Main/Get-ExpiringCacheItem.ps1
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<#
.SYNOPSIS Retrives a value from the local expiring cache .DESCRIPTION Retrieves either the cached value, or call the invocation definition to get a new value, which after being cached is returned to the caller .EXAMPLE PS> Get-ExpiringCacheItem -Key 'SomeKey' Retrieves the cached item for the given key, if the cache is expired the cache is updated with the new definition and returned to the caller #> function Get-ExpiringCacheItem { [CmdletBinding()] param( [Parameter(Mandatory)] [ValidateNotNullOrEmpty()] # The key to access the cached item [string] $Key = "" ) $ErrorActionPreference = "Stop" if (-not $script:expiringCacheObjects.Contains($Key)) { Write-Error "Item with key '$Key' was not found in the cache" } $cachedItem = $script:expiringCacheObjects[$Key] $now = Get-Date $refreshTime = $cachedItem.LastRefresh + $cachedItem.Expiration if ($refreshTime -lt $now) { # Need to refresh cache $cachedItem.Item = . $cachedItem.ItemDefinition $cachedItem.LastRefresh = $now $script:expiringCacheObjects[$Key] = $cachedItem } # Return cached object Write-Output $cachedItem.Item } |