53 lines
1.9 KiB
C
53 lines
1.9 KiB
C
/****************************************************************************
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* mm/iob/iob_tailroom.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <nuttx/mm/iob.h>
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#include "iob.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: iob_tailroom
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*
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* Description:
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* Return the number of bytes at the tail of the I/O buffer chain which
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* can be used to append data without additional allocations.
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*
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****************************************************************************/
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unsigned int iob_tailroom(FAR struct iob_s *iob)
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{
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while (iob->io_flink != NULL)
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{
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iob = iob->io_flink;
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}
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return CONFIG_IOB_BUFSIZE - (iob->io_offset + iob->io_len);
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}
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