Private/Classes/35-HttpResponse.ps1
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<# Handles formation of response to client #> class HttpResponse { # Culture for formatting response timestamps static hidden [System.Globalization.CultureInfo]$CultureEnUS = [System.Globalization.CultureInfo]::CreateSpecificCulture("en-US") # Default server identifier. Set to specific value during init. static hidden [string]$ServerIdentifier = 'PowerShellRest/0.0' # Status code for response [HttpStatus]$Status # Resonse body text [string]$Body # Encoded body text [byte[]]$BodyCompressed = $null # Default content type [string]$ContentType = 'text/plain' # Response headers [hashtable]$Headers = @{} # Number of bytes sent to client [int]$BytesSent = 0 # If a .NET exception (not one defined in this module) was caught, it is stored here for reporting to the error log file [Exception]$UnderlyingException = $null # Original request verb (GET etc.) [HttpRequest]$Request HttpResponse([HttpStatus]$status, [HttpRequest]$request) { $this.Request = $request $this.Status = $status $this.AddDefaultHeaders() } HttpResponse([HttpStatus]$status, [string]$body, [string]$contentType, [HttpRequest]$request) { $this.Request = $request $this.Status = $status $this.Body = $body if (-not [string]::IsNullOrEmpty($contentType)) { $this.ContentType = $contentType } $this.AddDefaultHeaders() $this.ApplyEncoding() } HttpResponse([HttpException]$exception, [HttpRequest]$request) { $this.Request = $request $stat = [HttpStatus]::GetStatus($exception.StatusCode) if ($null -eq $stat) { $this.Status = [HttpStatus]::InternalServerError $this.Body = "Unsupported status code $($exception.StatusCode)" } else { $this.Status = $stat $this.Body = $exception.Message } $this.AddDefaultHeaders() } HttpResponse([HttpStatus]$status, [Exception]$underlyingException, [HttpRequest]$request) { $this.Request = $request $this.Status = $status $this.Body = $status.StatusMessage $this.UnderlyingException = $underlyingException $this.ContentType = 'text/plain' $this.AddDefaultHeaders() } <# Called during initialisation to set the 'Server' header for responses #> static [void]SetServerIdentifier([string]$ServerIdentifier) { [HttpResponse]::ServerIdentifier = $ServerIdentifier } <# Gets the body text according to the request verb i.e. HEAD = don't return content #> [string]GetBodyText() { if (('OPTIONS', 'HEAD') -icontains $this.Request.RequestMethod -or [string]::IsNullOrEmpty($this.Body)) { return [string]::Empty } return $this.Body } <# Add or replace a response header #> [HttpResponse]AddHeader([string]$name, [string]$value) { $this.Headers[$name] = $value return $this } [string]ToString() { return $this.GetHeaderString() + $this.GetBodyText() } <# Format the header block (up to where the content begins) as a single string #> [string]GetHeaderString() { $sb = New-Object System.Text.StringBuilder $stat = $this.Status.StatusCode.ToString() + ' ' + $this.Status.StatusMessage $sb.Append("HTTP/1.1 $($stat)`r`n") | Out-Null $this.Headers.Keys | ForEach-Object { $val = $this.Headers[$_] $sb.Append("$($_): $val`r`n") | Out-Null } $sb.Append("`r`n") | Out-Null return $sb.ToString() } <# Get the response as a byte array for transmission to client #> [byte[]]GetBytes() { $bytes = [System.Text.Encoding]::UTF8.GetBytes($this.GetHeaderString()) + $( if ($null -ne $this.BodyCompressed) { #Write-EventLog -LogName Application -Source PowerShellRest -EventId 0x0f -EntryType Information -Message "Returning compressed response" $this.BodyCompressed } else { #Write-EventLog -LogName Application -Source PowerShellRest -EventId 0x0f -EntryType Information -Message "Returning uncompressed response" [System.Text.Encoding]::UTF8.GetBytes($this.GetBodyText()) } ) $this.BytesSent = $bytes.Length return $bytes } <# Apply encoding according to Accept-Encoding request header #> hidden [void]ApplyEncoding() { $bodyText = $this.GetBodyText() if ([string]::IsNullOrEmpty($bodyText)) { return } foreach ($encoding in $this.Request.PrioritisedAcceptEncodings) { $algorithm = $encoding.Value if (('*', 'identity') -icontains $algorithm) { return } $compressor = New-Compressor -Algorithm $algorithm if ($compressor) { $this.BodyCompressed = $compressor.Compress($bodyText) $this.AddHeader('Content-Encoding', $algorithm.ToLowerInvariant()) $this.AddHeader('Content-Length', $this.BodyCompressed.Length.ToString()) return } } # If we get here, then specific Accept-Encoding was supplied without 'identity' or '*' as an option throw [HttpException]::new([HttpStatus]::NotAcceptable) } <# Set the default headers on the response #> hidden [void]AddDefaultHeaders() { $dateAsString = [DateTime]::UtcNow.ToString('r', [HttpResponse]::CultureEnUS) $contentLength = $( if ([string]::IsNullOrEmpty($this.Body)) { 0 } else { [System.Text.Encoding]::UTF8.GetBytes($this.Body).Length } ) $this.Headers.Add('Content-Length', $contentLength.ToString()) $this.Headers.Add('Server', [HttpResponse]::ServerIdentifier) $this.Headers.Add('Date', $dateAsString) $this.Headers.Add('Last-Modified', $dateAsString) $this.Headers.Add('Content-Type', $this.ContentType) $this.Headers.Add('Connection', 'Closed') } } <# Subclass of HttpResponse to indicate the server wants to terminate #> class TerminationResponse : HttpResponse { TerminationResponse([HttpRequest]$request) : base([HttpStatus]::ServiceUnavailable, "The server is shutting down", $request) { } } |