set blob
}

proc logcksum {ckv1 ckv2 blob} {
  upvar $ckv1 c1
  upvar $ckv2 c2

  set scanpattern I*
  if {$::tcl_platform(byteOrder) eq "littleEndian"} {


    set scanpattern i*
  }

  binary scan $blob $scanpattern values
  foreach {v1 v2} $values {
    set c1 [expr {($c1 + $v1 + $c2)&0xFFFFFFFF}]
    set c2 [expr {($c2 + $v2 + $c1)&0xFFFFFFFF}]
  }
}

  set blob
}

proc logcksum {ckv1 ckv2 blob} {
  upvar $ckv1 c1
  upvar $ckv2 c2

  # Since the magic number at the start of the -wal file header is
  # 931071618 that indicates that the content should always be read as
  # little-endian.
  # 
  set scanpattern i*


  binary scan $blob $scanpattern values
  foreach {v1 v2} $values {
    set c1 [expr {($c1 + $v1 + $c2)&0xFFFFFFFF}]
    set c2 [expr {($c2 + $v2 + $c1)&0xFFFFFFFF}]
  }
}