/*
* Copyright (c) 1999-2008 Apple Inc. All Rights Reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
/*
hashtable2.m
Copyright 1989-1996 NeXT Software, Inc.
Created by Bertrand Serlet, Feb 89
*/
#include "objc-private.h"
#include "hashtable2.h"
/* In order to improve efficiency, buckets contain a pointer to an array or directly the data when the array size is 1 */
typedef union {
const void *one;
const void **many;
} oneOrMany;
/* an optimization consists of storing directly data when count = 1 */
typedef struct {
unsigned count;
oneOrMany elements;
} HashBucket;
/* private data structure; may change */
/*************************************************************************
*
* Macros and utilities
*
*************************************************************************/
static unsigned log2u (unsigned x) { return (x<2) ? 0 : log2u (x>>1)+1; };
#define PTRSIZE sizeof(void *)
#if !SUPPORT_ZONES
# define DEFAULT_ZONE NULL
# define ZONE_FROM_PTR(p) NULL
# define ALLOCTABLE(z) ((NXHashTable *) malloc (sizeof (NXHashTable)))
# define ALLOCBUCKETS(z,nb)((HashBucket *) calloc (nb, sizeof (HashBucket)))
/* Return interior pointer so a table of classes doesn't look like objects */
# define ALLOCPAIRS(z,nb) (1+(const void **) calloc (nb+1, sizeof (void *)))
# define FREEPAIRS(p) (free((void*)(-1+p)))
#else
# define DEFAULT_ZONE malloc_default_zone()
# define ZONE_FROM_PTR(p) malloc_zone_from_ptr(p)
# define ALLOCTABLE(z) ((NXHashTable *) malloc_zone_malloc ((malloc_zone_t *)z,sizeof (NXHashTable)))
# define ALLOCBUCKETS(z,nb)((HashBucket *) malloc_zone_calloc ((malloc_zone_t *)z, nb, sizeof (HashBucket)))
/* Return interior pointer so a table of classes doesn't look like objects */
# define ALLOCPAIRS(z,nb) (1+(const void **) malloc_zone_calloc ((malloc_zone_t *)z, nb+1, sizeof (void *)))
# define FREEPAIRS(p) (free((void*)(-1+p)))
#endif
#if !SUPPORT_MOD
/* nbBuckets must be a power of 2 */
# define BUCKETOF(table, data) (((HashBucket *)table->buckets)+((*table->prototype->hash)(table->info, data) & (table->nbBuckets-1)))
# define GOOD_CAPACITY(c) (c <= 1 ? 1 : 1 << (log2u (c-1)+1))
# define MORE_CAPACITY(b) (b*2)
#else
/* iff necessary this modulo can be optimized since the nbBuckets is of the form 2**n-1 */
# define BUCKETOF(table, data) (((HashBucket *)table->buckets)+((*table->prototype->hash)(table->info, data) % table->nbBuckets))
static unsigned exp2m1 (unsigned x) { return (1 << x) - 1; };
# define GOOD_CAPACITY(c) (exp2m1 (log2u (c)+1))
# define MORE_CAPACITY(b) (b*2+1)
#endif
#define ISEQUAL(table, data1, data2) ((data1 == data2) || (*table->prototype->isEqual)(table->info, data1, data2))
/* beware of double evaluation */
/*************************************************************************
*
* Global data and bootstrap
*
*************************************************************************/
static int isEqualPrototype (const void *info, const void *data1, const void *data2) {
NXHashTablePrototype *proto1 = (NXHashTablePrototype *) data1;
NXHashTablePrototype *proto2 = (NXHashTablePrototype *) data2;
return (proto1->hash == proto2->hash) && (proto1->isEqual == proto2->isEqual) && (proto1->free == proto2->free) && (proto1->style == proto2->style);
};
static uintptr_t hashPrototype (const void *info, const void *data) {
NXHashTablePrototype *proto = (NXHashTablePrototype *) data;
return NXPtrHash(info, (void*)proto->hash) ^ NXPtrHash(info, (void*)proto->isEqual) ^ NXPtrHash(info, (void*)proto->free) ^ (uintptr_t) proto->style;
};
void NXNoEffectFree (const void *info, void *data) {};
static NXHashTablePrototype protoPrototype = {
hashPrototype, isEqualPrototype, NXNoEffectFree, 0
};
static NXHashTable *prototypes = NULL;
