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source: stable/HeuristicLab.Problems.ExternalEvaluation/3.4/EvaluationCache.cs @ 16418

Last change on this file since 16418 was 15584, checked in by swagner, 7 years ago

#2640: Updated year of copyrights in license headers on stable

File size: 11.3 KB
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1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2018 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
4 *
5 * This file is part of HeuristicLab.
6 *
7 * HeuristicLab is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * HeuristicLab is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
19 *
20 * The LRU cache is based on an idea by Robert Rossney see
21 * <http://csharp-lru-cache.googlecode.com>.
22 */
23#endregion
24
25using System;
26using System.Collections.Generic;
27using System.Globalization;
28using System.IO;
29using System.Linq;
30using System.Text.RegularExpressions;
31using System.Threading;
32using Google.ProtocolBuffers;
33using HeuristicLab.Common;
34using HeuristicLab.Common.Resources;
35using HeuristicLab.Core;
36using HeuristicLab.Data;
37using HeuristicLab.Parameters;
38using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
39
40namespace HeuristicLab.Problems.ExternalEvaluation {
41
42  [Item("EvaluationCache", "Cache for external evaluation values")]
43  [StorableClass]
44  public class EvaluationCache : ParameterizedNamedItem {
45
46    #region Types
47    private sealed class CacheEntry {
48
49      public readonly string Key;
50
51      private QualityMessage message;
52      private byte[] rawMessage;
53
54      private object lockObject = new object();
55
56      public byte[] RawMessage {
57        get { return rawMessage; }
58        set {
59          lock (lockObject) {
60            rawMessage = value;
61            message = null;
62          }
63        }
64      }
65
66      public CacheEntry(string key) {
67        Key = key;
68      }
69
70      public QualityMessage GetMessage(ExtensionRegistry extensions) {
71        lock (lockObject) {
72          if (message == null && rawMessage != null)
73            message = QualityMessage.ParseFrom(ByteString.CopyFrom(rawMessage), extensions);
74        }
75        return message;
76      }
77      public void SetMessage(QualityMessage value) {
78        lock (lockObject) {
79          message = value;
80          rawMessage = value.ToByteArray();
81        }
82      }
83
84      public override bool Equals(object obj) {
85        CacheEntry other = obj as CacheEntry;
86        if (other == null)
87          return false;
88        return Key.Equals(other.Key);
89      }
90
91      public override int GetHashCode() {
92        return Key.GetHashCode();
93      }
94
95      public string QualityString(IFormatProvider formatProvider = null) {
96        if (formatProvider == null) formatProvider = CultureInfo.CurrentCulture;
97        if (RawMessage == null) return "-";
98        var msg = message ?? CreateBasicQualityMessage();
99        switch (msg.Type) {
100          case QualityMessage.Types.Type.SingleObjectiveQualityMessage:
101            return msg.GetExtension(SingleObjectiveQualityMessage.QualityMessage_).Quality.ToString(formatProvider);
102          case QualityMessage.Types.Type.MultiObjectiveQualityMessage:
103            var qualities = msg.GetExtension(MultiObjectiveQualityMessage.QualityMessage_).QualitiesList;
104            return string.Format("[{0}]", string.Join(",", qualities.Select(q => q.ToString(formatProvider))));
105          default:
106            return "-";
107        }
108      }
109      private QualityMessage CreateBasicQualityMessage() {
110        var extensions = ExtensionRegistry.CreateInstance();
111        ExternalEvaluationMessages.RegisterAllExtensions(extensions);
112        return QualityMessage.ParseFrom(ByteString.CopyFrom(rawMessage), extensions);
113      }
114
115      public override string ToString() {
