-/* Copyright (C) 1989, 1992 Free Software Foundation, Inc.
+/* Hash tables for Objective C method dispatch.
+ Copyright (C) 1992 Free Software Foundation, Inc.
This file is part of GNU CC.
This exception does not however invalidate any other reasons why
the executable file might be covered by the GNU General Public License. */
-/*
- $Header: /home/fsf/rms/c-runtime/dispatch/RCS/hash.c,v 0.15 1992/09/02 02:04:32 rms Exp rms $
- $Author: rms $
- $Date: 1992/09/02 02:04:32 $
- $Log: hash.c,v $
- * Revision 0.15 1992/09/02 02:04:32 rms
- * Changed some decls.
- *
- * Revision 0.14 1992/08/31 21:09:15 dglattin
- * minor documentation changes.
- *
- * Revision 0.13 1992/08/18 04:46:58 dglattin
- * Saving a working version before release.
- *
- * Revision 0.12 1992/04/13 11:43:08 dennisg
- * Check in after array version of run-time works.
- * Expect more changes as hash version and other changes are made.
- *
- * Revision 0.11 1992/01/03 02:55:03 dennisg
- * modified to handle new initialization scheme.
- * fixed code structure.
- *
- * Revision 0.10 1991/12/10 12:05:28 dennisg
- * Cleaned up file format for a distribution.
- *
- * Revision 0.9 1991/12/03 02:01:23 dennisg
- * fixed assert macro.
- * added memory allocation adjustment macro for hash size allocation.
- *
- * Revision 0.8 1991/11/24 01:20:02 dennisg
- * changed shorts back to ints.
- * the efficiency gained didn't out weight the grossness of the code.
- *
- * Revision 0.7 1991/11/23 22:18:29 dennisg
- * deleted hashIndex and moved it to hash-inline.h
- * converted hash_value_for_key to a inline and moved it to hash-inline.h.
- *
- * Revision 0.6 1991/11/21 22:27:06 dennisg
- * changed hash value calculation.
- * func name changed from hashValue to hashIndex. the
- * func really calculated a index anyway.
- * changed hash func impl. essentially it was calculating a hash value
- * from a hash value. this is a implementation thing.
- *
- * Revision 0.5 1991/11/20 23:29:20 dennisg
- * converted hashIndex to a inline.
- *
- * Revision 0.4 1991/11/19 12:34:41 dennisg
- * bug in hash_delete. It was using void* to obtain nodes to
- * pass to hash_remove. The value passed to hash_removed is a
- * entry from the node structure rather than the node itself. Using
- * void* removed compiler checking.
- * Modified to implement cache expansion.
- *
- * Revision 0.3 1991/11/07 23:23:40 dennisg
- * implemented hash table expansion as suggested by rms.
- *
- * Revision 0.2 1991/11/07 22:30:54 dennisg
- * added copyleft
- *
- * Revision 0.1 1991/10/24 00:45:39 dennisg
- * Initial check in. Preliminary development stage.
- *
-*/
-
-
#include "config.h"
+#include "gstddef.h"
+#include "assert.h"
+
#include "hash.h"
#include "objc.h"
-#include "objcP.h"
-#include "objc-protoP.h"
-
-#include "assert.h"
+#include "objc-proto.h"
/* 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 (u_int size, hash_func_type hash_func, compare_func_type compare_func)
+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) calloc (1, sizeof (struct cache));
assert (cache);
-
- /* Allocate the array of buckets for the cache.
+
+ /* Allocate the array of buckets for the cache.
calloc initializes all of the pointers to NULL. */
cache->node_table
= (node_ptr *) calloc (size, sizeof (node_ptr));
assert (cache->node_table);
-
+
cache->size = size;
/* This should work for all processor architectures? */
/* Store the hashing function so that codes can be computed. */
cache->hash_func = hash_func;
- /* Store the function that compares hash keys to
+ /* Store the function that compares hash keys to
determine if they are equal. */
cache->compare_func = compare_func;
}
-void
+void
hash_delete (cache_ptr cache)
{
node_ptr node;
}
-void
-hash_add (cache_ptr *cachep, void *key, void *value)
+void
+hash_add (cache_ptr *cachep, const void *key, void *value)
{
- u_int indx = (*(*cachep)->hash_func)(*cachep, key);
+ size_t indx = (*(*cachep)->hash_func)(*cachep, key);
node_ptr node = (node_ptr) calloc (1, sizeof (struct cache_node));
assert (node);
-
+
/* Initialize the new node. */
node->key = key;
node->value = value;
- node->next = (*(*cachep)->node_table)[indx];
-
+ node->next = (*cachep)->node_table[indx];
+
/* Debugging.
Check the list for another key. */
#ifdef DEBUG
- { node_ptr node1 = (*(*cachep)->node_table)[indx];
-
+ { 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;
+ (*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.
-
+ expand it.
+
I'm using a slow method here but is built on other
- primitive functions thereby increasing its
+ primitive functions thereby increasing its
correctness. */
node_ptr node1 = NULL;
- cache_ptr new = hash_new (EXPANSION (*cachep),
- (*cachep)->hash_func,
+ cache_ptr new = hash_new (EXPANSION (*cachep),
+ (*cachep)->hash_func,
(*cachep)->compare_func);
- DEBUG_PRINTF (stderr, "Expanding cache %#x from %d to %d\n",
+ 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, void *key)
+void
+hash_remove (cache_ptr cache, const void *key)
{
- u_int indx = (*cache->hash_func)(cache, key);
- node_ptr node = (*cache->node_table)[indx];
-
-
+ 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;
+ cache->node_table[indx] = node->next;
free (node);
} else {
/* Otherwise, find the hash entry. */
node_ptr prev = node;
- BOOL removed = NO;
-
+ BOOL removed = NO;
+
do {
-
+
if ((*cache->compare_func)(node->key, key)) {
prev->next = node->next, removed = YES;
free (node);
} while (!removed && node);
assert (removed);
}
-
+
/* Decrement the number of entries in the hash table. */
--cache->used;
}
-node_ptr
+node_ptr
hash_next (cache_ptr cache, node_ptr node)
{
- /* If the scan is being started then reset the last 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
+
+ /* 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
+ /* 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
+ /* 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];
+ 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
}
-/*
- * Given key, return its value. Return NULL if the
- * key/value pair isn't in the hash.
- */
+/* 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, void *key)
+hash_value_for_key (cache_ptr cache, const void *key)
{
- node_ptr node
- = (*cache->node_table)[(*cache->hash_func)(cache, key)];
+ node_ptr node = cache->node_table[(*cache->hash_func)(cache, key)];
void *retval = NULL;
-
if (node)
do {
else
node = node->next;
} while (!retval && node);
-
+
return retval;
}
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