| /**************************************************************************** |
| * lib/lib_libfwrite.c |
| * |
| * Copyright (C) 2007-2009 Gregory Nutt. All rights reserved. |
| * Author: Gregory Nutt <spudmonkey@racsa.co.cr> |
| * |
| * 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) |
| { |
| *get_errno_ptr() = 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 */ |
| |