1 /* MIT License
2  *
3  * Copyright (c) 2023 Brad House
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a copy
6  * of this software and associated documentation files (the "Software"), to deal
7  * in the Software without restriction, including without limitation the rights
8  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9  * copies of the Software, and to permit persons to whom the Software is
10  * furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice (including the next
13  * paragraph) shall be included in all copies or substantial portions of the
14  * Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  *
24  * SPDX-License-Identifier: MIT
25  */
26 #ifndef __ARES__HTABLE_STVP_H
27 #define __ARES__HTABLE_STVP_H
28 
29 /*! \addtogroup ares__htable_szvp HashTable with size_t Key and void pointer
30  * Value
31  *
32  * This data structure wraps the base ares__htable data structure in order to
33  * split the key and value data types as size_t and void pointer, respectively.
34  *
35  * Average time complexity:
36  *  - Insert: O(1)
37  *  - Search: O(1)
38  *  - Delete: O(1)
39  *
40  * @{
41  */
42 
43 struct ares__htable_szvp;
44 
45 /*! Opaque data type for size_t key, void pointer hash table implementation */
46 typedef struct ares__htable_szvp ares__htable_szvp_t;
47 
48 /*! Callback to free value stored in hashtable
49  *
50  *  \param[in] val  user-supplied value
51  */
52 typedef void                     (*ares__htable_szvp_val_free_t)(void *val);
53 
54 /*! Destroy hashtable
55  *
56  *  \param[in] htable  Initialized hashtable
57  */
58 void ares__htable_szvp_destroy(ares__htable_szvp_t *htable);
59 
60 /*! Create size_t key, void pointer value hash table
61  *
62  *  \param[in] val_free  Optional. Call back to free user-supplied value.  If
63  *                       NULL it is expected the caller will clean up any user
64  *                       supplied values.
65  */
66 ares__htable_szvp_t           *
67   ares__htable_szvp_create(ares__htable_szvp_val_free_t val_free);
68 
69 /*! Insert key/value into hash table
70  *
71  *  \param[in] htable Initialized hash table
72  *  \param[in] key    key to associate with value
73  *  \param[in] val    value to store (takes ownership). May be NULL.
74  *  \return ARES_TRUE on success, ARES_FALSE on failure or out of memory
75  */
76 ares_bool_t ares__htable_szvp_insert(ares__htable_szvp_t *htable, size_t key,
77                                      void *val);
78 
79 /*! Retrieve value from hashtable based on key
80  *
81  *  \param[in]  htable  Initialized hash table
82  *  \param[in]  key     key to use to search
83  *  \param[out] val     Optional.  Pointer to store value.
84  *  \return ARES_TRUE on success, ARES_FALSE on failure
85  */
86 ares_bool_t ares__htable_szvp_get(const ares__htable_szvp_t *htable, size_t key,
87                                   void **val);
88 
89 /*! Retrieve value from hashtable directly as return value.  Caveat to this
90  *  function over ares__htable_szvp_get() is that if a NULL value is stored
91  *  you cannot determine if the key is not found or the value is NULL.
92  *
93  *  \param[in] htable  Initialized hash table
94  *  \param[in] key     key to use to search
95  *  \return value associated with key in hashtable or NULL
96  */
97 void       *ares__htable_szvp_get_direct(const ares__htable_szvp_t *htable,
98                                          size_t                     key);
99 
100 /*! Remove a value from the hashtable by key
101  *
102  *  \param[in] htable  Initialized hash table
103  *  \param[in] key     key to use to search
104  *  \return ARES_TRUE if found, ARES_FALSE if not
105  */
106 ares_bool_t ares__htable_szvp_remove(ares__htable_szvp_t *htable, size_t key);
107 
108 /*! Retrieve the number of keys stored in the hash table
109  *
110  *  \param[in] htable  Initialized hash table
111  *  \return count
112  */
113 size_t      ares__htable_szvp_num_keys(const ares__htable_szvp_t *htable);
114 
115 /*! @} */
116 
117 #endif /* __ARES__HTABLE_STVP_H */
118