VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
END
Attribute VB_Name = "API_Timer"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
'=========== Precise timer wrapper =============
' Shared module version: 20210528
' Tested in:
' Depends on:
' Required reference:
Option Explicit

Private Type BigInt
  lowPart As Long
  highPart As Long
End Type

Private Declare PtrSafe Function QueryPerformanceCounter Lib "kernel32" (lpPerformanceCount As BigInt) As Long
Private Declare PtrSafe Function QueryPerformanceFrequency Lib "kernel32" (lpFrequency As BigInt) As Long

Private Const TWO_32 = 4294967296#

Private start_ As BigInt
Private finish_ As BigInt
Private frequency_ As Double

Public Function Start()
  Call QueryPerformanceCounter(start_)
End Function

' Time elapsed in milliseconds
Public Property Get TimeElapsed() As Double
  Dim crStart As Double
  Dim crStop As Double
  QueryPerformanceCounter finish_
  crStart = BigInt2Double(start_)
  crStop = BigInt2Double(finish_)
  TimeElapsed = 1000# * (crStop - crStart) / frequency_
End Property

Public Property Get TimeStr() As String
  TimeStr = VBA.Format(TimeElapsed, "# ##0.###") & " ms"
End Property

' ====
Private Function BigInt2Double(theInt As BigInt) As Double
  Dim lowPart As Double
  lowPart = theInt.lowPart
  If lowPart < 0 Then
    lowPart = lowPart + TWO_32
  End If
  BigInt2Double = theInt.highPart * TWO_32 + lowPart
End Function

Private Sub Class_Initialize()
  Dim freq As BigInt
  Call QueryPerformanceFrequency(freq)
  frequency_ = BigInt2Double(freq)
End Sub