因为快到圣诞节了:)
//////////////////////////////////////////////////////////////////////// Algorithmia is (c) 2008 Solutions Design. All rights reserved.// http://www.sd.nl//////////////////////////////////////////////////////////////////////// COPYRIGHTS:// Copyright (c) 2008 Solutions Design. All rights reserved.// // The Algorithmia library sourcepre and its accompanying tools, tests and support pre// are released under the following license: (BSD2)// ----------------------------------------------------------------------// Redistribution and use in source and binary forms, with or without modification, // are permitted provided that the following conditions are met: //// 1) Redistributions of source pre must retain the above copyright notice, this list of // conditions and the following disclaimer. // 2) Redistributions in binary form must reproduce the above copyright notice, this list of // conditions and the following disclaimer in the documentation and/or other materials // provided with the distribution. // // THIS SOFTWARE IS PROVIDED BY SOLUTIONS DESIGN ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, // INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A // PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SOLUTIONS DESIGN OR ConTRIBUTORS BE LIABLE FOR // ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR ConSEQUENTIAL DAMAGES (INCLUDING, BUT // NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR // BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE // USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. //// The views and conclusions contained in the software and documentation are those of the authors // and should not be interpreted as representing official policies, either expressed or implied, // of Solutions Design. ////////////////////////////////////////////////////////////////////////// Contributers to the pre:// - Frans Bouma [FB]//////////////////////////////////////////////////////////////////////using System;using System.Collections.Generic;using System.Linq;using System.Text;using SD.Tools.Algorithmia.UtilityClasses;namespace SD.Tools.Algorithmia.GeneralDataStructures{ /// <summary> /// Extension to the normal Dictionary. This class can store more than one value for every key. It keeps a HashSet for every Key value. /// Calling Add with the same Key and multiple values will store each value under the same Key in the Dictionary. Obtaining the values /// for a Key will return the HashSet with the Values of the Key. /// </summary> /// <typeparam name="TKey">The type of the key.</typeparam> /// <typeparam name="TValue">The type of the value.</typeparam> public class MultiValueDictionary<TKey, TValue> : Dictionary<TKey, HashSet<TValue>> { /// <summary> /// Initializes a new instance of the <see cref="MultiValueDictionary<TKey, TValue>"/> class. /// </summary> public MultiValueDictionary() : base() { } /// <summary> /// Adds the specified value under the specified key /// </summary> /// <param name="key">The key.</param> /// <param name="value">The value.</param> public void Add(TKey key, TValue value) { ArgumentVerifier.CantBeNull(key, "key"); HashSet<TValue> container = null; if(!this.TryGetValue(key, out container)) { container = new HashSet<TValue>(); base.Add(key, container); } container.Add(value); } /// <summary> /// Determines whether this dictionary contains the specified value for the specified key /// </summary> /// <param name="key">The key.</param> /// <param name="value">The value.</param> /// <returns>true if the value is stored for the specified key in this dictionary, false otherwise</returns> public bool ContainsValue(TKey key, TValue value) { ArgumentVerifier.CantBeNull(key, "key"); bool toReturn = false; HashSet<TValue> values = null; if(this.TryGetValue(key, out values)) { toReturn = values.Contains(value); } return toReturn; } /// <summary> /// Removes the specified value for the specified key. It will leave the key in the dictionary. /// </summary> /// <param name="key">The key.</param> /// <param name="value">The value.</param> public void Remove(TKey key, TValue value) { ArgumentVerifier.CantBeNull(key, "key"); HashSet<TValue> container = null; if(this.TryGetValue(key, out container)) { container.Remove(value); if(container.Count <= 0) { this.Remove(key); } } } /// <summary> /// Merges the specified multivaluedictionary into this instance. /// </summary> /// <param name="toMergeWith">To merge with.</param> public void Merge(MultiValueDictionary<TKey, TValue> toMergeWith) { if(toMergeWith==null) { return; } foreach(KeyValuePair<TKey, HashSet<TValue>> pair in toMergeWith) { foreach(TValue value in pair.Value) { this.Add(pair.Key, value); } } } /// <summary> /// Gets the values for the key specified. This method is useful if you want to avoid an exception for key value retrieval and you can't use TryGetValue /// (e.g. in lambdas) /// </summary> /// <param name="key">The key.</param> /// <param name="returnEmptySet">if set to true and the key isn't found, an empty hashset is returned, otherwise, if the key isn't found, null is returned</param> /// <returns> /// This method will return null (or an empty set if returnEmptySet is true) if the key wasn't found, or /// the values if key was found. /// </returns> public HashSet<TValue> GetValues(TKey key, bool returnEmptySet) { HashSet<TValue> toReturn = null; if(!base.TryGetValue(key, out toReturn) && returnEmptySet) { toReturn = new HashSet<TValue>(); } return toReturn; } }}
