Annotation of embedaddon/strongswan/src/libstrongswan/collections/hashtable.h, revision 1.1
1.1 ! misho 1: /*
! 2: * Copyright (C) 2008-2012 Tobias Brunner
! 3: * HSR Hochschule fuer Technik Rapperswil
! 4: *
! 5: * This program is free software; you can redistribute it and/or modify it
! 6: * under the terms of the GNU General Public License as published by the
! 7: * Free Software Foundation; either version 2 of the License, or (at your
! 8: * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
! 9: *
! 10: * This program is distributed in the hope that it will be useful, but
! 11: * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
! 12: * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
! 13: * for more details.
! 14: */
! 15:
! 16: /**
! 17: * @defgroup hashtable hashtable
! 18: * @{ @ingroup collections
! 19: */
! 20:
! 21: #ifndef HASHTABLE_H_
! 22: #define HASHTABLE_H_
! 23:
! 24: #include <collections/enumerator.h>
! 25:
! 26: typedef struct hashtable_t hashtable_t;
! 27:
! 28: /**
! 29: * Prototype for a function that computes the hash code from the given key.
! 30: *
! 31: * @param key key to hash
! 32: * @return hash code
! 33: */
! 34: typedef u_int (*hashtable_hash_t)(const void *key);
! 35:
! 36: /**
! 37: * Hashtable hash function calculation the hash solely based on the key pointer.
! 38: *
! 39: * @param key key to hash
! 40: * @return hash of key
! 41: */
! 42: u_int hashtable_hash_ptr(const void *key);
! 43:
! 44: /**
! 45: * Hashtable hash function calculation the hash for char* keys.
! 46: *
! 47: * @param key key to hash, a char*
! 48: * @return hash of key
! 49: */
! 50: u_int hashtable_hash_str(const void *key);
! 51:
! 52: /**
! 53: * Prototype for a function that compares the two keys for equality.
! 54: *
! 55: * @param key first key (the one we are looking for)
! 56: * @param other_key second key
! 57: * @return TRUE if the keys are equal
! 58: */
! 59: typedef bool (*hashtable_equals_t)(const void *key, const void *other_key);
! 60:
! 61: /**
! 62: * Hashtable equals function comparing pointers.
! 63: *
! 64: * @param key key to compare
! 65: * @param other_key other key to compare
! 66: * @return TRUE if key == other_key
! 67: */
! 68: bool hashtable_equals_ptr(const void *key, const void *other_key);
! 69:
! 70: /**
! 71: * Hashtable equals function comparing char* keys.
! 72: *
! 73: * @param key key to compare
! 74: * @param other_key other key to compare
! 75: * @return TRUE if streq(key, other_key)
! 76: */
! 77: bool hashtable_equals_str(const void *key, const void *other_key);
! 78:
! 79: /**
! 80: * Class implementing a hash table.
! 81: *
! 82: * General purpose hash table. This hash table is not synchronized.
! 83: */
! 84: struct hashtable_t {
! 85:
! 86: /**
! 87: * Create an enumerator over the hash table key/value pairs.
! 88: *
! 89: * @return enumerator over (void *key, void *value)
! 90: */
! 91: enumerator_t *(*create_enumerator) (hashtable_t *this);
! 92:
! 93: /**
! 94: * Adds the given value with the given key to the hash table, if there
! 95: * exists no entry with that key. NULL is returned in this case.
! 96: * Otherwise the existing value is replaced and the function returns the
! 97: * old value.
! 98: *
! 99: * @param key the key to store
! 100: * @param value the value to store
! 101: * @return NULL if no item was replaced, the old value otherwise
! 102: */
! 103: void *(*put) (hashtable_t *this, const void *key, void *value);
! 104:
! 105: /**
! 106: * Returns the value with the given key, if the hash table contains such an
! 107: * entry, otherwise NULL is returned.
! 108: *
! 109: * @param key the key of the requested value
! 110: * @return the value, NULL if not found
! 111: */
! 112: void *(*get) (hashtable_t *this, const void *key);
! 113:
! 114: /**
! 115: * Returns the value with a matching key, if the hash table contains such an
! 116: * entry, otherwise NULL is returned.
! 117: *
! 118: * Compared to get() the given match function is used to compare the keys
! 119: * for equality. The hash function does have to be devised properly in
! 120: * order to make this work if the match function compares keys differently
! 121: * than the equals function provided to the constructor. This basically
! 122: * allows to enumerate all entries with the same hash value.
! 123: *
! 124: * @param key the key to match against
! 125: * @param match match function to be used when comparing keys
! 126: * @return the value, NULL if not found
! 127: */
! 128: void *(*get_match) (hashtable_t *this, const void *key,
! 129: hashtable_equals_t match);
! 130:
! 131: /**
! 132: * Removes the value with the given key from the hash table and returns the
! 133: * removed value (or NULL if no such value existed).
! 134: *
! 135: * @param key the key of the value to remove
! 136: * @return the removed value, NULL if not found
! 137: */
! 138: void *(*remove) (hashtable_t *this, const void *key);
! 139:
! 140: /**
! 141: * Removes the key and value pair from the hash table at which the given
! 142: * enumerator currently points.
! 143: *
! 144: * @param enumerator enumerator, from create_enumerator
! 145: */
! 146: void (*remove_at) (hashtable_t *this, enumerator_t *enumerator);
! 147:
! 148: /**
! 149: * Gets the number of items in the hash table.
! 150: *
! 151: * @return number of items
! 152: */
! 153: u_int (*get_count) (hashtable_t *this);
! 154:
! 155: /**
! 156: * Destroys a hash table object.
! 157: */
! 158: void (*destroy) (hashtable_t *this);
! 159:
! 160: /**
! 161: * Destroys a hash table object and calls the given function for each
! 162: * item and its key in the hash table.
! 163: *
! 164: * @param function function to call on each item and key
! 165: */
! 166: void (*destroy_function)(hashtable_t *this,
! 167: void (*)(void *val, const void *key));
! 168: };
! 169:
! 170: /**
! 171: * Creates an empty hash table object.
! 172: *
! 173: * @param hash hash function
! 174: * @param equals equals function
! 175: * @param capacity initial capacity
! 176: * @return hashtable_t object.
! 177: */
! 178: hashtable_t *hashtable_create(hashtable_hash_t hash, hashtable_equals_t equals,
! 179: u_int capacity);
! 180:
! 181: #endif /** HASHTABLE_H_ @}*/
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