Private/deploy/Tokens/Update-TokensInStream.ps1
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<#
The MIT License (MIT) Copyright (c) 2015 Objectivity Bespoke Software Specialists Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. #> function Update-TokensInStream { <# .SYNOPSIS Replaces Tokens in the input stream and writes to the output stream (only if any change was made). .PARAMETER InputStream Input stream. .PARAMETER InputStreamDescription Description of InputStream. Used only in log messages. .PARAMETER Tokens Tokens to be used for doing the replacements. .PARAMETER ValidateTokensExistence If true and a token will be found in file that is not present in $Tokens, an error will be thrown. .PARAMETER OutputStream Output stream. .PARAMETER TokenRegex Regex used to find tokens in the file. Whole TokenRegex should match whole string to replace, first capture group should match name of the token. .EXAMPLE Update-TokensInStream -InputStream $configFileStream -InputStreamDescription $desc -OutputStream $configFileStream -Tokens $tokens -ValidateTokensExistence:$ValidateTokensExistence #> [CmdletBinding()] [OutputType([int])] param( [Parameter(Mandatory=$true)] [System.IO.Stream] $InputStream, [Parameter(Mandatory=$true)] [string] $InputStreamDescription, [Parameter(Mandatory=$true)] [hashtable] $Tokens, [Parameter(Mandatory=$false)] [switch] $ValidateTokensExistence = $true, [Parameter(Mandatory=$true)] [System.IO.Stream] $OutputStream, [Parameter(Mandatory=$true)] [string] $TokenRegex ) $numChanged = 0 try { $streamReader = New-Object System.IO.StreamReader $InputStream $memStream = New-Object System.IO.StreamWriter (New-Object System.IO.MemoryStream) $totalLen = 0 while ($streamReader.Peek() -gt 0) { $line = $streamReader.ReadLine() $totalLen += ($line.Length) $allMatches = Select-String -InputObject $line -AllMatches $TokenRegex | Foreach-Object { $_.Matches } if ($allMatches) { foreach ($tokenMatch in $allMatches) { if ($tokenMatch.Groups.Count -lt 2) { throw "Invalid TokenRegex: '$TokenRegex' - there must be at least one capture group that matches the name of the token" } $stringToReplace = $tokenMatch.Groups[0].Value $tokenName = $tokenMatch.Groups[1].Value if (!$Tokens.ContainsKey($tokenName)) { if ($ValidateTokensExistence) { throw ("Token '{0}' ({1}) is missing from configuration files." -f $tokenName, $InputStreamDescription) } } else { $newValue = $Tokens[$tokenName] #Write-Log -_debug "Replacing token '$tokenName' -> '$newValue'" $line = $line.Replace($stringToReplace, $newValue) $numChanged++ } } } $memStream.WriteLine($line) } if ($numChanged -gt 0) { $memStream.Flush() [void]($OutputStream.Seek(0, [System.IO.SeekOrigin]::Begin)) [void]($memStream.BaseStream.Seek(0, [System.IO.SeekOrigin]::Begin)) [void]($memStream.BaseStream.CopyTo($OutputStream)) $OutputStream.SetLength($memStream.BaseStream.Length) $OutputStream.Flush() $OutputStream.Dispose() } } finally { if ($streamReader -ne $null) { $streamReader.Dispose() } if ($memStream -ne $null) { $memStream.Dispose() } if ($OutputStream -ne $null) { $OutputStream.Dispose() } if ($InputStream -ne $null) { $InputStream.Dispose() } } return $numChanged } |