'Is there a way to speed up dynamic member look-up in ps-objects
In the following code, most time is spent in $v = $proc.$columnName and I am wondering if there
is a way to speed up looking up the objects's members's values.
In the code below, I have chosen $objs to be the result of get-process but in my case, $objs could be an array of any type of objects, thus the need to look up the objects's members dynamically.
$objs= get-process
$columnNames = @()
foreach ($member in ($objs | get-member -memberType property, noteproperty)) {
[string]$name = $member.name
$columnNames += $name
}
[Int64 ] $sum = 0
[string] $columnName = ''
foreach ($obj in $objs) {
foreach ($columnName in $columnNames) {
$v = $obj.$columnName
# $v = $obj.psObject.members.Item($columnName).value
if ($v -eq $null) {
}
elseif ($v -is [System.IntPtr]) {
$sum = $sum + ($v -as [int64] )
}
elseif ($v -is [System.Int64] -or $v -is [System.Int32]) {
$sum = $sum + $v
}
}
}
"sum = $sum"
Solution 1:[1]
Perhaps there are more ways to speed this up, but below I have taken out the unnecessary bits:
$objs= Get-Process
$columnNames = ($objs | Get-Member -MemberType property, noteproperty).Name
[Int64 ] $sum = 0
foreach ($obj in $objs) {
foreach ($v in $columnNames) {
if ($obj.$v -as [int64]) { $sum += [int64]$obj.$v }
}
}
"sum = $sum"
Solution 2:[2]
This is a hidden property on PSObjects called .PSObject that way too many people don't know about, including myself until a few weeks ago despite spending thousands of hours working with PowerShell. From there you can use .where to SIGNIFICANTLY increase filtering performance.
New Code Block
New-Variable -Force -Name:'Processes' -value:(Get-Process)
New-Variable -Force -Name:'Sum' -Value:([Int64]$Null)
ForEach ($Process in $Processes) {
$Process.PSObject.Properties.Where({
($_.MemberType -in @('Property','NoteProperty')) -and
($_.TypeNameOfValue -in @('System.IntPtr','System.Int64','System.Int32')) -and
(-Not [String]::IsNullOrWhiteSpace($_.value))
}) |ForEach-Object {
$Sum = $Sum + ($_.value -as [Int64])
}
}
"Sum = $Sum"
Comparison Result
Name Value
---- -----
BlockBTime 9.18
SameResult True
BlockATime 1.52
BlockASum 1037197387512388
Difference Block A (New Code) is ~7.66s faster than Block B (Old Code)
BlockBSum 1037197387512388
Validation & Comparison
#Stopwatch
New-Variable -Force -Name:'StopWatch' -Value:(New-Object -TypeName 'System.Diagnostics.Stopwatch')
New-Variable -Force -Name:'Result' -Value:@{
BlockATime = [Int]0
BlockASum = [Int64]0
BlockBTime = [Int]0
BlockBSum = [Int64]0
Difference = $Null
SameResult = $Null
}
New-Variable -Force -Name:'Processes' -value:(Get-Process)
$StopWatch.Restart()
New-Variable -Force -Name:'Sum' -Value:([Int64]$Null)
ForEach ($Process in $Processes) {
$Process.PSObject.Properties.Where({
($_.MemberType -in @('Property','NoteProperty')) -and
($_.TypeNameOfValue -in @('System.IntPtr','System.Int64','System.Int32')) -and
(-Not [String]::IsNullOrWhiteSpace($_.value))
}) |ForEach-Object {
$Sum = $Sum + ($_.value -as [Int64])
}
}
$Result.BlockATime = [math]::Round($StopWatch.Elapsed.TotalSeconds,2)
$Result.BlockASum = $Sum
$objs= $Processes
$StopWatch.Restart()
$columnNames = @()
foreach ($member in ($objs | get-member -memberType property, noteproperty)) {
[string]$name = $member.name
$columnNames += $name
}
[Int64 ] $sum = 0
[string] $columnName = ''
foreach ($obj in $objs) {
foreach ($columnName in $columnNames) {
$v = $obj.$columnName
# $v = $obj.psObject.members.Item($columnName).value
if ($v -eq $null) {
}
elseif ($v -is [System.IntPtr]) {
$sum = $sum + ($v -as [int64] )
}
elseif ($v -is [System.Int64] -or $v -is [System.Int32]) {
$sum = $sum + $v
}
}
}
$Result.BlockbTime = [math]::Round($StopWatch.Elapsed.TotalSeconds,2)
$Result.BlockbSum = $Sum
#Which block is faster?
If ($Result.BlockATime -lt $Result.BlockBTime) {
$Result.Difference = "Block A (New Code) is ~$(($Result.BlockBTime - $Result.BlockATime))s faster than Block B (Old Code)"
} Else {
$Result.Difference = "Block A (New Code) is ~$(($Result.BlockBTime - $Result.BlockATime))s Slower than Block B (Old Code)"
}
#Are the results the same?
If ($Result.BlockASum -eq $Result.BlockBSum) {
$Result.SameResult = $True
}
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | Theo |
| Solution 2 | Nick W. |
