option explicit
'/////////////////////////////////////////
'// 對磁盤的物理扇區數據讀/寫操作
'// last update: 2004-8-7
'// kwanhong young
'/////////////////////////////////////////
'//file system
private declare function createfile lib "kernel32" alias "createfilea" (byval lpfilename as string, byval dwdesiredaccess as long, byval dwsharemode as long, lpsecurityattributes as long, byval dwcreationdisposition as long, byval dwflagsandattributes as long, byval htemplatefile as long) as long
private declare function closehandle lib "kernel32" (byval hobject as long) as long
private declare function readfile lib "kernel32" (byval hfile as long, lpbuffer as any, byval nnumberofbytestoread as long, lpnumberofbytesread as long, byval lpoverlapped as long) as long '//declare has changed
private declare function writefile lib "kernel32" (byval hfile as long, lpbuffer as any, byval nnumberofbytestowrite as long, lpnumberofbyteswritten as long, byval lpoverlapped as long) as long '//declare has changed
private declare function setfilepointer lib "kernel32" (byval hfile as long, byval ldistancetomove as long, lpdistancetomovehigh as long, byval dwmovemethod as long) as long
private const generic_read = &h80000000
private const generic_write = &h40000000
private const file_share_read = &h1
private const file_share_write = &h2
private const open_existing = 3
private const invalid_handle_value = -1
'//file seek
private const file_begin = 0
private const file_current = 1
private const file_end = 2
private const error_success = 0&
'//device io control
private declare function deviceiocontrol lib "kernel32" (byval hdevice as long, byval dwiocontrolcode as long, lpinbuffer as any, byval ninbuffersize as long, lpoutbuffer as any, byval noutbuffersize as long, lpbytesreturned as long, byval lpoverlapped as long) as long
private const ioctl_disk_get_drive_geometry as long = &h70000 '458752
private const ioctl_storage_get_media_types_ex as long = &h2d0c04
private const ioctl_disk_format_tracks as long = &h7c018
private const fsctl_lock_volume as long = &h90018
private const fsctl_unlock_volume as long = &h9001c
private const fsctl_dismount_volume as long = &h90020
private const fsctl_get_volume_bitmap = &h9006f
'//type
private type large_integer
lowpart as long
highpart as long
end type
private enum media_type
unknown
f5_1pt2_512
f3_1pt44_512
f3_2pt88_512
f3_20pt8_512
f3_720_512
f5_360_512
f5_320_512
f5_320_1024
f5_180_512
f5_160_512
removablemedia
fixedmedia
end enum
private type disk_geometry
cylinders as large_integer
mediatype as media_type
trackspercylinder as long
sectorspertrack as long
bytespersector as long
end type
'//private vars
private hdisk as long 'disk handle
private lpgeometry as disk_geometry 'disk info
private lbuffersize as long 'the buffer size of read/write
public function opendisk(byval filename as string) as boolean
'// 打開磁盤
hdisk = createfile(filename, _
generic_read or generic_write, _
file_share_read or file_share_write, _
byval 0&, _
open_existing, _
0, _
0)
opendisk = not (hdisk = invalid_handle_value)
end function
public function closedisk() as boolean
'//關閉磁盤
closedisk = closehandle(hdisk)
end function
public function getdiskgeometry() as boolean
'//獲取磁盤參數
dim dwoutbytes as long
dim bresult as boolean
bresult = deviceiocontrol(hdisk, _
ioctl_disk_get_drive_geometry, _
byval 0&, 0, _
lpgeometry, len(lpgeometry), _
dwoutbytes, _
byval 0&)
if bresult then lbuffersize = lpgeometry.bytespersector * lpgeometry.sectorspertrack
getdiskgeometry = bresult
end function
public sub getdiskinfo(mediatype as long, _
cylinders as long, _
trackspercylinder as long, _
sectorspertrack as long, _
bytespersector as long)
'//返回磁盤的參數
mediatype = lpgeometry.mediatype
cylinders = lpgeometry.cylinders.lowpart
trackspercylinder = lpgeometry.trackspercylinder
sectorspertrack = lpgeometry.sectorspertrack
bytespersector = lpgeometry.bytespersector
end sub
public property get buffersize() as long
'//返回每次讀/寫的緩沖大小
buffersize = lbuffersize
end property
public function lockvolume() as boolean
'// 將卷鎖定
dim dwoutbytes as long
dim bresult as boolean
bresult = deviceiocontrol(hdisk, _
fsctl_lock_volume, _
byval 0&, 0, _
byval 0&, 0, _
dwoutbytes, _
byval 0&)
lockvolume = bresult
end function
public function unlockvolume() as boolean
'// 將卷解鎖
dim dwoutbytes as long
dim bresult as boolean
bresult = deviceiocontrol(hdisk, _
fsctl_unlock_volume, _
byval 0&, 0, _
byval 0&, 0, _
dwoutbytes, _
byval 0&)
unlockvolume = bresult
end function
public function dismountvolume() as boolean
'// 將卷卸下,使系統重新辨識磁盤，等效于重新插盤
dim dwoutbytes as long
dim bresult as boolean
bresult = deviceiocontrol(hdisk, _
fsctl_dismount_volume, _
byval 0&, 0, _
byval 0&, 0, _
dwoutbytes, _
byval 0&)
dismountvolume = bresult
end function
public function readdisk(byval cylinders as long, _
byval tracks as long, _
db() as byte) as boolean
'//按柱面和磁道來讀取磁盤數據
dim ipos as long
dim lread as long
ipos = cylinders * tracks * lbuffersize
if seekabsolute(0, ipos) then
readdisk = readbytes(lbuffersize, db(), lread)
end if
end function
public function writedisk(byval cylinders as long, _
byval tracks as long, _
db() as byte) as boolean
'//按柱面和磁道來寫磁盤數據
dim ipos as long
dim lread as long
ipos = cylinders * tracks * lbuffersize
if seekabsolute(0, ipos) then
writedisk = writebytes(lbuffersize, db())
end if
end function
'/////////////////////////////////////////////////////////////////////////////////////
'//file system
private function seekabsolute(byval highpos as long, byval lowpos as long) as boolean
'//seek file
'//notice: when you set lowpos=5, the read/write will begin with the 6th(lowpos+1) byte
lowpos = setfilepointer(hdisk, lowpos, highpos, file_begin)
if lowpos = -1 then
seekabsolute = (err.lastdllerror = error_success)
else
seekabsolute = true
end if
end function
private function readbytes(byval bytecount as long, byref databytes() as byte, byref actuallyreadbyte as long) as boolean
'//read data to array
dim retval as long
retval = readfile(hdisk, databytes(0), bytecount, actuallyreadbyte, 0)
'actuallyreadbyte =>> if the bytesread=0 mean eof
readbytes = not (retval = 0)
end function
private function writebytes(byval bytecount as long, byref databytes() as byte) as boolean
'//write data from array
dim retval as long
dim bytestowrite as long
dim byteswritten as long
retval = writefile(hdisk, databytes(0), bytecount, byteswritten, 0)
writebytes = not (retval = 0)
end function
