path: root/tests/freetype/src/base/ftstream.c

/***************************************************************************/
/*                                                                         */
/*  ftstream.c                                                             */
/*                                                                         */
/*    I/O stream support (body).                                           */
/*                                                                         */
/*  Copyright 2000-2001, 2002, 2004, 2005, 2006, 2008, 2009, 2010 by       */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#include <ft2build.h>
#include FT_INTERNAL_STREAM_H
#include FT_INTERNAL_DEBUG_H


  /*************************************************************************/
  /*                                                                       */
  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  /* messages during execution.                                            */
  /*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT  trace_stream


  FT_BASE_DEF( void )
  FT_Stream_OpenMemory( FT_Stream       stream,
                        const FT_Byte*  base,
                        FT_ULong        size )
  {
    stream->base   = (FT_Byte*) base;
    stream->size   = size;
    stream->pos    = 0;
    stream->cursor = 0;
    stream->read   = 0;
    stream->close  = 0;
  }


  FT_BASE_DEF( void )
  FT_Stream_Close( FT_Stream  stream )
  {
    if ( stream && stream->close )
      stream->close( stream );
  }


  FT_BASE_DEF( FT_Error )
  FT_Stream_Seek( FT_Stream  stream,
                  FT_ULong   pos )
  {
    FT_Error  error = FT_Err_Ok;


    if ( stream->read )
    {
      if ( stream->read( stream, pos, 0, 0 ) )
      {
        FT_ERROR(( "FT_Stream_Seek:"
                   " invalid i/o; pos = 0x%lx, size = 0x%lx\n",
                   pos, stream->size ));

        error = FT_Err_Invalid_Stream_Operation;
      }
    }
    /* note that seeking to the first position after the file is valid */
    else if ( pos > stream->size )
    {
      FT_ERROR(( "FT_Stream_Seek:"
                 " invalid i/o; pos = 0x%lx, size = 0x%lx\n",
                 pos, stream->size ));

      error = FT_Err_Invalid_Stream_Operation;
    }

    if ( !error )
      stream->pos = pos;

    return error;
  }


  FT_BASE_DEF( FT_Error )
  FT_Stream_Skip( FT_Stream  stream,
                  FT_Long    distance )
  {
    if ( distance < 0 )
      return FT_Err_Invalid_Stream_Operation;

    return FT_Stream_Seek( stream, (FT_ULong)( stream->pos + distance ) );
  }


  FT_BASE_DEF( FT_Long )
  FT_Stream_Pos( FT_Stream  stream )
  {
    return stream->pos;
  }


  FT_BASE_DEF( FT_Error )
  FT_Stream_Read( FT_Stream  stream,
                  FT_Byte*   buffer,
                  FT_ULong   count )
  {
    return FT_Stream_ReadAt( stream, stream->pos, buffer, count );
  }


  FT_BASE_DEF( FT_Error )
  FT_Stream_ReadAt( FT_Stream  stream,
                    FT_ULong   pos,
                    FT_Byte*   buffer,
                    FT_ULong   count )
  {
    FT_Error  error = FT_Err_Ok;
    FT_ULong  read_bytes;


    if ( pos >= stream->size )
    {
      FT_ERROR(( "FT_Stream_ReadAt:"
                 " invalid i/o; pos = 0x%lx, size = 0x%lx\n",
                 pos, stream->size ));

      return FT_Err_Invalid_Stream_Operation;
    }

    if ( stream->read )
      read_bytes = stream->read( stream, pos, buffer, count );
    else
    {
      read_bytes = stream->size - pos;
      if ( read_bytes > count )
        read_bytes = count;

      FT_MEM_COPY( buffer, stream->base + pos, read_bytes );
    }

    stream->pos = pos + read_bytes;

    if ( read_bytes < count )
    {
      FT_ERROR(( "FT_Stream_ReadAt:"
                 " invalid read; expected %lu bytes, got %lu\n",
                 count, read_bytes ));

      error = FT_Err_Invalid_Stream_Operation;
    }

    return error;
  }


  FT_BASE_DEF( FT_ULong )
  FT_Stream_TryRead( FT_Stream  stream,
                     FT_Byte*   buffer,
                     FT_ULong   count )
  {
    FT_ULong  read_bytes = 0;


    if ( stream->pos >= stream->size )
      goto Exit;

    if ( stream->read )
      read_bytes = stream->read( stream, stream->pos, buffer, count );
    else
    {
      read_bytes = stream->size - stream->pos;
      if ( read_bytes > count )
        read_bytes = count;

      FT_MEM_COPY( buffer, stream->base + stream->pos, read_bytes );
    }

    stream->pos += read_bytes;

  Exit:
    return read_bytes;
  }


  FT_BASE_DEF( FT_Error )
  FT_Stream_ExtractFrame( FT_Stream  stream,
                          FT_ULong   count,
                          FT_Byte**  pbytes )
  {
    FT_Error  error;


    error = FT_Stream_EnterFrame( stream, count );
    if ( !error )
    {
      *pbytes = (FT_Byte*)stream->cursor;

      /* equivalent to FT_Stream_ExitFrame(), with no memory block rel