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1 /* |
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2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. |
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3 * |
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4 * Copyright 2017 Mike Becker, Olaf Wintermann All rights reserved. |
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5 * |
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6 * Redistribution and use in source and binary forms, with or without |
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7 * modification, are permitted provided that the following conditions are met: |
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8 * |
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9 * 1. Redistributions of source code must retain the above copyright |
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10 * notice, this list of conditions and the following disclaimer. |
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11 * |
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12 * 2. Redistributions in binary form must reproduce the above copyright |
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13 * notice, this list of conditions and the following disclaimer in the |
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14 * documentation and/or other materials provided with the distribution. |
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15 * |
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16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
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17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE |
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20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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26 * POSSIBILITY OF SUCH DAMAGE. |
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27 */ |
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28 |
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29 /** |
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30 * @file map.h |
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31 * |
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32 * Hash map implementation. |
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33 * |
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34 * This implementation uses murmur hash 2 and separate chaining with linked |
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35 * lists. |
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36 * |
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37 * @author Mike Becker |
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38 * @author Olaf Wintermann |
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39 */ |
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40 |
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41 #ifndef UCX_MAP_H |
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42 #define UCX_MAP_H |
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43 |
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44 #include "ucx.h" |
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45 #include "string.h" |
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46 #include "allocator.h" |
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47 #include <stdio.h> |
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48 |
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49 #ifdef __cplusplus |
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50 extern "C" { |
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51 #endif |
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52 |
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53 /** |
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54 * Loop statement for UCX maps. |
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55 * |
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56 * The <code>key</code> variable is implicitly defined, but the |
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57 * <code>value</code> variable must be already declared as type information |
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58 * cannot be inferred. |
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59 * |
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60 * @param key the variable name for the key |
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61 * @param value the variable name for the value |
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62 * @param iter a UcxMapIterator |
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63 * @see ucx_map_iterator() |
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64 */ |
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65 #define UCX_MAP_FOREACH(key,value,iter) \ |
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66 for(UcxKey key;ucx_map_iter_next(&iter,&key, (void**)&value);) |
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67 |
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68 /** Type for the UCX map. @see UcxMap */ |
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69 typedef struct UcxMap UcxMap; |
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70 |
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71 /** Type for a key of a UcxMap. @see UcxKey */ |
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72 typedef struct UcxKey UcxKey; |
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73 |
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74 /** Type for an element of a UcxMap. @see UcxMapElement */ |
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75 typedef struct UcxMapElement UcxMapElement; |
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76 |
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77 /** Type for an iterator over a UcxMap. @see UcxMapIterator */ |
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78 typedef struct UcxMapIterator UcxMapIterator; |
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79 |
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80 /** Structure for the UCX map. */ |
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81 struct UcxMap { |
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82 /** An allocator that is used for the map elements. */ |
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83 UcxAllocator *allocator; |
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84 /** The array of map element lists. */ |
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85 UcxMapElement **map; |
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86 /** The size of the map is the length of the element list array. */ |
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87 size_t size; |
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88 /** The count of elements currently stored in this map. */ |
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89 size_t count; |
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90 }; |
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91 |
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92 /** Structure to publicly denote a key of a UcxMap. */ |
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93 struct UcxKey { |
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94 /** The key data. */ |
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95 const void *data; |
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96 /** The length of the key data. */ |
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97 size_t len; |
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98 /** A cache for the hash value of the key data. */ |
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99 int hash; |
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100 }; |
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101 |
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102 /** Internal structure for a key of a UcxMap. */ |
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103 struct UcxMapKey { |
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104 /** The key data. */ |
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105 void *data; |
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106 /** The length of the key data. */ |
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107 size_t len; |
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108 /** The hash value of the key data. */ |
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109 int hash; |
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110 }; |
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111 |
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112 /** Structure for an element of a UcxMap. */ |
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113 struct UcxMapElement { |
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114 /** The value data. */ |
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115 void *data; |
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116 |
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117 /** A pointer to the next element in the current list. */ |
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118 UcxMapElement *next; |
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119 |
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120 /** The corresponding key. */ |
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121 struct UcxMapKey key; |
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122 }; |
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123 |
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124 /** Structure for an iterator over a UcxMap. */ |
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125 struct UcxMapIterator { |
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126 /** The map to iterate over. */ |
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127 UcxMap *map; |
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128 |
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129 /** The current map element. */ |
