get-continiouscounterpoll.ps1

# Author: Sunny Chakraborty. 2014 (@sunnyc7)
# BasedOn: Matt Graeber's beautiful work with Powershell Lambda functions. 
# Powershell Magazine Source: http://www.powershellmagazine.com/2013/12/23/simplifying-data-manipulation-in-powershell-with-lambda-functions/

# Code: get-continiouscounterpoll.ps1
# Source: https://gist.github.com/9579625

<#
You can copy list of counters in counter-paths.txt. 
Please avoid using * based counter paths. Instead use (_total)

Content of counter-paths.txt
\Processor(_Total)\% User Time
\Processor(_Total)\% Privileged Time
\Processor(_Total)\Interrupts/sec
\Processor(_Total)\DPCs Queued/sec
\Processor(_Total)\% Processor Time
\Memory\Available MBytes
\Memory\Pages/sec
\Memory\Pool Nonpaged Bytes
\Memory\% Committed Bytes In Use
\Synchronization(_Total)\Spinlock Contentions/sec

#>

$counters = Get-Content .\counter-paths.txt

Function Map-Counter {
    param (
        [Parameter(Mandatory)]
        [ValidateScript({ $_.Ast.ParamBlock.Parameters.Count -eq 1 })]
        [Scriptblock] $Expression,
 
        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [Object[]] $Sequence
    )
 
    foreach ($member in $Sequence) { 
        $hash = @{}
        $hash.Add("$member",(Invoke-Expression (&$Expression $member)))
        $hash
    }
}

$cookedValue = {
    param($x) 
    (Get-Counter $x).CounterSamples.CookedValue
}

for (;;) {
    Map-Counter $cookedValue $counters
}