae92e7dcdf6f71d0f6 100644 (file)
--- a/chunk_queue.c
+++ b/chunk_queue.c
@@ -92,6 +92,34 @@ void cq_dequeue(struct chunk_queue *cq)
        free(qc);
 }
 
+/**
+ * Force to add a chunk to the given queue.
+ *
+ * \param cq See \ref cq_enqueue.
+ * \param buf See \ref cq_enqueue.
+ * \param num_bytes See \ref cq_enqueue.
+ *
+ * If queuing the given buffer would result in exceeding the maximal queue
+ * size, buffers are dropped from the beginning of the queue. Note that this
+ * function still might fail.
+ *
+ * \return Standard.
+ */
+int cq_force_enqueue(struct chunk_queue *cq, const char *buf, size_t num_bytes)
+{
+       int ret;
+
+       if (num_bytes > cq->max_pending)
+               return -E_QUEUE;
+       for (;;) {
+               ret = cq_enqueue(cq, buf, num_bytes);
+               if (ret >= 0)
+                       return ret;
+               cq_dequeue(cq);
+       }
+       /* never reached */
+}
+
 /**
  * Change the number of bytes sent for the current queued chunk.
  *