MemoryPipe

DoFlushWriter DoOpenWriter DoSeekReader DoSeekWriter

Attributes

Class MemoryPipe defines no new attributes.

Fields

instance MemoryPipe tag;
         target: nilObject;
   readerBuffer: nilObject;
          start: 0;
    lowPosition: 0;
   highPosition: 0;
currentPosition: 0;
         closed: false;
       seekable: false;
   intermittent: false;
         buffer: nilObject;
          start: 0;
            low: 0;
           high: 0;
        current: 0;
         closed: false;
       seekable: false;
     unbuffered: false;
      readBytes: 0;
 unwrittenBytes: 0;
        flipped: false;
end instance;

Define Class MemoryPipe;
    inherits from Object, Stream, Reader, Writer;
    uses extra;
    
    field readBytes: Unsigned;
        // The logical first page in the stream has this many read bytes at the start.
    field unwrittenBytes: Unsigned;
        // The logical last page in the stream has this many unwritten bytes at the end.
    field flipped: Boolean;
        // If false, the first logical page is at the start of the extra data.
        // If true, the first logical page is at the end of the extra data.

    overrides DoOpenWriter;
        // Resets extra size to zero, sets flipped to false.
    overrides DoSeekWriter, DoFlushWriter;
        // Empties the buffer into the logical end of the extra data.

    overrides DoSeekReader;
        // Fills the buffer with bytes from the start of what was written.
        // Also flips the buffer for faster read performance.

end class;