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 %TITLE 'WFSPLBKT - split the current bucket'
MODULE WFSPLBKT (				! Split the current bucket
		IDENT = '3-003'			! File: WFSPLBKT.BLI Edit: CJG3003
		) =
BEGIN
!
!			  COPYRIGHT (c) 1981, 1985 BY
!	      DIGITAL EQUIPMENT CORPORATION, MAYNARD, MASS.
!		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 WHICH IS NOT SUPPLIED BY DIGITAL.
!

!++
! FACILITY:	EDT -- The DEC Standard Editor
!
! ABSTRACT:
!
!	Split the current bucket.
!
! ENVIRONMENT:	Runs at any access mode - AST reentrant
!
! AUTHOR: Bob Kushlis, CREATION DATE: October 16, 1978
!
! MODIFIED BY:
!
! 1-001	- Original.  DJS 23-Feb-1981.  This module was created by
!	extracting routine SPLIT_BUKT from module EDTWF.
! 1-002	- Regularize headers.  JBS 19-Mar-1981
! 1-003 - Modify to use EDT$WORKIO. STS 15-Feb-1982
! 1-004 - Copy entire old bucket before split. STS 18-Feb-1982
! 1-005 - Don't copy on 11's since it uses too much stack. STS 01-Mar-1982
! 1-006 - Change stack storage to heap storage. STS 05-Mar-1982
! 1-007 - Add literals for callable EDT. STS 10-Mar-1982
! 1-008	- Give an error return if heap storage is exhausted.  JBS 09-Jun-1982
! 1-009 - Put code for edt$$wf_nxt_buf in line. STS 11-oct-1982
! 3-001 - Change arguments to EDT$$CPY_MEM - it nows copys words.  GB 21-Feb-1983
! 3-002 - Add updates from V3 sources.  GB 09-May-1983
! 3-003 - Remove call to EDT$$CALLWIO. CJG 13-Jun-1983
!--

%SBTTL 'Declarations'
!
! TABLE OF CONTENTS:
!

REQUIRE 'EDTSRC:TRAROUNAM';

FORWARD ROUTINE
    EDT$$WF_SPLTBUK;

!
! INCLUDE FILES:
!

REQUIRE 'EDTSRC:EDTREQ';

!
! MACROS:
!
!	NONE
!
! EQUATED SYMBOLS:
!
!	NONE
!
! OWN STORAGE:
!
!	NONE
!
! EXTERNAL REFERENCES:
!
!	In the routine
%SBTTL 'EDT$$WF_SPLTBUK  - split the current bucket'

GLOBAL ROUTINE EDT$$WF_SPLTBUK 			! Split the current bucket
    =

!++
! FUNCTIONAL DESCRIPTION:
!
!	This routine splits the current bucket at the current position into
!	two buckets.  In the special case that we are at the end of the bucket
!	this is done simply by appending a new bucket, otherwise, we must allocate
!	a new bucket and copy all the text from the current line to the end of the
!	bucket into the new bucket.
!
! FORMAL PARAMETERS:
!
!	NONE
!
! IMPLICIT INPUTS:
!
!	CUR_BUF
!	WF_DESC
!	WK_BUK
!	WK_CURBUK
!
! IMPLICIT OUTPUTS:
!
!	WK_MODFD
!	WK_BUK
!
! ROUTINE VALUE:
!
!	1 = OK
!	0 = heap storage exhausted
!
! SIDE EFFECTS:
!
!	NONE
!
!--

    BEGIN

    EXTERNAL ROUTINE
	EDT$$ALO_HEAP,				! allocate heap storage
	EDT$$DEA_HEAP : NOVALUE,		! deallocate heap storage
	EDT$$WF_WR : NOVALUE,			! Write to the work file
	EDT$$WF_NEWBUK : NOVALUE,
	EDT$$WF_ALOBUF : NOVALUE,
	EDT$$WF_MAKECUR : NOVALUE;

