helpers/ModulesTillPublishedonGallery/PoshRSJob/1.7.4.4/Public/Start-RSJob.ps1

Function Start-RSJob {
    <#
        .SYNOPSIS
            Starts a background job using runspaces.

        .DESCRIPTION
            This will run a command in the background, leaving your console available to perform other tasks. This uses
            runspaces in runspacepools which allows for throttling of running jobs. As the jobs are finished, they will automatically
            dispose of each runspace and allow other runspace jobs in queue to begin based on the throttling of the runspacepool.

            This is available on PowerShell V3 and above. By doing this, you can use the $Using: variable to take variables
            in the local scope and apply those directly into the scriptblock of the background runspace job.

        .PARAMETER ScriptBlock
            The scriptblock that holds all of the commands which will be run in the background runspace. You must specify
            at least one Parameter in the Param() to account for the item that is being piped into Start-Job.

        .PARAMETER FilePath
            This is the path to a file containing code that will be run in the background runspace job.

        .PARAMETER InputObject
            The object being piped into Start-RSJob or applied via the parameter.

        .PARAMETER Name
            The name of a background runspace job

        .PARAMETER Batch
            Name of the batch of RSJobs that will be run

        .PARAMETER ArgumentList
            List of values that will be applied at the end of the argument list in the Param() statement.

        .PARAMETER Throttle
            Number of concurrent running runspace jobs which are allowed at a time.

        .PARAMETER ModulesToImport
            A collection of modules that will be imported into the background runspace job.

        .PARAMETER PSSnapinsToImport
            A collection of PSSnapins that will be imported into the background runspace job.

        .PARAMETER FunctionsToImport
            A collection of functions that will be imported for use with a background runspace job.

        .PARAMETER FunctionFilesToImport
            A collection of files containing custom functions that will be imported into the background runspace job.

        .PARAMETER VariablesToImport
            A collection of variables that will be imported for use with a background runspace job.
            If used, $using:variable not expanded !

        .NOTES
            Name: Start-RSJob
            Author: Boe Prox/Max Kozlov

        .EXAMPLE
            Get-ChildItem -Directory | Start-RSjob -Name {$_.Name} -ScriptBlock {
                Param($Directory)
                Write-Verbose $_
                $Sum = (Get-ChildItem $Directory.FullName -Recurse -Force -ErrorAction SilentlyContinue |
                Measure-Object -Property Length -Sum).Sum
                [pscustomobject]@{
                    Name = $Directory.Name
                    SizeMB = ([math]::round(($Sum/1MB),2))
                }
            }

            Id Name State HasMoreData HasErrors Command
            -- ---- ----- ----------- --------- -------
            13 Contacts Running False False ...
            14 Desktop Running False False ...
            15 Documents Running False False ...
            16 Downloads Running False False ...
            17 Favorites Running False False ...
            18 Links Running False False ...
            19 Music Running False False ...
            20 OneDrive Running False False ...
            21 Pictures Running False False ...
            22 Saved Games Running False False ...
            23 Searches Running False False ...
            24 Videos Running False False ...

            Get-RSJob | Receive-RSJob

            Name SizeMB
            ---- ------
            Contacts 0
            Desktop 7.24
            Documents 83.99
            Downloads 10259.6
            Favorites 0
            Links 0
            Music 16691.89
            OneDrive 1485.24
            Pictures 1734.91
            Saved Games 0
            Searches 0
            Videos 17.19

            Description
            -----------
            Starts a background runspace job that looks at the total size of each folder. Using Get-RSJob | Recieve-RSJob shows
            the results when the State is Completed.

        .EXAMPLE
            $Test = 'test'
            $Something = 1..10
            1..5|start-rsjob -Name {$_} -ScriptBlock {
                Param($Object) [pscustomobject]@{
                    Result=($Object*2)
                    Test=$Using:Test
                    Something=$Using:Something
                }
            }

            Id Name State HasMoreData HasErrors Command
            -- ---- ----- ----------- --------- -------
            76 1 Completed True False ...
            77 2 Running False False ...
            78 3 Running False False ...
            79 4 Completed False False ...
            80 5 Completed False False ...

