1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/ucx/map.h Tue Oct 17 16:15:41 2017 +0200
1.3 @@ -0,0 +1,423 @@
1.4 +/*
1.5 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
1.6 + *
1.7 + * Copyright 2017 Olaf Wintermann. All rights reserved.
1.8 + *
1.9 + * Redistribution and use in source and binary forms, with or without
1.10 + * modification, are permitted provided that the following conditions are met:
1.11 + *
1.12 + * 1. Redistributions of source code must retain the above copyright
1.13 + * notice, this list of conditions and the following disclaimer.
1.14 + *
1.15 + * 2. Redistributions in binary form must reproduce the above copyright
1.16 + * notice, this list of conditions and the following disclaimer in the
1.17 + * documentation and/or other materials provided with the distribution.
1.18 + *
1.19 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
1.20 + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1.21 + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1.22 + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
1.23 + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
1.24 + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
1.25 + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
1.26 + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
1.27 + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
1.28 + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
1.29 + * POSSIBILITY OF SUCH DAMAGE.
1.30 + */
1.31 +
1.32 +/**
1.33 + * @file map.h
1.34 + *
1.35 + * Hash map implementation.
1.36 + *
1.37 + * This implementation uses murmur hash 2 and separate chaining with linked
1.38 + * lists.
1.39 + *
1.40 + * @author Mike Becker
1.41 + * @author Olaf Wintermann
1.42 + */
1.43 +
1.44 +#ifndef UCX_MAP_H
1.45 +#define UCX_MAP_H
1.46 +
1.47 +#include <ucx/ucx.h>
1.48 +#include <ucx/string.h>
1.49 +#include <ucx/allocator.h>
1.50 +#include <stdio.h>
1.51 +
1.52 +#ifdef __cplusplus
1.53 +extern "C" {
1.54 +#endif
1.55 +
1.56 +/**
1.57 + * Loop statement for UCX maps.
1.58 + *
1.59 + * The <code>key</code> variable is implicitly defined, but the
1.60 + * <code>value</code> variable must be already declared as type information
1.61 + * cannot be inferred.
1.62 + *
1.63 + * @param key the variable name for the key
1.64 + * @param value the variable name for the value
1.65 + * @param iter a UcxMapIterator
1.66 + * @see ucx_map_iterator()
1.67 + */
1.68 +#define UCX_MAP_FOREACH(key,value,iter) \
1.69 + for(UcxKey key;ucx_map_iter_next(&iter,&key, (void**)&value);)
1.70 +
1.71 +/** Type for the UCX map. @see UcxMap */
1.72 +typedef struct UcxMap UcxMap;
1.73 +
1.74 +/** Type for a key of a UcxMap. @see UcxKey */
1.75 +typedef struct UcxKey UcxKey;
1.76 +
1.77 +/** Type for an element of a UcxMap. @see UcxMapElement */
1.78 +typedef struct UcxMapElement UcxMapElement;
1.79 +
1.80 +/** Type for an iterator over a UcxMap. @see UcxMapIterator */
1.81 +typedef struct UcxMapIterator UcxMapIterator;
1.82 +
1.83 +/** Structure for the UCX map. */
1.84 +struct UcxMap {
1.85 + /** An allocator that is used for the map elements. */
1.86 + UcxAllocator *allocator;
1.87 + /** The array of map element lists. */
1.88 + UcxMapElement **map;
1.89 + /** The size of the map is the length of the element list array. */
1.90 + size_t size;
1.91 + /** The count of elements currently stored in this map. */
1.92 + size_t count;
1.93 +};
1.94 +
1.95 +/** Structure for a key of a UcxMap. */
1.96 +struct UcxKey {
1.97 + /** The key data. */
1.98 + void *data;
1.99 + /** The length of the key data. */
1.100 + size_t len;
1.101 + /** The hash value of the key data. */
1.102 + int hash;
1.103 +};
1.104 +
1.105 +/** Structure for an element of a UcxMap. */
1.106 +struct UcxMapElement {
1.107 + /** The value data. */
1.108 + void *data;
1.109 +
1.110 + /** A pointer to the next element in the current list. */
1.111 + UcxMapElement *next;
1.112 +
1.113 + /** The corresponding key. */
1.114 + UcxKey key;
1.115 +};
1.116 +
1.117 +/** Structure for an iterator over a UcxMap. */
1.118 +struct UcxMapIterator {
1.119 + /** The map to iterate over. */
1.120 + UcxMap *map;
1.121 +
1.122 + /** The current map element. */
1.123 + UcxMapElement *cur;
1.124 +
1.125 + /**
1.126 + * The current index of the element list array.
