/// <summary>
/// Gets the item expiration.
/// </summary>
/// <param name="item">The item.</param>
/// <returns>Returns the updated cache item.</returns>
/// <exception cref="System.ArgumentNullException">If item is null.</exception>
/// <exception cref="System.InvalidOperationException">
/// If expiration mode is defined without timeout.
/// </exception>
protected virtual ICacheItem <TKey, TValue> GetItemExpiration(ICacheItem <TKey, TValue> item)
{
NotNull(item, nameof(item));
// logic should be that the item setting overrules the handle setting if the item
// doesn't define a mode (value is Default) it should use the handle's setting. if the
// handle also doesn't define a mode (value is None|Default), we use None.
var expirationMode = ExpirationMode.Default;
var expirationTimeout = TimeSpan.Zero;
var useItemExpiration = item.ExpirationMode != ExpirationMode.Default && !item.UsesExpirationDefaults;
if (useItemExpiration)
{
expirationMode = item.ExpirationMode;
expirationTimeout = item.ExpirationTimeout;
}
else if (Configuration.ExpirationMode != ExpirationMode.Default)
{
expirationMode = Configuration.ExpirationMode;
expirationTimeout = Configuration.ExpirationTimeout;
}
if (expirationMode == ExpirationMode.Default || expirationMode == ExpirationMode.None)
{
expirationMode = ExpirationMode.None;
expirationTimeout = TimeSpan.Zero;
}
else if (expirationTimeout == TimeSpan.Zero)
{
throw new InvalidOperationException("Expiration mode is defined without timeout.");
}
return(item.WithExpiration(expirationMode, expirationTimeout, !useItemExpiration));
}
