A2OS/ARM/Minos/OFSStreams.Mos

MODULE OFSStreams;
(**
	AUTHOR Timothée Martiel, 01/2016
	PURPOSE Streams for OFS files.
*)

IMPORT
	Trace,
	StreamReaders, StreamWriters, OFS;

TYPE
	Reader * = RECORD (StreamReaders.Reader)
		rider *: OFS.Rider;
	END;

	Writer * = RECORD (StreamWriters.Writer)
		rider *: OFS.Rider;
	END;

	PROCEDURE OpenReader * (VAR reader: Reader; size: LONGINT; file: OFS.File);
	BEGIN
		StreamReaders.Init(reader, Receive, size);
		OFS.Set(reader.rider, file, 0)
	END OpenReader;

	PROCEDURE OpenWriter * (VAR writer: Writer; size: LONGINT; file: OFS.File);
	BEGIN
		StreamWriters.Init(writer, Send, size);
		OFS.Set(writer.rider, file, 0)
	END OpenWriter;

	PROCEDURE SetReaderPos * (VAR reader: Reader; pos: LONGINT);
	BEGIN
		OFS.Set(reader.rider, reader.rider.file, pos)
	END SetReaderPos;

	PROCEDURE SetWriterPos * (VAR writer: Writer; pos: LONGINT);
	BEGIN
		OFS.Set(writer.rider, writer.rider.file, pos)
	END SetWriterPos;

	PROCEDURE ReaderPos * (VAR reader: Reader): LONGINT;
	BEGIN
		RETURN OFS.Pos(reader.rider)
	END ReaderPos;

	PROCEDURE WriterPos * (VAR writer: Writer): LONGINT;
	BEGIN
		RETURN OFS.Pos(writer.rider)
	END WriterPos;

	PROCEDURE Send (VAR writer: StreamWriters.Writer; CONST buf: ARRAY OF CHAR;  ofs, len: LONGINT;  propagate: BOOLEAN;  VAR res: LONGINT);
	BEGIN
		WHILE len > 0 DO
			OFS.Write(writer(Writer).rider, buf[ofs]);
			INC(ofs);
			DEC(len)
		END
	END Send;

	PROCEDURE Receive (VAR reader: StreamReaders.Reader; VAR buf: ARRAY OF CHAR;  ofs, size, min: LONGINT;  VAR len, res: LONGINT);
	BEGIN
		len := 0;
		WHILE ((min > 0) OR ~reader(Reader).rider.eof) & (size > 0) DO
			OFS.Read(reader(Reader).rider, buf[ofs]);
			INC(ofs);
			INC(len);
			DEC(min);
			DEC(size)
		END
	END Receive;
	
END OFSStreams.