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fs: grow file size on fsPutC, if appropriate

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This commit is contained in:
Virgil Dupras 2019-06-05 16:34:14 -04:00
parent fc81bce70f
commit fb99f4ad91
1 changed files with 31 additions and 4 deletions
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35
kernel/fs.asm
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@ -440,11 +440,39 @@ fsWithinBounds:
.outOfBounds: .outOfBounds:
jp unsetZ ; returns jp unsetZ ; returns
; Adjust, if needed, file size of handle (IX) to HL+1.
; This adjustment only happens if this makes file size grow.
fsAdjustBounds:
call fsWithinBounds
ret z
; Not within bounds? let's increase them
push hl
ld hl, 0
call fsPlaceH ; fs blkdev is now at beginning of content
; we need the blkdev to be on filesize's offset
ld hl, FS_METASIZE-FS_META_FSIZE_OFFSET
ld a, BLOCKDEV_SEEK_BACKWARD
call fsblkSeek
pop hl
; blkdev is at the right spot, HL is back to its original value, let's
; write it.
push hl
inc hl ; We write HL+1, remember
; now let's write our new filesize both in blkdev and in file handle's
; cache.
ld a, l
ld (ix+4), a
call fsblkPutC
ld a, h
ld (ix+5), a
call fsblkPutC
pop hl
xor a ; ensure Z
ret
; Read a byte in handle at (IX) at position HL and put it into A. ; Read a byte in handle at (IX) at position HL and put it into A.
; Z is set on success, unset if handle is at the end of the file. ; Z is set on success, unset if handle is at the end of the file.
fsGetC: fsGetC:
ld a, h
ld a, l
call fsWithinBounds call fsWithinBounds
jr z, .proceed jr z, .proceed
; We want to unset Z, but also return 0 to ensure that a GetC that ; We want to unset Z, but also return 0 to ensure that a GetC that
@ -461,13 +489,12 @@ fsGetC:
; Write byte A in handle (IX) and advance the handle's position. ; Write byte A in handle (IX) and advance the handle's position.
; Z is set on success, unset if handle is at the end of the file. ; Z is set on success, unset if handle is at the end of the file.
; TODO: detect end of block alloc ; TODO: detect end of block alloc
; TODO: grow file size if appropriate
fsPutC: fsPutC:
push hl push hl
call fsPlaceH call fsPlaceH
call fsblkPutC call fsblkPutC
pop hl pop hl
ret jp fsAdjustBounds ; returns
; Mount the fs subsystem upon the currently selected blockdev at current offset. ; Mount the fs subsystem upon the currently selected blockdev at current offset.
; Verify is block is valid and error out if its not, mounting nothing. ; Verify is block is valid and error out if its not, mounting nothing.