mm/iob: add iob_get_queue_size() helper

Change-Id: I117530f364cbef1e011638ff6d14087b7447bde7
Signed-off-by: chao.an <anchao@xiaomi.com>

include/nuttx/mm/iob.h

@@ -457,6 +457,18 @@ void iob_destroy_queue(FAR struct iob_queue_s *qhead,
 int iob_get_queue_count(FAR struct iob_queue_s *queue);
 #endif /* CONFIG_IOB_NCHAINS > 0 */
 
+/****************************************************************************
+ * Name: iob_get_queue_size
+ *
+ * Description:
+ *   Queue helper for get the iob entry size.
+ *
+ ****************************************************************************/
+
+#if CONFIG_IOB_NCHAINS > 0
+size_t iob_get_queue_size(FAR struct iob_queue_s *queue);
+#endif /* CONFIG_IOB_NCHAINS > 0 */
+
 /****************************************************************************
  * Name: iob_copyin
  *

mm/iob/Make.defs

@@ -25,7 +25,7 @@ ifeq ($(CONFIG_MM_IOB),y)
 CSRCS += iob_add_queue.c iob_alloc.c iob_alloc_qentry.c iob_clone.c
 CSRCS += iob_concat.c iob_copyin.c iob_copyout.c iob_contig.c iob_free.c
 CSRCS += iob_free_chain.c iob_free_qentry.c iob_destroy_queue.c
-CSRCS += iob_free_queue.c iob_get_queue_count.c
+CSRCS += iob_free_queue.c iob_get_queue_count.c iob_get_queue_size.c
 CSRCS += iob_initialize.c iob_pack.c iob_peek_queue.c iob_remove_queue.c
 CSRCS += iob_statistics.c iob_trimhead.c iob_trimhead_queue.c iob_trimtail.c
 CSRCS += iob_navail.c

mm/iob/iob_get_queue_size.c

@@ -0,0 +1,60 @@
+/****************************************************************************
+ * mm/iob/iob_get_queue_size.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/mm/iob.h>
+#include "iob.h"
+
+#if CONFIG_IOB_NCHAINS > 0
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: iob_get_queue_size
+ *
+ * Description:
+ *   Queue helper for get the iob entry count.
+ *
+ ****************************************************************************/
+
+size_t iob_get_queue_size(FAR struct iob_queue_s *queue)
+{
+  FAR struct iob_qentry_s *iobq;
+  FAR struct iob_s *iob;
+  size_t total = 0;
+
+  for (iobq = queue->qh_head; iobq != NULL; iobq = iobq->qe_flink)
+    {
+      for (iob = iobq->qe_head; iob; iob = iob->io_flink)
+        {
+          total += iob->io_len;
+        }
+    }
+
+  return total;
+}
+
+#endif /* CONFIG_IOB_NCHAINS > 0 */