-/* 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.h,v 0.12 1992/09/02 01:59:40 rms Exp rms $
- $Author: rms $
- $Date: 1992/09/02 01:59:40 $
- $Log: hash.h,v $
- * Revision 0.12 1992/09/02 01:59:40 rms
- * Changed the format of various sections to conform with GNU standard.
- * Deleted dependencies on some header files.
- * Replaced the use of the functions from memory.h with funtions like bzero.
- * Changed the include format.
- *
- * Revision 0.11 1992/08/31 21:15:02 dglattin
- * minor documentation changes.
- *
- * Revision 0.10 1992/08/18 04:46:58 dglattin
- * Saving a working version before release.
- *
- * Revision 0.9 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 0.8 1991/12/10 12:05:28 dennisg
- * Cleaned up file format for a distribution.
- *
- * Revision 0.7 1991/12/03 02:01:23 dennisg
- * fixed assert macro.
- * added memory allocation adjustment macro for hash size allocation.
- *
- * Revision 0.6 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 0.5 1991/11/23 22:19:21 dennisg
- * converted some entries in the hash structure from ints to shorts.
- * this was done to use a less expensive division instruction
- * in the hashIndex routine.
- *
- * Revision 0.4 1991/11/21 22:25:19 dennisg
- * deleted hash mask information from hash struct.
- * changed hashing algorithm. those values are no longer needed.
- *
- * 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.
- *
-*/
-
-#ifndef _hash_INCLUDE_GNU
-#define _hash_INCLUDE_GNU
+#ifndef __hash_INCLUDE_GNU
+#define __hash_INCLUDE_GNU
-
-#include "assert.h"
#include "mutex.h"
* stored in a hash table. Each node holds
* a key/value pair.
*
- * Items in the cache are really of type void*.
+ * Items in the cache are really of type void *.
*/
-typedef struct cache_node {
+typedef struct cache_node
+{
struct cache_node *next; /* Pointer to next entry on the list.
NULL indicates end of list. */
- void *key; /* Key used to locate the value. Used
+ const void *key; /* Key used to locate the value. Used
to locate value when more than one
key computes the same hash
value. */
* typedef. Therefore, to remove compiler warnings the functions passed to
* hash_new will have to be casted to this type.
*/
-typedef unsigned int (*hash_func_type)(void*, void*);
+typedef unsigned int (*hash_func_type)(void *, const void *);
/*
* This data type is the function that compares two hash keys and returns an
* second.
*/
-typedef int (*compare_func_type)(void*, void*);
+typedef int (*compare_func_type)(const void *, const void *);
/*
* It must be passed to all of the hashing routines
* (except for new).
*/
-typedef struct cache {
+typedef struct cache
+{
/* Variables used to implement the hash itself. */
- node_ptr (*node_table)[]; /* Pointer to an array of hash nodes. */
+ node_ptr *node_table; /* Pointer to an array of hash nodes. */
/* Variables used to track the size of the hash table so to determine
when to resize it. */
unsigned int size; /* Number of buckets allocated for the hash table
} *cache_ptr;
+/* Two important hash tables. */
+extern cache_ptr module_hash_table, class_hash_table;
+
/* Allocate and initialize a hash table. */
cache_ptr hash_new (unsigned int size,
- hash_func_type hash_func, compare_func_type compare_func);
+ hash_func_type hash_func,
+ compare_func_type compare_func);
/* Deallocate all of the hash nodes and the cache itself. */
assert if the key is already in the hash. */
-void hash_add (cache_ptr *cachep, void *key, void *value);
+void hash_add (cache_ptr *cachep, const void *key, void *value);
/* Remove the key/value pair from the hash table.
assert if the key isn't in the table. */
-void hash_remove (cache_ptr cache, void *key);
+void hash_remove (cache_ptr cache, const void *key);
/* Used to index through the hash table. Start with NULL
to get the first entry.
/* Used to return a value from a hash table using a given key. */
-void *hash_value_for_key (cache_ptr cache, void *key);
+void *hash_value_for_key (cache_ptr cache, const void *key);
/************************************************
************************************************/
/* Calculate a hash code by performing some
- manipulation of the key pointer. */
+ manipulation of the key pointer. (Use the lowest bits
+ except for those likely to be 0 due to alignment.) */
+
static inline unsigned int
-hash_int (cache_ptr cache, void *key)
+hash_int (cache_ptr cache, const void *key)
{
- assert (sizeof (unsigned int) == sizeof (key));
-
- return ((unsigned int)key >> (sizeof (void *) - 1)) & cache->mask;
+ return ((unsigned int)key / sizeof (void *)) & cache->mask;
}
/* Calculate a hash code by iterating over a NULL
terminate string. */
static inline unsigned int
-hash_string (cache_ptr cache, void *key)
+hash_string (cache_ptr cache, const void *key)
{
unsigned int ret = 0;
unsigned int ctr = 0;
/* Compare two integers. */
static inline int
-compare_ints (void *k1, void *k2)
+compare_ints (const void *k1, const void *k2)
{
return !((int)k1 - (int)k2);
}
/* Compare two strings. */
static inline int
-compare_strings (void *k1, void *k2)
+compare_strings (const void *k1, const void *k2)
{
return !strcmp (k1, k2);
}
-#endif /* _hash_INCLUDE_GNU */
+#endif /* not __hash_INCLUDE_GNU */
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