Some comments and whitespace cleaned up. RCS headers removed.

Include gstddef.h and objc-proto.h.
Don't include objcP.h or objc-protoP.h.
Avoid use of u_int, etc. so no need for sys/types.h.
Adjust for change in node_table field data type.

Fix calls to DEBUG_PRINTF; no longer wants stream as arg.

From-SVN: r2456
This commit is contained in:
Richard Stallman 1992-10-14 09:49:27 +00:00
parent 437b93370d
commit a4f6608ca2
1 changed files with 63 additions and 130 deletions

View File

@ -1,4 +1,5 @@
/* 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.
@ -22,92 +23,27 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
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;
@ -115,18 +51,18 @@ hash_new (u_int size, hash_func_type hash_func, compare_func_type compare_func)
/* 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? */
@ -135,7 +71,7 @@ hash_new (u_int size, hash_func_type hash_func, compare_func_type compare_func)
/* 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;
@ -143,7 +79,7 @@ hash_new (u_int size, hash_func_type hash_func, compare_func_type compare_func)
}
void
void
hash_delete (cache_ptr cache)
{
node_ptr node;
@ -159,27 +95,27 @@ hash_delete (cache_ptr cache)
}
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;
}
@ -187,64 +123,64 @@ hash_add (cache_ptr *cachep, void *key, void *value)
#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);
@ -253,42 +189,42 @@ hash_remove (cache_ptr cache, void *key)
} 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
@ -296,17 +232,14 @@ hash_next (cache_ptr cache, node_ptr node)
}
/*
* 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 {
@ -315,6 +248,6 @@ hash_value_for_key (cache_ptr cache, void *key)
else
node = node->next;
} while (!retval && node);
return retval;
}