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source: branches/2839_HiveProjectManagement/HeuristicLab.Persistence/3.3/Default/CompositeSerializers/CompactNumberArray2StringSerializer.cs @ 16057

Last change on this file since 16057 was 16057, checked in by jkarder, 6 years ago

#2839:

File size: 6.7 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#endregion
21
22using System;
23using System.Collections;
24using System.Collections.Generic;
25using System.Text;
26using HeuristicLab.Persistence.Auxiliary;
27using HeuristicLab.Persistence.Core;
28using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
29using HeuristicLab.Persistence.Interfaces;
30
31namespace HeuristicLab.Persistence.Default.CompositeSerializers {
32
33  [StorableClass]
34  public sealed class CompactNumberArray2StringSerializer : ICompositeSerializer {
35
36    private class ElementEnumerator : IEnumerator<string> {
37
38      private IEnumerator<Tag> tagIt;
39      private IEnumerator<string> valIt;
40
41      public ElementEnumerator(IEnumerable<Tag> tags) {
42        tagIt = tags.GetEnumerator();
43      }
44
45      public string Current {
46        get {
47          if (valIt == null)
48            throw new InvalidOperationException("no current value");
49          return valIt.Current;
50        }
51      }
52
53      public void Dispose() {
54        valIt.Dispose();
55        valIt = null;
56        tagIt.Dispose();
57      }
58
59      object IEnumerator.Current {
60        get { return this.Current; }
61      }
62
63      public bool MoveNext() {
64        if (valIt != null && valIt.MoveNext())
65          return true;
66        if (tagIt.MoveNext()) {
67          if (valIt != null)
68            valIt.Dispose();
69          valIt = ((string)tagIt.Current.Value).GetSplitEnumerator(';');
70          return MoveNext();
71        }
72        valIt.Dispose();
73        valIt = null;
74        return false;
75      }
76
77      public void Reset() {
78        valIt.Dispose();
79        tagIt.Reset();
80      }
81    }
82
83    [StorableConstructor]
84    private CompactNumberArray2StringSerializer(bool deserializing) { }
85    public CompactNumberArray2StringSerializer() { }
86
87    public const int SPLIT_THRESHOLD = 1024 * 1024;
88
89    public int Priority {
90      get { return 200; }
91    }
92
93    private static readonly Number2StringSerializer numberConverter =
94      new Number2StringSerializer();
95
96    public bool CanSerialize(Type type) {
97      return
98        (type.IsArray || type == typeof(Array)) &&
99        numberConverter.CanSerialize(type.GetElementType());
100    }
101
102    public string JustifyRejection(Type type) {
103      if (!type.IsArray && type != typeof(Array))
104        return "not an array";
105      return string.Format("number converter cannot serialize elements: " +
106        numberConverter.JustifyRejection(type.GetElementType()));
107    }
108
109    public IEnumerable<Tag> CreateMetaInfo(object obj) {
110      Array a = (Array)obj;
111      int[] lengths = new int[a.Rank];
112      int[] lowerBounds = new int[a.Rank];
113      StringBuilder sb = new StringBuilder(a.Rank * 6);
114      sb.Append(a.Rank).Append(';');
115      for (int i = 0; i < a.Rank; i++) {
116        sb.Append(a.GetLength(i)).Append(';');
117        lengths[i] = a.GetLength(i);
118      }
119      for (int i = 0; i < a.Rank; i++) {
120        sb.Append(a.GetLowerBound(i)).Append(';');
121        lowerBounds[i] = a.GetLowerBound(i);
122      }
123      int nElements = 1;
124      for (int i = 0; i < a.Rank; i++) {
125        lowerBounds[i] = a.GetLowerBound(i);
126        lengths[i] = a.GetLength(i);
127        nElements *= lengths[i];
128      }
129      sb.Capacity += Math.Min(nElements * 3, SPLIT_THRESHOLD);
130      int[] positions = (int[])lowerBounds.Clone();
131      while (positions[a.Rank - 1] < lengths[a.Rank - 1] + lowerBounds[a.Rank - 1]) {
132        sb.Append(numberConverter.Format(a.GetValue(positions))).Append(';');
133        if (sb.Length > SPLIT_THRESHOLD && sb.Length > sb.Capacity - 18) {
134          yield return new Tag(sb.ToString());
135          sb = new StringBuilder(Math.Min(nElements * 3, SPLIT_THRESHOLD));
136        }
137        positions[0] += 1;
138        for (int i = 0; i < a.Rank - 1; i++) {
139          if (positions[i] >= lengths[i] + lowerBounds[i]) {
140            positions[i] = lowerBounds[i];
141            positions[i + 1] += 1;
142          } else {
143            break;
144          }
145        }
146      }
147      if (sb.Length > 0)
148        yield return new Tag(sb.ToString());
149    }
150
151    private static Tag[] emptyTag = new Tag[0];
152    public IEnumerable<Tag> Decompose(object obj) {
153      return emptyTag;
154    }
155
156    public object CreateInstance(Type type, IEnumerable<Tag> metaInfo) {
157      try {
158        var valueIter = new ElementEnumerator(metaInfo);
159        valueIter.MoveNext();
160        int rank = int.Parse(valueIter.Current);
161        int[] lengths = new int[rank];
162        int[] lowerBounds = new int[rank];
163        for (int i = 0; i < rank; i++) {
164          valueIter.MoveNext();
165          lengths[i] = int.Parse(valueIter.Current);
166        }
167        for (int i = 0; i < rank; i++) {
168          valueIter.MoveNext();
169          lowerBounds[i] = int.Parse(valueIter.Current);
170        }
171        Type elementType = type.GetElementType();
172        Array a = Array.CreateInstance(elementType, lengths, lowerBounds);
173        if (a == null) throw new PersistenceException("invalid instance data type, expected array");
174        int[] positions = (int[])lowerBounds.Clone();
175
176        while (valueIter.MoveNext()) {
177          a.SetValue(numberConverter.Parse(valueIter.Current, elementType), positions);
178          positions[0] += 1;
179          for (int i = 0; i < a.Rank - 1; i++) {
180            if (positions[i] >= lengths[i] + lowerBounds[i]) {
181              positions[i + 1] += 1;
182              positions[i] = lowerBounds[i];
183            } else {
184              break;
185            }
186          }
187        }
188        return a;
189      }
190      catch (InvalidOperationException e) {
191        throw new PersistenceException("Insuffictient data to deserialize compact array", e);
192      }
193      catch (InvalidCastException e) {
194        throw new PersistenceException("Invalid element data during compact array deserialization", e);
195      }
196    }
197
198    public void Populate(object instance, IEnumerable<Tag> tags, Type type) {
199      // Nothing to do. Arrays are populated during instance creation;
200    }
201
202  }
203
204}
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