diff options
Diffstat (limited to 'nuttx/libc/stdio/lib_libfwrite.c')
-rw-r--r-- | nuttx/libc/stdio/lib_libfwrite.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/nuttx/libc/stdio/lib_libfwrite.c b/nuttx/libc/stdio/lib_libfwrite.c new file mode 100644 index 000000000..b917b3b56 --- /dev/null +++ b/nuttx/libc/stdio/lib_libfwrite.c @@ -0,0 +1,179 @@ +/**************************************************************************** + * libc/stdio/lib_libfwrite.c + * + * Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> /* for CONFIG_STDIO_BUFFER_SIZE */ + +#include <sys/types.h> +#include <stdbool.h> +#include <stdio.h> +#include <unistd.h> +#include <fcntl.h> +#include <errno.h> + +#include "lib_internal.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Type Declarations + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * Global Constant Data + ****************************************************************************/ + +/**************************************************************************** + * Global Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Constant Data + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: lib_fwrite + ****************************************************************************/ + +ssize_t lib_fwrite(FAR const void *ptr, size_t count, FAR FILE *stream) +#if CONFIG_STDIO_BUFFER_SIZE > 0 +{ + FAR const unsigned char *start = ptr; + FAR const unsigned char *src = ptr; + ssize_t ret = ERROR; + unsigned char *dest; + + /* Make sure that writing to this stream is allowed */ + + if (!stream || (stream->fs_oflags & O_WROK) == 0) + { + set_errno(EBADF); + goto errout; + } + + /* Get exclusive access to the stream */ + + lib_take_semaphore(stream); + + /* If the buffer is currently being used for read access, then + * discard all of the read-ahead data. We do not support concurrent + * buffered read/write access. + */ + + if (lib_rdflush(stream) < 0) + { + goto errout_with_semaphore; + } + + /* Loop until all of the bytes have been buffered */ + + while (count > 0) + { + /* Determine the number of bytes left in the buffer */ + + size_t gulp_size = stream->fs_bufend - stream->fs_bufpos; + + /* Will the user data fit into the amount of buffer space + * that we have left? + */ + + if (gulp_size > count) + { + /* Yes, clip the gulp to the size of the user data */ + + gulp_size = count; + } + + /* Adjust the number of bytes remaining to be transferred + * on the next pass through the loop (might be zero). + */ + + count -= gulp_size; + + /* Transfer the data into the buffer */ + + for (dest = stream->fs_bufpos; gulp_size > 0; gulp_size--) + { + *dest++ = *src++; + } + stream->fs_bufpos = dest; + + /* Is the buffer full? */ + + if (dest >= stream->fs_bufend) + { + /* Flush the buffered data to the IO stream */ + + int bytes_buffered = lib_fflush(stream, false); + if (bytes_buffered < 0) + { + goto errout_with_semaphore; + } + } + } + + /* Return the number of bytes written */ + + ret = src - start; + +errout_with_semaphore: + lib_give_semaphore(stream); + +errout: + return ret; +} +#else +{ + return write(stream->fs_filedes, ptr, count); +} +#endif /* CONFIG_STDIO_BUFFER_SIZE */ + |