1 | // Copyright 2012 Georg-August-Universität Göttingen, Germany |
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2 | // |
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3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
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4 | // you may not use this file except in compliance with the License. |
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5 | // You may obtain a copy of the License at |
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6 | // |
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7 | // http://www.apache.org/licenses/LICENSE-2.0 |
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8 | // |
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9 | // Unless required by applicable law or agreed to in writing, software |
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10 | // distributed under the License is distributed on an "AS IS" BASIS, |
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11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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12 | // See the License for the specific language governing permissions and |
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13 | // limitations under the License. |
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14 | |
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15 | package de.ugoe.cs.autoquest.usageprofiles; |
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16 | |
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17 | import java.io.Serializable; |
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18 | import java.util.Collection; |
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19 | |
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20 | /** |
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21 | * <p> |
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22 | * This interface defines a data structure for holding symbols. Its implementations can be used to |
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23 | * improve the performance of a trie by tuning its internal symbol storage management. |
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24 | * </p> |
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25 | * <p> |
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26 | * The interface is called a map, although it is not necessarily. It may contain the same element |
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27 | * as separate keys. This is allowed for performance improvements. If it is required to really |
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28 | * assure, that a key exists only once, then each call to the {@link #addSymbol(Object, Object)} |
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29 | * method should be done only, if the {@link #containsSymbol(Object)} method for the same symbol |
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30 | * returns false. |
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31 | * </p> |
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32 | * <p> |
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33 | * Mapping a symbol to the value null is possible. In this case {@link #getValue(Object)} returns |
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34 | * null for the symbol. But {@link #containsSymbol(Object)} returns true. |
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35 | * </p> |
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36 | * |
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37 | * @author Patrick Harms |
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38 | * |
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39 | * @param <K> |
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40 | * Type of the symbols that are stored |
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41 | * @param <V> |
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42 | * Type of the values associated with the symbols |
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43 | * |
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44 | * @see SymbolStrategy |
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45 | */ |
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46 | public interface SymbolMap<K, V> extends Serializable { |
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47 | |
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48 | /** |
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49 | * <p> |
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50 | * Returns the size of the map, i.e. the number of symbol entries |
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51 | * </p> |
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52 | * |
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53 | * @return as described |
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54 | */ |
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55 | public int size(); |
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56 | |
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57 | /** |
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58 | * <p> |
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59 | * Returns true if this map is empty, i.e. if {@link #size()} returns 0 |
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60 | * </p> |
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61 | * |
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62 | * @return as described |
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63 | */ |
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64 | public boolean isEmpty(); |
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65 | |
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66 | /** |
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67 | * <p> |
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68 | * Returns true if the provided symbol was stored in this map. |
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69 | * </p> |
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70 | * |
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71 | * @param symbol the symbol to check if it was stored in this map |
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72 | * |
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73 | * @return as described |
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74 | * |
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75 | * @throws IllegalArgumentException if the provided symbol is null |
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76 | */ |
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77 | public boolean containsSymbol(K symbol); |
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78 | |
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79 | /** |
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80 | * <p> |
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81 | * Returns the value associated to the provided symbol in this map. If there is no value |
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82 | * associated to the given symbol or if the symbol is not stored in this map, the method |
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83 | * returns null. |
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84 | * </p> |
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85 | * |
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86 | * @param symbol the symbol to return the value for |
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87 | * |
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88 | * @return as described |
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89 | * |
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90 | * @throws IllegalArgumentException if the provided symbol is null |
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91 | */ |
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92 | public V getValue(K symbol); |
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93 | |
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94 | /** |
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95 | * <p> |
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96 | * Adds a symbol and an associated value to the map. If the value is null, the symbol is added, |
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97 | * anyway and {@link #containsSymbol(Object)} will return true for that symbol. Adding the |
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98 | * same symbol twice may produce two entries. This is contradictory to typical map |
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99 | * implementations. To prevent this, the {@link #containsSymbol(Object)} and |
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100 | * {@link #removeSymbol(Object)} methods should be used to ensure map behavior. |
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101 | * </p> |
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102 | * |
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103 | * @param symbol the symbol to add to the map |
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104 | * @param value the value to associate to the symbol in this map |
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105 | * |
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106 | * @throws IllegalArgumentException if the provided symbol is null |
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107 | */ |
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108 | public void addSymbol(K symbol, V value); |
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109 | |
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110 | /** |
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111 | * <p> |
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112 | * Removes a symbol and its associated value from the map. If the symbol is stored several |
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113 | * times, the first of its occurrences is removed. |
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114 | * </p> |
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115 | * |
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116 | * @param symbol the symbol to be removed from the map |
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117 | * |
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118 | * @return as described |
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119 | * |
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120 | * @throws IllegalArgumentException if the provided symbol is null |
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121 | */ |
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122 | public V removeSymbol(K symbol); |
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123 | |
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124 | /** |
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125 | * <p> |
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126 | * Returns a collection of all symbols in this map. |
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127 | * </p> |
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128 | * |
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129 | * @return as described |
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130 | */ |
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131 | public Collection<K> getSymbols(); |
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132 | |
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133 | /** |
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134 | * <p> |
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135 | * Returns a collection of all values associated to symbols in this map. May contain null |
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136 | * values, if some of the symbols are mapped to null. The length of the returned collection |
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137 | * is in any case the same as the size of the map. |
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138 | * </p> |
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139 | * |
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140 | * @return as described |
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141 | */ |
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142 | public Collection<V> getValues(); |
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143 | |
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144 | /** |
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145 | * <p> |
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146 | * Removes all symbols and associated values from the map. |
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147 | * </p> |
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148 | */ |
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149 | public void clear(); |
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150 | |
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151 | /* (non-Javadoc) |
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152 | * @see java.lang.Object#hashCode() |
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153 | */ |
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154 | @Override |
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155 | public int hashCode(); |
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156 | |
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157 | /* (non-Javadoc) |
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158 | * @see java.lang.Object#equals(java.lang.Object) |
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159 | */ |
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160 | @Override |
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161 | public boolean equals(Object obj); |
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162 | |
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163 | } |
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