116        return string.Format("{{{0} : {1}}}", Key, QualityString());
117      }
118    }
119
120    public delegate QualityMessage Evaluator(SolutionMessage message);
121    #endregion
122
123    #region Fields
124    private LinkedList<CacheEntry> list;
125    private Dictionary<CacheEntry, LinkedListNode<CacheEntry>> index;
126
127    private HashSet<string> activeEvaluations = new HashSet<string>();
128    private object cacheLock = new object();
129    #endregion
130
131    #region Properties
132    public static new System.Drawing.Image StaticItemImage {
133      get { return VSImageLibrary.Database; }
134    }
135    public int Size { get { lock (cacheLock) return index.Count; } }
136    public int ActiveEvaluations { get { lock (cacheLock) return activeEvaluations.Count; } }
137
138    [Storable]
139    public int Hits { get; private set; }
140    #endregion
141
142    #region events
143    public event EventHandler Changed;
144
145    protected virtual void OnChanged() {
146      EventHandler handler = Changed;
147      if (handler != null)
148        handler(this, EventArgs.Empty);
149    }
150    #endregion
151
152    #region Parameters
153    public FixedValueParameter<IntValue> CapacityParameter {
154      get { return (FixedValueParameter<IntValue>)Parameters["Capacity"]; }
155    }
156    public FixedValueParameter<BoolValue> PersistentCacheParameter {
157      get { return (FixedValueParameter<BoolValue>)Parameters["PersistentCache"]; }
158    }
159    #endregion
160
161    #region Parameter Values
162    public int Capacity {
163      get { return CapacityParameter.Value.Value; }
164      set { CapacityParameter.Value.Value = value; }
165    }
166    public bool IsPersistent {
167      get { return PersistentCacheParameter.Value.Value; }
168    }
169    #endregion
170
171    #region Persistence
172    #region BackwardsCompatibility3.4
173    [Storable(Name = "Cache")]
174    private IEnumerable<KeyValuePair<string, double>> Cache_Persistence_backwardscompatability {
175      get { return Enumerable.Empty<KeyValuePair<string, double>>(); }
176      set {
177        var rawMessages = value.ToDictionary(kvp => kvp.Key,
178          kvp => QualityMessage.CreateBuilder()
179            .SetSolutionId(0)
180            .SetExtension(
181              SingleObjectiveQualityMessage.QualityMessage_,
182              SingleObjectiveQualityMessage.CreateBuilder().SetQuality(kvp.Value).Build())
183            .Build().ToByteArray());
184        SetCacheValues(rawMessages);
185      }
186    }
187    #endregion
188    [Storable(Name = "CacheNew")]
189    private IEnumerable<KeyValuePair<string, byte[]>> Cache_Persistence {
190      get { return IsPersistent ? GetCacheValues() : Enumerable.Empty<KeyValuePair<string, byte[]>>(); }
191      set { SetCacheValues(value); }
192    }
193    [StorableHook(HookType.AfterDeserialization)]
194    private void AfterDeserialization() {
195      RegisterEvents();
196    }
197    #endregion
198
199    #region Construction & Cloning
200    [StorableConstructor]
201    protected EvaluationCache(bool deserializing) : base(deserializing) { }
202    protected EvaluationCache(EvaluationCache original, Cloner cloner)
203        : base(original, cloner) {
204      SetCacheValues(original.GetCacheValues());
205      Hits = original.Hits;
206      RegisterEvents();
207    }
208    public EvaluationCache() {
209      list = new LinkedList<CacheEntry>();
210      index = new Dictionary<CacheEntry, LinkedListNode<CacheEntry>>();
211      Parameters.Add(new FixedValueParameter<IntValue>("Capacity", "Maximum number of cache entries.", new IntValue(10000)));
212      Parameters.Add(new FixedValueParameter<BoolValue>("PersistentCache", "Save cache when serializing object graph?", new BoolValue(false)));
213      RegisterEvents();
214    }
215    public override IDeepCloneable Clone(Cloner cloner) {
216      return new EvaluationCache(this, cloner);
217    }
218    #endregion
219
220    #region Event Handling
221    private void RegisterEvents() {
