PSParallelPipeline.psm1
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using namespace System.Collections.Generic using namespace System.Management.Automation using namespace System.Management.Automation.Runspaces using namespace System.Management.Automation.Language using namespace System.Text function Invoke-Parallel { <# .SYNOPSIS Enables parallel processing of pipeline input objects. .DESCRIPTION PowerShell function that intends to emulate [`ForEach-Object -Parallel`](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/foreach-object?view=powershell-7.2#-parallel) for those stuck with Windows PowerShell. This function shares similar usage and capabilities than the ones available in the built-in cmdlet. This project is greatly inspired by RamblingCookieMonster's [`Invoke-Parallel`](https://github.com/RamblingCookieMonster/Invoke-Parallel) and Boe Prox's [`PoshRSJob`](https://github.com/proxb/PoshRSJob) and is merely a simplified take on those with some few improvements. TO DO: - Add `-TimeoutSeconds` parameter. .PARAMETER InputObject Specifies the input objects to be processed in the ScriptBlock. Note: This parameter is intended to be bound from pipeline. .PARAMETER ScriptBlock Specifies the operation that is performed on each input object. This script block is run for every object in the pipeline. .PARAMETER ThrottleLimit Specifies the number of script blocks that are invoked in parallel. Input objects are blocked until the running script block count falls below the ThrottleLimit. The default value is `5`. .PARAMETER Variables Specifies a hash table of variables to have available in the Script Block (Runspaces). The hash table `Keys` become the Variable Name inside the Script Block. .PARAMETER Functions Existing functions in the Local Session to have available in the Script Block (Runspaces). .PARAMETER ThreadOptions These options control whether a new thread is created when a command is executed within a Runspace. This parameter is limited to `ReuseThread` and `UseNewThread`. Default value is `ReuseThread`. See [`PSThreadOptions` Enum](https://learn.microsoft.com/en-us/dotnet/api/system.management.automation.runspaces.psthreadoptions?view=powershellsdk-7.2.0) for details. .EXAMPLE $message = 'Hello world from {0}' 0..10 | Invoke-Parallel { $using:message -f [runspace]::DefaultRunspace.InstanceId Start-Sleep 3 } -ThrottleLimit 3 Run slow script in parallel batches. .EXAMPLE $message = 'Hello world from {0}' 0..10 | Invoke-Parallel { $message -f [runspace]::DefaultRunspace.InstanceId Start-Sleep 3 } -Variables @{ message = $message } -ThrottleLimit 3 Same as Example 1 but with `-Variables` parameter. .EXAMPLE $sync = [hashtable]::Synchronized(@{}) Get-Process | Invoke-Parallel { $sync = $using:sync $sync[$_.Name] += @( $_ ) } $sync Adding to a single thread safe instance. .EXAMPLE $sync = [hashtable]::Synchronized(@{}) Get-Process | Invoke-Parallel { $sync[$_.Name] += @( $_ ) } -Variables @{ sync = $sync } $sync Same as Example 3, but using `-Variables` to pass the reference instance to the runspaces. This method is the recommended when passing reference instances to the runspaces, `$using:` may fail in some situations. .EXAMPLE function Greet { param($s) "$s hey there!" } 0..10 | Invoke-Parallel { Greet $_ } -Functions Greet This example demonstrates how to pass a locally defined Function to the Runspaces scope. .LINK https://github.com/santisq/PSParallelPipeline #> [CmdletBinding(PositionalBinding = $false)] [Alias('parallel', 'parallelpipeline')] param( [Parameter(Mandatory, ValueFromPipeline)] [object] $InputObject, [Parameter(Mandatory, Position = 0)] [scriptblock] $ScriptBlock, [Parameter()] [int] $ThrottleLimit = 5, [Parameter()] [hashtable] $Variables, [Parameter()] [ArgumentCompleter({ param( [string] $commandName, [string] $parameterName, [string] $wordToComplete ) (Get-Command -CommandType Filter, Function).Name -like "$wordToComplete*" })] [string[]] $Functions, [Parameter()] [ValidateSet('ReuseThread', 'UseNewThread')] [PSThreadOptions] $ThreadOptions = [PSThreadOptions]::ReuseThread ) begin { try { $iss = [initialsessionstate]::CreateDefault2() foreach($key in $Variables.PSBase.Keys) { $iss.Variables.Add([SessionStateVariableEntry]::new($key, $Variables[$key], '')) } foreach($function in $Functions) { $def = (Get-Command $function).Definition $iss.Commands.Add([SessionStateFunctionEntry]::new($function, $def)) } $usingParams = @{} # Credits to mklement0 for catching up a bug here. Thank you! # https://github.com/mklement0 foreach($usingstatement in $ScriptBlock.Ast.FindAll({ $args[0] -is [UsingExpressionAst] }, $true)) { $varText = $usingstatement.Extent.Text $varPath = $usingstatement.SubExpression.VariablePath.UserPath $key = [Convert]::ToBase64String([Encoding]::Unicode.GetBytes($varText.ToLower())) if(-not $usingParams.ContainsKey($key)) { $usingParams.Add($key, $ExecutionContext.SessionState.PSVariable.GetValue($varPath)) } } $pool = [runspacefactory]::CreateRunspacePool(1, $ThrottleLimit, $iss, $Host) $tasks = [List[hashtable]]::new() $pool.ThreadOptions = $ThreadOptions $pool.Open() } catch { $PSCmdlet.ThrowTerminatingError($_) } } process { try { # Thanks to Patrick Meinecke for his help here. # https://github.com/SeeminglyScience/ $ps = [powershell]::Create().AddScript({ $args[0].InvokeWithContext($null, [psvariable]::new('_', $args[1])) }).AddArgument($ScriptBlock.Ast.GetScriptBlock()).AddArgument($InputObject) # This is how `Start-Job` does it's magic. # Credits to Jordan Borean for his help here. # https://github.com/jborean93 # Reference in the source code: # https://github.com/PowerShell/PowerShell/blob/7dc4587014bfa22919c933607bf564f0ba53db2e/src/System.Management.Automation/engine/ParameterBinderController.cs#L647-L653 if($usingParams.Count) { $null = $ps.AddParameters(@{ '--%' = $usingParams }) } $ps.RunspacePool = $pool $tasks.Add(@{ Instance = $ps AsyncResult = $ps.BeginInvoke() }) } catch { $PSCmdlet.WriteError($_) } } end { try { foreach($task in $tasks) { $task['Instance'].EndInvoke($task['AsyncResult']) if($task['Instance'].HadErrors) { $task['Instance'].Streams.Error } } } catch { $PSCmdlet.WriteError($_) } finally { $tasks.Instance, $pool | ForEach-Object Dispose } } } |