PowerShell-Toolmaking

2.1.0.0

Chapters/scripting-at-scale/pipelinesamples.ps1


#demonstrate pipeline performance differences
return "This is a demo script file."

#region pipeline vs parameter

$names = Get-Service | Select-Object -ExpandProperty name

#57ms
Measure-Command {
 $names | Get-Service
}

#40ms
Measure-Command {
 Get-Service $names
}

$big = $names+$names+$names+$names+$names
#253ms
Measure-Command {
 $big | Get-Service
}

#169ms
Measure-Command {
 Get-Service $big
}

#endregion

#region breakup a command

#861ms
Measure-Command {
$data = Get-ChildItem $env:temp -file -Recurse | 
Group-Object -Property extension |
Sort-Object -Property Count | 
Select-Object -Property Count,Name,
@{Name="Size";Expression = {($_.group | Measure-object -Property length -sum).sum}}
}

#779ms
Measure-Command {
$files = Get-ChildItem $env:temp -file -Recurse
$grouped = $files | Group-Object -Property extension
$sorted = $grouped | Sort-Object -Property Count
$data = $sorted | Select-Object -Property Count,Name,
@{Name="Size";Expression = {($_.group | Measure-Object -Property length -sum).sum}}
}

#endregion

#region ForEach vs Foreach-Object

$n = 1..10000

#51.7ms
Measure-command {
 $a = 0
 foreach ($i in $n) {
   $a+=$i
 }
}

#227ms
Measure-command {

 $n | foreach-object -Begin { $a = 0 } -process {
   $a+=$_
 }

}

#endregion

ize";Expression = {($_.group | Measure-object -Property length -sum).sum}} } #779ms Measure-Command { $files = Get-ChildItem $env:temp -file -Recurse $grouped = $files | Group-Object -Property extension $sorted = $grouped | Sort-Object -Property Count $data = $sorted | Select-Object -Property Count,Name, @{Name="Size";Expression = {($_.group | Measure-Object -Property length -sum).sum}} } #endregion #region ForEach vs Foreach-Object $n = 1..10000 #51.7ms Measure-command { $a = 0 foreach ($i in $n) { $a+=$i } } #227ms Measure-command { $n | foreach-object -Begin { $a = 0 } -process { $a+=$_ } } #endregion