incubator-nuttx/libs/libc/stream/lib_rawoutstream.c

118 lines
3.9 KiB
C

/****************************************************************************
* libs/libc/stream/lib_rawoutstream.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 <unistd.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include "libc.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: rawsostream_putc
****************************************************************************/
static void rawsostream_putc(FAR struct lib_sostream_s *this, int ch)
{
FAR struct lib_rawsostream_s *rthis = (FAR struct lib_rawsostream_s *)this;
char buffer = ch;
int nwritten;
int errcode;
DEBUGASSERT(this && rthis->fd >= 0);
/* Loop until the character is successfully transferred or until an
* irrecoverable error occurs.
*/
do
{
nwritten = _NX_WRITE(rthis->fd, &buffer, 1);
if (nwritten == 1)
{
this->nput++;
return;
}
/* The only expected error is EINTR, meaning that the write operation
* was awakened by a signal. Zero would not be a valid return value
* from _NX_WRITE().
*/
errcode = _NX_GETERRNO(nwritten);
DEBUGASSERT(nwritten < 0);
}
while (errcode == EINTR);
}
/****************************************************************************
* Name: rawsostream_seek
****************************************************************************/
static off_t rawsostream_seek(FAR struct lib_sostream_s *this, off_t offset,
int whence)
{
FAR struct lib_rawsostream_s *mthis = (FAR struct lib_rawsostream_s *)this;
DEBUGASSERT(this);
return _NX_SEEK(mthis->fd, offset, whence);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: lib_rawsostream
*
* Description:
* Initializes a stream for use with a file descriptor.
*
* Input Parameters:
* outstream - User allocated, uninitialized instance of struct
* lib_rawsostream_s to be initialized.
* fd - User provided file/socket descriptor (must have been opened
* for write access).
*
* Returned Value:
* None (User allocated instance initialized).
*
****************************************************************************/
void lib_rawsostream(FAR struct lib_rawsostream_s *outstream, int fd)
{
outstream->public.put = rawsostream_putc;
outstream->public.flush = lib_snoflush;
outstream->public.seek = rawsostream_seek;
outstream->public.nput = 0;
outstream->fd = fd;
}