antoine-source/appleworksgs/Heap/Src/Heap.aii

;
; Heap.aii
;
; Heap memory managment module
;
; Copyright <20> 1989 Claris Corporation
;
; 1-13-89 Begun by Kevin A. Watts

;
; Heap routines:
;
; H_Init()		; Initialize heap code when loaded.
; H_SegLoaded()		; Called when the heap code is loaded.
; H_SegUnloaded()		; Called when the heap code is unloaded.
; H_CurrentHeap(): HeapID:ax	; Return the ID of the current heap.
; H_SetHeap(HeapID:xy)	; Set the current heap.
; H_UnsetHeap()		; Unset the current heap.
; H_ResetHeap()		; Reset (relock) the current heap.
; H_NewHeap(): HeapID:ax	; Create a new heap, make it current & return its ID.
; H_DisposeHeap()		; Dispose of the current heap.
; H_WriteHeap(FileID:x)	; Write the current heap to disk.
; H_ReadHeap(FileID:x): HeapID:ax	; Read the current heap from disk.
; CalcHeaderPtrs		; Calculate pointers to arrays within the header.

;--------------------------------------------------------------

	PRINT	PUSH
	PRINT	OFF

	LOAD	'Macros.Dump'

	gblc	&__FILE__
&__FILE__	setc	'Heap'

	include	'Heap.mac'
	include	'HeapPrivate.equ'
	include	'Heap.aii.i'
	include	'm16.profile'		; must be after H.equ
	include	'Driver.equ'

	IMPORT	D_Deref

	ENTRY	H_Init
  IF DriverSupport = 0 THEN
	ENTRY	H_SegLoaded
	ENTRY	H_SegUnloaded
  ENDIF
  IF ErrorCheck THEN
	ENTRY	H_CurrentHeap
  ENDIF
	ENTRY	H_SetHeap
	ENTRY	H_UnsetHeap
	ENTRY	H_ResetHeap
	ENTRY	H_NewHeap
	ENTRY	H_DisposeHeap
	ENTRY	H_ReadHeap
	ENTRY	H_WriteHeap
	ENTRY	CalcHeaderPtrs
	
	PRINT	POP

	ProfileData 16,_H
	ProfileCode _H

;<3B>;--------------------------------------------------------------
; H_Init()
;	no error status returned
;
; Store the address of the heap zero page into the other heap routines
; prologue.
; THIS ROUTINE MUST BE CALLED BEFORE ANY OTHER HEAP ROUTINE IS CALLED!!
; i.e. immediately after the code segment is loaded.

; Zpage variables modified:
;	H_ZPptr

H_Init	PROC	EXPORT

	ProfileInit _H

; get the Zpage address from the driver global
	IMPORT	D_HeapZPage
	lda	>D_HeapZPage

	phd

; store the Zpage address in the Zpage
	tcd			; set up the Zpage
	sta	H_ZPptr
	stz	H_ZPptr+2		; redundant, but so what?
	
; determine the maximum possible number of data or index segments and thus header size.
; we allow the same # of each type of segment, equal to
;	_TotalMem / H_DSEG_SIZE
; H_MaxSegments will be 3 times this (3/4, *4 bytes/segment handle).
; The 3/4 is based upon H_ISEG_SIZE = 1/4 H_DSEG_SIZE, and will allow the heap
; to use 15/16 of _TotalMem.  This should be sufficient.
	SpaceLong
	_TotalMem
	pla			; discard low word
	pla			; # of banks
	sta	H_MaxSegments	; multiply by 3
	asl	a
	asl	a
	sec
	sbc	H_MaxSegments
	MulByPwr2	a,($10000/H_DSEG_SIZE)	; # of banks * (64K/H_DSEG_SIZE)
	cmp	#$1000			; ensure high nibble unused
	blt	@1
	lda	#$1000-4
@1	sta	H_MaxSegments

	lda	#HANDLE_ARRAY	; offset to **index_seg[]

	clc
	adc	H_MaxSegments
	sta	H_DSegHOffsetLo	; offset to **data_seg[]
	tax
	inx
	inx
	stx	H_DSegHOffsetHi

	clc
	adc	H_MaxSegments
	sta	H_ISegPOffsetLo	; offset to *index_seg[]
	tax
	inx
	inx
	stx	H_ISegPOffsetHi

	clc
	adc	H_MaxSegments
	sta	H_DSegPOffsetLo	; offset to *data_seg[]
	tax
	inx
	inx
	stx	H_DSegPOffsetHi

	clc
	adc	H_MaxSegments
	sta	H_HeaderSize	; total size of heap header

	tdc			; load accumulator with Heap Zpage
	pld

; embed the ZP address in the other routines
; DefineZ will correctly modify any routine using BeginZ as a prologue.

	; set data bank to code bank
	phb
	phk
	plb

  IF ErrorCheck THEN
	DefineZ	H_CurrentHeap
  ENDIF
	DefineZ	H_SetHeap
	DefineZ	H_UnsetHeap
	DefineZ	H_ResetHeap
	DefineZ	H_NewHeap
	DefineZ	H_DisposeHeap

  IF HeapIO AND 1 THEN
	DefineZ	H_WriteHeap
  ENDIF
  IF HeapIO AND 2 THEN
	DefineZ	H_ReadHeap
  ENDIF
	DefineZ	H_TruncHeap

	DefineZ	H_NewBlock
	DefineZ	H_DisposeBlock
	DefineZ	H_ResizeBlock
	DefineZ	H_CopyBlock

	DefineZ	H_GetBlockPtr
	DefineZ	H_GetBlockSize

	plb	; restore data bank
	rtl
	
	ENDP

;<3B>;--------------------------------------------------------------
  IF DriverSupport = 0 THEN
; H_SegLoaded()
;	errors returned in accumulator (via ErrFlag)
;
; Allocate a zero page block for later use and store its address
; in