js/src/liveconnect/jsj_hash.h

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  *
   3  * ***** BEGIN LICENSE BLOCK *****
   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
   8  * the License. You may obtain a copy of the License at
   9  * http://www.mozilla.org/MPL/
  10  *
  11  * Software distributed under the License is distributed on an "AS IS" basis,
  12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  13  * for the specific language governing rights and limitations under the
  14  * License.
  15  *
  16  * The Original Code is Mozilla Communicator client code, released
  17  * March 31, 1998.
  18  *
  19  * The Initial Developer of the Original Code is
  20  * Netscape Communications Corporation.
  21  * Portions created by the Initial Developer are Copyright (C) 1998
  22  * the Initial Developer. All Rights Reserved.
  23  *
  24  * Contributor(s):
  25  *
  26  * Alternatively, the contents of this file may be used under the terms of
  27  * either of the GNU General Public License Version 2 or later (the "GPL"),
  28  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  29  * in which case the provisions of the GPL or the LGPL are applicable instead
  30  * of those above. If you wish to allow use of your version of this file only
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  35  * the provisions above, a recipient may use your version of this file under
  36  * the terms of any one of the MPL, the GPL or the LGPL.
  37  *
  38  * ***** END LICENSE BLOCK ***** */
  39
  40 /*
  41  * This is a copy of the NSPR hash-table library, but it has been slightly
  42  * modified to allow an additional argument to be passed into the hash
  43  * key-comparison function.  This is used to maintain thread-safety by
  44  * passing in a JNIEnv pointer to the key-comparison function rather
  45  * than storing it in a global.  All types,function names, etc. have
  46  * been renamed from their original NSPR names to protect the innocent.
  47  */
  48
  49 #ifndef jsj_hash_h___
  50 #define jsj_hash_h___
  51 /*
  52  * API to portable hash table code.
  53  */
  54 #include <stddef.h>
  55 #include <stdio.h>
  56 #include "jstypes.h"
  57
  58 JS_BEGIN_EXTERN_C
  59
  60 typedef struct JSJHashEntry  JSJHashEntry;
  61 typedef struct JSJHashTable  JSJHashTable;
  62 typedef JSUint32 JSJHashNumber;
  63 #define JSJ_HASH_BITS 32
  64 typedef JSJHashNumber (* JSJHashFunction)(const void *key, void *arg);
  65 typedef JSIntn (* JSJHashComparator)(const void *v1, const void *v2, void *arg);
  66 typedef JSIntn (* JSJHashEnumerator)(JSJHashEntry *he, JSIntn i, void *arg);
  67
  68 /* Flag bits in JSJHashEnumerator's return value */
  69 #define HT_ENUMERATE_NEXT       0       /* continue enumerating entries */
  70 #define HT_ENUMERATE_STOP       1       /* stop enumerating entries */
  71 #define HT_ENUMERATE_REMOVE     2       /* remove and free the current entry */
  72 #define HT_ENUMERATE_UNHASH     4       /* just unhash the current entry */
  73
  74 typedef struct JSJHashAllocOps {
  75     void *              (*allocTable)(void *pool, size_t size);
  76     void                (*freeTable)(void *pool, void *item);
  77     JSJHashEntry *      (*allocEntry)(void *pool, const void *key);
  78     void                (*freeEntry)(void *pool, JSJHashEntry *he, JSUintn flag);
  79 } JSJHashAllocOps;
  80
  81 #define HT_FREE_VALUE   0               /* just free the entry's value */
  82 #define HT_FREE_ENTRY   1               /* free value and entire entry */
  83
  84 struct JSJHashEntry {
  85     JSJHashEntry        *next;          /* hash chain linkage */
  86     JSJHashNumber       keyHash;        /* key hash function result */
  87     const void          *key;           /* ptr to opaque key */
  88     void                *value;         /* ptr to opaque value */
  89 };
  90
  91 struct JSJHashTable {
  92     JSJHashEntry         **buckets;      /* vector of hash buckets */
  93     JSUint32              nentries;       /* number of entries in table */
  94     JSUint32              shift;          /* multiplicative hash shift */
  95     JSJHashFunction     keyHash;        /* key hash function */
  96     JSJHashComparator   keyCompare;     /* key comparison function */
  97     JSJHashComparator   valueCompare;   /* value comparison function */
  98     JSJHashAllocOps     *allocOps;      /* allocation operations */
  99     void                *allocPriv;     /* allocation private data */
 100 #ifdef HASHMETER
 101     JSUint32              nlookups;       /* total number of lookups */
 102     JSUint32              nsteps;         /* number of hash chains traversed */
 103     JSUint32              ngrows;         /* number of table expansions */
 104     JSUint32              nshrinks;       /* number of table contractions */
 105 #endif
 106 };
 107
 108 /*
 109  * Create a new hash table.
 110  * If allocOps is null, use default allocator ops built on top of malloc().
 111  */
 112 JS_EXTERN_API(JSJHashTable *)
 113 JSJ_NewHashTable(JSUint32 n, JSJHashFunction keyHash,
 114                 JSJHashComparator keyCompare, JSJHashComparator valueCompare,
 115                 JSJHashAllocOps *allocOps, void *allocPriv);
 116
 117 JS_EXTERN_API(void)
 118 JSJ_HashTableDestroy(JSJHashTable *ht);
 119
 120 /* Low level access methods */
 121 JS_EXTERN_API(JSJHashEntry **)
 122 JSJ_HashTableRawLookup(JSJHashTable *ht, JSJHashNumber keyHash, const void *key, void *arg);
 123
 124 JS_EXTERN_API(JSJHashEntry *)
 125 JSJ_HashTableRawAdd(JSJHashTable *ht, JSJHashEntry **hep, JSJHashNumber keyHash,
 126                    const void *key, void *value, void *arg);
 127
 128 JS_EXTERN_API(void)
 129 JSJ_HashTableRawRemove(JSJHashTable *ht, JSJHashEntry **hep, JSJHashEntry *he, void *arg);
 130
 131 /* Higher level access methods */
 132 JS_EXTERN_API(JSJHashEntry *)
 133 JSJ_HashTableAdd(JSJHashTable *ht, const void *key, void *value, void *arg);
 134
 135 JS_EXTERN_API(JSBool)
 136 JSJ_HashTableRemove(JSJHashTable *ht, const void *key, void *arg);
 137
 138 JS_EXTERN_API(JSIntn)
 139 JSJ_HashTableEnumerateEntries(JSJHashTable *ht, JSJHashEnumerator f, void *arg);
 140
 141 JS_EXTERN_API(void *)
 142 JSJ_HashTableLookup(JSJHashTable *ht, const void *key, void *arg);
 143
 144 JS_EXTERN_API(JSIntn)
 145 JSJ_HashTableDump(JSJHashTable *ht, JSJHashEnumerator dump, FILE *fp);
 146
 147 /* General-purpose C string hash function. */
 148 JS_EXTERN_API(JSJHashNumber)
 149 JSJ_HashString(const void *key);
 150
 151 /* Compare strings using strcmp(), return true if equal. */
 152 JS_EXTERN_API(int)
 153 JSJ_CompareStrings(const void *v1, const void *v2);
 154
 155 /* Stub function just returns v1 == v2 */
 156 JS_EXTERN_API(JSIntn)
 157 JSJ_CompareValues(const void *v1, const void *v2);
 158
 159 JS_END_EXTERN_C
 160
 161 #endif /* jsj_hash_h___ */