/* * Implementation of the hash table type. * * Author : Stephen Smalley, */ #include #include #include #include #include "hashtab.h" struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, const void *key), int (*keycmp)(struct hashtab *h, const void *key1, const void *key2), u32 size) { struct hashtab *p; u32 i; p = kzalloc(sizeof(*p), GFP_KERNEL); if (p == NULL) return p; p->size = size; p->nel = 0; p->hash_value = hash_value; p->keycmp = keycmp; p->htable = kmalloc(sizeof(*(p->htable)) * size, GFP_KERNEL); if (p->htable == NULL) { kfree(p); return NULL; } for (i = 0; i < size; i++) p->htable[i] = NULL; return p; } int hashtab_insert(struct hashtab *h, void *key, void *datum) { u32 hvalue; struct hashtab_node *prev, *cur, *newnode; cond_resched(); if (!h || h->nel == HASHTAB_MAX_NODES) return -EINVAL; hvalue = h->hash_value(h, key); prev = NULL; cur = h->htable[hvalue]; while (cur && h->keycmp(h, key, cur->key) > 0) { prev = cur; cur = cur->next; } if (cur && (h->keycmp(h, key, cur->key) == 0)) return -EEXIST; newnode = kzalloc(sizeof(*newnode), GFP_KERNEL); if (newnode == NULL) return -ENOMEM; newnode->key = key; newnode->datum = datum; if (prev) { newnode->next = prev->next; prev->next = newnode; } else { newnode->next = h->htable[hvalue]; h->htable[hvalue] = newnode; } h->nel++; return 0; } void *hashtab_search(struct hashtab *h, const void *key) { u32 hvalue; struct hashtab_node *cur; if (!h) return NULL; hvalue = h->hash_value(h, key); cur = h->htable[hvalue]; while (cur && h->keycmp(h, key, cur->key) > 0) cur = cur->next; if (cur == NULL || (h->keycmp(h, key, cur->key) != 0)) return NULL; return cur->datum; } void hashtab_destroy(struct hashtab *h) { u32 i; struct hashtab_node *cur, *temp; if (!h) return; for (i = 0; i < h->size; i++) { cur = h->htable[i]; while (cur) { temp = cur; cur = cur->next; kfree(temp); } h->htable[i] = NULL; } kfree(h->htable); h->htable = NULL; kfree(h); } int hashtab_map(struct hashtab *h, int (*apply)(void *k, void *d, void *args), void *args) { u32 i; int ret; struct hashtab_node *cur; if (!h) return 0; for (i = 0; i < h->size; i++) { cur = h->htable[i]; while (cur) { ret = apply(cur->key, cur->datum, args); if (ret) return ret; cur = cur->next; } } return 0; } void hashtab_stat(struct hashtab *h, struct hashtab_info *info) { u32 i, chain_len, slots_used, max_chain_len; struct hashtab_node *cur; slots_used = 0; max_chain_len = 0; for (slots_used = max_chain_len = i = 0; i < h->size; i++) { cur = h->htable[i]; if (cur) { slots_used++; chain_len = 0; while (cur) { chain_len++; cur = cur->next; } if (chain_len > max_chain_len) max_chain_len = chain_len; } } info->slots_used = slots_used; info->max_chain_len = max_chain_len; } d01682393be56d2be237e81610'>op-2.h
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