Tricks

2007-01-13T05:13:01Z

Uten: /* AutoIt configuration */ Fixed link

== This page is intended to list simple but useful tricks. ==

=== Show Error Message and Exit in one line ===
The following line shows an error message and exits the script with an error code of 99 if $x is bigger than 5:<pre>If $x > 5 Then Exit 99 + 0*MsgBox(0, 'Error', '$x is bigger than 5!')</pre>The trick works as follows: When $x is bigger than 5, the statement after the "Then" is executed. This statement consists of a calculation. While parsing this calculation, AutoIt notes that it has to execute the MsgBox() function to be able to fill in all values into the calculation. However, since the value can change depending on which button is used to close the box, we need to eliminate the return code from our calculation. That's why the return value of the MsgBox() function is multiplied by 0. Since we don't want 0 to be the error code we'll just add 99 to it. Now AutoIt is able to execute the Exit command so the script exits at this point.

=== Save a variable to a file ===
A variable's value can be saved to a file for later use.
For example if you have a variable called $Data and you wanted to save it for later just use IniWrite.
<pre>IniWrite("Variables.ini","Main","Data",$Data) </pre>

To get it back later just do.
<pre>$Data = IniRead("Variables.ini","Main","Data","") </pre>
You can even get it back after the script has exited and restarted.

=== AutoIt configuration ===
Has it's own page called [[Tricks Autoit Configuration]]

Tutorial Optimizing

2007-01-05T00:47:40Z

Uten: /* Optimizing */ Added some text, Changed titles

NOTE: This document is work in progress. Your view and contribution on content is welcome. Spellchecking and grammar will be worked on when the document approaches a stable state.

=Introduction=
This tutorial will be about profiling and optimizing code when we have identified a bottleneck. There are several paths down this road. You could analytically evaluate your code, or fragments of it. You could optimize parts that don't feel good. And you can measure how long time the code takes to run.

=Profiling=
When we profile the code we use a stopwatch to log how much time that is spent from the code starts until it ends execution. There are two types of time we can use. The real time spent and the CPU time spent to execute the code. Both methodes has it usage. But meassuring the CPU time should normally result in better knowledge than measuring clock time. The exception could be in routines where the code calls external resources that depends on other factors than the CPU. Ex: printer, network, disk IO.
==The simplest aproach==
Autoit has two handy clock functions to do a regular stopwatch measure of code execution time. Namely
TimerInit and TimerDiff. TimerInit is used to get a reference point and TimerDiff to get the diffrence between the reference point and the call to TimerDiff in milliseconds.
So a simplest possible sample could be:
<pre>
Local $i, $j, $sum, $count, $ts, $td
For $j = 1 to 10
$ts = TimerInit()
Do
$count += 1
$sum += Random(-5, 5, 1)
Until $sum = 0 OR $count = 100000
; Write/create report
$td = TimerDiff($ts)
ConsoleWrite( StringFormat("%#.6g ms, Iter=%.6d, avg=%.6g", $td, $count, $td/$count) & @LF)
$count = 0
Next
</pre>
Now although this is a reasonable way of measuring execution time it does not give an accurate picture to identify bottlenecks. And the reason is that it measure real time and not the time spent by the CPU to execute this part of the code. You can probably see this if on of the iterations reaches a $sum=0 in few iterations compared to one that use max iterations.

==The more accurate approach==
API notes: GetProcessTimes, GetThreadTimes
Windows versions based on NT kernel has at least two api calls to make profiling easier for us. GetProcessTimes will return the CPU time spent by the given process. GetThreadTimes will return the CPU time spent by the given thread. As AutoIt does not suport user defined threads we will use the GetProcessTimes call. A [http://www.autoitscript.com/forum/index.php?s=&showtopic=38751 profiling UDF] has been created by [http://www.autoitscript.com/forum/index.php?showuser=7836 @uten] in the autoitscript forum. As for now we will use that code. Save the code in a include file. I have called mine profiler.au3 and saved it in a include directory. (TODO: Link to page explaining userdefined include directories.)
<pre>Global $FILETIME = "dword;dword" ;Contains a 64-bit value representing the number of 100-nanosecond intervals since January 1, 1601 (UTC).
Global $SYSTEMTIME = "ushort;ushort;ushort;ushort;ushort;ushort;ushort;ushort"
Func FileTimeToNum(ByRef $FT)
Return BITOr(BitShift(DllStructGetData($FT, 1), 32), DllStructGetData($FT, 2))
EndFunc
Func OpenProcess($pid = @AutoItPID)
Local $PROCESS_QUERY_INFORMATION = 0x0400
Local $PROCESS_VM_READ = 0x0010
$Process = DLLCall("kernel32.dll","int","OpenProcess","int", _
BitOR($PROCESS_QUERY_INFORMATION,$PROCESS_VM_READ),"int",0,"int", $pid)
If $Process[0] = 0 Then Return SetError(1, 0, 0)
Return $Process[0]
EndFunc
Func GetProcessTimes(ByRef $hProcess, ByRef $t1, ByRef $t2, ByRef $t3, ByRef $t4)