/* table of all prototypes */
static void bootstrap (void) {
free(malloc(8));
prototypes = ALLOCTABLE (DEFAULT_ZONE);
prototypes->prototype = &protoPrototype;
prototypes->count = 1;
prototypes->nbBuckets = 1; /* has to be 1 so that the right bucket is 0 */
prototypes->buckets = ALLOCBUCKETS(DEFAULT_ZONE, 1);
prototypes->info = NULL;
((HashBucket *) prototypes->buckets)[0].count = 1;
((HashBucket *) prototypes->buckets)[0].elements.one = &protoPrototype;
};
int NXPtrIsEqual (const void *info, const void *data1, const void *data2) {
return data1 == data2;
};
/*************************************************************************
*
* On z'y va
*
*************************************************************************/
NXHashTable *NXCreateHashTable (NXHashTablePrototype prototype, unsigned capacity, const void *info) {
return NXCreateHashTableFromZone(prototype, capacity, info, DEFAULT_ZONE);
}
NXHashTable *NXCreateHashTableFromZone (NXHashTablePrototype prototype, unsigned capacity, const void *info, void *z) {
NXHashTable *table;
NXHashTablePrototype *proto;
table = ALLOCTABLE(z);
if (! prototypes) bootstrap ();
if (! prototype.hash) prototype.hash = NXPtrHash;
if (! prototype.isEqual) prototype.isEqual = NXPtrIsEqual;
if (! prototype.free) prototype.free = NXNoEffectFree;
if (prototype.style) {
_objc_inform ("*** NXCreateHashTable: invalid style\n");
return NULL;
};
proto = (NXHashTablePrototype *)NXHashGet (prototypes, &prototype);
if (! proto) {
proto
= (NXHashTablePrototype *) malloc(sizeof (NXHashTablePrototype));
bcopy ((const char*)&prototype, (char*)proto, sizeof (NXHashTablePrototype));
(void) NXHashInsert (prototypes, proto);
proto = (NXHashTablePrototype *)NXHashGet (prototypes, &prototype);
if (! proto) {
_objc_inform ("*** NXCreateHashTable: bug\n");
return NULL;
};
};
table->prototype = proto; table->count = 0; table->info = info;
table->nbBuckets = GOOD_CAPACITY(capacity);
table->buckets = ALLOCBUCKETS(z, table->nbBuckets);
return table;
}
static void freeBucketPairs (void (*freeProc)(const void *info, void *data), HashBucket bucket, const void *info) {
unsigned j = bucket.count;
const void **pairs;
if (j == 1) {
(*freeProc) (info, (void *) bucket.elements.one);
return;
};
pairs = bucket.elements.many;
while (j--) {
(*freeProc) (info, (void *) *pairs);
pairs ++;
};
FREEPAIRS (bucket.elements.many);
};
static void freeBuckets (NXHashTable *table, int freeObjects) {
unsigned i = table->nbBuckets;
HashBucket *buckets = (HashBucket *) table->buckets;
while (i--) {
if (buckets->count) {
freeBucketPairs ((freeObjects) ? table->prototype->free : NXNoEffectFree, *buckets, table->info);
buckets->count = 0;
buckets->elements.one = NULL;
};
buckets++;
};
};
void NXFreeHashTable (NXHashTable *table) {
freeBuckets (table, YES);
free (table->buckets);
free (table);
};
void NXEmptyHashTable (NXHashTable *table) {
freeBuckets (table, NO);
table->count = 0;
}
void NXResetHashTable (NXHashTable *table) {
freeBuckets (table, YES);
table->count = 0;
}
BOOL NXCompareHashTables (NXHashTable *table1, NXHashTable *table2) {
if (table1 == table2) return YES;
if (NXCountHashTable (table1) != NXCountHashTable (table2)) return NO;
else {
void *data;
NXHashState state = NXInitHashState (table1);
while (NXNextHashState (table1, &state, &data)) {
if (! NXHashMember (table2, data)) return NO;
}
return YES;
}
}
NXHashTable *NXCopyHashTable (NXHashTable *table) {
NXHashTable *newt;
NXHashState state = NXInitHashState (table);
void *data;
__unused void *z = ZONE_FROM_PTR(table);
newt = ALLOCTABLE(z);
newt->prototype = table->prototype; newt->count = 0;
newt->info = table->info;
newt->nbBuckets = table->nbBuckets;
newt->buckets = ALLOCBUCKETS(z, newt->nbBuckets);
