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Timing Split; getting a handle on things.

Tonight I decided that, before I attempt to match the speed of Split, I'd better measure it out to see how fast it is. Here's the results of some simple tests...

Imports System.Text
Imports Microsoft.VisualBasic

Module StringTimers
    Private mString As String
    Private startTime, endTime As DateTime

    Sub Main()
        ' initialize a test string
        InitializeString()

        ' Test the VB Split Function
        Console.WriteLine("========== DoFunction() ==========")
        DoFunction()
        DisplayTime("DoFunction()")
        DoFunction()
        DisplayTime("DoFunction()")
        DoFunction()
        DisplayTime(vbCrLf & "DoFunction()")



        ' Test the String instance method Split
        Console.WriteLine(vbCrLf & vbCrLf & "========== DoMethod() ==========")
        DoMethod()
        DisplayTime("DoMethod()")
        DoMethod()
        DisplayTime("DoMethod()")
        DoMethod()
        DisplayTime(vbCrLf & "DoMethod()")

        ' Test a Regex who's pattern has been internalized prior to timing
        Console.WriteLine(vbCrLf & vbCrLf & "========== DoRegex_Compiled() ==========")
        DoRegex_Compiled()
        DisplayTime("DoRegex_Compiled()")
        DoRegex_Compiled()
        DisplayTime("DoRegex_Compiled()")
        DoRegex_Compiled()
        DisplayTime(vbCrLf & "DoRegex_Compiled()")

        ' Test a Regex who's pattern in internalized during timing
        Console.WriteLine(vbCrLf & vbCrLf & "========== DoRegex_AdHoc() ==========")
        DoRegex_AdHoc()
        DisplayTime("DoRegex_AdHoc()")
        DoRegex_AdHoc()
        DisplayTime("DoRegex_AdHoc()")
        DoRegex_AdHoc()
        DisplayTime(vbCrLf & "DoRegex_AdHoc()")

        Console.ReadLine()
    End Sub

    Private Sub InitializeString()
        Dim sb As New StringBuilder
        For i As Integer = 0 To 100000
            sb.Append("a b c d" & vbCrLf)
        Next
        mString = sb.ToString
    End Sub

    ' Test the VB Split Function
    Private Sub DoFunction()
        Console.WriteLine("Entering DoFunction()...")
        startTime = DateTime.Now()
        Dim arr As String() = Split(mString, vbCrLf)
        endTime = DateTime.Now()
    End Sub

    ' Test the String instance method Split
    Private Sub DoMethod()
        Console.WriteLine("Entering DoMethod()...")
        startTime = DateTime.Now()
        Dim arr As String() = mString.Split(New Char() {Chr(13), Chr(10)})
        endTime = DateTime.Now()
    End Sub

    ' Test a Regex who's pattern has been internalized prior to timing
    Private Sub DoRegex_Compiled()
        Console.WriteLine("Entering DoRegex_Compiled...")
        Dim re As New RegularExpressions.Regex("[\n\r]+", _
            RegularExpressions.RegexOptions.Compiled Or RegularExpressions.RegexOptions.Singleline)
        startTime = DateTime.Now()
        Dim arr As String() = re.Split(mString)
        endTime = DateTime.Now()
    End Sub

    ' Test a Regex who's pattern in internalized during timing
    Private Sub DoRegex_AdHoc()
        Console.WriteLine("Entering DoRegex_AdHoc...")
        startTime = DateTime.Now()
        Dim arr As String() = RegularExpressions.Regex.Split(mString, "[\n\r]+")
        endTime = DateTime.Now()
    End Sub

    ' Helper method to display results to the console
    Private Sub DisplayTime(ByVal operationName As String)
        Console.WriteLine(operationName & " took " & _
            endTime.Subtract(startTime).TotalMilliseconds.ToString & " milliseconds.")
    End Sub

End Module

...and here's the output...

========== DoFunction() ==========
Entering DoFunction()...
DoFunction() took 4947.1136 milliseconds.
Entering DoFunction()...
DoFunction() took 4927.0848 milliseconds.
Entering DoFunction()...
DoFunction() took 4927.0848 milliseconds.

========== DoMethod() ==========
Entering DoMethod()...
DoMethod() took 50.072 milliseconds.
Entering DoMethod()...
DoMethod() took 40.0576 milliseconds.
Entering DoMethod()...
DoMethod() took 60.0864 milliseconds.

========== DoRegex_Compiled() ==========
Entering DoRegex_Compiled...
DoRegex_Compiled() took 460.6624 milliseconds.
Entering DoRegex_Compiled...
DoRegex_Compiled() took 440.6336 milliseconds.
Entering DoRegex_Compiled...
DoRegex_Compiled() took 480.6912 milliseconds.

========== DoRegex_AdHoc() ==========
Entering DoRegex_AdHoc...
DoRegex_AdHoc() took 981.4112 milliseconds.
Entering DoRegex_AdHoc...
DoRegex_AdHoc() took 1051.512 milliseconds.
Entering DoRegex_AdHoc...
DoRegex_AdHoc() took 971.3968 milliseconds.