src/base/ftstream.c

#include <ftstream.h>
#include <ftdebug.h>

#undef  FT_COMPONENT
#define FT_COMPONENT  trace_stream


  BASE_FUNC
  void  FT_New_Memory_Stream( FT_Library     library,
                              void*          base,
     			      unsigned long  size,
                              FT_Stream      stream )
  {
    stream->memory = library->memory;
    stream->base   = (char*)base;
    stream->size   = size;
    stream->pos    = 0;
    stream->cursor = 0;
    stream->read   = 0;
    stream->close  = 0;
  }


  BASE_FUNC
  FT_Error  FT_Seek_Stream( FT_Stream  stream,
                            FT_ULong   pos )
  {
    FT_Error  error;
    
    stream->pos = pos;
    
    if (stream->read)
    {
      if (stream->read( stream, pos, 0, 0 ))
      {
        error = FT_Err_Invalid_Stream_Operation;

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

      FT_ERROR(( "FT_Seek_Stream:" ));
      FT_ERROR(( " invalid i/o, pos = 0x%lx, size = 0x%lx\n",
                 pos, stream->size ));
    }
 
    else
      error = FT_Err_Ok;
 
    return error; 
  }
  
  
  BASE_FUNC
  FT_Error  FT_Skip_Stream( FT_Stream  stream,
                            FT_Long    distance )
  {
    return FT_Seek_Stream( stream, (FT_ULong)(stream->pos + distance) );
  }
  
  
  
  BASE_FUNC
  FT_Long   FT_Stream_Pos( FT_Stream  stream )
  {
    return stream->pos;
  }
  
  
  BASE_FUNC
  FT_Error  FT_Read_Stream( FT_Stream  stream,
                            void*      buffer,
                            FT_ULong   count )
  {
    return FT_Read_Stream_At( stream, stream->pos, buffer, count );
  }
  
  
  BASE_FUNC
  FT_Error  FT_Read_Stream_At( FT_Stream  stream,
                               FT_ULong   pos,
                               void*      buffer,
                               FT_ULong   count )
  {
    FT_Error  error = FT_Err_Ok;
    FT_ULong  read_bytes;
    
    if (pos >= stream->size)
    {
      FT_ERROR(( "FT_Read_Stream_At:" ));
      FT_ERROR(( " 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;
      
      MEM_Copy( buffer, stream->base + pos, read_bytes );
    }
    
    stream->pos = pos + read_bytes;

    if (read_bytes < count)
    {
      FT_ERROR(( "FT_Read_Stream_At:" ));
      FT_ERROR(( " invalid read, expected %lu bytes, got %lu",
                 count, read_bytes ));
      error = FT_Err_Invalid_Stream_Operation;
    }

    return error;
  }
  
  
  
  BASE_FUNC
  FT_Error  FT_Access_Frame( FT_Stream  stream,
                             FT_ULong   count )
  {
    FT_Error  error = FT_Err_Ok;
    FT_ULong  read_bytes;

    /* check for nested frame access */
    FT_Assert( stream && stream->cursor == 0 );    
     
    if (stream->read)
    {
      /* allocate the frame in memory */
      FT_Memory  memory = stream->memory;
        
      if ( ALLOC( stream->base, count ) )
        goto Exit;
          
      /* read it */
      read_bytes = stream->read( stream, stream->pos,
                                 stream->base, count ); 
      if (read_bytes < count)
      {
        FT_ERROR(( "FT_Access_Frame:" ));
        FT_ERROR(( " invalid read, expected %lu bytes, got %lu",
                   count, read_bytes ));
                   
        FREE( stream->base );
        error = FT_Err_Invalid_Stream_Operation;
      }
      stream->cursor = stream->base;
      stream->limit  = stream->cursor + count;
      stream->pos   += read_bytes;
    }
    else
    {
      /* check current and new position */
      if (stream->pos >= stream->size || stream->pos + count > stream->size)
      {
        FT_ERROR(( "FT_Access_Frame:" ));
        FT_ERROR(( " invalid i/o, pos = 0x%lx, count = %lu, size = 0x%lx",
                   stream->pos, count, stream->size ));
                   
        error = FT_Err_Invalid_Stream_Operation;
        goto Exit;
      }
      
      /* set cursor */
      stream->cursor = stream->base + stream->pos;      
      stream->limit  = stream->cursor + count;
      stream->pos   += count;
    }
  Exit:
    return error;
  }
  
  
  BASE_FUNC
  void  FT_Forget_Frame( FT_Stream  stream )
  {
    FT_Assert( stream && stream->cursor != 0 );
    
    if (stream->read)
    {
      FT_Memory  memory = stream->memory;
      
      FREE( stream->base );
    }
    stream->cursor = 0;
    stream->limit  = 0;
  }


  BASE_FUNC
  FT_Char  FT_Get_Char( FT_Stream  stream )
  {
    FT_Char  result;
    