222      CapacityParameter.Value.ValueChanged += new EventHandler(CapacityChanged);
223    }
224
225    void CapacityChanged(object sender, EventArgs e) {
226      if (Capacity < 0)
227        throw new ArgumentOutOfRangeException("Cache capacity cannot be less than zero");
228      lock (cacheLock)
229        Trim();
230      OnChanged();
231    }
232    #endregion
233
234    #region Methods
235    public void Reset() {
236      lock (cacheLock) {
237        list = new LinkedList<CacheEntry>();
238        index = new Dictionary<CacheEntry, LinkedListNode<CacheEntry>>();
239        Hits = 0;
240      }
241      OnChanged();
242    }
243
244    public QualityMessage GetValue(SolutionMessage message, Evaluator evaluate, ExtensionRegistry extensions) {
245      var entry = new CacheEntry(message.ToString());
246      bool lockTaken = false;
247      bool waited = false;
248      try {
249        Monitor.Enter(cacheLock, ref lockTaken);
250        while (true) {
251          LinkedListNode<CacheEntry> node;
252          if (index.TryGetValue(entry, out node)) {
253            list.Remove(node);
254            list.AddLast(node);
255            Hits++;
256            lockTaken = false;
257            Monitor.Exit(cacheLock);
258            OnChanged();
259            return node.Value.GetMessage(extensions);
260          } else {
261            if (!waited && activeEvaluations.Contains(entry.Key)) {
262              while (activeEvaluations.Contains(entry.Key))
263                Monitor.Wait(cacheLock);
264              waited = true;
265            } else {
266              activeEvaluations.Add(entry.Key);
267              lockTaken = false;
268              Monitor.Exit(cacheLock);
269              OnChanged();
270              try {
271                entry.SetMessage(evaluate(message));
272                Monitor.Enter(cacheLock, ref lockTaken);
273                index[entry] = list.AddLast(entry);
274                Trim();
275              } finally {
276                if (!lockTaken)
277                  Monitor.Enter(cacheLock, ref lockTaken);
278                activeEvaluations.Remove(entry.Key);
279                Monitor.PulseAll(cacheLock);
280                lockTaken = false;
281                Monitor.Exit(cacheLock);
282              }
283              OnChanged();
284              return entry.GetMessage(extensions);
285            }
286          }
287        }
288      } finally {
289        if (lockTaken)
290          Monitor.Exit(cacheLock);
291      }
292    }
293
294    private void Trim() {
295      while (list.Count > Capacity) {
296        var item = list.First;
297        list.Remove(item);
298        index.Remove(item.Value);
299      }
300    }
301
302    private IEnumerable<KeyValuePair<string, byte[]>> GetCacheValues() {
303      lock (cacheLock) {
304        return index.ToDictionary(kvp => kvp.Key.Key, kvp => kvp.Key.RawMessage);
305      }
306    }
307
308    private void SetCacheValues(IEnumerable<KeyValuePair<string, byte[]>> value) {
309      lock (cacheLock) {
310        if (list == null) list = new LinkedList<CacheEntry>();
311        if (index == null) index = new Dictionary<CacheEntry, LinkedListNode<CacheEntry>>();
312        foreach (var kvp in value) {
313          var entry = new CacheEntry(kvp.Key) { RawMessage = kvp.Value };
314          index[entry] = list.AddLast(entry);
315        }
316      }
317    }
318
319    public void Save(string filename) {
320      using (var writer = new StreamWriter(filename)) {
321        lock (cacheLock) {
322          foreach (var entry in list) {
323            writer.WriteLine(string.Format(CultureInfo.InvariantCulture,
324              "\"{0}\", {1}",
325              Regex.Replace(entry.Key, "\\s", "").Replace("\"", "\"\""),
326              entry.QualityString(CultureInfo.InvariantCulture)));
327          }
328        }
329        writer.Close();
330      }
331    }
332    #endregion
333  }
334}
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