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130 UcxMapElement *cur; |
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131 |
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132 /** |
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133 * The current index of the element list array. |
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134 * <b>Attention: </b> this is <b>NOT</b> the element index! Do <b>NOT</b> |
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135 * manually iterate over the map by increasing this index. Use |
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136 * ucx_map_iter_next(). |
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137 * @see UcxMap.map*/ |
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138 size_t index; |
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139 }; |
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140 |
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141 /** |
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142 * Creates a new hash map with the specified size. |
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143 * @param size the size of the hash map |
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144 * @return a pointer to the new hash map |
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145 */ |
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146 UcxMap *ucx_map_new(size_t size); |
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147 |
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148 /** |
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149 * Creates a new hash map with the specified size using a UcxAllocator. |
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150 * @param allocator the allocator to use |
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151 * @param size the size of the hash map |
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152 * @return a pointer to the new hash map |
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153 */ |
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154 UcxMap *ucx_map_new_a(UcxAllocator *allocator, size_t size); |
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155 |
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156 /** |
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157 * Frees a hash map. |
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158 * |
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159 * <b>Note:</b> the contents are <b>not</b> freed, use ucx_map_free_content() |
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160 * before calling this function to achieve that. |
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161 * |
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162 * @param map the map to be freed |
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163 * @see ucx_map_free_content() |
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164 */ |
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165 void ucx_map_free(UcxMap *map); |
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166 |
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167 /** |
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168 * Frees the contents of a hash map. |
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169 * |
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170 * This is a convenience function that iterates over the map and passes all |
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171 * values to the specified destructor function. |
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172 * |
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173 * If no destructor is specified (<code>NULL</code>), the free() function of |
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174 * the map's own allocator is used. |
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175 * |
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176 * You must ensure, that it is valid to pass each value in the map to the same |
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177 * destructor function. |
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178 * |
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179 * You should free or clear the map afterwards, as the contents will be invalid. |
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180 * |
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181 * @param map for which the contents shall be freed |
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182 * @param destr optional pointer to a destructor function |
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183 * @see ucx_map_free() |
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184 * @see ucx_map_clear() |
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185 */ |
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186 void ucx_map_free_content(UcxMap *map, ucx_destructor destr); |
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187 |
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188 /** |
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189 * Clears a hash map. |
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190 * |
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191 * <b>Note:</b> the contents are <b>not</b> freed, use ucx_map_free_content() |
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192 * before calling this function to achieve that. |
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193 * |
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194 * @param map the map to be cleared |
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195 * @see ucx_map_free_content() |
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196 */ |
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197 void ucx_map_clear(UcxMap *map); |
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198 |
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199 |
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200 /** |
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201 * Copies contents from a map to another map using a copy function. |
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202 * |
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203 * <b>Note:</b> The destination map does not need to be empty. However, if it |
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204 * contains data with keys that are also present in the source map, the contents |
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205 * are overwritten. |
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206 * |
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207 * @param from the source map |
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208 * @param to the destination map |
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209 * @param fnc the copy function or <code>NULL</code> if the pointer address |
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210 * shall be copied |
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211 * @param data additional data for the copy function |
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212 * @return 0 on success or a non-zero value on memory allocation errors |
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213 */ |
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214 int ucx_map_copy(UcxMap *from, UcxMap *to, copy_func fnc, void *data); |
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215 |
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216 /** |
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217 * Clones the map and rehashes if necessary. |
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218 * |
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219 * <b>Note:</b> In contrast to ucx_map_rehash() the load factor is irrelevant. |
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220 * This function <i>always</i> ensures a new UcxMap.size of at least |
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221 * 2.5*UcxMap.count. |
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222 * |
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223 * @param map the map to clone |
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224 * @param fnc the copy function to use or <code>NULL</code> if the new and |
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225 * the old map shall share the data pointers |
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226 * @param data additional data for the copy function |
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227 * @return the cloned map |
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228 * @see ucx_map_copy() |
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229 */ |
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230 UcxMap *ucx_map_clone(UcxMap *map, copy_func fnc, void *data); |
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231 |
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232 /** |
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233 * Increases size of the hash map, if necessary. |
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234 * |
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235 * The load value is 0.75*UcxMap.size. If the element count exceeds the load |
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236 * value, the map needs to be rehashed. Otherwise no action is performed and |
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237 * this function simply returns 0. |
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238 * |
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239 * The rehashing process ensures, that the UcxMap.size is at least |
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240 * 2.5*UcxMap.count. So there is enough room for additional elements without |
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241 * the need of another soon rehashing. |
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242 * |
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243 * You can use this function to dramatically increase access performance. |
