/**************************************************************************** * mm/iob/iob_tailroom.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 #include #include "iob.h" /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: iob_tailroom * * Description: * Return the number of bytes at the tail of the I/O buffer chain which * can be used to append data without additional allocations. * ****************************************************************************/ unsigned int iob_tailroom(FAR struct iob_s *iob) { while (iob->io_flink != NULL) { iob = iob->io_flink; } return CONFIG_IOB_BUFSIZE - (iob->io_offset + iob->io_len); }