/jansson/src/hashtable.h
http://github.com/nicolasff/webdis · C Header · 207 lines · 47 code · 22 blank · 138 comment · 0 complexity · f76887273f80646abf95a6fe36a92827 MD5 · raw file
- /*
- * Copyright (c) 2009, 2010 Petri Lehtinen <petri@digip.org>
- *
- * This library is free software; you can redistribute it and/or modify
- * it under the terms of the MIT license. See LICENSE for details.
- */
- #ifndef HASHTABLE_H
- #define HASHTABLE_H
- typedef size_t (*key_hash_fn)(const void *key);
- typedef int (*key_cmp_fn)(const void *key1, const void *key2);
- typedef void (*free_fn)(void *key);
- struct hashtable_list {
- struct hashtable_list *prev;
- struct hashtable_list *next;
- };
- struct hashtable_pair {
- void *key;
- void *value;
- size_t hash;
- struct hashtable_list list;
- };
- struct hashtable_bucket {
- struct hashtable_list *first;
- struct hashtable_list *last;
- };
- typedef struct hashtable {
- size_t size;
- struct hashtable_bucket *buckets;
- size_t num_buckets; /* index to primes[] */
- struct hashtable_list list;
- key_hash_fn hash_key;
- key_cmp_fn cmp_keys; /* returns non-zero for equal keys */
- free_fn free_key;
- free_fn free_value;
- } hashtable_t;
- /**
- * hashtable_create - Create a hashtable object
- *
- * @hash_key: The key hashing function
- * @cmp_keys: The key compare function. Returns non-zero for equal and
- * zero for unequal unequal keys
- * @free_key: If non-NULL, called for a key that is no longer referenced.
- * @free_value: If non-NULL, called for a value that is no longer referenced.
- *
- * Returns a new hashtable object that should be freed with
- * hashtable_destroy when it's no longer used, or NULL on failure (out
- * of memory).
- */
- hashtable_t *hashtable_create(key_hash_fn hash_key, key_cmp_fn cmp_keys,
- free_fn free_key, free_fn free_value);
- /**
- * hashtable_destroy - Destroy a hashtable object
- *
- * @hashtable: The hashtable
- *
- * Destroys a hashtable created with hashtable_create().
- */
- void hashtable_destroy(hashtable_t *hashtable);
- /**
- * hashtable_init - Initialize a hashtable object
- *
- * @hashtable: The (statically allocated) hashtable object
- * @hash_key: The key hashing function
- * @cmp_keys: The key compare function. Returns non-zero for equal and
- * zero for unequal unequal keys
- * @free_key: If non-NULL, called for a key that is no longer referenced.
- * @free_value: If non-NULL, called for a value that is no longer referenced.
- *
- * Initializes a statically allocated hashtable object. The object
- * should be cleared with hashtable_close when it's no longer used.
- *
- * Returns 0 on success, -1 on error (out of memory).
- */
- int hashtable_init(hashtable_t *hashtable,
- key_hash_fn hash_key, key_cmp_fn cmp_keys,
- free_fn free_key, free_fn free_value);
- /**
- * hashtable_close - Release all resources used by a hashtable object
- *
- * @hashtable: The hashtable
- *
- * Destroys a statically allocated hashtable object.
- */
- void hashtable_close(hashtable_t *hashtable);
- /**
- * hashtable_set - Add/modify value in hashtable
- *
- * @hashtable: The hashtable object
- * @key: The key
- * @value: The value
- *
- * If a value with the given key already exists, its value is replaced
- * with the new value.
- *
- * Key and value are "stealed" in the sense that hashtable frees them
- * automatically when they are no longer used. The freeing is
- * accomplished by calling free_key and free_value functions that were
- * supplied to hashtable_new. In case one or both of the free
- * functions is NULL, the corresponding item is not "stealed".
- *
- * Returns 0 on success, -1 on failure (out of memory).
- */
- int hashtable_set(hashtable_t *hashtable, void *key, void *value);
- /**
- * hashtable_get - Get a value associated with a key
- *
- * @hashtable: The hashtable object
- * @key: The key
- *
- * Returns value if it is found, or NULL otherwise.
- */
- void *hashtable_get(hashtable_t *hashtable, const void *key);
- /**
- * hashtable_del - Remove a value from the hashtable
- *
- * @hashtable: The hashtable object
- * @key: The key
- *
- * Returns 0 on success, or -1 if the key was not found.
- */
- int hashtable_del(hashtable_t *hashtable, const void *key);
- /**
- * hashtable_clear - Clear hashtable
- *
- * @hashtable: The hashtable object
- *
- * Removes all items from the hashtable.
- */
- void hashtable_clear(hashtable_t *hashtable);
- /**
- * hashtable_iter - Iterate over hashtable
- *
- * @hashtable: The hashtable object
- *
- * Returns an opaque iterator to the first element in the hashtable.
- * The iterator should be passed to hashtable_iter_* functions.
- * The hashtable items are not iterated over in any particular order.
- *
- * There's no need to free the iterator in any way. The iterator is
- * valid as long as the item that is referenced by the iterator is not
- * deleted. Other values may be added or deleted. In particular,
- * hashtable_iter_next() may be called on an iterator, and after that
- * the key/value pair pointed by the old iterator may be deleted.
- */
- void *hashtable_iter(hashtable_t *hashtable);
- /**
- * hashtable_iter_at - Return an iterator at a specific key
- *
- * @hashtable: The hashtable object
- * @key: The key that the iterator should point to
- *
- * Like hashtable_iter() but returns an iterator pointing to a
- * specific key.
- */
- void *hashtable_iter_at(hashtable_t *hashtable, const void *key);
- /**
- * hashtable_iter_next - Advance an iterator
- *
- * @hashtable: The hashtable object
- * @iter: The iterator
- *
- * Returns a new iterator pointing to the next element in the
- * hashtable or NULL if the whole hastable has been iterated over.
- */
- void *hashtable_iter_next(hashtable_t *hashtable, void *iter);
- /**
- * hashtable_iter_key - Retrieve the key pointed by an iterator
- *
- * @iter: The iterator
- */
- void *hashtable_iter_key(void *iter);
- /**
- * hashtable_iter_value - Retrieve the value pointed by an iterator
- *
- * @iter: The iterator
- */
- void *hashtable_iter_value(void *iter);
- /**
- * hashtable_iter_set - Set the value pointed by an iterator
- *
- * @iter: The iterator
- * @value: The value to set
- */
- void hashtable_iter_set(hashtable_t *hashtable, void *iter, void *value);
- #endif