Tag Cache is a full fledged cache that also enables associating tags (aka labels) with cache items. The tags can later be used to invalidate multiple cache items that match the tag in one go.

TagCache tagCache = new TagCache();

Action fillCacheItems = delegate
{
    tagCache.Set("honda", new object(), new List<string> { "Vehicle", "Car", "Economy" });
    tagCache.Set("lexus", new object(), new List<string> { "Vehicle", "Car", "Luxury" });
    tagCache.Set("harley", new object(), new List<string> { "Vehicle", "Bike", "Luxury" });
    tagCache.Set("yamaha", new object(), new List<string> { "Vehicle", "Bike", "Economy" });
};

fillCacheItems();
tagCache.Invalidate("Bike");  // invalidates all bikes

fillCacheItems();
tagCache.Invalidate("Luxury");  // invalidates all luxury vehicles

fillCacheItems();
tagCache.Invalidate("Vehicle");  // invalidates all vehicles

fillCacheItems();
tagCache.Invalidate(new List<string> { "Car", "Luxury" });  // invalidates all luxury cars

fillCacheItems();
tagCache.Invalidate(new List<string> { "Bike", "Economy" });  // invalidates all economy bikes

fillCacheItems();
tagCache.Invalidate(new List<List<string>> { 
    new List<string> { "Bike", "Luxury" }, 
    new List<string> { "Car", "Economy" } 
});  // invalidates all luxury bikes, economy cars

(The MIT License)

Copyright (c) 2011 Shiva Shankar P

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.