            Get-RSjob | Receive-RSJob

            Result Test Something
            ------ ---- ---------
                 2 test {1, 2, 3, 4...}
                 4 test {1, 2, 3, 4...}
                 6 test {1, 2, 3, 4...}
                 8 test {1, 2, 3, 4...}
                10 test {1, 2, 3, 4...}

            Description
            -----------
            Shows an example of the $Using: variable being used in the scriptblock.

        .EXAMPLE
            $Test = 42
            $AnotherTest = 7
            $String = 'SomeString'
            $ProcName = 'powershell_ise'
            $ScriptBlock = {
                Param($y,$z)
                [pscustomobject] @{
                    Test = $y
                    Proc = (Get-Process -Name $Using:ProcName)
                    String = $Using:String
                    AnotherTest = ($z+$_)
                    PipedObject = $_
                }
            }

            1..5|Start-RSJob $ScriptBlock -ArgumentList $test, $anothertest

            Description
            -----------
            Shows an example of the $Using: variable being used in the scriptblock as well as $_ and multiple -ArgumentList parameters.

    #>

    [OutputType('RSJob')]
    [cmdletbinding(
        DefaultParameterSetName = 'ScriptBlock'
    )]
    Param (
        [parameter(Mandatory = $True, Position = 0, ParameterSetName = 'ScriptBlock')]
        [ScriptBlock]$ScriptBlock,
        [parameter(Position = 0, ParameterSetName = 'ScriptPath')]
        [string]$FilePath,
        [parameter(ValueFromPipeline = $True, ValueFromPipelineByPropertyName = $True)]
        [object]$InputObject,
        [parameter()]
        [object]$Name,
        [parameter()]
        [string]$Batch = $([guid]::NewGuid().ToString()),
        [parameter()]
        [array]$ArgumentList = @(),
        [parameter()]
        [int]$Throttle = 5,
        [parameter()]
        [Alias('ModulesToLoad')]
        [string[]]$ModulesToImport,
        [parameter()]
        [Alias('PSSnapinsToLoad')]
        [string[]]$PSSnapinsToImport,
        [parameter()]
        [Alias('FunctionsToLoad')]
        [string[]]$FunctionsToImport,
        [parameter()]
        [Alias('FunctionFilesToLoad')]
        [string[]]$FunctionFilesToImport,
        [parameter()]
        [Alias('VariablesToLoad')]
        [string[]]$VariablesToImport
    )
    Begin {

        If ($PSBoundParameters['Debug']) {
            $DebugPreference = 'Continue'
        }

        Write-Debug "[BEGIN]"

        If ($PSBoundParameters.ContainsKey('Verbose')) {
            Write-Verbose "Displaying PSBoundParameters"
            $PSBoundParameters.GetEnumerator() | ForEach-Object {
                Write-Verbose $_
            }
        }

        If ($PSBoundParameters.ContainsKey('Name')) {
            If ($Name -isnot [scriptblock]) {
                $JobName = [scriptblock]::Create("Write-Output `"$Name`"")
            }
            Else {
                $JobName = [scriptblock]::Create( ($Name -replace '\$_', '$Item'))
            }
        }
        Else {
            Write-Verbose "Creating default Job Name"
            $JobName = [scriptblock]::Create('Write-Output Job$($Id)')
        }

        $InitialSessionState = [System.Management.Automation.Runspaces.InitialSessionState]::CreateDefault()

        If ($PSBoundParameters['ModulesToImport']) {
            [void]$InitialSessionState.ImportPSModule($ModulesToImport)
        }

        If ($PSBoundParameters['PSSnapinsToImport']) {
            ForEach ($PSSnapin in $PSSnapinsToImport) {
                [void]$InitialSessionState.ImportPSSnapIn($PSSnapin, [ref]$Null)
            }
        }

        If ($PSBoundParameters['FunctionsToImport']) {
            Write-Verbose "Loading custom functions: $($FunctionsToImport -join '; ')"
            ForEach ($Function in $FunctionsToImport) {
                Try {
                    RegisterScriptScopeFunction -Name $Function
                    $Definition = Get-Content Function:\$Function -ErrorAction Stop
                    Write-Debug "Definition: $($Definition)"
                    $SessionStateFunction = New-Object System.Management.Automation.Runspaces.SessionStateFunctionEntry -ArgumentList $Function, $Definition
                    $InitialSessionState.Commands.Add($SessionStateFunction)
                }
                Catch {
                    Write-Warning "$($Function): $($_.Exception.Message)"
                }