    EXTERNAL
	WF_DESC : BLOCK,		! descriptor for the workfile record
    	WK_AVAIL,
    	WK_GRTSTBUK,
	CUR_BUF : REF TBCB_BLOCK,	! Current text buffer control block
	WK_BUK : 			! Pointer to current bucket
	    REF BLOCK [WF_BUKT_SIZE] FIELD (WFB_FIELDS),
	WK_CURBUK,			! Number of the current bucket
	WK_MODFD;			! Flag indicating bucket was modified

    LOCAL
	OLD_NEXT,
	LEN,
	ORIG_BUKT;

!+
! Remember the next bucket number, and the original one
!-
    OLD_NEXT = .WK_BUK [WFB_NEXT_BUKT];
    ORIG_BUKT = .WK_CURBUK;
!+
! First check to see if we are at the end of a bucket.
!-

    IF (.CUR_BUF [TBCB_LINE_ADDR] EQL .WK_BUK [WFB_END])
    THEN
!+
! We are at the end, just link a new bucket to this one
!-
	BEGIN
    	IF .WK_AVAIL NEQ 0
    	THEN
	    WK_BUK [WFB_NEXT_BUKT] = .WK_AVAIL
        ELSE
    	    WK_BUK [WFB_NEXT_BUKT] = .WK_GRTSTBUK;

	WK_MODFD = 1;
	EDT$$WF_NEWBUK (.OLD_NEXT, .ORIG_BUKT)
	END
    ELSE
	BEGIN
!+
! Split the bucket into two, at the beginning of the current line.
!-

	LOCAL
	    OLD_BUKT,
	    NEW_BUKT;

	LEN = .WK_BUK [WFB_END] - .CUR_BUF [TBCB_LINE_ADDR];
	WK_BUK [WFB_END] = .CUR_BUF [TBCB_LINE_ADDR];
    	IF .WK_AVAIL NEQ 0
    	THEN
	    WK_BUK [WFB_NEXT_BUKT] = NEW_BUKT = .WK_AVAIL
    	ELSE
    	    WK_BUK [WFB_NEXT_BUKT] = NEW_BUKT = .WK_GRTSTBUK;

	EDT$$WF_WR (.WK_CURBUK, WF_DESC);
!+
! Save out the bucket so that later we can extract a portion
!-

	IF ( NOT EDT$$ALO_HEAP (%REF (WF_BUKT_SIZE * BYTES_PER_WORD), OLD_BUKT)) THEN RETURN (0);

	EDT$$CPY_MEM (WF_BUKT_SIZE, .WK_BUK, .OLD_BUKT);
!+
! Now get a fresh buffer
!-
	EDT$$WF_ALOBUF ();
	WK_BUK [WFB_NEXT_BUKT] = .OLD_NEXT;
	WK_BUK [WFB_PREV_BUKT] = .ORIG_BUKT;
!+
! Copy a portion of the old buffer into the new buffer
!-
	EDT$$CPY_MEM (.LEN, .OLD_BUKT + .CUR_BUF [TBCB_LINE_ADDR], 	!
	    .WK_BUK + WFB_FIXED_SIZE);
	EDT$$DEA_HEAP (%REF (WF_BUKT_SIZE * BYTES_PER_WORD), OLD_BUKT);
	WK_BUK [WFB_END] = .LEN + WFB_FIXED_SIZE;
	WK_MODFD = 1;

	IF (.OLD_NEXT EQL 0)
	THEN
	    BEGIN

	    IF (.ORIG_BUKT EQL .CUR_BUF [TBCB_LAST_BUKT])
	    THEN
		CUR_BUF [TBCB_LAST_BUKT] = .NEW_BUKT;

	    END
	ELSE
	    BEGIN
	    EDT$$WF_MAKECUR (.OLD_NEXT);
	    WK_BUK [WFB_PREV_BUKT] = .NEW_BUKT;
	    WK_MODFD = 1;
	    END;

	EDT$$WF_MAKECUR (.ORIG_BUKT)
	END;

    RETURN (1);
    END;					! of routine EDT$$WF_SPLTBUK


END
ELUDOM