    FT_Assert( stream && stream->cursor && stream->cursor );

    result = 0;
    if (stream->cursor < stream->limit)    
      result = *stream->cursor++;
      
    return result;
  }
  
  
  BASE_FUNC
  FT_Short  FT_Get_Short( FT_Stream  stream )
  {
    char*     p;
    FT_Short  result;
    
    FT_Assert( stream && stream->cursor );
    
    result         = 0;
    p              = stream->cursor;
    if (p+1 < stream->limit)
      result       = NEXT_Short(p);
    stream->cursor = p;
    return result;
  }
  

  BASE_FUNC
  FT_Long  FT_Get_Offset( FT_Stream  stream )
  {
    char*    p;
    FT_Long  result;
    
    FT_Assert( stream && stream->cursor );
    
    result         = 0;
    p              = stream->cursor;
    if (p+2 < stream->limit)
      result       = NEXT_Offset(p);
    stream->cursor = p;
    return result;
  }
  

  BASE_FUNC
  FT_Long  FT_Get_Long( FT_Stream  stream )
  {
    char*    p;
    FT_Long  result;
    
    FT_Assert( stream && stream->cursor );

    result         = 0;    
    p              = stream->cursor;
    if (p+3 < stream->limit)
      result       = NEXT_Long(p);
    stream->cursor = p;
    return result;
  }
  
 
  BASE_FUNC
  FT_Char  FT_Read_Char( FT_Stream  stream,
                         FT_Error*  error )
  {
    char  result = 0;
    
    FT_Assert( stream );
    
    *error = FT_Err_Ok;
    
    if (stream->read)
    {
      if ( stream->read( stream, stream->pos, &result, 1L ) != 1L )
        goto Fail;
    }
    else
    {
      if (stream->pos < stream->size)
        result = stream->base[stream->pos++];
      else
        goto Fail;
    }
    return result;
    
  Fail:
    *error = FT_Err_Invalid_Stream_Operation;
    FT_ERROR(( "FT_Read_Char:" ));
    FT_ERROR(( " invalid i/o, pos = 0x%lx, size = 0x%lx",
               stream->pos, stream->size ));
    return 0;
  }
 

  BASE_FUNC
  FT_Short  FT_Read_Short( FT_Stream  stream,
                           FT_Error*  error )
  {
    char     reads[2];
    char*    p = 0;
    FT_Short result = 0;
    
    FT_Assert( stream );
    
    *error = FT_Err_Ok;
    
    if (stream->pos+1 < stream->size)
    {
      if (stream->read)
      {
        if (stream->read( stream, stream->pos, reads, 2L ) != 2L )
          goto Fail;
          
        p = reads;
      }
      else
      {
        p = stream->base + stream->pos;
      }
      
      if (p)
      {
        result       = NEXT_Short(p);
        stream->pos += 2;
      }
    }
    else goto Fail;

    return result;
    
  Fail:
    *error = FT_Err_Invalid_Stream_Operation;
    FT_ERROR(( "FT_Read_Short:" ));
    FT_ERROR(( " invalid i/o, pos = 0x%lx, size = 0x%lx",
               stream->pos, stream->size ));
    return 0;
  }
 

  BASE_FUNC
  FT_Long  FT_Read_Offset( FT_Stream  stream,
                           FT_Error*  error )
  {
    char     reads[3];
    char*    p = 0;
    FT_Long  result = 0;
    
    FT_Assert( stream );
    
    *error = FT_Err_Ok;
    
    if (stream->pos+2 < stream->size)
    {
      if (stream->read)
      {
        if (stream->read( stream, stream->pos, reads, 3L ) != 3L )
          goto Fail;
          
        p = reads;
      }
      else
      {
        p = stream->base + stream->pos;
      }
      
      if (p)
      {
        result       = NEXT_Offset(p);
        stream->pos += 3;
      }
    }
    else goto Fail;
      
    return result;
    
  Fail:
    *error = FT_Err_Invalid_Stream_Operation;
    FT_ERROR(( "FT_Read_Offset:" ));
    FT_ERROR(( " invalid i/o, pos = 0x%lx, size = 0x%lx",
               stream->pos, stream->size ));
    return 0;
  }
 

  BASE_FUNC
  FT_Long  FT_Read_Long( FT_Stream  stream,
                         FT_Error*  error )
  {
    char     reads[4];
    char*    p = 0;
    FT_Long  result = 0;
    
    FT_Assert( stream );
    
    *error = FT_Err_Ok;
    
    if (stream->pos+3 < stream->size)
    {
      if (stream->read)
      {
        if (stream->read( stream, stream->pos, reads, 4L ) != 4L )
          goto Fail;
          
        p = reads;
      }
      else
      {
        p = stream->base + stream->pos;
      }
      
      if (p)
      {
        result       = NEXT_Long(p);
        stream->pos += 4;
      }
    }
    else goto Fail;

    return result;
    
  Fail:
    *error = FT_Err_Invalid_Stream_Operation;
    FT_ERROR(( "FT_Read_Long:" ));
    FT_ERROR(( " invalid i/o, pos = 0x%lx, size = 0x%lx",
               stream->pos, stream->size ));
    return 0;
  }