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 libc_hidden_proto(memchr)
  11 libc_hidden_proto(memcpy)
  12 libc_hidden_proto(memrchr)
  13
  14 #ifdef __STDIO_BUFFERS
  15
  16 /* Either buffer data or (commit buffer if necessary and) write. */
  17
  18 size_t attribute_hidden __stdio_fwrite(const unsigned char * __restrict buffer,
  19                                           size_t bytes,
  20                                           register FILE * __restrict stream)
  21 {
  22         size_t pending;
  23         const unsigned char *p;
  24
  25         __STDIO_STREAM_VALIDATE(stream);
  26         assert(__STDIO_STREAM_IS_WRITING(stream));
  27         assert(buffer);
  28         assert(bytes);
  29
  30         if (!__STDIO_STREAM_IS_NBF(stream)) { /* FBF or LBF. */
  31 #ifdef __UCLIBC_MJN3_ONLY__
  32 #warning CONSIDER: Try to consolidate some of the code?
  33 #endif
  34                 if (__STDIO_STREAM_IS_FAKE_VSNPRINTF(stream)) {
  35                         pending = __STDIO_STREAM_BUFFER_WAVAIL(stream);
  36                         if (pending > bytes) {
  37                                 pending = bytes;
  38                         }
  39                         memcpy(stream->__bufpos, buffer, pending);
  40                         stream->__bufpos += pending;
  41                         __STDIO_STREAM_VALIDATE(stream);
  42                         return bytes;
  43                 }
  44
  45 /*      RETRY: */
  46                 if (bytes <= __STDIO_STREAM_BUFFER_WAVAIL(stream)) {
  47                         memcpy(stream->__bufpos, buffer, bytes);
  48                         stream->__bufpos += bytes;
  49                         if (__STDIO_STREAM_IS_LBF(stream)
  50                                 && memrchr(buffer, '\n', bytes) /* Search backwards. */
  51                                 ) {
  52                                 if ((pending = __STDIO_COMMIT_WRITE_BUFFER(stream)) > 0) {
  53                                         if (pending > bytes) {
  54                                                 pending = bytes;
  55                                         }
  56                                         buffer += (bytes - pending);
  57                                         if ((p = memchr(buffer, '\n', pending)) != NULL) {
  58                                                 pending = (buffer + pending) - p;
  59                                                 bytes -= pending;
  60                                                 stream->__bufpos -= pending;
  61                                         }
  62                                 }
  63                         }
  64                         __STDIO_STREAM_VALIDATE(stream);
  65                         return bytes;
  66                 }
  67                 /* FBF or LBF and not enough space in buffer. */
  68                 if (__STDIO_STREAM_BUFFER_WUSED(stream)) { /* Buffered data. */
  69                         if (__STDIO_COMMIT_WRITE_BUFFER(stream)) { /* Commit failed! */
  70                                 return 0;
  71                         }
  72 #ifdef __UCLIBC_MJN3_ONLY__
  73 #warning CONSIDER: Do we want to try again if data now fits in buffer?
  74 #endif
  75 /*                      goto RETRY; */
  76                 }
  77         }
  78
  79         return __stdio_WRITE(stream, buffer, bytes);
  80 }
  81
  82 #endif