third_party/harfbuzz/src/harfbuzz-stream.c

   1 /*
   2  * Copyright (C) 2005  David Turner
   3  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
   4  * Copyright (C) 2007  Red Hat, Inc.
   5  *
   6  * This is part of HarfBuzz, an OpenType Layout engine library.
   7  *
   8  * Permission is hereby granted, without written agreement and without
   9  * license or royalty fees, to use, copy, modify, and distribute this
  10  * software and its documentation for any purpose, provided that the
  11  * above copyright notice and the following two paragraphs appear in
  12  * all copies of this software.
  13  *
  14  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  15  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  16  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  17  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  18  * DAMAGE.
  19  *
  20  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  21  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  22  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  23  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  24  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  25  *
  26  * Red Hat Author(s): Behdad Esfahbod
  27  */
  28
  29 #include "harfbuzz-impl.h"
  30 #include "harfbuzz-stream-private.h"
  31 #include <stdlib.h>
  32
  33 #if 0
  34 #include <stdio.h>
  35 #define  LOG(x)  _hb_log x
  36
  37 static void
  38 _hb_log( const char*   format, ... )
  39 {
  40   va_list  ap;
  41
  42   va_start( ap, format );
  43   vfprintf( stderr, format, ap );
  44   va_end( ap );
  45 }
  46
  47 #else
  48 #define  LOG(x)  do {} while (0)
  49 #endif
  50
  51 HB_INTERNAL void
  52 _hb_close_stream( HB_Stream stream )
  53 {
  54   if (!stream)
  55       return;
  56   free(stream->base);
  57   free(stream);
  58 }
  59
  60
  61 HB_INTERNAL HB_Int
  62 _hb_stream_pos( HB_Stream stream )
  63 {
  64   LOG(( "_hb_stream_pos() -> %ld\n", stream->pos ));
  65   return stream->pos;
  66 }
  67
  68
  69 HB_INTERNAL HB_Error
  70 _hb_stream_seek( HB_Stream stream,
  71                  HB_UInt pos )
  72 {
  73   HB_Error  error = (HB_Error)0;
  74
  75   stream->pos = pos;
  76   if (pos > stream->size)
  77       error = ERR(HB_Err_Read_Error);
  78
  79   LOG(( "_hb_stream_seek(%ld) -> 0x%04X\n", pos, error ));
  80   return error;
  81 }
  82
  83
  84 HB_INTERNAL HB_Error
  85 _hb_stream_frame_enter( HB_Stream stream,
  86                         HB_UInt count )
  87 {
  88   HB_Error  error = HB_Err_Ok;
  89
  90   /* check new position, watch for overflow */
  91   if (HB_UNLIKELY (stream->pos + count > stream->size ||
  92                    stream->pos + count < stream->pos))
  93   {
  94     error = ERR(HB_Err_Read_Error);
  95     goto Exit;
  96   }
  97
  98   /* set cursor */
  99   stream->cursor = stream->base + stream->pos;
 100   stream->pos   += count;
 101
 102 Exit:
 103   LOG(( "_hb_stream_frame_enter(%ld) -> 0x%04X\n", count, error ));
 104   return error;
 105 }
 106
 107
 108 HB_INTERNAL void
 109 _hb_stream_frame_exit( HB_Stream stream )
 110 {
 111   stream->cursor = NULL;
 112
 113   LOG(( "_hb_stream_frame_exit()\n" ));
 114 }