Private/Get-RetryDelay.ps1
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function Get-RetryDelay { # Returns a milliseconds value [OutputType([int])] param ( [int]$RetryCount = 0, [int]$BaseDelay = 1000, #1sec [int]$MaxDelay = 129000, #129sec [bool]$UseJitter = $true, [System.Collections.IEnumerable]$ResponseHeaders ) if ($ResponseHeaders) { [int]$FromHeaderValue = -1 try { # First, try parsing the `retry-after-ms` header value as milliseconds if ($ResponseHeaders.Contains('retry-after-ms')) { $FromHeaderValue = @($ResponseHeaders.GetValues('retry-after-ms'))[0] -as [int] } elseif ($ResponseHeaders.Contains('retry-after')) { $retry_after = @($ResponseHeaders.GetValues('retry-after'))[0] # Second, try parsing the `retry-after` header as seconds if ($s = $retry_after -as [int]) { $FromHeaderValue = $s * 1000 } # Third, try parsing the `retry-after` header as http-date elseif ($dt = $retry_after -as [datetime]) { $FromHeaderValue = ($dt - [datetime]::Now).TotalMilliseconds } } } catch {} if ($FromHeaderValue -gt 0 -and $FromHeaderValue -le 60000) { return $FromHeaderValue } } # Finally, use exponential backoff # 2^RetryCount * BaseDelay * Random(0.8 to 1.2) if ($UseJitter) { $jitter = [System.Random]::new().NextDouble() * 0.4 + 0.8 } else { $jitter = 1.0 } [int][Math]::Min([Math]::Pow(2, $RetryCount) * $BaseDelay * $jitter, $MaxDelay) } |