while (NXNextHashState (table, &state, &data))
NXHashInsert (newt, data);
return newt;
}
unsigned NXCountHashTable (NXHashTable *table) {
return table->count;
}
int NXHashMember (NXHashTable *table, const void *data) {
HashBucket *bucket = BUCKETOF(table, data);
unsigned j = bucket->count;
const void **pairs;
if (! j) return 0;
if (j == 1) {
return ISEQUAL(table, data, bucket->elements.one);
};
pairs = bucket->elements.many;
while (j--) {
/* we don't cache isEqual because lists are short */
if (ISEQUAL(table, data, *pairs)) return 1;
pairs ++;
};
return 0;
}
void *NXHashGet (NXHashTable *table, const void *data) {
HashBucket *bucket = BUCKETOF(table, data);
unsigned j = bucket->count;
const void **pairs;
if (! j) return NULL;
if (j == 1) {
return ISEQUAL(table, data, bucket->elements.one)
? (void *) bucket->elements.one : NULL;
};
pairs = bucket->elements.many;
while (j--) {
/* we don't cache isEqual because lists are short */
if (ISEQUAL(table, data, *pairs)) return (void *) *pairs;
pairs ++;
};
return NULL;
}
unsigned _NXHashCapacity (NXHashTable *table) {
return table->nbBuckets;
}
void _NXHashRehashToCapacity (NXHashTable *table, unsigned newCapacity) {
/* Rehash: we create a pseudo table pointing really to the old guys,
extend self, copy the old pairs, and free the pseudo table */
NXHashTable *old;
NXHashState state;
void *aux;
__unused void *z = ZONE_FROM_PTR(table);
old = ALLOCTABLE(z);
old->prototype = table->prototype; old->count = table->count;
old->nbBuckets = table->nbBuckets; old->buckets = table->buckets;
table->nbBuckets = newCapacity;
table->count = 0; table->buckets = ALLOCBUCKETS(z, table->nbBuckets);
state = NXInitHashState (old);
while (NXNextHashState (old, &state, &aux))
(void) NXHashInsert (table, aux);
freeBuckets (old, NO);
if (old->count != table->count)
_objc_inform("*** hashtable: count differs after rehashing; probably indicates a broken invariant: there are x and y such as isEqual(x, y) is TRUE but hash(x) != hash (y)\n");
free (old->buckets);
free (old);
}
static void _NXHashRehash (NXHashTable *table) {
_NXHashRehashToCapacity (table, MORE_CAPACITY(table->nbBuckets));
}
void *NXHashInsert (NXHashTable *table, const void *data) {
HashBucket *bucket = BUCKETOF(table, data);
unsigned j = bucket->count;
const void **pairs;
const void **newt;
__unused void *z = ZONE_FROM_PTR(table);
if (! j) {
bucket->count++; bucket->elements.one = data;
table->count++;
return NULL;
};
if (j == 1) {
if (ISEQUAL(table, data, bucket->elements.one)) {
const void *old = bucket->elements.one;
bucket->elements.one = data;
return (void *) old;
};
newt = ALLOCPAIRS(z, 2);
newt[1] = bucket->elements.one;
*newt = data;
bucket->count++; bucket->elements.many = newt;
table->count++;
if (table->count > table->nbBuckets) _NXHashRehash (table);
return NULL;
};
pairs = bucket->elements.many;
while (j--) {
/* we don't cache isEqual because lists are short */
if (ISEQUAL(table, data, *pairs)) {
const void *old = *pairs;
*pairs = data;
return (void *) old;
};
pairs ++;
};
/* we enlarge this bucket; and put new data in front */
newt = ALLOCPAIRS(z, bucket->count+1);
if (bucket->count) bcopy ((const char*)bucket->elements.many, (char*)(newt+1), bucket->count * PTRSIZE);
*newt = data;
FREEPAIRS (bucket->elements.many);
bucket->count++; bucket->elements.many = newt;
table->count++;
if (table->count > table->nbBuckets) _NXHashRehash (table);
return NULL;
}
void *NXHashInsertIfAbsent (NXHashTable *table, const void *data) {
HashBucket *bucket = BUCKETOF(table, data);
unsigned j = bucket->count;
const void **pairs;
const void **newt;
__unused void *z = ZONE_FROM_PTR(table);
if (! j) {
bucket->count++; bucket->elements.one = data;
table->count++;
return (void *) data;
};
if (j == 1) {