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244 * |
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245 * @param map the map to rehash |
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246 * @return 1, if a memory allocation error occurred, 0 otherwise |
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247 */ |
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248 int ucx_map_rehash(UcxMap *map); |
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249 |
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250 /** |
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251 * Puts a key/value-pair into the map. |
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252 * |
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253 * @param map the map |
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254 * @param key the key |
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255 * @param value the value |
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256 * @return 0 on success, non-zero value on failure |
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257 */ |
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258 int ucx_map_put(UcxMap *map, UcxKey key, void *value); |
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259 |
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260 /** |
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261 * Retrieves a value by using a key. |
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262 * |
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263 * @param map the map |
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264 * @param key the key |
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265 * @return the value |
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266 */ |
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267 void* ucx_map_get(UcxMap *map, UcxKey key); |
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268 |
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269 /** |
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270 * Removes a key/value-pair from the map by using the key. |
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271 * |
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272 * @param map the map |
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273 * @param key the key |
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274 * @return the removed value |
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275 */ |
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276 void* ucx_map_remove(UcxMap *map, UcxKey key); |
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277 |
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278 /** |
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279 * Creates a new map containing all elements from the maps a and b. |
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280 * |
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281 * If a key exists in both maps, the value is taken from map a. |
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282 * |
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283 * @param a map a |
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284 * @param b map b |
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285 * @param fnc the copy function to use or <code>NULL</code> if the new and |
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286 * the old map shall share the data pointers |
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287 * @param data additional data for the copy function |
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288 * @return the new union map |
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289 * @see ucx_map_copy() |
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290 */ |
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291 UcxMap *ucx_map_union(UcxMap *a, UcxMap *b, copy_func fnc, void *data); |
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292 |
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293 /** |
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294 * intersection |
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295 * |
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296 * If a key exists in both maps, the value is taken from map a. |
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297 * |
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298 * @param a map a |
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299 * @param b map b |
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300 * @param fnc the copy function to use or <code>NULL</code> if the new and |
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301 * the old map shall share the data pointers |
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302 * @param data additional data for the copy function |
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303 * @return the new intersection map |
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304 * @see ucx_map_copy() |
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305 */ |
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306 UcxMap *ucx_map_intersection(UcxMap *a, UcxMap *b, copy_func fnc, void *data); |
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307 |
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308 /** |
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309 * relative complement |
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310 * |
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311 * If a key exists in both maps, the value is taken from map a. |
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312 * |
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313 * @param a map a |
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314 * @param b map b |
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315 * @param fnc the copy function to use or <code>NULL</code> if the new and |
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316 * the old map shall share the data pointers |
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317 * @param data additional data for the copy function |
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318 * @return the new intersection map |
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319 * @see ucx_map_copy() |
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320 */ |
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321 UcxMap *ucx_map_relcomplement(UcxMap *a, UcxMap *b, copy_func fnc, void *data); |
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322 |
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323 /** |
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324 * Shorthand for putting data with a sstr_t key into the map. |
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325 * @param map the map |
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326 * @param key the key |
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327 * @param value the value |
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328 * @return 0 on success, non-zero value on failure |
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329 * @see ucx_map_put() |
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330 */ |
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331 #define ucx_map_sstr_put(map, key, value) \ |
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332 ucx_map_put(map, ucx_key(key.ptr, key.length), (void*)value) |
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333 |
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334 /** |
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335 * Shorthand for putting data with a C string key into the map. |
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336 * @param map the map |
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337 * @param key the key |
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338 * @param value the value |
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339 * @return 0 on success, non-zero value on failure |
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340 * @see ucx_map_put() |
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341 */ |
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342 #define ucx_map_cstr_put(map, key, value) \ |
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343 ucx_map_put(map, ucx_key(key, strlen(key)), (void*)value) |
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344 |
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345 /** |
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346 * Shorthand for putting data with an integer key into the map. |
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347 * @param map the map |
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348 * @param key the key |
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349 * @param value the value |
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350 * @return 0 on success, non-zero value on failure |
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351 * @see ucx_map_put() |
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352 */ |
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353 #define ucx_map_int_put(map, key, value) \ |
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354 ucx_map_put(map, ucx_key(&key, sizeof(key)), (void*)value) |
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355 |
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356 /** |
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357 * Shorthand for getting data from the map with a sstr_t key. |
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358 * @param map the map |
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359 * @param key the key |
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360 * @return the value |
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361 * @see ucx_map_get() |
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362 */ |
