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Deep copying a PSObject

I have a powershell script in which I do the following

$somePSObjectHashtables = New-Object Hashtable[] $somePSObject.Length;
$somePSObjects = Import-CSV $csvPath
0..($somePSObject.Length - 1) | ForEach-Object {
    $i = $_;
    $somePSObjectHashtables[$i] = @{};
    $somePSObject[$_].PSObject.Properties | ForEach-Object {
        $somePSObjectHashtables[$i][$_.Name] = $_.Value;
    }
}

I need to do this because I want to make several distinct copies of the data in the CSV to perform several distinct manipulations. In a sense I'm performing an "INNER JOIN" on the resulting array of PSObject. I can easily iterate through $somePSObjectHashtables with a ForEach-Object and call Hashtable.Clone() on each member of the array. I can then use New-Object PSObject -Property $someHashTable[$i] to get a deep copy of the PSObject.

My question is, is there some easier way of making the deep copy, without an intermediary Hashtable?

like image 992
Justin Dearing Avatar asked Feb 09 '12 03:02

Justin Dearing


2 Answers

Note that here is a shorter, maybe a bit cleaner version of this (that I quite enjoy):

$data = Import-Csv .\test.csv

$serialData = [System.Management.Automation.PSSerializer]::Serialize($data)

$data2 = [System.Management.Automation.PSSerializer]::Deserialize($serialData)

Note: However, weirdly, it does not keep the ordering of ordered hashtables.

$data = [ordered] @{
    1 = 1
    2 = 2
}

$serialData = [System.Management.Automation.PSSerializer]::Serialize($data)

$data2 = [System.Management.Automation.PSSerializer]::Deserialize($serialData)
$data2

Will output:

Name                           Value
----                           -----
2                              2
1                              1

While with other types it works just fine:

$data = [PsCustomObject] @{
    1 = 1
    2 = 2
}

$data = @(1, 2, 3)
like image 112
Cosmin Avatar answered Sep 25 '22 10:09

Cosmin


For getting really deep copies we can use binary serialization (assuming that all data are serializable; this is definitely the case for data that come from CSV):

# Get original data
$data = Import-Csv ...

# Serialize and Deserialize data using BinaryFormatter
$ms = New-Object System.IO.MemoryStream
$bf = New-Object System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
$bf.Serialize($ms, $data)
$ms.Position = 0
$data2 = $bf.Deserialize($ms)
$ms.Close()

# Use deep copied data
$data2
like image 35
Roman Kuzmin Avatar answered Sep 25 '22 10:09

Roman Kuzmin