                #Check for an alias and add it as well
                If ($Alias = Get-Alias | Where-Object { $_.Definition -eq $Function }) {
                    $AliasEntry = New-Object System.Management.Automation.Runspaces.SessionStateAliasEntry -ArgumentList $Alias.Name, $Alias.Definition
                    $InitialSessionState.Commands.Add($AliasEntry)
                }
            }
        }

        If ($PSBoundParameters['FunctionFilesToImport']) {
            Write-Verbose "Loading custom function files : $($FunctionFilesToImport -join '; ')"
            $functionsInFiles = GetFunctionByFile -FilePath $FunctionFilesToImport

            if ($null -eq $functionsInFiles) {
                Write-Warning "Cannot find any functions in given files"
            }
            else {
                ForEach ($function in $functionsInFiles) {
                    $functionName = $function.Name
                    Write-Verbose "Loading custom function : $functionName"

                    try {
                        $functionDefinition = GetFunctionDefinitionByFunction -FunctionItem $function
                        $SessionStateFunction = New-Object System.Management.Automation.Runspaces.SessionStateFunctionEntry -ArgumentList $functionName, $functionDefinition
                        $InitialSessionState.Commands.Add($SessionStateFunction)
                    }
                    catch {
                        Write-Warning "$($functionName): $($_.Exception.Message)"
                    }

                    #Check for an alias and add it as well
                    if ($Alias = Get-Alias | Where-Object { $_.Definition -eq $Function }) {
                        $AliasEntry = New-Object System.Management.Automation.Runspaces.SessionStateAliasEntry -ArgumentList $Alias.Name, $Alias.Definition
                        $InitialSessionState.Commands.Add($AliasEntry)
                    }
                }
            }
        }

        If ($PSBoundParameters['VariablesToImport']) {
            Write-Verbose "Loading variables: $($VariablesToImport -join '; ')"
            $UserVariables = New-Object System.Collections.ArrayList
            $vartable = $null
            foreach ($varname in $VariablesToImport) {
                If ($MyInvocation.CommandOrigin -eq 'Runspace') {
                    $vars = @(Get-Variable $varname -ErrorAction Continue | Where-Object { $_.Options -notmatch 'Constant' })
                }
                else {
                    # matching support uses powershell internals
                    if ([System.Management.Automation.WildcardPattern]::ContainsWildcardCharacters($varname)) {
                        if (-not $vartable) {
                            $Flags = 'static', 'nonpublic', 'instance'
                            $internal_p = $PSCmdlet.SessionState.GetType().GetProperty('Internal',$Flags)
                            $internal = $internal_p.GetValue($PSCmdlet.SessionState, $null)
                            $vartable_m = $internal.GetType().GetMethod('GetVariableTable',$Flags)
                            $vartable = $vartable_m.Invoke($internal, $null).GetEnumerator() | Select-Object -ExpandProperty Key
                        }
                        $vars = @($vartable | Where-Object { $_ -like $varname } | ForEach-Object {
                            $PSCmdlet.SessionState.PSVariable.Get($_)
                        })
                    }
                    else {
                        $vars = @($PSCmdlet.SessionState.PSVariable.Get($varname))
                    }
                }
                [void]$UserVariables.AddRange($vars)
            }
            if ($UserVariables.Count -gt 0) {
                Write-Verbose "Loaded variables: $(($UserVariables | Select-Object -ExpandProperty Name) -join '; ')"
                foreach($var in $UserVariables)
                {
                    $v = New-Object -TypeName System.Management.Automation.Runspaces.SessionStateVariableEntry -ArgumentList $var.Name, $var.Value, $var.Description
                    $InitialSessionState.Variables.Add($v)
                }
            }
        }

        If ($PSBoundParameters['FilePath']) {
            $ScriptBlock = [scriptblock]::Create((Get-Content $FilePath | Out-String))
        }