if (ISEQUAL(table, data, bucket->elements.one))
return (void *) bucket->elements.one;
newt = ALLOCPAIRS(z, 2);
newt[1] = bucket->elements.one;
*newt = data;
bucket->count++; bucket->elements.many = newt;
table->count++;
if (table->count > table->nbBuckets) _NXHashRehash (table);
return (void *) data;
};
pairs = bucket->elements.many;
while (j--) {
/* we don't cache isEqual because lists are short */
if (ISEQUAL(table, data, *pairs))
return (void *) *pairs;
pairs ++;
};
/* we enlarge this bucket; and put new data in front */
newt = ALLOCPAIRS(z, bucket->count+1);
if (bucket->count) bcopy ((const char*)bucket->elements.many, (char*)(newt+1), bucket->count * PTRSIZE);
*newt = data;
FREEPAIRS (bucket->elements.many);
bucket->count++; bucket->elements.many = newt;
table->count++;
if (table->count > table->nbBuckets) _NXHashRehash (table);
return (void *) data;
}
void *NXHashRemove (NXHashTable *table, const void *data) {
HashBucket *bucket = BUCKETOF(table, data);
unsigned j = bucket->count;
const void **pairs;
const void **newt;
__unused void *z = ZONE_FROM_PTR(table);
if (! j) return NULL;
if (j == 1) {
if (! ISEQUAL(table, data, bucket->elements.one)) return NULL;
data = bucket->elements.one;
table->count--; bucket->count--; bucket->elements.one = NULL;
return (void *) data;
};
pairs = bucket->elements.many;
if (j == 2) {
if (ISEQUAL(table, data, pairs[0])) {
bucket->elements.one = pairs[1]; data = pairs[0];
}
else if (ISEQUAL(table, data, pairs[1])) {
bucket->elements.one = pairs[0]; data = pairs[1];
}
else return NULL;
FREEPAIRS (pairs);
table->count--; bucket->count--;
return (void *) data;
};
while (j--) {
if (ISEQUAL(table, data, *pairs)) {
data = *pairs;
/* we shrink this bucket */
newt = (bucket->count-1)
? ALLOCPAIRS(z, bucket->count-1) : NULL;
if (bucket->count-1 != j)
bcopy ((const char*)bucket->elements.many, (char*)newt, PTRSIZE*(bucket->count-j-1));
if (j)
bcopy ((const char*)(bucket->elements.many + bucket->count-j), (char*)(newt+bucket->count-j-1), PTRSIZE*j);
FREEPAIRS (bucket->elements.many);
table->count--; bucket->count--; bucket->elements.many = newt;
return (void *) data;
};
pairs ++;
};
return NULL;
}
NXHashState NXInitHashState (NXHashTable *table) {
NXHashState state;
state.i = table->nbBuckets;
state.j = 0;
return state;
};
int NXNextHashState (NXHashTable *table, NXHashState *state, void **data) {
HashBucket *buckets = (HashBucket *) table->buckets;
while (state->j == 0) {
if (state->i == 0) return NO;
state->i--; state->j = buckets[state->i].count;
}
state->j--;
buckets += state->i;
*data = (void *) ((buckets->count == 1)
? buckets->elements.one : buckets->elements.many[state->j]);
return YES;
};
/*************************************************************************
*
* Conveniences
*
*************************************************************************/
uintptr_t NXPtrHash (const void *info, const void *data) {
return (((uintptr_t) data) >> 16) ^ ((uintptr_t) data);
};
uintptr_t NXStrHash (const void *info, const void *data) {
register uintptr_t hash = 0;
register unsigned char *s = (unsigned char *) data;
/* unsigned to avoid a sign-extend */
/* unroll the loop */
if (s) for (; ; ) {
if (*s == '\0') break;
hash ^= (uintptr_t) *s++;
if (*s == '\0') break;
hash ^= (uintptr_t) *s++ << 8;
if (*s == '\0') break;
hash ^= (uintptr_t) *s++ << 16;
if (*s == '\0') break;
hash ^= (uintptr_t) *s++ << 24;
}
return hash;
};
int NXStrIsEqual (const void *info, const void *data1, const void *data2) {
if (data1 == data2) return YES;
if (! data1) return ! strlen ((char *) data2);
if (! data2) return ! strlen ((char *) data1);
if (((char *) data1)[0] != ((char *) data2)[0]) return NO;
return (strcmp ((char *) data1, (char *) data2)) ? NO : YES;