1.127 + * <b>Attention: </b> this is <b>NOT</b> the element index! Do <b>NOT</b>
1.128 + * manually iterate over the map by increasing this index. Use
1.129 + * ucx_map_iter_next().
1.130 + * @see UcxMap.map*/
1.131 + size_t index;
1.132 +};
1.133 +
1.134 +/**
1.135 + * Creates a new hash map with the specified size.
1.136 + * @param size the size of the hash map
1.137 + * @return a pointer to the new hash map
1.138 + */
1.139 +UcxMap *ucx_map_new(size_t size);
1.140 +
1.141 +/**
1.142 + * Creates a new hash map with the specified size using a UcxAllocator.
1.143 + * @param allocator the allocator to use
1.144 + * @param size the size of the hash map
1.145 + * @return a pointer to the new hash map
1.146 + */
1.147 +UcxMap *ucx_map_new_a(UcxAllocator *allocator, size_t size);
1.148 +
1.149 +/**
1.150 + * Frees a hash map.
1.151 + *
1.152 + * <b>Note:</b> the contents are <b>not</b> freed, use ucx_map_free_content()
1.153 + * before calling this function to achieve that.
1.154 + *
1.155 + * @param map the map to be freed
1.156 + * @see ucx_map_free_content()
1.157 + */
1.158 +void ucx_map_free(UcxMap *map);
1.159 +
1.160 +/**
1.161 + * Frees the contents of a hash map.
1.162 + *
1.163 + * This is a convenience function that iterates over the map and passes all
1.164 + * values to the specified destructor function (e.g. stdlib free()).
1.165 + *
1.166 + * You must ensure, that it is valid to pass each value in the map to the same
1.167 + * destructor function.
1.168 + *
1.169 + * You should free or clear the map afterwards, as the contents will be invalid.
1.170 + *
1.171 + * @param map for which the contents shall be freed
1.172 + * @param destr pointer to the destructor function
1.173 + * @see ucx_map_free()
1.174 + * @see ucx_map_clear()
1.175 + */
1.176 +void ucx_map_free_content(UcxMap *map, ucx_destructor destr);
1.177 +
1.178 +/**
1.179 + * Clears a hash map.
1.180 + *
1.181 + * <b>Note:</b> the contents are <b>not</b> freed, use ucx_map_free_content()
1.182 + * before calling this function to achieve that.
1.183 + *
1.184 + * @param map the map to be cleared
1.185 + * @see ucx_map_free_content()
1.186 + */
1.187 +void ucx_map_clear(UcxMap *map);
1.188 +
1.189 +
1.190 +/**
1.191 + * Copies contents from a map to another map using a copy function.
1.192 + *
1.193 + * <b>Note:</b> The destination map does not need to be empty. However, if it
1.194 + * contains data with keys that are also present in the source map, the contents
1.195 + * are overwritten.
1.196 + *
1.197 + * @param from the source map
1.198 + * @param to the destination map
1.199 + * @param fnc the copy function or <code>NULL</code> if the pointer address
1.200 + * shall be copied
1.201 + * @param data additional data for the copy function
1.202 + * @return 0 on success or a non-zero value on memory allocation errors
1.203 + */
1.204 +int ucx_map_copy(UcxMap *restrict from, UcxMap *restrict to,
1.205 + copy_func fnc, void *data);
1.206 +
1.207 +/**
1.208 + * Clones the map and rehashes if necessary.
1.209 + *
1.210 + * <b>Note:</b> In contrast to ucx_map_rehash() the load factor is irrelevant.
1.211 + * This function <i>always</i> ensures a new UcxMap.size of at least
1.212 + * 2.5*UcxMap.count.
