24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
26 * POSSIBILITY OF SUCH DAMAGE. |
26 * POSSIBILITY OF SUCH DAMAGE. |
27 */ |
27 */ |
28 /** |
28 /** |
29 * \file hash_map.h |
29 * @file hash_map.h |
30 * \brief Hash map implementation. |
30 * @brief Hash map implementation. |
31 * \author Mike Becker |
31 * @author Mike Becker |
32 * \author Olaf Wintermann |
32 * @author Olaf Wintermann |
33 * \copyright 2-Clause BSD License |
33 * @copyright 2-Clause BSD License |
34 */ |
34 */ |
35 |
35 |
36 #ifndef UCX_HASH_MAP_H |
36 #ifndef UCX_HASH_MAP_H |
37 #define UCX_HASH_MAP_H |
37 #define UCX_HASH_MAP_H |
38 |
38 |
65 |
65 |
66 |
66 |
67 /** |
67 /** |
68 * Creates a new hash map with the specified number of buckets. |
68 * Creates a new hash map with the specified number of buckets. |
69 * |
69 * |
70 * If \p buckets is zero, an implementation defined default will be used. |
70 * If @p buckets is zero, an implementation defined default will be used. |
71 * |
71 * |
72 * If \p elem_size is CX_STORE_POINTERS, the created map will be created as if |
72 * If @p elem_size is CX_STORE_POINTERS, the created map will be created as if |
73 * cxMapStorePointers() was called immediately after creation. |
73 * cxMapStorePointers() was called immediately after creation. |
74 * |
74 * |
75 * @note Iterators provided by this hash map implementation provide the remove operation. |
75 * @note Iterators provided by this hash map implementation provide the remove operation. |
76 * The index value of an iterator is incremented when the iterator advanced without removal. |
76 * The index value of an iterator is incremented when the iterator advanced without removal. |
77 * In other words, when the iterator is finished, \c index==size . |
77 * In other words, when the iterator is finished, @c index==size . |
78 * |
78 * |
79 * @param allocator the allocator to use |
79 * @param allocator the allocator to use |
80 * (if \c NULL, a default stdlib allocator will be used) |
80 * (if @c NULL, a default stdlib allocator will be used) |
81 * @param itemsize the size of one element |
81 * @param itemsize the size of one element |
82 * @param buckets the initial number of buckets in this hash map |
82 * @param buckets the initial number of buckets in this hash map |
83 * @return a pointer to the new hash map |
83 * @return a pointer to the new hash map |
84 */ |
84 */ |
85 cx_attr_nodiscard |
85 cx_attr_nodiscard |
92 ); |
92 ); |
93 |
93 |
94 /** |
94 /** |
95 * Creates a new hash map with a default number of buckets. |
95 * Creates a new hash map with a default number of buckets. |
96 * |
96 * |
97 * If \p elem_size is CX_STORE_POINTERS, the created map will be created as if |
97 * If @p elem_size is CX_STORE_POINTERS, the created map will be created as if |
98 * cxMapStorePointers() was called immediately after creation. |
98 * cxMapStorePointers() was called immediately after creation. |
99 * |
99 * |
100 * @note Iterators provided by this hash map implementation provide the remove operation. |
100 * @note Iterators provided by this hash map implementation provide the remove operation. |
101 * The index value of an iterator is incremented when the iterator advanced without removal. |
101 * The index value of an iterator is incremented when the iterator advanced without removal. |
102 * In other words, when the iterator is finished, \c index==size . |
102 * In other words, when the iterator is finished, @c index==size . |
103 * |
103 * |
104 * @param itemsize the size of one element |
104 * @param itemsize (@c size_t) the size of one element |
105 * @return a pointer to the new hash map |
105 * @return (@c CxMap*) a pointer to the new hash map |
106 */ |
106 */ |
107 #define cxHashMapCreateSimple(itemsize) \ |
107 #define cxHashMapCreateSimple(itemsize) cxHashMapCreate(NULL, itemsize, 0) |
108 cxHashMapCreate(cxDefaultAllocator, itemsize, 0) |
|
109 |
108 |
110 /** |
109 /** |
111 * Increases the number of buckets, if necessary. |
110 * Increases the number of buckets, if necessary. |
112 * |
111 * |
113 * The load threshold is \c 0.75*buckets. If the element count exceeds the load |
112 * The load threshold is @c 0.75*buckets. If the element count exceeds the load |
114 * threshold, the map will be rehashed. Otherwise, no action is performed and |
113 * threshold, the map will be rehashed. Otherwise, no action is performed and |
115 * this function simply returns 0. |
114 * this function simply returns 0. |
116 * |
115 * |
117 * The rehashing process ensures, that the number of buckets is at least |
116 * The rehashing process ensures, that the number of buckets is at least |
118 * 2.5 times the element count. So there is enough room for additional |
117 * 2.5 times the element count. So there is enough room for additional |
121 * You can use this function after filling a map to increase access performance. |
120 * You can use this function after filling a map to increase access performance. |
122 * |
121 * |
123 * @note If the specified map is not a hash map, the behavior is undefined. |
122 * @note If the specified map is not a hash map, the behavior is undefined. |
124 * |
123 * |
125 * @param map the map to rehash |
124 * @param map the map to rehash |
126 * @return zero on success, non-zero if a memory allocation error occurred |
125 * @retval zero success |
|
126 * @retval non-zero if a memory allocation error occurred |
127 */ |
127 */ |
128 cx_attr_nonnull |
128 cx_attr_nonnull |
129 int cxMapRehash(CxMap *map); |
129 int cxMapRehash(CxMap *map); |
130 |
130 |
131 |
131 |