libc/stdio/_fwrite.c

   1 /* Copyright (C) 2004       Manuel Novoa III    <mjn3@codepoet.org>
   2  *
   3  * GNU Library General Public License (LGPL) version 2 or later.
   4  *
   5  * Dedicated to Toni.  See uClibc/DEDICATION.mjn3 for details.
   6  */
   7
   8 #include "_stdio.h"
   9
  10
  11 #ifdef __STDIO_BUFFERS
  12
  13 /* Either buffer data or (commit buffer if necessary and) write. */
  14
  15 size_t attribute_hidden __stdio_fwrite(const unsigned char * __restrict buffer,
  16                                           size_t bytes,
  17                                           register FILE * __restrict stream)
  18 {
  19         size_t pending;
  20         const unsigned char *p;
  21
  22         __STDIO_STREAM_VALIDATE(stream);
  23         assert(__STDIO_STREAM_IS_WRITING(stream));
  24         assert(buffer);
  25         assert(bytes);
  26
  27         if (!__STDIO_STREAM_IS_NBF(stream)) { /* FBF or LBF. */
  28                 if (__STDIO_STREAM_IS_FAKE_VSNPRINTF(stream)) {
  29                         pending = __STDIO_STREAM_BUFFER_WAVAIL(stream);
  30                         if (pending > bytes) {
  31                                 pending = bytes;
  32                         }
  33                         memcpy(stream->__bufpos, buffer, pending);
  34                         stream->__bufpos += pending;
  35                         __STDIO_STREAM_VALIDATE(stream);
  36                         return bytes;
  37                 }
  38
  39 /*      RETRY: */
  40                 if (bytes <= __STDIO_STREAM_BUFFER_WAVAIL(stream)) {
  41                         memcpy(stream->__bufpos, buffer, bytes);
  42                         stream->__bufpos += bytes;
  43                         if (__STDIO_STREAM_IS_LBF(stream)
  44                                 && memrchr(buffer, '\n', bytes) /* Search backwards. */
  45                                 ) {
  46                                 if ((pending = __STDIO_COMMIT_WRITE_BUFFER(stream)) > 0) {
  47                                         if (pending > bytes) {
  48                                                 pending = bytes;
  49                                         }
  50                                         buffer += (bytes - pending);
  51                                         if ((p = memchr(buffer, '\n', pending)) != NULL) {
  52                                                 pending = (buffer + pending) - p;
  53                                                 bytes -= pending;
  54                                                 stream->__bufpos -= pending;
  55                                         }
  56                                 }
  57                         }
  58                         __STDIO_STREAM_VALIDATE(stream);
  59                         return bytes;
  60                 }
  61                 /* FBF or LBF and not enough space in buffer. */
  62                 if (__STDIO_STREAM_BUFFER_WUSED(stream)) { /* Buffered data. */
  63                         if (__STDIO_COMMIT_WRITE_BUFFER(stream)) { /* Commit failed! */
  64                                 return 0;
  65                         }
  66 /*                      goto RETRY; */
  67                 }
  68         }
  69
  70         return __stdio_WRITE(stream, buffer, bytes);
  71 }
  72
  73 #endif