BinaryIO.ahk

Bin2Hex(ByRef h, ByRef b, n=0)      ; n bytes binary data -> stream of 2-digit hex
{                                   ; n = 0: all (SetCapacity can be larger than used!)
   format = %A_FormatInteger%       ; save original integer format
   SetFormat Integer, Hex           ; for converting bytes to hex

   m := VarSetCapacity(b)
   If (n < 1 or n > m)
       n := m
   Address := &b
   h =
   Loop %n%
   {
      x := *Address                 ; get byte in hex
      StringTrimLeft x, x, 2        ; remove 0x
      x = 0%x%                      ; pad left
      StringRight x, x, 2           ; 2 hex digits
      h = %h%%x%
      Address++
   }
   SetFormat Integer, %format%      ; restore original format
}

Hex2Bin(ByRef b, h, n=0)            ; n hex digit-pairs -> binary data
{                                   ; n = 0: all. (Only ByRef can handle binaries)
   m := Ceil(StrLen(h)/2)
   If (n < 1 or n > m)
       n := m
   Granted := VarSetCapacity(b, n, 0)
   IfLess Granted,%n%, {
      ErrorLevel = Mem=%Granted%
      Return
   }
   Address := &b
   Loop %n%
   {
      StringLeft  x, h, 2
      StringTrimLeft h, h, 2
      x = 0x%x%
      DllCall("RtlFillMemory", "UInt", Address, "UInt", 1, "UChar", x)
      Address++
   }
}

/* ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; BinWrite ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|  - Open binary file
|  - (Over)Write n bytes (n = 0: all)
|  - From offset (offset < 0: counted from end)
|  - Close file
|  (Binary)data -> file[offset + 0..n-1], rest of file unchanged
|  Return #bytes actually written
*/ ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

BinWrite(file, ByRef data, n=0, offset=0)
{
   ; Open file for WRITE (0x40..), OPEN_ALWAYS (4): creates only if it does not exists
   h := DllCall("CreateFile","str",file,"Uint",0x40000000,"Uint",0,"UInt",0,"UInt",4,"Uint",0,"UInt",0)
   IfEqual h,-1, SetEnv, ErrorLevel, -1
   IfNotEqual ErrorLevel,0,Return,0 ; couldn't create the file

   m = 0                            ; seek to offset
   IfLess offset,0, SetEnv,m,2
   r := DllCall("SetFilePointerEx","Uint",h,"Int64",offset,"UInt *",p,"Int",m)
   IfEqual r,0, SetEnv, ErrorLevel, -3
   IfNotEqual ErrorLevel,0, {
      t = %ErrorLevel%              ; save ErrorLevel to be returned
      DllCall("CloseHandle", "Uint", h)
      ErrorLevel = %t%              ; return seek error
      Return 0
   }

   m := VarSetCapacity(data)        ; get the capacity ( >= used length )
   If (n < 1 or n > m)
       n := m
   result := DllCall("WriteFile","UInt",h,"Str",data,"UInt",n,"UInt *",Written,"UInt",0)
   if (!result or Written < n)
       ErrorLevel = -3
   IfNotEqual ErrorLevel,0, SetEnv,t,%ErrorLevel%

   h := DllCall("CloseHandle", "Uint", h)
   IfEqual h,-1, SetEnv, ErrorLevel, -2
   IfNotEqual t,,SetEnv, ErrorLevel, %t%-%ErrorLevel%

   Return Written
}

/* ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; BinRead ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|  - Open binary file
|  - Read n bytes (n = 0: file size)
|  - From offset (offset < 0: counted from end)
|  - Close file
|  (Binary)data (replaced) <- file[offset + 0..n-1]
|  Return #bytes actually read
*/ ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

BinRead(file, ByRef data, n=0, offset=0)
{
   h := DllCall("CreateFile","Str",file,"Uint",0x80000000,"Uint",3,"UInt",0,"UInt",3,"Uint",0,"UInt",0)
   IfEqual h,-1, SetEnv, ErrorLevel, -1
   IfNotEqual ErrorLevel,0,Return,0 ; couldn't open the file

   m = 0                            ; seek to offset
   IfLess offset,0, SetEnv,m,2
   r := DllCall("SetFilePointerEx","Uint",h,"Int64",offset,"UInt *",p,"Int",m)
   IfEqual r,0, SetEnv, ErrorLevel, -3
   IfNotEqual ErrorLevel,0, {
      t = %ErrorLevel%              ; save ErrorLevel to be returned
      DllCall("CloseHandle", "Uint", h)
      ErrorLevel = %t%              ; return seek error
      Return 0
   }

   m := DllCall("GetFileSize","UInt",h,"Int64 *",r)
   If (n < 1 or n > m)
       n := m
   Granted := VarSetCapacity(data, n, 0)
   IfLess Granted,%n%, {
      ErrorLevel = Mem=%Granted%
      Return 0
   }

   result := DllCall("ReadFile","UInt",h,"Str",data,"UInt",n,"UInt *",Read,"UInt",0)

   if (!result or Read < n)
       t = -3
   IfNotEqual ErrorLevel,0, SetEnv,t,%ErrorLevel%

   h := DllCall("CloseHandle", "Uint", h)
   IfEqual h,-1, SetEnv, ErrorLevel, -2
   IfNotEqual t,,SetEnv, ErrorLevel, %t%-%ErrorLevel%

   Return Read
}