Source/Private/Convert-DockerSizeToPSSize.ps1
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<# .SYNOPSIS Converts Docker size string to size in KB, type Double .DESCRIPTION Converts Docker size string to a size in KB, data type number Double. Docker size strings - for example image size - are text values like 123MB, 1.91kB, etc. - different numerical bases (KB, MB, etc.) not hole values. This function converts the string to a numerical value whose base is KB. .PARAMETER DockerSize Docker size string .EXAMPLE Convert-DockerSizeToPSSize '1.84kB' 1.84 .EXAMPLE Convert-DockerSizeToPSSize '100MB' 107374182400 #> function Convert-DockerSizeToPSSize { #region Function parameters [CmdletBinding()] [OutputType([double])] param( [Parameter(Mandatory = $true)] [ValidateNotNullOrEmpty()] [string]$DockerSize ) #endregion process { Write-Verbose "DockerSize passed to function: $DockerSize" $DockerSizeNumberRegex = '^(?<Number>[0-9\.]+)(?<Unit>[a-z]+$)' Write-Verbose "RegEx used to parse this value: : $DockerSizeNumberRegex" $UnitB = 'B' $UnitKB = 'KB' $UnitMB = 'MB' $UnitGB = 'GB' $ValidUnits = $UnitB, $UnitKB, $UnitMB, $UnitGB #region Notes about Docker size string and validation/conversion # Examples of Docker size: 1.84kB, 123MB # I have not personally encounterd a Docker image that is gigabytes in size (I hope they are rare) so # I am guessing the suffix would be 'GB'. # With this regex I assume only letters are at end and only numbers and . are at the beginning # Yes, this regex could allow some errors (multiple . in beginning, invalid suffix, etc., these will be # found in validation/parsing below. #endregion $Matches = $null $Valid = $DockerSize -match $DockerSizeNumberRegex if ($Valid -eq $false) { Write-Verbose "Not a valid size: $DockerSize" throw "DockerSize '$DockerSize' (no quotes) should be a number (no comma, decimal optional) followed by a unit ($ValidUnits)" return } # get/validate unit portion first; need to know in order to convert number between KB/MB/GB $Unit = $Matches.Unit.ToString().ToUpper() Write-Verbose "Unit parsed via RegEx: $Unit" if ($Unit -notin $ValidUnits) { Write-Verbose "Not a valid Unit (see regex): $Unit" throw "DockerSize $DockerSize has invalid unit $Unit - expected value in: $ValidUnits" return } # get/validate number portion [double]$Number = $null $Valid = [double]::TryParse($Matches.Number, [ref]$Number) Write-Verbose "Number parsed via RegEx: $Number" if ($Valid -eq $false) { Write-Verbose "Not a valid Number (see regex): $($Matches.Number)" throw "DockerSize $DockerSize is invalid number; should be only numbers and one optional decimal" return } # convert between units (MB -> KB or GB -> KB) and return value # KB -> KB conversation * 1 is completely unnecessary but pleasing in a symmetic way # no need for else block, units validated above if ($Unit -eq $UnitB) { $Number / 1KB } elseif ($Unit -eq $UnitKB) { $Number * 1 } elseif ($Unit -eq $UnitMB) { $Number * 1KB } elseif ($Unit -eq $UnitGB) { $Number * 1MB } } } |