diff options
Diffstat (limited to 'source4/lib/json/linkhash.c')
-rw-r--r-- | source4/lib/json/linkhash.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/source4/lib/json/linkhash.c b/source4/lib/json/linkhash.c new file mode 100644 index 0000000000..6cfc9a0ea6 --- /dev/null +++ b/source4/lib/json/linkhash.c @@ -0,0 +1,217 @@ +/* + * $Id: linkhash.c,v 1.4 2006/01/26 02:16:28 mclark Exp $ + * + * Copyright (c) 2004, 2005 Metaparadigm Pte. Ltd. + * Michael Clark <michael@metaparadigm.com> + * + * This library is free software; you can redistribute it and/or modify + * it under the terms of the MIT license. See COPYING for details. + * + */ + +#include "config.h" + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <stdarg.h> +#include <stddef.h> +#include <limits.h> + +#include "linkhash.h" + +void lh_abort(const char *msg, ...) +{ + va_list ap; + va_start(ap, msg); + vprintf(msg, ap); + exit(1); +} + +unsigned long lh_ptr_hash(void *k) +{ + /* CAW: refactored to be 64bit nice */ + return (unsigned long)((((ptrdiff_t)k * LH_PRIME) >> 4) & ULONG_MAX); +} + +int lh_ptr_equal(void *k1, void *k2) +{ + return (k1 == k2); +} + +unsigned long lh_char_hash(void *k) +{ + unsigned int h = 0; + const char* data = k; + + while( *data!=0 ) h = h*129 + (unsigned int)(*data++) + LH_PRIME; + + return h; +} + +int lh_char_equal(void *k1, void *k2) +{ + return (strcmp((char*)k1, (char*)k2) == 0); +} + +struct lh_table* lh_table_new(int size, char *name, + lh_entry_free_fn *free_fn, + lh_hash_fn *hash_fn, + lh_equal_fn *equal_fn) +{ + int i; + struct lh_table *t; + + t = calloc(1, sizeof(struct lh_table)); + if(!t) lh_abort("lh_table_new: calloc failed\n"); + t->count = 0; + t->size = size; + t->name = name; + t->table = calloc(size, sizeof(struct lh_entry)); + if(!t->table) lh_abort("lh_table_new: calloc failed\n"); + t->free_fn = free_fn; + t->hash_fn = hash_fn; + t->equal_fn = equal_fn; + for(i = 0; i < size; i++) t->table[i].k = LH_EMPTY; + return t; +} + +struct lh_table* lh_kchar_table_new(int size, char *name, + lh_entry_free_fn *free_fn) +{ + return lh_table_new(size, name, free_fn, lh_char_hash, lh_char_equal); +} + +struct lh_table* lh_kptr_table_new(int size, char *name, + lh_entry_free_fn *free_fn) +{ + return lh_table_new(size, name, free_fn, lh_ptr_hash, lh_ptr_equal); +} + +void lh_table_resize(struct lh_table *t, int new_size) +{ + struct lh_table *new_t; + struct lh_entry *ent; + + new_t = lh_table_new(new_size, t->name, NULL, t->hash_fn, t->equal_fn); + ent = t->head; + while(ent) { + lh_table_insert(new_t, ent->k, ent->v); + ent = ent->next; + } + free(t->table); + t->table = new_t->table; + t->size = new_size; + t->head = new_t->head; + t->tail = new_t->tail; + t->resizes++; + free(new_t); +} + +void lh_table_free(struct lh_table *t) +{ + struct lh_entry *c; + for(c = t->head; c != NULL; c = c->next) { + if(t->free_fn) { + t->free_fn(c); + } + } + free(t->table); + free(t); +} + + +int lh_table_insert(struct lh_table *t, void *k, void *v) +{ + unsigned long h, n; + + t->inserts++; + if(t->count > t->size * 0.66) lh_table_resize(t, t->size * 2); + + h = t->hash_fn(k); + n = h % t->size; + + while( 1 ) { + if(t->table[n].k == LH_EMPTY || t->table[n].k == LH_FREED) break; + t->collisions++; + if(++n == t->size) n = 0; + } + + t->table[n].k = k; + t->table[n].v = v; + t->count++; + + if(t->head == NULL) { + t->head = t->tail = &t->table[n]; + t->table[n].next = t->table[n].prev = NULL; + } else { + t->tail->next = &t->table[n]; + t->table[n].prev = t->tail; + t->table[n].next = NULL; + t->tail = &t->table[n]; + } + + return 0; +} + + +struct lh_entry* lh_table_lookup_entry(struct lh_table *t, void *k) +{ + unsigned long h = t->hash_fn(k); + unsigned long n = h % t->size; + + t->lookups++; + while( 1 ) { + if(t->table[n].k == LH_EMPTY) return NULL; + if(t->table[n].k != LH_FREED && + t->equal_fn(t->table[n].k, k)) return &t->table[n]; + if(++n == t->size) n = 0; + } + return NULL; +} + + +void* lh_table_lookup(struct lh_table *t, void *k) +{ + struct lh_entry *e = lh_table_lookup_entry(t, k); + if(e) return e->v; + return NULL; +} + + +int lh_table_delete_entry(struct lh_table *t, struct lh_entry *e) +{ + ptrdiff_t n = (ptrdiff_t)(e - t->table); /* CAW: fixed to be 64bit nice, still need the crazy negative case... */ + + /* CAW: this is bad, really bad, maybe stack goes other direction on this machine... */ + if(n < 0) { return -2; } + + if(t->table[n].k == LH_EMPTY || t->table[n].k == LH_FREED) return -1; + t->count--; + if(t->free_fn) t->free_fn(e); + t->table[n].v = NULL; + t->table[n].k = LH_FREED; + if(t->tail == &t->table[n] && t->head == &t->table[n]) { + t->head = t->tail = NULL; + } else if (t->head == &t->table[n]) { + t->head->next->prev = NULL; + t->head = t->head->next; + } else if (t->tail == &t->table[n]) { + t->tail->prev->next = NULL; + t->tail = t->tail->prev; + } else { + t->table[n].prev->next = t->table[n].next; + t->table[n].next->prev = t->table[n].prev; + } + t->table[n].next = t->table[n].prev = NULL; + return 0; +} + + +int lh_table_delete(struct lh_table *t, void *k) +{ + struct lh_entry *e = lh_table_lookup_entry(t, k); + if(!e) return -1; + return lh_table_delete_entry(t, e); +} + |