1  /****************************************************************************
       2   *
       3   * psread.c
       4   *
       5   *   Adobe's code for stream handling (body).
       6   *
       7   * Copyright 2007-2013 Adobe Systems Incorporated.
       8   *
       9   * This software, and all works of authorship, whether in source or
      10   * object code form as indicated by the copyright notice(s) included
      11   * herein (collectively, the "Work") is made available, and may only be
      12   * used, modified, and distributed under the FreeType Project License,
      13   * LICENSE.TXT.  Additionally, subject to the terms and conditions of the
      14   * FreeType Project License, each contributor to the Work hereby grants
      15   * to any individual or legal entity exercising permissions granted by
      16   * the FreeType Project License and this section (hereafter, "You" or
      17   * "Your") a perpetual, worldwide, non-exclusive, no-charge,
      18   * royalty-free, irrevocable (except as stated in this section) patent
      19   * license to make, have made, use, offer to sell, sell, import, and
      20   * otherwise transfer the Work, where such license applies only to those
      21   * patent claims licensable by such contributor that are necessarily
      22   * infringed by their contribution(s) alone or by combination of their
      23   * contribution(s) with the Work to which such contribution(s) was
      24   * submitted.  If You institute patent litigation against any entity
      25   * (including a cross-claim or counterclaim in a lawsuit) alleging that
      26   * the Work or a contribution incorporated within the Work constitutes
      27   * direct or contributory patent infringement, then any patent licenses
      28   * granted to You under this License for that Work shall terminate as of
      29   * the date such litigation is filed.
      30   *
      31   * By using, modifying, or distributing the Work you indicate that you
      32   * have read and understood the terms and conditions of the
      33   * FreeType Project License as well as those provided in this section,
      34   * and you accept them fully.
      35   *
      36   */
      37  
      38  
      39  #include "psft.h"
      40  #include <freetype/internal/ftdebug.h>
      41  
      42  #include "psglue.h"
      43  
      44  #include "pserror.h"
      45  
      46  
      47    /* Define CF2_IO_FAIL as 1 to enable random errors and random */
      48    /* value errors in I/O.                                       */
      49  #define CF2_IO_FAIL  0
      50  
      51  
      52  #if CF2_IO_FAIL
      53  
      54    /* set the .00 value to a nonzero probability */
      55    static int
      56    randomError2( void )
      57    {
      58      /* for region buffer ReadByte (interp) function */
      59      return (double)rand() / RAND_MAX < .00;
      60    }
      61  
      62    /* set the .00 value to a nonzero probability */
      63    static CF2_Int
      64    randomValue()
      65    {
      66      return (double)rand() / RAND_MAX < .00 ? rand() : 0;
      67    }
      68  
      69  #endif /* CF2_IO_FAIL */
      70  
      71  
      72    /* Region Buffer                                      */
      73    /*                                                    */
      74    /* Can be constructed from a copied buffer managed by */
      75    /* `FCM_getDatablock'.                                */
      76    /* Reads bytes with check for end of buffer.          */
      77  
      78    /* reading past the end of the buffer sets error and returns zero */
      79    FT_LOCAL_DEF( CF2_Int )
      80    cf2_buf_readByte( CF2_Buffer  buf )
      81    {
      82      if ( buf->ptr < buf->end )
      83      {
      84  #if CF2_IO_FAIL
      85        if ( randomError2() )
      86        {
      87          CF2_SET_ERROR( buf->error, Invalid_Stream_Operation );
      88          return 0;
      89        }
      90  
      91        return *(buf->ptr)++ + randomValue();
      92  #else
      93        return *(buf->ptr)++;
      94  #endif
      95      }
      96      else
      97      {
      98        CF2_SET_ERROR( buf->error, Invalid_Stream_Operation );
      99        return 0;
     100      }
     101    }
     102  
     103  
     104    /* note: end condition can occur without error */
     105    FT_LOCAL_DEF( FT_Bool )
     106    cf2_buf_isEnd( CF2_Buffer  buf )
     107    {
     108      return FT_BOOL( buf->ptr >= buf->end );
     109    }
     110  
     111  
     112  /* END */