1.213 + *
1.214 + * @param map the map to clone
1.215 + * @param fnc the copy function to use or <code>NULL</code> if the new and
1.216 + * the old map shall share the data pointers
1.217 + * @param data additional data for the copy function
1.218 + * @return the cloned map
1.219 + * @see ucx_map_copy()
1.220 + */
1.221 +UcxMap *ucx_map_clone(UcxMap *map, copy_func fnc, void *data);
1.222 +
1.223 +/**
1.224 + * Increases size of the hash map, if necessary.
1.225 + *
1.226 + * The load value is 0.75*UcxMap.size. If the element count exceeds the load
1.227 + * value, the map needs to be rehashed. Otherwise no action is performed and
1.228 + * this function simply returns 0.
1.229 + *
1.230 + * The rehashing process ensures, that the UcxMap.size is at least
1.231 + * 2.5*UcxMap.count. So there is enough room for additional elements without
1.232 + * the need of another soon rehashing.
1.233 + *
1.234 + * You can use this function to dramatically increase access performance.
1.235 + *
1.236 + * @param map the map to rehash
1.237 + * @return 1, if a memory allocation error occurred, 0 otherwise
1.238 + */
1.239 +int ucx_map_rehash(UcxMap *map);
1.240 +
1.241 +/**
1.242 + * Puts a key/value-pair into the map.
1.243 + *
1.244 + * @param map the map
1.245 + * @param key the key
1.246 + * @param value the value
1.247 + * @return 0 on success, non-zero value on failure
1.248 + */
1.249 +int ucx_map_put(UcxMap *map, UcxKey key, void *value);
1.250 +
1.251 +/**
1.252 + * Retrieves a value by using a key.
1.253 + *
1.254 + * @param map the map
1.255 + * @param key the key
1.256 + * @return the value
1.257 + */
1.258 +void* ucx_map_get(UcxMap *map, UcxKey key);
1.259 +
1.260 +/**
1.261 + * Removes a key/value-pair from the map by using the key.
1.262 + *
1.263 + * @param map the map
1.264 + * @param key the key
1.265 + * @return the removed value
1.266 + */
1.267 +void* ucx_map_remove(UcxMap *map, UcxKey key);
1.268 +
1.269 +/**
1.270 + * Shorthand for putting data with a sstr_t key into the map.
1.271 + * @param map the map
1.272 + * @param key the key
1.273 + * @param value the value
1.274 + * @return 0 on success, non-zero value on failure
1.275 + * @see ucx_map_put()
1.276 + */
1.277 +#define ucx_map_sstr_put(map, key, value) \
1.278 + ucx_map_put(map, ucx_key(key.ptr, key.length), (void*)value)
1.279 +
1.280 +/**
1.281 + * Shorthand for putting data with a C string key into the map.
1.282 + * @param map the map
1.283 + * @param key the key
1.284 + * @param value the value
1.285 + * @return 0 on success, non-zero value on failure
1.286 + * @see ucx_map_put()
1.287 + */
1.288 +#define ucx_map_cstr_put(map, key, value) \
1.289 + ucx_map_put(map, ucx_key((void*)key, strlen(key)), (void*)value)
1.290 +
1.291 +/**
1.292 + * Shorthand for putting data with an integer key into the map.
1.293 + * @param map the map
1.294 + * @param key the key
1.295 + * @param value the value
1.296 + * @return 0 on success, non-zero value on failure
1.297 + * @see ucx_map_put()
1.298 + */
1.299 +#define ucx_map_int_put(map, key, value) \
1.300 + ucx_map_put(map, ucx_key((void*)&key, sizeof(key)), (void*)value)
1.301 +
1.302 +/**
1.303 + * Shorthand for getting data from the map with a sstr_t key.
1.304 + * @param map the map
1.305 + * @param key the key
1.306 + * @return the value
1.307 + * @see ucx_map_get()
1.308 + */
1.309 +#define ucx_map_sstr_get(map, key) \
1.310 + ucx_map_get(map, ucx_key(key.ptr, key.length))
1.311 +
1.312 +/**
1.313 + * Shorthand for getting data from the map with a C string key.
1.314 + * @param map the map
1.315 + * @param key the key
1.316 + * @return the value
1.317 + * @see ucx_map_get()
1.318 + */
1.319 +#define ucx_map_cstr_get(map, key) \
1.320 + ucx_map_get(map, ucx_key((void*)key, strlen(key)))
1.321 +
1.322 +/**
1.323 + * Shorthand for getting data from the map with an integer key.