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363 #define ucx_map_sstr_get(map, key) \ |
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364 ucx_map_get(map, ucx_key(key.ptr, key.length)) |
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365 |
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366 /** |
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367 * Shorthand for getting data from the map with a C string key. |
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368 * @param map the map |
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369 * @param key the key |
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370 * @return the value |
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371 * @see ucx_map_get() |
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372 */ |
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373 #define ucx_map_cstr_get(map, key) \ |
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374 ucx_map_get(map, ucx_key(key, strlen(key))) |
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375 |
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376 /** |
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377 * Shorthand for getting data from the map with an integer key. |
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378 * @param map the map |
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379 * @param key the key |
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380 * @return the value |
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381 * @see ucx_map_get() |
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382 */ |
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383 #define ucx_map_int_get(map, key) \ |
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384 ucx_map_get(map, ucx_key(&key, sizeof(int))) |
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385 |
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386 /** |
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387 * Shorthand for removing data from the map with a sstr_t key. |
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388 * @param map the map |
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389 * @param key the key |
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390 * @return the removed value |
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391 * @see ucx_map_remove() |
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392 */ |
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393 #define ucx_map_sstr_remove(map, key) \ |
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394 ucx_map_remove(map, ucx_key(key.ptr, key.length)) |
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395 |
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396 /** |
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397 * Shorthand for removing data from the map with a C string key. |
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398 * @param map the map |
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399 * @param key the key |
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400 * @return the removed value |
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401 * @see ucx_map_remove() |
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402 */ |
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403 #define ucx_map_cstr_remove(map, key) \ |
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404 ucx_map_remove(map, ucx_key(key, strlen(key))) |
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405 |
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406 /** |
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407 * Shorthand for removing data from the map with an integer key. |
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408 * @param map the map |
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409 * @param key the key |
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410 * @return the removed value |
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411 * @see ucx_map_remove() |
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412 */ |
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413 #define ucx_map_int_remove(map, key) \ |
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414 ucx_map_remove(map, ucx_key(&key, sizeof(key))) |
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415 |
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416 /** |
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417 * Creates a UcxKey based on the given data. |
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418 * |
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419 * This function implicitly computes the hash. |
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420 * |
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421 * @param data the data for the key |
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422 * @param len the length of the data |
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423 * @return a UcxKey with implicitly computed hash |
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424 * @see ucx_hash() |
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425 */ |
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426 UcxKey ucx_key(const void *data, size_t len); |
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427 |
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428 /** |
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429 * Computes a murmur hash-2. |
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430 * |
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431 * @param data the data to hash |
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432 * @param len the length of the data |
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433 * @return the murmur hash-2 of the data |
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434 */ |
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435 int ucx_hash(const char *data, size_t len); |
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436 |
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437 /** |
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438 * Creates an iterator for a map. |
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439 * |
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440 * <b>Note:</b> A UcxMapIterator iterates over all elements in all element |
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441 * lists successively. Therefore the order highly depends on the key hashes and |
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442 * may vary under different map sizes. So generally you may <b>NOT</b> rely on |
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443 * the iteration order. |
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444 * |
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445 * <b>Note:</b> The iterator is <b>NOT</b> initialized. You need to call |
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446 * ucx_map_iter_next() at least once before accessing any information. However, |
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447 * it is not recommended to access the fields of a UcxMapIterator directly. |
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448 * |
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449 * @param map the map to create the iterator for |
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450 * @return an iterator initialized on the first element of the |
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451 * first element list |
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452 * @see ucx_map_iter_next() |
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453 */ |
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454 UcxMapIterator ucx_map_iterator(UcxMap *map); |
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455 |
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456 /** |
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457 * Proceeds to the next element of the map (if any). |
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458 * |
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459 * Subsequent calls on the same iterator proceed to the next element and |
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460 * store the key/value-pair into the memory specified as arguments of this |
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461 * function. |
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462 * |
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463 * If no further elements are found, this function returns zero and leaves the |
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464 * last found key/value-pair in memory. |
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465 * |
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466 * @param iterator the iterator to use |
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467 * @param key a pointer to the memory where to store the key |
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468 * @param value a pointer to the memory where to store the value |
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469 * @return 1, if another element was found, 0 if all elements has been processed |
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470 * @see ucx_map_iterator() |
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471 */ |
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472 int ucx_map_iter_next(UcxMapIterator *iterator, UcxKey *key, void **value); |
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473 |
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474 |
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475 #ifdef __cplusplus |
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476 } |
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477 #endif |
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478 |
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479 #endif /* UCX_MAP_H */ |
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480 |