nuttx/libs/libc/stream/lib_meminstream.c
Xiang Xiao b869c1ce0e libc: Move stream implementation from libs/libc/stdio to libs/libc/stream
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
2021-12-14 00:51:59 -06:00

88 lines
3.0 KiB
C

/****************************************************************************
* libs/libc/stream/lib_meminstream.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 <assert.h>
#include "libc.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: meminstream_getc
****************************************************************************/
static int meminstream_getc(FAR struct lib_instream_s *this)
{
FAR struct lib_meminstream_s *mthis = (FAR struct lib_meminstream_s *)this;
int ret;
DEBUGASSERT(this);
/* Get the next character (if any) from the buffer */
if (this->nget < mthis->buflen)
{
ret = mthis->buffer[this->nget];
this->nget++;
}
else
{
ret = EOF;
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: lib_meminstream
*
* Description:
* Initializes a stream for use with a fixed-size memory buffer.
*
* Input Parameters:
* instream - User allocated, uninitialized instance of struct
* lib_meminstream_s to be initialized.
* bufstart - Address of the beginning of the fixed-size memory buffer
* buflen - Size of the fixed-sized memory buffer in bytes
*
* Returned Value:
* None (instream initialized).
*
****************************************************************************/
void lib_meminstream(FAR struct lib_meminstream_s *instream,
FAR const char *bufstart, int buflen)
{
instream->public.get = meminstream_getc;
instream->public.nget = 0; /* Will be buffer index */
instream->buffer = bufstart; /* Start of buffer */
instream->buflen = buflen; /* Length of the buffer */
}