1.324 + * @param map the map
1.325 + * @param key the key
1.326 + * @return the value
1.327 + * @see ucx_map_get()
1.328 + */
1.329 +#define ucx_map_int_get(map, key) \
1.330 + ucx_map_get(map, ucx_key((void*)&key, sizeof(int)))
1.331 +
1.332 +/**
1.333 + * Shorthand for removing data from the map with a sstr_t key.
1.334 + * @param map the map
1.335 + * @param key the key
1.336 + * @return the removed value
1.337 + * @see ucx_map_remove()
1.338 + */
1.339 +#define ucx_map_sstr_remove(map, key) \
1.340 + ucx_map_remove(map, ucx_key(key.ptr, key.length))
1.341 +
1.342 +/**
1.343 + * Shorthand for removing data from the map with a C string key.
1.344 + * @param map the map
1.345 + * @param key the key
1.346 + * @return the removed value
1.347 + * @see ucx_map_remove()
1.348 + */
1.349 +#define ucx_map_cstr_remove(map, key) \
1.350 + ucx_map_remove(map, ucx_key((void*)key, strlen(key)))
1.351 +
1.352 +/**
1.353 + * Shorthand for removing data from the map with an integer key.
1.354 + * @param map the map
1.355 + * @param key the key
1.356 + * @return the removed value
1.357 + * @see ucx_map_remove()
1.358 + */
1.359 +#define ucx_map_int_remove(map, key) \
1.360 + ucx_map_remove(map, ucx_key((void*)&key, sizeof(key)))
1.361 +
1.362 +/**
1.363 + * Creates a UcxKey based on the given data.
1.364 + *
1.365 + * This function implicitly computes the hash.
1.366 + *
1.367 + * @param data the data for the key
1.368 + * @param len the length of the data
1.369 + * @return a UcxKey with implicitly computed hash
1.370 + * @see ucx_hash()
1.371 + */
1.372 +UcxKey ucx_key(void *data, size_t len);
1.373 +
1.374 +/**
1.375 + * Computes a murmur hash-2.
1.376 + *
1.377 + * @param data the data to hash
1.378 + * @param len the length of the data
1.379 + * @return the murmur hash-2 of the data
1.380 + */
1.381 +int ucx_hash(const char *data, size_t len);
1.382 +
1.383 +/**
1.384 + * Creates an iterator for a map.
1.385 + *
1.386 + * <b>Note:</b> A UcxMapIterator iterates over all elements in all element
1.387 + * lists successively. Therefore the order highly depends on the key hashes and
1.388 + * may vary under different map sizes. So generally you may <b>NOT</b> rely on
1.389 + * the iteration order.
1.390 + *
1.391 + * <b>Note:</b> The iterator is <b>NOT</b> initialized. You need to call
1.392 + * ucx_map_iter_next() at least once before accessing any information. However,
1.393 + * it is not recommended to access the fields of a UcxMapIterator directly.
1.394 + *
1.395 + * @param map the map to create the iterator for
1.396 + * @return an iterator initialized on the first element of the
1.397 + * first element list
1.398 + * @see ucx_map_iter_next()
1.399 + */
1.400 +UcxMapIterator ucx_map_iterator(UcxMap *map);
1.401 +
1.402 +/**
1.403 + * Proceeds to the next element of the map (if any).
1.404 + *
1.405 + * Subsequent calls on the same iterator proceed to the next element and
1.406 + * store the key/value-pair into the memory specified as arguments of this
1.407 + * function.
1.408 + *
1.409 + * If no further elements are found, this function returns zero and leaves the
1.410 + * last found key/value-pair in memory.
1.411 + *
1.412 + * @param iterator the iterator to use
1.413 + * @param key a pointer to the memory where to store the key
1.414 + * @param value a pointer to the memory where to store the value
1.415 + * @return 1, if another element was found, 0 if all elements has been processed
1.416 + * @see ucx_map_iterator()
1.417 + */
1.418 +int ucx_map_iter_next(UcxMapIterator *iterator, UcxKey *key, void **value);
1.419 +
1.420 +
1.421 +#ifdef __cplusplus
1.422 +}
1.423 +#endif
1.424 +
1.425 +#endif /* UCX_MAP_H */
1.426 +
