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95 lines
3.6 KiB
C
95 lines
3.6 KiB
C
#ifndef BASE_DATA_STRUCT_HASH_H
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#define BASE_DATA_STRUCT_HASH_H
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#include <stdint.h>
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//----------------------------------------------------------------
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struct dm_hash_table;
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struct dm_hash_node;
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typedef void (*dm_hash_iterate_fn) (void *data);
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struct dm_hash_table *dm_hash_create(unsigned size_hint)
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__attribute__((__warn_unused_result__));
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void dm_hash_destroy(struct dm_hash_table *t);
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void dm_hash_wipe(struct dm_hash_table *t);
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void *dm_hash_lookup(struct dm_hash_table *t, const char *key);
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int dm_hash_insert(struct dm_hash_table *t, const char *key, void *data);
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void dm_hash_remove(struct dm_hash_table *t, const char *key);
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void *dm_hash_lookup_binary(struct dm_hash_table *t, const void *key, uint32_t len);
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int dm_hash_insert_binary(struct dm_hash_table *t, const void *key, uint32_t len,
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void *data);
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void dm_hash_remove_binary(struct dm_hash_table *t, const void *key, uint32_t len);
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unsigned dm_hash_get_num_entries(struct dm_hash_table *t);
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void dm_hash_iter(struct dm_hash_table *t, dm_hash_iterate_fn f);
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char *dm_hash_get_key(struct dm_hash_table *t, struct dm_hash_node *n);
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void *dm_hash_get_data(struct dm_hash_table *t, struct dm_hash_node *n);
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struct dm_hash_node *dm_hash_get_first(struct dm_hash_table *t);
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struct dm_hash_node *dm_hash_get_next(struct dm_hash_table *t, struct dm_hash_node *n);
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/*
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* dm_hash_insert() replaces the value of an existing
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* entry with a matching key if one exists. Otherwise
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* it adds a new entry.
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*
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* dm_hash_insert_with_val() inserts a new entry if
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* another entry with the same key already exists.
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* val_len is the size of the data being inserted.
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*
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* If two entries with the same key exist,
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* (added using dm_hash_insert_allow_multiple), then:
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* . dm_hash_lookup() returns the first one it finds, and
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* dm_hash_lookup_with_val() returns the one with a matching
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* val_len/val.
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* . dm_hash_remove() removes the first one it finds, and
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* dm_hash_remove_with_val() removes the one with a matching
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* val_len/val.
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*
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* If a single entry with a given key exists, and it has
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* zero val_len, then:
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* . dm_hash_lookup() returns it
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* . dm_hash_lookup_with_val(val_len=0) returns it
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* . dm_hash_remove() removes it
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* . dm_hash_remove_with_val(val_len=0) removes it
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*
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* dm_hash_lookup_with_count() is a single call that will
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* both lookup a key's value and check if there is more
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* than one entry with the given key.
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*
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* (It is not meant to retrieve all the entries with the
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* given key. In the common case where a single entry exists
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* for the key, it is useful to have a single call that will
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* both look up the value and indicate if multiple values
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* exist for the key.)
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*
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* dm_hash_lookup_with_count:
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* . If no entries exist, the function returns NULL, and
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* the count is set to 0.
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* . If only one entry exists, the value of that entry is
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* returned and count is set to 1.
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* . If N entries exists, the value of the first entry is
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* returned and count is set to N.
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*/
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void *dm_hash_lookup_with_val(struct dm_hash_table *t, const char *key,
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const void *val, uint32_t val_len);
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void dm_hash_remove_with_val(struct dm_hash_table *t, const char *key,
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const void *val, uint32_t val_len);
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int dm_hash_insert_allow_multiple(struct dm_hash_table *t, const char *key,
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const void *val, uint32_t val_len);
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void *dm_hash_lookup_with_count(struct dm_hash_table *t, const char *key, int *count);
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#define dm_hash_iterate(v, h) \
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for (v = dm_hash_get_first((h)); v; \
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v = dm_hash_get_next((h), v))
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//----------------------------------------------------------------
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#endif
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