;BOOL WINAPI GetProcessTimes(
; HANDLE hProcess,
; LPFILETIME lpCreationTime,
; LPFILETIME lpExitTime,
; LPFILETIME lpKernelTime,
; LPFILETIME lpUserTime
; )
;
Local $p1 = DllStructGetPtr($t1)
Local $p2 = DllStructGetPtr($t2)
Local $p3 = DllStructGetPtr($t3)
Local $p4 = DllStructGetPtr($t4)
;ConsoleWrite($p1 & ", " & $p2& ", " & $p3 & ", " & $p4 & @LF)
Local $ret = dllcall("kernel32.dll","int", "GetProcessTimes","int",$hProcess , "ptr", $p1, "ptr", $p2, "ptr", $p3, "ptr", $p4)
If $ret[0] = 0 Then
ConsoleWrite("(" & @ScriptLineNumber & ") : = Error in GetProcessTimes call" & @LF)
SetError(1, 0 , $ret[0])
EndIf
Return $ret[0]
EndFunc
Func ProfileInit()
Local $process = OpenProcess(@AutoItPID)
if @error then
ConsoleWrite("!OpenProcess failed terminating" & @LF)
Exit
EndIf
Local $ret[4]
$ret[0] = 2
Local $t1 = DllStructCreate($FILETIME)
Local $t2 = DllStructCreate($FILETIME)
Local $t3 = DllStructCreate($FILETIME)
Local $t4 = DllStructCreate($FILETIME)
If GetProcessTimes($process, $t1, $t2, $t3, $t4) Then
$ret[$ret[0] + 1] = $process
$ret[1] = FileTimeToNum($t3)
$ret[2] = FileTimeToNum($t4)
Else
ConsoleWrite("(" & @ScriptLineNumber & ") := @error:=" & @error & ", @extended:?" & @extended & @LF)
SetError(@error, @extended, 0)
EndIf
;ArrayDump($ret, "ProfileInit Out")
Return $ret
EndFunc
Func ProfileDiff(ByRef $init)
Local $ret[3]
$ret[0] = 2
;ArrayDump($init, "ProfileDiff($init)")
Local $t1 = DllStructCreate($FILETIME)
Local $t2 = DllStructCreate($FILETIME)
Local $t3 = DllStructCreate($FILETIME)
Local $t4 = DllStructCreate($FILETIME)
Local $n1, $n2
If GetProcessTimes($init[$init[0] + 1], $t1, $t2, $t3, $t4) Then
$ret[1] = FileTimeToNum($t3) - $init[1]
$ret[2] = FileTimeToNum($t4) - $init[2]
Else
ConsoleWrite("(" & @ScriptLineNumber & ") := @error:=" & @error & ", @extended:=" & @extended & @LF)
SetError(@error, 0 , 0)
EndIf
Return $ret
EndFunc</pre>

Now that we have a some profiling routines. ProfileInit and ProfileDiff we can change our sample to make use of those udf's.
Note that the time returned from ProfileDiff are in 100-nanoseconds intervals. TO get ms we have to divide by 10000.
<pre>
#include <profiler.au3>
Local $i, $j, $sum, $count, $ps, $pd, $uk
For $j = 1 to 10
$ps = ProfileInit()
Do
$count += 1
$sum += Random(-5, 5, 1)
Until $sum = 0 OR $count = 100000
; Write/create report
$pd = ProfileDiff($ps)
$uk = Round(($pd[1] + $pd[2])/10000, 0) ;User and kernel time
ConsoleWrite( StringFormat("%#.6g ms, Iter=%.6d, avg=%.6g", $uk, $count, $uk/$count) & @LF)
$count = 0
Next
</pre>

=Optimizing code=
When do we need to optimize our code? Well, thats a good question. A roule of thumb is to make the code work first. If we experience that the code is slow we have to find the reason. When one or more reasons are found we have to consider if it is possible to optimize the code.

Let's have a look at a ''real world'' sample. Sorting stuff is a classic.
==Getting some data==
Let's grab some data from autoitscript. The data is not relevant for the sample so if you have a fearly big html file on your disk you could use that instead.
<pre>
#include <inet.au3>
$data = _InetGet("http://www.autoitscript.com/forum/index.php?showtopic=36941")
;$data = ReadFile("<your file>")
</pre>
==Data to plain text. Take one==
<pre>
Func WordList(ByRef $data)
;Shave of html tags
Local $res
;Return string
EndFunc
</pre>
==Data to plain text. Take two==
<pre>
Func Wordlist2(ByRef $data)
Local $res = StringRegExp($data, "TODO", 3)
;Array to string
;Return string
EndFunc
</pre>
==Sorting the text. Take one==
Using bouble sort
==Sorting the text. Take two==
Using something faster.

User:Uten

2006-10-21T19:32:43Z

Uten: Just a first edit of my Uten's page

===The first entry===
This is kind of my first AutoIt wiki entry so be gentle.

I will try out a few features in this page and see how I can contribute to the tutorial part of the wiki.

The wikipedia [http://en.wikipedia.org/wiki/Wikipedia:Quick_guide cheatsheet] seems to be a nice place to start to understan formating of a wiki pedia page
--[[User:Uten|Uten]] 12:32, 21 October 2006 (PDT)

AutoIt Wiki - User contributions [en]

Tricks

Tutorial Optimizing

User:Uten