Anton's Digital Garden

Compare static and dynamic property calculation

1 min read

Add static values

$EXAMPLE_PATH = "$env:TEMP\example.txt"
 
New-Item -Path $EXAMPLE_PATH -Force | Out-Null
$file = Get-Item -Path $EXAMPLE_PATH
Write-Host "Does file exist after creation:" $file.Exists
 
Remove-Item -Path $EXAMPLE_PATH
Write-Host "Does file exist after deletion:" $file.Exists
 
$file.Refresh()
Write-Host "Does file exist after refresh:" $file.Exists

Add dynamic values

$EXAMPLE_PATH = "$env:TEMP\example.txt"
$TEST_EXISTANCE = { Test-Path -Path $this.FullName }
 
New-Item -Path $EXAMPLE_PATH -Force | Out-Null
$file = Get-Item -Path $EXAMPLE_PATH
$file | Add-Member -MemberType ScriptProperty -Name TestExistance -Value $TEST_EXISTANCE
Write-Host "Does file exist after creation:" $file.TestExistance
 
Remove-Item -Path $EXAMPLE_PATH
Write-Host "Does file exist after deletion:" $file.TestExistance
 
Write-Host "Does file exist after refresh:" $file.TestExistance

Compare performance

$files = Get-ChildItem -Path $env:SystemRoot
$TEST_EXISTANCE = { Test-Path -Path $this.FullName }
$files | Add-Member -MemberType AliasProperty -Name StaticExistance -Value Exists
$files | Add-Member -MemberType ScriptProperty -Name DynamicExistance -Value $TEST_EXISTANCE
 
"StaticExistance", "DynamicExistance" | ForEach-Object {
    $executionTime = Measure-Command { $files."$_" }
    [PSCustomObject]@{
        AccessTest = $_
        Ticks = $executionTime.Ticks
        Milliseconds = $executionTime.Milliseconds
    }
}
AccessTest        Ticks Milliseconds
----------        ----- ------------
StaticExistance   15388            1
DynamicExistance 371345           37

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Tags: Properties - Inspect, filter, select, enrich, and sort objects

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