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83 lines
2 KiB
C
83 lines
2 KiB
C
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#pragma once
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#ifndef hash_h_
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#define hash_h_
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// Hash functions
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#define DJB_MAGIC 5381u
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typedef struct hashitem // size is 12/24 bytes.
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{
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char *string;
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intptr_t key;
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struct hashitem *next;
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} hashitem_t;
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typedef struct
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{
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int32_t size;
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hashitem_t **items;
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} hashtable_t;
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// djb3 algorithm
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static inline uint32_t hash_getcode(const char *s)
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{
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uint32_t h = DJB_MAGIC;
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char ch;
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while ((ch = Btolower(*s++)) != '\0')
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h = ((h << 5) + h) ^ ch;
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return h;
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}
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void hash_init(hashtable_t *t);
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void hash_loop(hashtable_t *t, void (*func)(const char *, intptr_t));
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void hash_free(hashtable_t *t);
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void hash_add(hashtable_t *t, const char *s, intptr_t key, int32_t replace);
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void hash_delete(hashtable_t *t, const char *s);
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intptr_t hash_findcase(hashtable_t const *t, char const *s);
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intptr_t hash_find(hashtable_t const *t, char const *s);
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// Hash functions
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// modified for raw binary keys and one big allocation, and maximum find() performance
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typedef struct inthashitem
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{
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intptr_t key;
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intptr_t value;
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struct inthashitem *collision; // use NULL to signify empty and pointer identity to signify end of linked list
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} inthashitem_t;
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typedef struct
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{
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inthashitem_t *items;
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uint32_t count;
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} inthashtable_t;
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// djb3 algorithm
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static inline uint32_t inthash_getcode(intptr_t key)
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{
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uint32_t h = DJB_MAGIC;
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for (auto keybuf = (uint8_t const *) &key, keybuf_end = keybuf + sizeof(key); keybuf < keybuf_end; ++keybuf)
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h = ((h << 5) + h) ^ (uint32_t) *keybuf;
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return h;
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}
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void inthash_init(inthashtable_t *t);
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void inthash_loop(inthashtable_t const *t, void (*func)(intptr_t, intptr_t));
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void inthash_free(inthashtable_t *t);
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void inthash_add(inthashtable_t *t, intptr_t key, intptr_t value, int32_t replace);
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void inthash_delete(inthashtable_t *t, intptr_t key);
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intptr_t inthash_find(inthashtable_t const *t, intptr_t key);
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// keep the load factor below 0.75 and make sure the size is odd
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// ideally we would find the next largest prime number
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#define INTHASH_SIZE(size) ((size * 4u / 3u) | 1u)
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#endif // hash_h_
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