1/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2/*
3 * The contents of this file are subject to the Mozilla Public
4 * License Version 1.1 (the "License"); you may not use this file
5 * except in compliance with the License. You may obtain a copy of
6 * the License at http://www.mozilla.org/MPL/
7 *
8 * Software distributed under the License is distributed on an "AS
9 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
10 * implied. See the License for the specific language governing
11 * rights and limitations under the License.
12 *
13 * The Original Code is the Netscape Portable Runtime (NSPR).
14 *
15 * The Initial Developer of the Original Code is Netscape
16 * Communications Corporation.  Portions created by Netscape are
17 * Copyright (C) 1998-2000 Netscape Communications Corporation.  All
18 * Rights Reserved.
19 *
20 * Contributor(s):
21 *
22 * Alternatively, the contents of this file may be used under the
23 * terms of the GNU General Public License Version 2 or later (the
24 * "GPL"), in which case the provisions of the GPL are applicable
25 * instead of those above.  If you wish to allow use of your
26 * version of this file only under the terms of the GPL and not to
27 * allow others to use your version of this file under the MPL,
28 * indicate your decision by deleting the provisions above and
29 * replace them with the notice and other provisions required by
30 * the GPL.  If you do not delete the provisions above, a recipient
31 * may use your version of this file under either the MPL or the
32 * GPL.
33 */
34
35#ifndef plhash_h___
36#define plhash_h___
37/*
38 * API to portable hash table code.
39 */
40#include <stdio.h>
41#include <security_asn1/prtypes.h>
42// @@@ for Boolean
43#include <Security/SecBase.h>
44
45PR_BEGIN_EXTERN_C
46
47typedef struct PLHashEntry  PLHashEntry;
48typedef struct PLHashTable  PLHashTable;
49typedef PRUint32 PLHashNumber;
50#define PL_HASH_BITS 32  /* Number of bits in PLHashNumber */
51typedef PLHashNumber (PR_CALLBACK *PLHashFunction)(const void *key);
52typedef PRIntn (PR_CALLBACK *PLHashComparator)(const void *v1, const void *v2);
53
54#if defined(XP_OS2_VACPP) && defined(VACPP_FLIP) /* for nsSpaceManager.cpp */
55PR_END_EXTERN_C                                  /* and nsHTMLDocument.cpp */
56#endif
57typedef PRIntn (PR_CALLBACK *PLHashEnumerator)(PLHashEntry *he, PRIntn i, void *arg);
58
59#if defined(XP_OS2_VACPP) && defined(VACPP_FLIP)
60PR_BEGIN_EXTERN_C
61#endif
62
63/* Flag bits in PLHashEnumerator's return value */
64#define HT_ENUMERATE_NEXT       0       /* continue enumerating entries */
65#define HT_ENUMERATE_STOP       1       /* stop enumerating entries */
66#define HT_ENUMERATE_REMOVE     2       /* remove and free the current entry */
67#define HT_ENUMERATE_UNHASH     4       /* just unhash the current entry */
68
69typedef struct PLHashAllocOps {
70    void *              (PR_CALLBACK *allocTable)(void *pool, PRSize size);
71    void                (PR_CALLBACK *freeTable)(void *pool, void *item);
72    PLHashEntry *       (PR_CALLBACK *allocEntry)(void *pool, const void *key);
73    void                (PR_CALLBACK *freeEntry)(void *pool, PLHashEntry *he, PRUintn flag);
74} PLHashAllocOps;
75
76#define HT_FREE_VALUE   0               /* just free the entry's value */
77#define HT_FREE_ENTRY   1               /* free value and entire entry */
78
79struct PLHashEntry {
80    PLHashEntry         *next;          /* hash chain linkage */
81    PLHashNumber        keyHash;        /* key hash function result */
82    const void          *key;           /* ptr to opaque key */
83    void                *value;         /* ptr to opaque value */
84};
85
86struct PLHashTable {
87    PLHashEntry         **buckets;      /* vector of hash buckets */
88    PRUint32              nentries;       /* number of entries in table */
89    PRUint32              shift;          /* multiplicative hash shift */
90    PLHashFunction      keyHash;        /* key hash function */
91    PLHashComparator    keyCompare;     /* key comparison function */
92    PLHashComparator    valueCompare;   /* value comparison function */
93    const PLHashAllocOps *allocOps;     /* allocation operations */
94    void                *allocPriv;     /* allocation private data */
95#ifdef HASHMETER
96    PRUint32              nlookups;       /* total number of lookups */
97    PRUint32              nsteps;         /* number of hash chains traversed */
98    PRUint32              ngrows;         /* number of table expansions */
99    PRUint32              nshrinks;       /* number of table contractions */
100#endif
101};
102
103/*
104 * Create a new hash table.
105 * If allocOps is null, use default allocator ops built on top of malloc().
106 */
107PR_EXTERN(PLHashTable *)
108PL_NewHashTable(PRUint32 numBuckets, PLHashFunction keyHash,
109                PLHashComparator keyCompare, PLHashComparator valueCompare,
110                const PLHashAllocOps *allocOps, void *allocPriv);
111
112PR_EXTERN(void)
113PL_HashTableDestroy(PLHashTable *ht);
114
115/* Higher level access methods */
116PR_EXTERN(PLHashEntry *)
117PL_HashTableAdd(PLHashTable *ht, const void *key, void *value);
118
119PR_EXTERN(Boolean)
120PL_HashTableRemove(PLHashTable *ht, const void *key);
121
122PR_EXTERN(void *)
123PL_HashTableLookup(PLHashTable *ht, const void *key);
124
125PR_EXTERN(void *)
126PL_HashTableLookupConst(PLHashTable *ht, const void *key);
127
128PR_EXTERN(PRIntn)
129PL_HashTableEnumerateEntries(PLHashTable *ht, PLHashEnumerator f, void *arg);
130
131/* General-purpose C string hash function. */
132PR_EXTERN(PLHashNumber)
133PL_HashString(const void *key);
134
135/* Compare strings using strcmp(), return true if equal. */
136PR_EXTERN(PRIntn)
137PL_CompareStrings(const void *v1, const void *v2);
138
139/* Stub function just returns v1 == v2 */
140PR_EXTERN(PRIntn)
141PL_CompareValues(const void *v1, const void *v2);
142
143/* Low level access methods */
144PR_EXTERN(PLHashEntry **)
145PL_HashTableRawLookup(PLHashTable *ht, PLHashNumber keyHash, const void *key);
146
147PR_EXTERN(PLHashEntry **)
148PL_HashTableRawLookupConst(PLHashTable *ht, PLHashNumber keyHash,
149                           const void *key);
150
151PR_EXTERN(PLHashEntry *)
152PL_HashTableRawAdd(PLHashTable *ht, PLHashEntry **hep, PLHashNumber keyHash,
153                   const void *key, void *value);
154
155PR_EXTERN(void)
156PL_HashTableRawRemove(PLHashTable *ht, PLHashEntry **hep, PLHashEntry *he);
157
158/* This can be trivially implemented using PL_HashTableEnumerateEntries. */
159PR_EXTERN(PRIntn)
160PL_HashTableDump(PLHashTable *ht, PLHashEnumerator dump, FILE *fp);
161
162PR_END_EXTERN_C
163
164#endif /* plhash_h___ */
165