};
void NXReallyFree (const void *info, void *data) {
free (data);
};
/* All the following functions are really private, made non-static only for the benefit of shlibs */
static uintptr_t hashPtrStructKey (const void *info, const void *data) {
return NXPtrHash(info, *((void **) data));
};
static int isEqualPtrStructKey (const void *info, const void *data1, const void *data2) {
return NXPtrIsEqual (info, *((void **) data1), *((void **) data2));
};
static uintptr_t hashStrStructKey (const void *info, const void *data) {
return NXStrHash(info, *((char **) data));
};
static int isEqualStrStructKey (const void *info, const void *data1, const void *data2) {
return NXStrIsEqual (info, *((char **) data1), *((char **) data2));
};
const NXHashTablePrototype NXPtrPrototype = {
NXPtrHash, NXPtrIsEqual, NXNoEffectFree, 0
};
const NXHashTablePrototype NXStrPrototype = {
NXStrHash, NXStrIsEqual, NXNoEffectFree, 0
};
const NXHashTablePrototype NXPtrStructKeyPrototype = {
hashPtrStructKey, isEqualPtrStructKey, NXReallyFree, 0
};
const NXHashTablePrototype NXStrStructKeyPrototype = {
hashStrStructKey, isEqualStrStructKey, NXReallyFree, 0
};
/*************************************************************************
*
* Unique strings
*
*************************************************************************/
#if !__OBJC2__ && !TARGET_OS_WIN32
/* the implementation could be made faster at the expense of memory if the size of the strings were kept around */
static NXHashTable *uniqueStrings = NULL;
/* this is based on most apps using a few K of strings, and an average string size of 15 using sqrt(2*dataAlloced*perChunkOverhead) */
#define CHUNK_SIZE 360
static int accessUniqueString = 0;
static char *z = NULL;
static size_t zSize = 0;
static mutex_t lock = MUTEX_INITIALIZER;
static const char *CopyIntoReadOnly (const char *str) {
size_t len = strlen (str) + 1;
char *result;
if (len > CHUNK_SIZE/2) { /* dont let big strings waste space */
result = (char *)malloc (len);
bcopy (str, result, len);
return result;
}
mutex_lock (&lock);
if (zSize < len) {
zSize = CHUNK_SIZE *((len + CHUNK_SIZE - 1) / CHUNK_SIZE);
/* not enough room, we try to allocate. If no room left, too bad */
z = (char *)malloc (zSize);
};
result = z;
bcopy (str, result, len);
z += len;
zSize -= len;
mutex_unlock (&lock);
return result;
};
NXAtom NXUniqueString (const char *buffer) {
const char *previous;
if (! buffer) return buffer;
accessUniqueString++;
if (! uniqueStrings)
uniqueStrings = NXCreateHashTable (NXStrPrototype, 0, NULL);
previous = (const char *) NXHashGet (uniqueStrings, buffer);
if (previous) return previous;
previous = CopyIntoReadOnly (buffer);
if (NXHashInsert (uniqueStrings, previous)) {
_objc_inform ("*** NXUniqueString: invariant broken\n");
return NULL;
};
return previous;
};
NXAtom NXUniqueStringNoCopy (const char *string) {
accessUniqueString++;
if (! uniqueStrings)
uniqueStrings = NXCreateHashTable (NXStrPrototype, 0, NULL);
return (const char *) NXHashInsertIfAbsent (uniqueStrings, string);
};
#define BUF_SIZE 256
NXAtom NXUniqueStringWithLength (const char *buffer, int length) {
NXAtom atom;
char *nullTermStr;
char stackBuf[BUF_SIZE];
if (length+1 > BUF_SIZE)
nullTermStr = (char *)malloc (length+1);
else
nullTermStr = stackBuf;
bcopy (buffer, nullTermStr, length);
nullTermStr[length] = '\0';
atom = NXUniqueString (nullTermStr);
if (length+1 > BUF_SIZE)
free (nullTermStr);
return atom;
};
char *NXCopyStringBufferFromZone (const char *str, void *zone) {
#if !SUPPORT_ZONES
return strdup(str);
#else
return strcpy ((char *) malloc_zone_malloc((malloc_zone_t *)zone, strlen (str) + 1), str);
#endif
};
char *NXCopyStringBuffer (const char *str) {
return strdup(str);
};
#endif