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%title 'F L U S H   -- process $FLUSH call'
!<BLF/REQUIRE 'RMSBLF.REQ'>
MODULE flush (IDENT = '2.0'
		) =
BEGIN
!
!	COPYRIGHT (C) DIGITAL EQUIPMENT CORPORATION 1984, 1986.
!	ALL RIGHTS RESERVED.
!
!	THIS SOFTWARE IS FURNISHED UNDER A LICENSE AND MAY  BE  USED  AND
!	COPIED ONLY IN ACCORDANCE WITH THE TERMS OF SUCH LICENSE AND WITH
!	THE INCLUSION OF THE ABOVE COPYRIGHT NOTICE.   THIS  SOFTWARE  OR
!	ANY  OTHER  COPIES  THEREOF MAY NOT BE PROVIDED OR OTHERWISE MADE
!	AVAILABLE TO ANY OTHER PERSON.  NO TITLE TO AND OWNERSHIP OF  THE
!	SOFTWARE IS HEREBY TRANSFERRED.
!
!	THE INFORMATION IN THIS SOFTWARE IS  SUBJECT  TO  CHANGE  WITHOUT
!	NOTICE  AND  SHOULD  NOT  BE CONSTRUED AS A COMMITMENT BY DIGITAL
!	EQUIPMENT CORPORATION.
!
!	DIGITAL ASSUMES NO RESPONSIBILITY FOR THE USE OR  RELIABILITY  OF
!	ITS SOFTWARE ON EQUIPMENT THAT IS NOT SUPPLIED BY DIGITAL.
!
!++
! FACILITY:	RMS
!
! ABSTRACT:
!
!	FLUSH contains all routines which
!	process the $FLUSH call in RMS-20.
!
! ENVIRONMENT:	User mode, top level
!
! AUTHOR: Ron Lusk , CREATION DATE:  1-Apr-83
!
! MODIFIED BY:
!
!	, : VERSION
! 01	-
!--

!
! TABLE OF CONTENTS
!
!
!	$FLUSH	-   processor for $FLUSH
!	FLUBUF	-   write buffers to disk
!
!
! INCLUDE FILES:
!

REQUIRE 'rmsreq';

!
! MACROS:
!
!   None.
!
! EQUATED SYMBOLS:
!
!   None.
!
! OWN STORAGE:
!
!   None.
!
! EXTERNAL REFERENCES:
!
!   None.
!

GLOBAL ROUTINE $flush (rabblock, errorreturn) =

!++
! FUNCTIONAL DESCRIPTION:
!
!	$FLUSH flushes all current buffers for a record
!	stream.  This operation is valid for all file
!	organizations, but has important use primarily for
!	sequential files with ASCII or LSA record formats,
!	or for files on sequential devices.  This operation
!	can be done to an indexed file, but unless
!	Write-Behind is being used, there is no advantage in
!	doing so.
!
! FORMAL PARAMETERS
!
!	RABBLOCK	-   Record Access Block address
!	ERRORRETURN	-   user error return address
!
! IMPLICIT INPUTS
!
!	?
!
! ROUTINE VALUE:
!
!	None, yet not novalue.
!
! SIDE EFFECTS:
!
!	?
!
!--

    BEGIN
    rmsentry ($flush);
!+
!   Fetch the address of the user's RAB and his
!   error-processing routine, if any.
!-
    rab = .rabblock;				! Fetch RAB address
    erradr = .errorreturn;			!   and user error address
!+
!   Set up all system-wide pointers, etc., and allow him to
!   perform this operation no matter what his FAB value was
!   when he opened the file.
!-
    rsetup (true);				! Set up all stuff
    flubuf ();					! Clear all buffers
!+
!   Exit to the user.
!-
    usrret ()
    END;					!End of $FLUSH

GLOBAL ROUTINE flubuf : NOVALUE =

!++
! FUNCTIONAL DESCRIPTION:
!
!	FLUBUF insures that all updated buffers are written
!	to disk.
!
! FORMAL PARAMETERS
!
!	None.
!
! IMPLICIT INPUTS
!
!	FST	-   File Status Table
!	RST	-   Record Status Table
!
! ROUTINE VALUE:
!
!	NONE.
!
! SIDE EFFECTS:
!
!	None.
!
!--

    BEGIN

    REGISTER
	bdptr : ref block;

    TRACE ('FLUBUF');
!+
!   Note that this routine performs its function primarily
!   for stream or LSA records, or for sequential devices.
!   Also, the file must be currently in output mode for this
!   operation to have any effect.
!-

    IF ((mta) OR (asciifile)) 			! Magtape (?) or ASCII files
    AND ( NOT inputmode)			! We must be writing the file
    THEN                                        ! Flush buffers?        !m577
	IF .rst[rst$v_last_sequential]		! If last operation was
        AND .rst[rst$v_last_operation] EQL C$Put! sequential $Put
	THEN
	    BEGIN				! Yes
	    writebuffer ();			! Output current buffer

            IF (dasd)                                                   !m577
	    THEN pagout (.fst [fstjfn], 	! JFN
		         .currentfilepage, 	! Page to output
                         -1, 			! Just verify to disk
                         asciibktsize);         ! Number of pages
	    END;

!+
!   For disk files, we can cycle through the RST buffers and
!   update all the buffers in this stream.
!-

    IF dasd
    THEN
	BEGIN
	bdptr = bfdoffset;			! First buffer descriptor
!+
!   Loop over all buffers and update them to the disk.
!-

	INCR j FROM 1 TO .rst [rstbfdcount] DO
	    BEGIN
!+
!   If the buffer empty or have old data in it?  If the
!   buffer size is non-zero and the update flag is set, then
!   we have a full buffer that must be updated.
!-

	    IF (.bdptr [bfdbktsiz] neq 0) AND bfdupd (bdptr)
	    THEN
		pagout (.fst [fstjfn], 		! JFN
		    .bdptr [bfdfpage], 		! Page
		    .bdptr [bfdbpage], 		! Memory page
		    .bdptr [bfdbktsiz]);	! Count of pages

	    clearbfdupd (bdptr);
!+
!   Bump the buffer descriptor pointer
!-
	    bdptr = .bdptr + 1;
	    END

	END;

    RETURN;
    END;					!End of FLUBUF

END						!End of Module FLUSH

ELUDOM