ucx: src/cx/hash_map.h@8603709932b9 (annotated)

src/cx/hash_map.h@8603709932b9 (annotated)

src/cx/hash_map.h

Fri, 27 May 2022 14:02:14 +0200

author: Mike Becker <universe@uap-core.de>
date: Fri, 27 May 2022 14:02:14 +0200
changeset 559: 8603709932b9
parent 550: 89b2a83728b1
child 562: fd3368c20413
permissions: -rw-r--r--

corrects documentation of iterator behavior

 /*
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
  *
  * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *   1. Redistributions of source code must retain the above copyright
  *      notice, this list of conditions and the following disclaimer.
  *
  *   2. Redistributions in binary form must reproduce the above copyright
  *      notice, this list of conditions and the following disclaimer in the
  *      documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 /**
  * \file map.h
  * \brief Interface for map implementations.
  * \author Mike Becker
  * \author Olaf Wintermann
  * \version 3.0
  * \copyright 2-Clause BSD License
  */
 #ifndef UCX_HASH_MAP_H
 #define UCX_HASH_MAP_H
 #include "map.h"
 #ifdef __cplusplus
 extern "C" {
 #endif
 /** Internal structure for a key within a hash map. */
 struct cx_hash_map_key_s {
     /** The key data. */
     unsigned char *data;
     /**
      * The key data length.
      */
     size_t len;
     /** The hash value of the key data. */
     unsigned hash;
 };
 /** Internal structure for an element of a hash map. */
 struct cx_hash_map_element_s {
     /** The value data. */
     void *data;
     /** A pointer to the next element in the current bucket. */
     struct cx_hash_map_element_s *next;
     /** The corresponding key. */
     struct cx_hash_map_key_s key;
 };
 /**
  * Internal structure for a hash map.
  */
 struct cx_hash_map_s {
     /**
      * Base structure for maps.
      */
     struct cx_map_s base;
     /**
      * The buckets of this map, each containing a linked list of elements.
      */
     struct cx_hash_map_element_s **buckets;
     /**
      * The number of buckets.
      */
     size_t bucket_count;
 };
 /**
  * Creates a new hash map with the specified number of buckets.
  *
  * If \p buckets is zero, an implementation defined default will be used.
  *
  * @note Iterators provided by this hash map implementation provide the remove operation.
  * The index value of an iterator is the incremented when the iterator advanced without removal.
  * In other words, when the iterator is finished, \c index==size .
  *
  * @param allocator the allocator to use
  * @param buckets the initial number of buckets in this hash map
  * @return a pointer to the new hash map
  */
 __attribute__((__nonnull__, __warn_unused_result__))
 CxMap *cxHashMapCreate(
         CxAllocator *allocator,
         size_t buckets
 );
 /**
  * Increases the number of buckets, if necessary.
  *
  * The load value is \c loadFactor*buckets. If the element count exceeds the load
  * value, the map needs to be rehashed. Otherwise, no action is performed and
  * this function simply returns 0.
  *
  * The rehashing process ensures, that the number of buckets is at least
  * \p bucketFactor times the number of stored items. So there is enough room for additional
  * elements without the need of another soon rehashing.
  *
  * You can use this function after filling a map to dramatically increase access performance.
  *
  * @note If the specified map is not a hash map, the behavior is undefined.
  *
  * @param map the map to rehash
  * @param loadFactor a percentage threshold for the load of the map
  * @param bucketFactor a factor for the number of buckets that shall be available after rehashing
  * @return zero on success, non-zero if a memory allocation error occurred
  */
 __attribute__((__nonnull__))
 int cxMapRehash2(
         CxMap *map,
         float loadFactor,
         float bucketFactor
 );
 /**
  * Rehashes the map with load factor 0.75 and bucket factor 2.5.
  *
  * @param map the map to rehash
  * @return zero on success, non-zero if a memory allocation error occurred
  * @see cxMapRehash2()
  */
 __attribute__((__nonnull__))
 static inline int cxMapRehash(CxMap *map) {
     return cxMapRehash2(map, 0.75f, 2.5f);
 }
 #ifdef __cplusplus
 } // extern "C"
 #endif
 #endif // UCX_HASH_MAP_H

Mercurial > hg > ucx / annotate

src/cx/hash_map.h@8603709932b9 (annotated)

src/cx/hash_map.h