// crudwork // Copyright 2004 by Steve T. Pham (http://www.crudwork.com) // // This program is free software: you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation, either version 3 of the License, or // (at your option) any later version. // // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with This program. If not, see <http://www.gnu.org/licenses/>. using System; using System.Collections.Generic; using System.Text; namespace crudwork.Utilities { /// <summary> /// Provide a memory caching mechanism to save and retrieve results based on the associated key names /// </summary> /// <typeparam name="T">the key</typeparam> /// <typeparam name="U">the result</typeparam> public class CacheManager<T, U> { private Dictionary<T, U> cache; /// <summary> /// Create an empty instance /// </summary> public CacheManager() { cache = new Dictionary<T, U>(); } /// <summary> /// Generate a key based on the input provided. /// </summary> /// <param name="keys"></param> /// <returns></returns> public string MakeKey(params string[] keys) { if (keys == null || keys.Length == 0) throw new ArgumentNullException("keys"); StringBuilder sb = new StringBuilder(); for (int i = 0; i < keys.Length; i++) { if (i > 0) sb.Append("ƒ"); // delimiter by ASCII 159 sb.Append(keys[i].ToUpper().Trim(' ', ' ')); } return sb.ToString(); } /// <summary> /// Check whether or not the result exists in the cache by the associated key /// </summary> /// <param name="key"></param> /// <returns></returns> public bool Exists(T key) { return cache.ContainsKey(key); } /// <summary> /// Retrieve the result from cache by the associated key /// </summary> /// <param name="key"></param> /// <returns></returns> public U Get(T key) { return cache[key]; } /// <summary> /// Add the result/key pair to the cache /// </summary> /// <param name="key"></param> /// <param name="value"></param> public void Add(T key, U value) { if (cache.ContainsKey(key)) cache[key] = value; else cache.Add(key, value); } /// <summary> /// Remove the result from cache by the associated key /// </summary> /// <param name="key"></param> public void Delete(T key) { cache.Remove(key); } /// <summary> /// Clear all cache from memory /// </summary> public void Clear() { cache.Clear(); } /// <summary> /// Load cache entries from given file /// </summary> /// <param name="filename"></param> public void Load(string filename) { throw new NotImplementedException("not done"); } /// <summary> /// Save all cache entries to given file /// </summary> /// <param name="filename"></param> public void Save(string filename) { throw new NotImplementedException("not done"); } } }