        $List = New-Object System.Collections.ArrayList
        $ForeachDetected = $false
        $ForeachValue = $null
        # in v2 $_ variable always defined, so $ForeachDetected always be true on this state
        If ($PSCmdlet.SessionState.PSVariable.Get('_')) {
               Write-Debug 'it may be ForEach loop'
            $ForeachDetected = $true
            # on v2 $_ always exists in begin block, on v3+ only in process for foreach loop like $data | Foreach-Object { "here it is: $_" }
            Try {
                $ForeachValue = $PSCmdlet.SessionState.PSVariable.Get('_') | Select-Object -ExpandProperty Value
                if ($ForeachValue -eq $null) {
                    $ForeachDetected = $false # since psv2 traps on above code, we always do not support $null in $_
                }
            }
            Catch {
                #useless message: always exists on v2 when $_ absent and never on v3+
                # Write-Warning "Start-RSJob : Error adding pipeline variable $($_.Exception.Message)"
                $ForeachDetected = $false # on psv2 we doesn't support "$null | %{ Start-RSJob }" pattern
            }
        }
        Write-Debug "ListCount: $($List.Count)"
    }

    Process {
        Write-Debug "[PROCESS]"
        If ($PSBoundParameters.ContainsKey('InputObject')) {
            [void]$List.AddRange(@($InputObject))
            # If we here - it is not foreach loop
            $ForeachDetected = $false
        }
    }

    End {
        Write-Debug "[END]"
        $SBParamVars = @(GetParamVariable -ScriptBlock $ScriptBlock)
        $SBParamCount = $SBParamVars.Count
        $ArgumentCount = $ArgumentList.Count
        # We add $_ into list only if there is no InputObject
        # so in case: $data | Foreach-Object { $_.Value | Start-RSJob }
        # rsjob get as input $_.Value but not $_
        # but for: $data | Foreach-Object { Start-RSJob }
        # rsjob can get $_ as input
        ### for long param() lists it can lead to insert null as first param
        ###if ($List.Count -eq 0 -and -not $ForeachDetected) {
        ### #make empty call ( Start-RSJob ) like ( $null | Start-RSJob ) call to support $null as InputObject in $null | Foreach-Object { Start-RSJob } case
        ### $ForeachDetected = $true
        ###}
        if ($ForeachDetected) {
            Write-Debug 'it is ForEach loop'
            [void]$List.Add($ForeachValue)
        }
        # NewParam variant
        if ($List.Count) {
            $ArgumentCount++
        }
        # we add $_ into param() block when (ArgumentList+InputObject).Count > scriptBlock.Param().Count #or ForeachDetected
        #$InsertPSItemParam = ($ArgumentCount -gt $SBParamCount -and $List.Count)

        # Current version behaviour variant
        $ArgumentCount = $ArgumentList.Count
        # Without 'Ignore' fix
        #$InsertPSItemParam = ($SBParamCount -ne 1 -or (($SBParamCount -ne $ArgumentCount) -xor $List.Count))
        # With 'Ignore' fix
        $InsertPSItemParam = (($SBParamCount -ne 1 -or $SBParamCount -eq $ArgumentCount) -and $List.Count)
        #

        Write-Debug ("ArgumentCount: $ArgumentCount | List.Count: $($List.Count) | SBParamCount: $SBParamCount | InsertPSItemParam: $InsertPSItemParam")
        #region Convert ScriptBlock for $Using:
        $PreviousErrorAction = $ErrorActionPreference
        $ErrorActionPreference = 'Stop'
        Write-Verbose "PowerShell Version: $($PSVersionTable.PSVersion.Major)"
        $UsingVariables = $UsingVariableValues = @()
        if (-Not $PSBoundParameters['VariablesToImport']) {
            Switch ($PSVersionTable.PSVersion.Major) {
                2 {
                    Write-Verbose "Using PSParser with PowerShell V2"
                    $UsingVariables = @(GetUsingVariablesV2 -ScriptBlock $ScriptBlock)
                    Write-Verbose "Using Count: $($UsingVariables.count)"
                    Write-Verbose "$($UsingVariables|Out-String)"
                    Write-Verbose "CommandOrigin: $($MyInvocation.CommandOrigin)"
                    If ($UsingVariables.count -gt 0) {
                        $UsingVariableValues = @($UsingVariables | ForEach-Object {
                            $Name = $_.Content -replace 'Using:'
                            Try {
                                If ($MyInvocation.CommandOrigin -eq 'Runspace') {
                                    $Value = (Get-Variable -Name $Name).Value
                                }
                                Else {
                                    $Value = $PSCmdlet.SessionState.PSVariable.Get($Name).Value
                                    If ([string]::IsNullOrEmpty($Value)) {
                                        Throw 'No value!'
                                    }
                                }
                                New-Object V2UsingVariable -Property @{
                                    Name = $Name
                                    NewName = '$__using_{0}' -f $Name
                                    Value = $Value
                                    NewVarName = ('__using_{0}') -f $Name
                                }
                            }
                            Catch {
                                Throw "Start-RSJob : The value of the using variable '$($Var.SubExpression.Extent.Text)' cannot be retrieved because it has not been set in the local session."
                            }
                        })

