WebSVN – NedoOS – Blame – /src/gp/common/memorystream.asm

Rev	Author	Line No.	Line
1797	galstaff	1	memorystreamloadfile
		2	;de = file name
		3	;out: zf=1 if successful, zf=0 otherwise
1945	galstaff	4	;configurable params:
		5	; .pagestoload <= MEMORYSTREAMMAXPAGES
		6	; .errormask = 0xff to require loading the entire file into memory, 0x00 if only [pagestoload] needed
2272	galstaff	7	;ON_DATA_LOADED_CALLBACK defines label called upon every page load
1797	galstaff	8	call openstream_file
		9	or a
		10	ret nz
		11	ld hl,0
		12	ld de,hl
		13	ld c,l
1945	galstaff	14	.pagestoload=$+1
1878	galstaff	15	ld b,MEMORYSTREAMMAXPAGES
1797	galstaff	16	.loadloop
2272	galstaff	17	ld a,c
		18	ld (.pageindex),a
1797	galstaff	19	push bc
		20	push de
		21	push hl
		22	OS_NEWPAGE
		23	or a
		24	jr z,.pageallocated
		25	pop hl
		26	pop de
		27	pop bc
		28	jr .breakloop
		29	.pageallocated
2272	galstaff	30	.pageindex=$+1
		31	ld a,0
		32	add a,memorystreampages%256
		33	ld l,a
		34	adc a,memorystreampages/256
		35	sub l
		36	ld h,a
1797	galstaff	37	ld (hl),e
		38	inc hl
		39	ld (memorystreampageaddr),hl
		40	ld a,e
2272	galstaff	41	ld (memorystreamcurrentpage),a
1797	galstaff	42	SETPG8000
		43	ld de,0x8000
		44	ld hl,0x4000
		45	call readstream_file
		46	ex (sp),hl
		47	pop bc
2272	galstaff	48	pop de
1797	galstaff	49	add hl,bc
		50	jr nc,$+3
		51	inc e
		52	ld a,b
		53	pop bc
2272	galstaff	54	ifdef ON_DATA_LOADED_CALLBACK
		55	push hl,de,bc,af
		56	res 6,h
		57	set 7,h
		58	and 0x40
		59	jr z,$+5
		60	ld hl,0xc000
		61	ld (memorystreamcurrentaddr),hl
		62	call ON_DATA_LOADED_CALLBACK
		63	pop bc
		64	ld a,b
		65	pop bc,de,hl
		66	jr nz,.breakloop
		67	endif
1797	galstaff	68	inc c
		69	and 0x40
		70	jr z,.breakloop
		71	djnz .loadloop
1870	galstaff	72	.errormask=$+1
1950	galstaff	73	and MEMORYSTREAMERRORMASK
1797	galstaff	74	.breakloop
		75	push af
		76	ld (memorystreamsize+0),hl
		77	ld (memorystreamsize+2),de
		78	ld a,c
		79	ld (memorystreampagecount),a
		80	call closestream_file
		81	pop af
		82	ret z
		83	jp memorystreamfree
		84
		85	memorystreamallocate
		86	;dehl = buffer size
		87	;out: zf=1 if successful, zf=0 otherwise
		88	ld (memorystreamsize+0),hl
		89	ld (memorystreamsize+2),de
		90	ld a,e
		91	ld de,0x3fff
		92	add hl,de
		93	ld c,0
		94	adc a,c
		95	sla h
		96	rla
		97	sla h
		98	rla
		99	ld b,a
		100	ld a,MEMORYSTREAMMAXPAGES
		101	cp b
		102	ret c
		103	ld hl,memorystreampages
2272	galstaff	104	.loop push bc
1797	galstaff	105	push hl
		106	OS_NEWPAGE
		107	pop hl
		108	pop bc
		109	or a
		110	jr z,.pageallocated
		111	ld a,c
		112	ld (memorystreampagecount),a
		113	jp memorystreamfree
		114
		115	.pageallocated
		116	ld (hl),e
		117	inc hl
		118	inc c
		119	djnz .loop
		120	ld a,c
		121	ld (memorystreampagecount),a
		122	xor a
		123	ret
		124
		125	memorystreamfree
		126	;out: zf=0 so that this function can be used to return error condition
		127	memorystreampagecount=$+1
		128	ld a,0
2272	galstaff	129	call memorystreamfreecustompagecount
		130	or 1
		131	ret
		132
		133	memorystreamfreecustompagecount
		134	;a = page count
		135	;UNUSED_PAGE_ADDR defines address containing page index used to mark the pages that are already released
1797	galstaff	136	or a
		137	ret z
		138	ld b,a
		139	ld hl,memorystreampages
		140	.pagefreeloop
2272	galstaff	141	ld e,(hl)
		142	ifdef UNUSED_PAGE_ADDR
		143	ld a,(UNUSED_PAGE_ADDR)
		144	cp e
		145	jr z,.alreadydeleted
		146	ld (hl),a
		147	endif
1797	galstaff	148	push bc
		149	push hl
		150	OS_DELPAGE
		151	pop hl
		152	pop bc
2272	galstaff	153	.alreadydeleted
1797	galstaff	154	inc hl
		155	djnz .pagefreeloop
		156	ret
		157
		158	memorystreamstart
		159	ld hl,0xffff
		160	ld (memorystreamcurrentaddr),hl
		161	ld hl,memorystreampages
		162	ld (memorystreampageaddr),hl
		163	ret
