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
2286	galstaff	10	ld a,MEMORYSTREAMERROR_FILEIO
		11	ld (memorystreamerrorcode),a
1797	galstaff	12	ret nz
		13	ld hl,0
		14	ld de,hl
		15	ld c,l
1945	galstaff	16	.pagestoload=$+1
1878	galstaff	17	ld b,MEMORYSTREAMMAXPAGES
1797	galstaff	18	.loadloop
2272	galstaff	19	ld a,c
		20	ld (.pageindex),a
2286	galstaff	21	inc c ;increase page count
1797	galstaff	22	push bc
		23	push de
		24	push hl
		25	OS_NEWPAGE
		26	or a
		27	jr z,.pageallocated
		28	pop hl
		29	pop de
		30	pop bc
2286	galstaff	31	dec c ;decrease page count because there's no page
		32	ld a,MEMORYSTREAMERROR_OOM
		33	ld (memorystreamerrorcode),a
1797	galstaff	34	jr .breakloop
		35	.pageallocated
2272	galstaff	36	.pageindex=$+1
		37	ld a,0
		38	add a,memorystreampages%256
		39	ld l,a
		40	adc a,memorystreampages/256
		41	sub l
		42	ld h,a
1797	galstaff	43	ld (hl),e
		44	inc hl
		45	ld (memorystreampageaddr),hl
		46	ld a,e
2272	galstaff	47	ld (memorystreamcurrentpage),a
1797	galstaff	48	SETPG8000
		49	ld de,0x8000
		50	ld hl,0x4000
		51	call readstream_file
		52	ex (sp),hl
		53	pop bc
2272	galstaff	54	pop de
1797	galstaff	55	add hl,bc
		56	jr nc,$+3
		57	inc e
		58	ld a,b
		59	pop bc
2272	galstaff	60	ifdef ON_DATA_LOADED_CALLBACK
		61	push hl,de,bc,af
		62	res 6,h
		63	set 7,h
		64	and 0x40
		65	jr z,$+5
		66	ld hl,0xc000
		67	ld (memorystreamcurrentaddr),hl
		68	call ON_DATA_LOADED_CALLBACK
		69	pop bc
		70	ld a,b
		71	pop bc,de,hl
		72	jr nz,.breakloop
		73	endif
1797	galstaff	74	and 0x40
		75	jr z,.breakloop
		76	djnz .loadloop
1870	galstaff	77	.errormask=$+1
1950	galstaff	78	and MEMORYSTREAMERRORMASK
1797	galstaff	79	.breakloop
		80	push af
		81	ld (memorystreamsize+0),hl
		82	ld (memorystreamsize+2),de
		83	ld a,c
		84	ld (memorystreampagecount),a
		85	call closestream_file
		86	pop af
2286	galstaff	87	jp nz,memorystreamfree
		88	ld a,MEMORYSTREAMERROR_SUCCESS
		89	ld (memorystreamerrorcode),a
1797	galstaff	90	ret
		91
		92	memorystreamfree
		93	;out: zf=0 so that this function can be used to return error condition
		94	memorystreampagecount=$+1
		95	ld a,0
2272	galstaff	96	call memorystreamfreecustompagecount
		97	or 1
		98	ret
		99
		100	memorystreamfreecustompagecount
		101	;a = page count
		102	;UNUSED_PAGE_ADDR defines address containing page index used to mark the pages that are already released
1797	galstaff	103	or a
		104	ret z
		105	ld b,a
		106	ld hl,memorystreampages
		107	.pagefreeloop
2272	galstaff	108	ld e,(hl)
		109	ifdef UNUSED_PAGE_ADDR
		110	ld a,(UNUSED_PAGE_ADDR)
		111	cp e
		112	jr z,.alreadydeleted
		113	ld (hl),a
		114	endif
1797	galstaff	115	push bc
		116	push hl
		117	OS_DELPAGE
		118	pop hl
		119	pop bc
2272	galstaff	120	.alreadydeleted
1797	galstaff	121	inc hl
		122	djnz .pagefreeloop
		123	ret
		124
		125	memorystreamstart
		126	ld hl,0xffff
		127	ld (memorystreamcurrentaddr),hl
		128	ld hl,memorystreampages
		129	ld (memorystreampageaddr),hl
		130	ret
		131
		132	memorystreamnextpage
		133	memorystreampageaddr=$+1
		134	ld hl,0
		135	push af
		136	ld a,(hl)
		137	inc hl
		138	ld (memorystreamcurrentpage),a
		139	ld (memorystreampageaddr),hl
		140	push bc
		141	SETPG8000
		142	pop bc
		143	pop af
		144	ld hl,0x8000
		145	ret
		146
		147	memorystreamskip
		148	;b = byte count
		149	ld hl,(memorystreamcurrentaddr)
2272	galstaff	150	.loop bit 6,h
1797	galstaff	151	call nz,memorystreamnextpage
		152	inc hl
		153	djnz .loop
		154	ld (memorystreamcurrentaddr),hl
