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Diffstat (limited to 'contrib/gcc/objc/hash.c')
| -rw-r--r-- | contrib/gcc/objc/hash.c | 283 |
1 files changed, 0 insertions, 283 deletions
diff --git a/contrib/gcc/objc/hash.c b/contrib/gcc/objc/hash.c deleted file mode 100644 index 7534330..0000000 --- a/contrib/gcc/objc/hash.c +++ /dev/null @@ -1,283 +0,0 @@ -/* Hash tables for Objective C internal structures - Copyright (C) 1993, 1996, 1997 Free Software Foundation, Inc. - -This file is part of GNU CC. - -GNU CC is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) -any later version. - -GNU CC is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -GNU General Public License for more details. - -You should have received a copy of the GNU General Public License -along with GNU CC; see the file COPYING. If not, write to -the Free Software Foundation, 59 Temple Place - Suite 330, -Boston, MA 02111-1307, USA. */ - -/* As a special exception, if you link this library with files - compiled with GCC to produce an executable, this does not cause - the resulting executable to be covered by the GNU General Public License. - This exception does not however invalidate any other reasons why - the executable file might be covered by the GNU General Public License. */ - -#include "assert.h" - -#include "objc/hash.h" - -#include "runtime.h" /* for DEBUG_PRINTF */ - -/* These two macros determine when a hash table is full and - by how much it should be expanded respectively. - - These equations are percentages. */ -#define FULLNESS(cache) \ - ((((cache)->size * 75) / 100) <= (cache)->used) -#define EXPANSION(cache) \ - ((cache)->size * 2) - -cache_ptr -hash_new (unsigned int size, hash_func_type hash_func, - compare_func_type compare_func) -{ - cache_ptr cache; - - /* Pass me a value greater than 0 and a power of 2. */ - assert (size); - assert (!(size & (size - 1))); - - /* Allocate the cache structure. calloc insures - its initialization for default values. */ - cache = (cache_ptr) objc_calloc (1, sizeof (struct cache)); - assert (cache); - - /* Allocate the array of buckets for the cache. - calloc initializes all of the pointers to NULL. */ - cache->node_table - = (node_ptr *) objc_calloc (size, sizeof (node_ptr)); - assert (cache->node_table); - - cache->size = size; - - /* This should work for all processor architectures? */ - cache->mask = (size - 1); - - /* Store the hashing function so that codes can be computed. */ - cache->hash_func = hash_func; - - /* Store the function that compares hash keys to - determine if they are equal. */ - cache->compare_func = compare_func; - - return cache; -} - - -void -hash_delete (cache_ptr cache) -{ - node_ptr node; - node_ptr next_node; - unsigned int i; - - /* Purge all key/value pairs from the table. */ - /* Step through the nodes one by one and remove every node WITHOUT - using hash_next. this makes hash_delete much more efficient. */ - for (i = 0;i < cache->size;i++) { - if ((node = cache->node_table[i])) { - /* an entry in the hash table has been found, now step through the - nodes next in the list and free them. */ - while ((next_node = node->next)) { - hash_remove (cache,node->key); - node = next_node; - } - - hash_remove (cache,node->key); - } - } - - /* Release the array of nodes and the cache itself. */ - objc_free(cache->node_table); - objc_free(cache); -} - - -void -hash_add (cache_ptr *cachep, const void *key, void *value) -{ - size_t indx = (*(*cachep)->hash_func)(*cachep, key); - node_ptr node = (node_ptr) objc_calloc (1, sizeof (struct cache_node)); - - - assert (node); - - /* Initialize the new node. */ - node->key = key; - node->value = value; - node->next = (*cachep)->node_table[indx]; - - /* Debugging. - Check the list for another key. */ -#ifdef DEBUG - { node_ptr node1 = (*cachep)->node_table[indx]; - - while (node1) { - - assert (node1->key != key); - node1 = node1->next; - } - } -#endif - - /* Install the node as the first element on the list. */ - (*cachep)->node_table[indx] = node; - - /* Bump the number of entries in the cache. */ - ++(*cachep)->used; - - /* Check the hash table's fullness. We're going - to expand if it is above the fullness level. */ - if (FULLNESS (*cachep)) { - - /* The hash table has reached its fullness level. Time to - expand it. - - I'm using a slow method here but is built on other - primitive functions thereby increasing its - correctness. */ - node_ptr node1 = NULL; - cache_ptr new = hash_new (EXPANSION (*cachep), - (*cachep)->hash_func, - (*cachep)->compare_func); - - DEBUG_PRINTF ("Expanding cache %#x from %d to %d\n", - *cachep, (*cachep)->size, new->size); - - /* Copy the nodes from the first hash table to the new one. */ - while ((node1 = hash_next (*cachep, node1))) - hash_add (&new, node1->key, node1->value); - - /* Trash the old cache. */ - hash_delete (*cachep); - - /* Return a pointer to the new hash table. */ - *cachep = new; - } -} - - -void -hash_remove (cache_ptr cache, const void *key) -{ - size_t indx = (*cache->hash_func)(cache, key); - node_ptr node = cache->node_table[indx]; - - - /* We assume there is an entry in the table. Error if it is not. */ - assert (node); - - /* Special case. First element is the key/value pair to be removed. */ - if ((*cache->compare_func)(node->key, key)) { - cache->node_table[indx] = node->next; - objc_free(node); - } else { - - /* Otherwise, find the hash entry. */ - node_ptr prev = node; - BOOL removed = NO; - - do { - - if ((*cache->compare_func)(node->key, key)) { - prev->next = node->next, removed = YES; - objc_free(node); - } else - prev = node, node = node->next; - } while (!removed && node); - assert (removed); - } - - /* Decrement the number of entries in the hash table. */ - --cache->used; -} - - -node_ptr -hash_next (cache_ptr cache, node_ptr node) -{ - /* If the scan is being started then reset the last node - visitied pointer and bucket index. */ - if (!node) - cache->last_bucket = 0; - - /* If there is a node visited last then check for another - entry in the same bucket; Otherwise step to the next bucket. */ - if (node) { - if (node->next) - /* There is a node which follows the last node - returned. Step to that node and retun it. */ - return node->next; - else - ++cache->last_bucket; - } - - /* If the list isn't exhausted then search the buckets for - other nodes. */ - if (cache->last_bucket < cache->size) { - /* Scan the remainder of the buckets looking for an entry - at the head of the list. Return the first item found. */ - while (cache->last_bucket < cache->size) - if (cache->node_table[cache->last_bucket]) - return cache->node_table[cache->last_bucket]; - else - ++cache->last_bucket; - - /* No further nodes were found in the hash table. */ - return NULL; - } else - return NULL; -} - - -/* Given KEY, return corresponding value for it in CACHE. - Return NULL if the KEY is not recorded. */ - -void * -hash_value_for_key (cache_ptr cache, const void *key) -{ - node_ptr node = cache->node_table[(*cache->hash_func)(cache, key)]; - void *retval = NULL; - - if (node) - do { - if ((*cache->compare_func)(node->key, key)) { - retval = node->value; - break; - } else - node = node->next; - } while (!retval && node); - - return retval; -} - -/* Given KEY, return YES if it exists in the CACHE. - Return NO if it does not */ - -BOOL -hash_is_key_in_hash (cache_ptr cache, const void *key) -{ - node_ptr node = cache->node_table[(*cache->hash_func)(cache, key)]; - - if (node) - do { - if ((*cache->compare_func)(node->key, key)) - return YES; - else - node = node->next; - } while (node); - - return NO; -} |
