xref: /third_party/node/deps/cares/src/lib/ares__htable_strvp.h

/* MIT License
 *
 * Copyright (c) 2023 Brad House
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * SPDX-License-Identifier: MIT
 */
#ifndef __ARES__HTABLE_STRVP_H
#define __ARES__HTABLE_STRVP_H

/*! \addtogroup ares__htable_strvp HashTable with string Key and void pointer
 * Value
 *
 * This data structure wraps the base ares__htable data structure in order to
 * split the key and value data types as string and void pointer, respectively.
 *
 * Average time complexity:
 *  - Insert: O(1)
 *  - Search: O(1)
 *  - Delete: O(1)
 *
 * @{
 */

struct ares__htable_strvp;

/*! Opaque data type for size_t key, void pointer hash table implementation */
typedef struct ares__htable_strvp ares__htable_strvp_t;

/*! Callback to free value stored in hashtable
 *
 *  \param[in] val  user-supplied value
 */
typedef void                      (*ares__htable_strvp_val_free_t)(void *val);

/*! Destroy hashtable
 *
 *  \param[in] htable  Initialized hashtable
 */
void ares__htable_strvp_destroy(ares__htable_strvp_t *htable);

/*! Create string, void pointer value hash table
 *
 *  \param[in] val_free  Optional. Call back to free user-supplied value.  If
 *                       NULL it is expected the caller will clean up any user
 *                       supplied values.
 */
ares__htable_strvp_t           *
  ares__htable_strvp_create(ares__htable_strvp_val_free_t val_free);

/*! Insert key/value into hash table
 *
 *  \param[in] htable Initialized hash table
 *  \param[in] key    key to associate with value
 *  \param[in] val    value to store (takes ownership). May be NULL.
 *  \return ARES_TRUE on success, ARES_FALSE on failure or out of memory
 */
ares_bool_t ares__htable_strvp_insert(ares__htable_strvp_t *htable,
                                      const char *key, void *val);

/*! Retrieve value from hashtable based on key
 *
 *  \param[in]  htable  Initialized hash table
 *  \param[in]  key     key to use to search
 *  \param[out] val     Optional.  Pointer to store value.
 *  \return ARES_TRUE on success, ARES_FALSE on failure
 */
ares_bool_t ares__htable_strvp_get(const ares__htable_strvp_t *htable,
                                   const char *key, void **val);

/*! Retrieve value from hashtable directly as return value.  Caveat to this
 *  function over ares__htable_strvp_get() is that if a NULL value is stored
 *  you cannot determine if the key is not found or the value is NULL.
 *
 *  \param[in] htable  Initialized hash table
 *  \param[in] key     key to use to search
 *  \return value associated with key in hashtable or NULL
 */
void       *ares__htable_strvp_get_direct(const ares__htable_strvp_t *htable,
                                          const char                 *key);

/*! Remove a value from the hashtable by key
 *
 *  \param[in] htable  Initialized hash table
 *  \param[in] key     key to use to search
 *  \return ARES_TRUE if found, ARES_FALSE if not
 */
ares_bool_t ares__htable_strvp_remove(ares__htable_strvp_t *htable,
                                      const char           *key);

/*! Retrieve the number of keys stored in the hash table
 *
 *  \param[in] htable  Initialized hash table
 *  \return count
 */
size_t      ares__htable_strvp_num_keys(const ares__htable_strvp_t *htable);

/*! @} */

#endif /* __ARES__HTABLE_STVP_H */