                        Write-Verbose ("Found {0} `$Using: variables!" -f $UsingVariableValues.count)
                    }
                }
                Default {
                    Write-Debug "Using AST with PowerShell V3+"
                    $UsingVariables = @(GetUsingVariables $ScriptBlock)
                    #region Get Variable Values
                    If ($UsingVariables.count -gt 0) {
                        $UsingVar = $UsingVariables | Group-Object SubExpression | ForEach-Object {$_.Group | Select-Object -First 1}
                        Write-Debug "CommandOrigin: $($MyInvocation.CommandOrigin)"
                        $UsingVariableValues = @(ForEach ($Var in $UsingVar) {
                            Try {
                                If ($MyInvocation.CommandOrigin -eq 'Runspace') {
                                    $Value = Get-Variable -Name $Var.SubExpression.VariablePath.UserPath
                                }
                                Else {
                                    $Value = ($PSCmdlet.SessionState.PSVariable.Get($Var.SubExpression.VariablePath.UserPath))
                                    If ([string]::IsNullOrEmpty($Value)) {
                                        Throw 'No value!'
                                    }
                                }
                                [pscustomobject]@{
                                    Name = $Var.SubExpression.Extent.Text
                                    Value = $Value.Value
                                    NewName = ('$__using_{0}' -f $Var.SubExpression.VariablePath.UserPath)
                                    NewVarName = ('__using_{0}' -f $Var.SubExpression.VariablePath.UserPath)
                                }
                            }
                            Catch {
                                Throw "Start-RSJob : The value of the using variable '$($Var.SubExpression.Extent.Text)' cannot be retrieved because it has not been set in the local session."
                            }
                        })
                        #endregion Get Variable Values
                        Write-Verbose ("Found {0} `$Using: variables!" -f $UsingVariableValues.count)
                    }
                }
            }
        }
        $ConvertScriptParams = @{
            ScriptBlock = $ScriptBlock
            HasParam = ($SBParamVars.Count -ne 0)
            UsingVariables = $UsingVariables
            UsingVariableValues = $UsingVariableValues
            InsertPSItem = $InsertPSItemParam
        }
        If ($UsingVariableValues.Count -gt 0 -OR $InsertPSItemParam) {
            Switch ($PSVersionTable.PSVersion.Major) {
                2 {
                    $NewScriptBlock = ConvertScriptBlockV2 @ConvertScriptParams
                }
                Default {
                    $NewScriptBlock = ConvertScript @ConvertScriptParams
                }
            }
        }
        Else {
            $NewScriptBlock = $ScriptBlock
        }

        $ErrorActionPreference = $PreviousErrorAction
        #endregion Convert ScriptBlock for $Using:

        Write-Debug "NewScriptBlock: $($NewScriptBlock)"

