/// <summary>
/// Retrieves the object by the specified key from the cache. If the object does not exist in the cache, it will be added.
/// </summary>
/// <typeparam name="T">Type of object to return</typeparam>
/// <param name="cache">Cache to work with</param>
/// <param name="key">Cache key for the object</param>
/// <param name="cacheAction">Action to perform if the object does not exist in the cache.</param>
/// <returns></returns>
public static T GetOrCache <T>(this ICacheClient cache, string key, Func <ICacheContext, T> cacheAction) where T : class
{
var item = cache.Get <T>(key);
var eventArgs = new CacheHitEventArgs
{
CacheKey = key,
Type = typeof(T)
};
if (item == null)
{
CacheStackSettings.OnCacheMiss(cache, eventArgs);
var context = new CacheContext(cache);
item = cacheAction(context);
// No need to cache null values
if (item != null)
{
cache.CacheAndSetTriggers(context, key, item);
}
}
else
{
CacheStackSettings.OnCacheHit(cache, eventArgs);
}
return(item);
}
/// <summary>
/// Caches the specified item using the context information
/// </summary>
/// <typeparam name="T">Type of object to cache</typeparam>
/// <param name="cache">Cache to store the object</param>
/// <param name="context">Context information for how to cache the object</param>
/// <param name="key">Cache key</param>
/// <param name="item">Item to cache</param>
public static void CacheAndSetTriggers <T>(this ICacheClient cache, CacheContext context, string key, T item)
{
// Don't cache if there is no context
if (context == null)
{
return;
}
// Don't cache if there are no profile durations configured
if (CacheStackSettings.CacheProfileDurations == null)
{
return;
}
var expiration = CacheStackSettings.CacheProfileDurations(context.CacheProfile);
cache.Set(key, item, expiration);
// Rip through all other keys for this object type and add the item under those cache keys too
var itemType = typeof(T);
if (CacheStackSettings.CacheKeysForObject != null && CacheStackSettings.CacheKeysForObject.ContainsKey(itemType))
{
var keys = CacheStackSettings.CacheKeysForObject[itemType](item).ToList();
// Only setup the other cache keys if the current key exists in them. Should prevent some undesirable results if caching partial objects
if (keys.Any(x => x == key))
{
foreach (var k in keys)
{
if (k == key)
{
continue;
}
cache.Set(k, item, expiration);
AddKeyToTriggers(context, k);
}
}
}
AddKeyToTriggers(context, key);
}