		155	ret
		156
		157	macro memory_stream_write_byte src
		158	bit 6,h
		159	call nz,memorystreamnextpage
		160	ld (hl),src
		161	inc hl
		162	endm
		163
		164	macro memory_stream_read_byte dest
		165	bit 6,h
		166	call nz,memorystreamnextpage
		167	ld dest,(hl)
		168	inc hl
		169	endm
		170
		171	macro memory_stream_read_1 dst
		172	ld hl,(memorystreamcurrentaddr)
		173	memory_stream_read_byte dst
		174	ld (memorystreamcurrentaddr),hl
		175	endm
		176
		177	macro memory_stream_read_2 dst1,dst2
		178	ld hl,(memorystreamcurrentaddr)
		179	memory_stream_read_byte dst1
		180	memory_stream_read_byte dst2
		181	ld (memorystreamcurrentaddr),hl
		182	endm
		183
		184	macro memory_stream_read_3 dst1,dst2,dst3
		185	ld hl,(memorystreamcurrentaddr)
		186	memory_stream_read_byte dst1
		187	memory_stream_read_byte dst2
		188	memory_stream_read_byte dst3
		189	ld (memorystreamcurrentaddr),hl
		190	endm
		191
		192	memorystreamread1
		193	;out: a = byte
		194	memory_stream_read_1 a
		195	ret
		196
		197	memorystreamread2
		198	;out: de = word
		199	memory_stream_read_2 e,d
		200	ret
		201
		202	memorystreamread3
		203	;out: c = byte0, e = byte1, d = byte2
		204	memory_stream_read_3 c,e,d
		205	ret
		206
		207	memorystreamread4
		208	;out: adbc = dword
		209	memorystreamcurrentaddr=$+1
		210	ld hl,0
		211	memory_stream_read_byte c
		212	memory_stream_read_byte b
		213	memory_stream_read_byte d
		214	memory_stream_read_byte a
		215	ld (memorystreamcurrentaddr),hl
		216	ret
		217
		218	memorystreamread
		219	;bc = number of bytes
		220	;de = dest addr
		221	ld a,c
		222	dec bc
		223	inc b
		224	ld c,b
		225	ld b,a
		226	ld hl,(memorystreamcurrentaddr)
		227	.readloop
		228	memory_stream_read_byte a
		229	ld (de),a
		230	inc de
		231	djnz .readloop
		232	dec c
		233	jr nz,.readloop
		234	ld (memorystreamcurrentaddr),hl
		235	ret
		236
		237	memorystreamwrite
		238	;bc = number of bytes
		239	;de = src addr
		240	ld a,c
		241	dec bc
		242	inc b
		243	ld c,b
		244	ld b,a
		245	ld hl,(memorystreamcurrentaddr)
		246	.writeloop
		247	ld a,(de)
		248	memory_stream_write_byte a
		249	inc de
		250	djnz .writeloop
		251	dec c
		252	jr nz,.writeloop
		253	ld (memorystreamcurrentaddr),hl
		254	ret
		255
		256	memorystreamseek
		257	;dehl = absolute position
		258	;out: hl = read address
		259	ld a,e
		260	ld b,h
		261	sla b
		262	rla
		263	sla b
		264	rla
		265	add a,memorystreampages%256
		266	ld e,a
		267	adc a,memorystreampages/256
		268	sub e
		269	ld d,a
		270	ld a,(de)
		271	ld (memorystreamcurrentpage),a
		272	inc de
		273	ld (memorystreampageaddr),de
		274	SETPG8000
		275	res 6,h
		276	set 7,h
		277	ld (memorystreamcurrentaddr),hl
		278	ret
		279
		280	memorystreamgetpos
		281	;out: dehl = absolute position
		282	ld hl,(memorystreampageaddr)
		283	ld de,-memorystreampages-1
		284	add hl,de
		285	ex de,hl
		286	ld hl,(memorystreamcurrentaddr)
		287	res 7,h
		288	bit 6,h
		289	jr z,$+6
		290	inc de
		291	ld hl,0
		292	xor a
		293	rr e
		294	rra
		295	rr e
		296	rra
		297	or h
		298	ld h,a
		299	ret
		300
2286	galstaff	301	MEMORYSTREAMERROR_SUCCESS = 0
		302	MEMORYSTREAMERROR_FILEIO = 1
		303	MEMORYSTREAMERROR_OOM = 2
		304
1797	galstaff	305	memorystreamsize
		306	ds 4
		307	memorystreampages
		308	ds MEMORYSTREAMMAXPAGES
		309	memorystreamcurrentpage
		310	ds 1
2286	galstaff	311	memorystreamerrorcode
		312	ds 1

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(root)/src/gp/common/memorystream.asm – Rev 2286