		164
		165	memorystreamnextpage
		166	memorystreampageaddr=$+1
		167	ld hl,0
		168	push af
		169	ld a,(hl)
		170	inc hl
		171	ld (memorystreamcurrentpage),a
		172	ld (memorystreampageaddr),hl
		173	push bc
		174	SETPG8000
		175	pop bc
		176	pop af
		177	ld hl,0x8000
		178	ret
		179
		180	memorystreamskip
		181	;b = byte count
		182	ld hl,(memorystreamcurrentaddr)
2272	galstaff	183	.loop bit 6,h
1797	galstaff	184	call nz,memorystreamnextpage
		185	inc hl
		186	djnz .loop
		187	ld (memorystreamcurrentaddr),hl
		188	ret
		189
		190	macro memory_stream_write_byte src
		191	bit 6,h
		192	call nz,memorystreamnextpage
		193	ld (hl),src
		194	inc hl
		195	endm
		196
		197	macro memory_stream_read_byte dest
		198	bit 6,h
		199	call nz,memorystreamnextpage
		200	ld dest,(hl)
		201	inc hl
		202	endm
		203
		204	macro memory_stream_read_1 dst
		205	ld hl,(memorystreamcurrentaddr)
		206	memory_stream_read_byte dst
		207	ld (memorystreamcurrentaddr),hl
		208	endm
		209
		210	macro memory_stream_read_2 dst1,dst2
		211	ld hl,(memorystreamcurrentaddr)
		212	memory_stream_read_byte dst1
		213	memory_stream_read_byte dst2
		214	ld (memorystreamcurrentaddr),hl
		215	endm
		216
		217	macro memory_stream_read_3 dst1,dst2,dst3
		218	ld hl,(memorystreamcurrentaddr)
		219	memory_stream_read_byte dst1
		220	memory_stream_read_byte dst2
		221	memory_stream_read_byte dst3
		222	ld (memorystreamcurrentaddr),hl
		223	endm
		224
		225	memorystreamread1
		226	;out: a = byte
		227	memory_stream_read_1 a
		228	ret
		229
		230	memorystreamread2
		231	;out: de = word
		232	memory_stream_read_2 e,d
		233	ret
		234
		235	memorystreamread3
		236	;out: c = byte0, e = byte1, d = byte2
		237	memory_stream_read_3 c,e,d
		238	ret
		239
		240	memorystreamread4
		241	;out: adbc = dword
		242	memorystreamcurrentaddr=$+1
		243	ld hl,0
		244	memory_stream_read_byte c
		245	memory_stream_read_byte b
		246	memory_stream_read_byte d
		247	memory_stream_read_byte a
		248	ld (memorystreamcurrentaddr),hl
		249	ret
		250
		251	memorystreamread
		252	;bc = number of bytes
		253	;de = dest addr
		254	ld a,c
		255	dec bc
		256	inc b
		257	ld c,b
		258	ld b,a
		259	ld hl,(memorystreamcurrentaddr)
		260	.readloop
		261	memory_stream_read_byte a
		262	ld (de),a
		263	inc de
		264	djnz .readloop
		265	dec c
		266	jr nz,.readloop
		267	ld (memorystreamcurrentaddr),hl
		268	ret
		269
		270	memorystreamwrite
		271	;bc = number of bytes
		272	;de = src addr
		273	ld a,c
		274	dec bc
		275	inc b
		276	ld c,b
		277	ld b,a
		278	ld hl,(memorystreamcurrentaddr)
		279	.writeloop
		280	ld a,(de)
		281	memory_stream_write_byte a
		282	inc de
		283	djnz .writeloop
		284	dec c
		285	jr nz,.writeloop
		286	ld (memorystreamcurrentaddr),hl
		287	ret
		288
		289	memorystreamseek
		290	;dehl = absolute position
		291	;out: hl = read address
		292	ld a,e
		293	ld b,h
		294	sla b
		295	rla
		296	sla b
		297	rla
		298	add a,memorystreampages%256
		299	ld e,a
		300	adc a,memorystreampages/256
		301	sub e
		302	ld d,a
		303	ld a,(de)
		304	ld (memorystreamcurrentpage),a
		305	inc de
		306	ld (memorystreampageaddr),de
		307	SETPG8000
		308	res 6,h
		309	set 7,h
		310	ld (memorystreamcurrentaddr),hl
		311	ret
		312
		313	memorystreamgetpos
		314	;out: dehl = absolute position
		315	ld hl,(memorystreampageaddr)
		316	ld de,-memorystreampages-1
		317	add hl,de
		318	ex de,hl
		319	ld hl,(memorystreamcurrentaddr)
		320	res 7,h
		321	bit 6,h
		322	jr z,$+6
		323	inc de
		324	ld hl,0
		325	xor a
		326	rr e
		327	rra
		328	rr e
		329	rra
		330	or h
		331	ld h,a
		332	ret
		333
		334	memorystreamsize
		335	ds 4
		336	memorystreampages
		337	ds MEMORYSTREAMMAXPAGES
		338	memorystreamcurrentpage
		339	ds 1

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(root)/src/gp/common/memorystream.asm – Rev 2272