        #region RunspacePool Creation
        [System.Threading.Monitor]::Enter($PoshRS_RunspacePools.syncroot)
        try {
            $__RSPObject = $PoshRS_RunspacePools | Where-Object {
                $_.RunspacePoolID -eq $Batch
            }
            If ($__RSPObject) {
                Write-Verbose "Using current runspacepool <$($__RSPObject.RunspacePoolID)>"
                $RunspacePoolID = $__RSPObject.RunspacePoolID
                $RSPObject = $__RSPObject
                $RSPObject.LastActivity = Get-Date
            }
            Else {
                Write-Verbose "Creating new runspacepool <$Batch>"
                $RunspacePoolID = $Batch
                $PSModulePath = $env:PSModulePath
                $RunspacePool = [runspacefactory]::CreateRunspacePool($InitialSessionState)
                If ($RunspacePool.psobject.Properties["ApartmentState"]) {
                    #ApartmentState doesn't exist in Nano Server
                    $RunspacePool.ApartmentState = 'STA'
                }
                [void]$RunspacePool.SetMaxRunspaces($Throttle)
                If ($PSVersionTable.PSVersion.Major -gt 2) {
                    $RunspacePool.CleanupInterval = [timespan]::FromMinutes(2)
                }
                $RunspacePool.Open()
                $RSPObject = New-Object RSRunspacePool -Property @{
                    RunspacePool = $RunspacePool
                    MaxJobs = $RunspacePool.GetMaxRunspaces()
                    RunspacePoolID = $RunspacePoolID
                    LastActivity = Get-Date
                }

                #[System.Threading.Monitor]::Enter($PoshRS_RunspacePools.syncroot) #Temp add
                [void]$PoshRS_RunspacePools.Add($RSPObject)
                $env:PSModulePath = $PSModulePath
            }
        }
        finally {
            [System.Threading.Monitor]::Exit($PoshRS_RunspacePools.syncroot)
        }
        #endregion RunspacePool Creation

        Write-Debug "ListCount: $($List.Count)"
        $RealPipeline = $List.Count -gt 0;
        if (-Not $RealPipeline) {
            [void]$List.Add($null) # fake job creation cycle
        }
        ForEach ($Item in $List) {
            $ID = Increment
            $PowerShell = [powershell]::Create().AddScript($NewScriptBlock, $True)
            $PowerShell.RunspacePool = $RSPObject.RunspacePool

            if ($RealPipeline) {
                Write-Verbose "Using $($Item) as pipeline variable"
                [void]$PowerShell.AddArgument($Item)
            }
            else {
                Write-Verbose "No InputObject"
            }
            Write-Verbose "Checking for Using: variables"
            If ($UsingVariableValues.count -gt 0) {
                For ($i=0;$i -lt $UsingVariableValues.count;$i++) {
                    Write-Verbose "Adding Param: $($UsingVariableValues[$i].Name) Value: $($UsingVariableValues[$i].Value)"
                    [void]$PowerShell.AddParameter($UsingVariableValues[$i].NewVarName, $UsingVariableValues[$i].Value)
                }
            }
            Write-Verbose "Checking for ArgumentList"
# if ($ArgumentList.Count -eq 1) {
# Write-Verbose "Adding Argument: $($ArgumentList[0]) <$($ArgumentList[0].GetType().Fullname)>"
# [void]$PowerShell.AddArgument($ArgumentList[0])
# }
# else {
                ForEach ($Argument in $ArgumentList) {
                    Write-Verbose "Adding Argument: $($Argument) <$($Argument.GetType().Fullname)>"
                    [void]$PowerShell.AddArgument($Argument)
                }
# }

            Write-Verbose "Invoking Runspace"
            $Handle = $PowerShell.BeginInvoke()
            Write-Verbose "Determining Job Name"
            $_JobName = If ($PSVersionTable.PSVersion.Major -eq 2) {
                $JobName.Invoke()
            }
            Else {
                $JobName.InvokeReturnAsIs()
            }
            $Object = New-Object RSJob -Property @{
                Name = $_JobName
                InputObject = $Item
                InstanceID = [guid]::NewGuid().ToString()
                ID = $ID
                Handle = $Handle
                InnerJob = $PowerShell
                Runspace = $PowerShell.Runspace
                Finished = $Handle.IsCompleted
                Command  = $ScriptBlock.ToString()
                RunspacePoolID = $RunSpacePoolID
                Batch          = $Batch
            }

            $RSPObject.LastActivity = Get-Date
            Write-Verbose "Adding RSJob to Jobs queue"
            [System.Threading.Monitor]::Enter($PoshRS_Jobs.syncroot)
            [void]$PoshRS_Jobs.Add($Object)
            [System.Threading.Monitor]::Exit($PoshRS_Jobs.syncroot)
            Write-Verbose "Display RSJob"
            $Object

        }
    }
}