nuttx/libs/libc/stream/lib_rawoutstream.c
yinshengkai b8e622ea5d libc/stream: unify stream behavior
Return the error code when all gets occur when an error is wrong
and return immediately when obtaining any valid data

Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>
2023-03-04 01:48:22 +08:00

111 lines
3.7 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: rawoutstream_puts
****************************************************************************/
static int rawoutstream_puts(FAR struct lib_outstream_s *this,
FAR const void *buf, int len)
{
FAR struct lib_rawoutstream_s *rthis =
(FAR struct lib_rawoutstream_s *)this;
int nwritten = 0;
do
{
nwritten = _NX_WRITE(rthis->fd, buf, len);
if (nwritten >= 0)
{
this->nput += nwritten;
return nwritten;
}
/* 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().
*/
nwritten = _NX_GETERRVAL(nwritten);
DEBUGASSERT(nwritten < 0);
}
while (nwritten == -EINTR);
return nwritten;
}
/****************************************************************************
* Name: rawoutstream_putc
****************************************************************************/
static void rawoutstream_putc(FAR struct lib_outstream_s *this, int ch)
{
char tmp = ch;
rawoutstream_puts(this, &tmp, 1);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: lib_rawoutstream
*
* Description:
* Initializes a stream for use with a file descriptor.
*
* Input Parameters:
* outstream - User allocated, uninitialized instance of struct
* lib_rawoutstream_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_rawoutstream(FAR struct lib_rawoutstream_s *outstream, int fd)
{
outstream->public.putc = rawoutstream_putc;
outstream->public.puts = rawoutstream_puts;
outstream->public.flush = lib_noflush;
outstream->public.nput = 0;
outstream->fd = fd;
}