internal/Compress-Data.ps1
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<# .SYNOPSIS Compress data using DEFLATE (RFC 1951) and optionally GZIP file format (RFC 1952). .DESCRIPTION .EXAMPLE PS C:\>Compress-Data 'A string for compression' Compress string using Deflate. .INPUTS System.String .LINK https://github.com/jasoth/Utility.PS #> function Compress-Data { [CmdletBinding()] [Alias('Deflate-Data')] [OutputType([byte[]])] param ( # Value to convert [Parameter(Mandatory = $true, Position = 0, ValueFromPipeline = $true)] [object] $InputObjects, # Output gzip format [Parameter(Mandatory = $false)] [switch] $GZip, # Level of compression [Parameter(Mandatory = $false)] [System.IO.Compression.CompressionLevel] $CompressionLevel = ([System.IO.Compression.CompressionLevel]::Optimal), # Input encoding to use for text strings [Parameter (Mandatory = $false)] [ValidateSet('Ascii', 'UTF32', 'UTF7', 'UTF8', 'BigEndianUnicode', 'Unicode')] [string] $Encoding = 'Default', # Set gzip OS header byte to unknown [Parameter(Mandatory = $false)] [switch] $GZipUnknownOS ) begin { function Compress ([byte[]]$InputBytes, [bool]$GZip) { try { $streamInput = New-Object System.IO.MemoryStream -ArgumentList @($InputBytes, $false) try { $streamOutput = New-Object System.IO.MemoryStream try { if ($GZip) { $streamCompression = New-Object System.IO.Compression.GZipStream -ArgumentList $streamOutput, $CompressionLevel, $true } else { $streamCompression = New-Object System.IO.Compression.DeflateStream -ArgumentList $streamOutput, $CompressionLevel, $true } $streamInput.CopyTo($streamCompression) } finally { $streamCompression.Dispose() } if ($GZip) { [void] $streamOutput.Seek(8, [System.IO.SeekOrigin]::Begin) switch ($CompressionLevel) { 'Optimal' { $streamOutput.WriteByte(2) } 'Fastest' { $streamOutput.WriteByte(4) } Default { $streamOutput.WriteByte(0) } } if ($GZipUnknownOS) { $streamOutput.WriteByte(255) } elseif ($PSVersionTable.PSEdition -eq 'Desktop' -or $IsWindows) { $streamOutput.WriteByte(11) } elseif ($IsLinux) { $streamOutput.WriteByte(3) } elseif ($IsMacOS) { $streamOutput.WriteByte(7) } else { $streamOutput.WriteByte(255) } } [byte[]] $OutputBytes = $streamOutput.ToArray() } finally { $streamOutput.Dispose() } } finally { $streamInput.Dispose() } Write-Output $OutputBytes -NoEnumerate } ## Create list to capture byte stream from piped input. [System.Collections.Generic.List[byte]] $listBytes = New-Object System.Collections.Generic.List[byte] } process { if ($InputObjects -is [byte[]]) { Write-Output (Compress $InputObjects -GZip:$GZip) -NoEnumerate } else { foreach ($InputObject in $InputObjects) { [byte[]] $InputBytes = $null if ($InputObject -is [byte]) { ## Populate list with byte stream from piped input. if ($listBytes.Count -eq 0) { Write-Verbose 'Creating byte array from byte stream.' Write-Warning ('For better performance when piping a single byte array, use "Write-Output $byteArray -NoEnumerate | {0}".' -f $MyInvocation.MyCommand) } $listBytes.Add($InputObject) } elseif ($InputObject -is [byte[]]) { $InputBytes = $InputObject } elseif ($InputObject -is [string]) { $InputBytes = [Text.Encoding]::$Encoding.GetBytes($InputObject) } elseif ($InputObject -is [bool] -or $InputObject -is [char] -or $InputObject -is [single] -or $InputObject -is [double] -or $InputObject -is [int16] -or $InputObject -is [int32] -or $InputObject -is [int64] -or $InputObject -is [uint16] -or $InputObject -is [uint32] -or $InputObject -is [uint64]) { $InputBytes = [System.BitConverter]::GetBytes($InputObject) } elseif ($InputObject -is [guid]) { $InputBytes = $InputObject.ToByteArray() } elseif ($InputObject -is [System.IO.FileSystemInfo]) { if ($PSVersionTable.PSVersion -ge [version]'6.0') { $InputBytes = Get-Content $InputObject.FullName -Raw -AsByteStream } else { $InputBytes = Get-Content $InputObject.FullName -Raw -Encoding Byte } } else { ## Non-Terminating Error $Exception = New-Object ArgumentException -ArgumentList ('Cannot compress input of type {0}.' -f $InputObject.GetType()) Write-Error -Exception $Exception -Category ([System.Management.Automation.ErrorCategory]::ParserError) -CategoryActivity $MyInvocation.MyCommand -ErrorId 'CompressDataFailureTypeNotSupported' -TargetObject $InputObject } if ($null -ne $InputBytes -and $InputBytes.Count -gt 0) { Write-Output (Compress $InputBytes -GZip:$GZip) -NoEnumerate } } } } end { ## Output captured byte stream from piped input. if ($listBytes.Count -gt 0) { Write-Output (Compress $listBytes.ToArray() -GZip:$GZip) -NoEnumerate } } } |