TurboSort

Description

Sort arrays much faster with a better string

swapping routine!

Wow, I couldn't believe all the rewrites of the

same sorting routines in PSC. "Look at

mine", "No, use mine", yadda, yadda, yadda. They

all use the horribly slow:

vTemp = String1

String1 = String2

String1 = vTemp

Geezzzz - When you have to sort 30,000+ strings

this is slllooooowwwwwww.

Here's a solution. It uses the the same sorting

routine (or choose your own), but implements a much

faster swap routine using the CopyMemory() API. Now,

instead of swapping strings, which in my case could

be up to 9,000 characters, you are only swapping a

4 byte memory address.

Rock On!!

More Info

Create a new EXE and throw in Command1 - Paste the rest.

Submitted On
By	Brian Cidern
Level	Beginner
User Rating	4.9 (69 globes from 14 users)
Compatibility	VB 5.0, VB 6.0
Category	String Manipulation
World	Visual Basic
Archive File

Source Code

Option Explicit
Private Declare Sub CopyMemory _
 Lib "kernel32" _
 Alias "RtlMoveMemory" ( _
 lpDest As Any, _
 lpSource As Any, _
 ByVal cbCopy As Long _
 )
Private Sub Command1_Click()
 ' Sort an array with CopyMemory()
 Dim i As Integer
 Dim str_Unsorted As String, _
 str_Sorted As String
 ' Populate some sample data
 Dim vArray(25) As String
 vArray(0) = "EFGHIJKLMNOPQRSTUVWXYZABCD"
 vArray(1) = "RSTUVWXYZABCDEFGHIJKLMNOPQ"
 vArray(2) = "PQRSTUVWXYZABCDEFGHIJKLMNO"
 vArray(3) = "DEFGHIJKLMNOPQRSTUVWXYZABC"
 vArray(4) = "IJKLMNOPQRSTUVWXYZABCDEFGH"
 vArray(5) = "ZABCDEFGHIJKLMNOPQRSTUVWXY"
 vArray(6) = "HIJKLMNOPQRSTUVWXYZABCDEFG"
 vArray(7) = "LMNOPQRSTUVWXYZABCDEFGHIJK"
 vArray(8) = "STUVWXYZABCDEFGHIJKLMNOPQR"
 vArray(9) = "TUVWXYZABCDEFGHIJKLMNOPQRS"
 vArray(10) = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 vArray(11) = "CDEFGHIJKLMNOPQRSTUVWXYZAB"
 vArray(12) = "VWXYZABCDEFGHIJKLMNOPQRSTU"
 vArray(13) = "MNOPQRSTUVWXYZABCDEFGHIJKL"
 vArray(14) = "FGHIJKLMNOPQRSTUVWXYZABCDE"
 vArray(15) = "JKLMNOPQRSTUVWXYZABCDEFGHI"
 vArray(16) = "YZABCDEFGHIJKLMNOPQRSTUVWX"
 vArray(17) = "XYZABCDEFGHIJKLMNOPQRSTUVW"
 vArray(18) = "OPQRSTUVWXYZABCDEFGHIJKLMN"
 vArray(19) = "BCDEFGHIJKLMNOPQRSTUVWXYZA"
 vArray(20) = "GHIJKLMNOPQRSTUVWXYZABCDEF"
 vArray(21) = "KLMNOPQRSTUVWXYZABCDEFGHIJ"
 vArray(22) = "NOPQRSTUVWXYZABCDEFGHIJKLM"
 vArray(23) = "WXYZABCDEFGHIJKLMNOPQRSTUV"
 vArray(24) = "QRSTUVWXYZABCDEFGHIJKLMNOP"
 vArray(25) = "UVWXYZABCDEFGHIJKLMNOPQRST"
 ' Here's the unsorted array
 For i = 0 To UBound(vArray)
 str_Unsorted = str_Unsorted & vArray(i) & vbCrLf
 Next i
 MsgBox str_Unsorted
 ' Sort the array
 SortMe vArray
 ' Here's the sorted array
 For i = 0 To UBound(vArray)
 str_Sorted = str_Sorted & vArray(i) & vbCrLf
 Next i
 MsgBox str_Sorted
End Sub
Sub SortMe(varArray() As String)
 Dim i As Long, j As Long
 Dim l_Count As Long
 Dim l_Hold As Long
 ' Typical sorting routine
 l_Count = UBound(varArray)
 For i = 0 To l_Count
 For j = i + 1 To l_Count
 If varArray(i) > varArray(j) Then
 ' Here's the juice!
 SwapStrings varArray(i), varArray(j)
 End If
 Next
 Next
End Sub
Sub SwapStrings(pbString1 As String, pbString2 As String)
 Dim l_Hold As Long
 CopyMemory l_Hold, ByVal VarPtr(pbString1), 4
 CopyMemory ByVal VarPtr(pbString1), ByVal VarPtr(pbString2), 4
 CopyMemory ByVal VarPtr(pbString2), l_Hold, 4
End Sub