libsecurity_smime/lib/plhash.h

   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
  43 PR_BEGIN_EXTERN_C
  44
  45 typedef struct PLHashEntry  PLHashEntry;
  46 typedef struct PLHashTable  PLHashTable;
  47 typedef PRUint32 PLHashNumber;
  48 #define PL_HASH_BITS 32  /* Number of bits in PLHashNumber */
  49 typedef PLHashNumber (PR_CALLBACK *PLHashFunction)(const void *key);
  50 typedef PRIntn (PR_CALLBACK *PLHashComparator)(const void *v1, const void *v2);
  51
  52 #if defined(XP_OS2_VACPP) && defined(VACPP_FLIP) /* for nsSpaceManager.cpp */
  53 PR_END_EXTERN_C                                  /* and nsHTMLDocument.cpp */
  54 #endif
  55 typedef PRIntn (PR_CALLBACK *PLHashEnumerator)(PLHashEntry *he, PRIntn i, void *arg);
  56
  57 #if defined(XP_OS2_VACPP) && defined(VACPP_FLIP)
  58 PR_BEGIN_EXTERN_C
  59 #endif
  60
  61 /* Flag bits in PLHashEnumerator's return value */
  62 #define HT_ENUMERATE_NEXT       0       /* continue enumerating entries */
  63 #define HT_ENUMERATE_STOP       1       /* stop enumerating entries */
  64 #define HT_ENUMERATE_REMOVE     2       /* remove and free the current entry */
  65 #define HT_ENUMERATE_UNHASH     4       /* just unhash the current entry */
  66
  67 typedef struct PLHashAllocOps {
  68     void *              (PR_CALLBACK *allocTable)(void *pool, PRSize size);
  69     void                (PR_CALLBACK *freeTable)(void *pool, void *item);
  70     PLHashEntry *       (PR_CALLBACK *allocEntry)(void *pool, const void *key);
  71     void                (PR_CALLBACK *freeEntry)(void *pool, PLHashEntry *he, PRUintn flag);
  72 } PLHashAllocOps;
  73
  74 #define HT_FREE_VALUE   0               /* just free the entry's value */
  75 #define HT_FREE_ENTRY   1               /* free value and entire entry */
  76
  77 struct PLHashEntry {
  78     PLHashEntry         *next;          /* hash chain linkage */
  79     PLHashNumber        keyHash;        /* key hash function result */
  80     const void          *key;           /* ptr to opaque key */
  81     void                *value;         /* ptr to opaque value */
  82 };
  83
  84 struct PLHashTable {
  85     PLHashEntry         **buckets;      /* vector of hash buckets */
  86     PRUint32              nentries;       /* number of entries in table */
  87     PRUint32              shift;          /* multiplicative hash shift */
  88     PLHashFunction      keyHash;        /* key hash function */
  89     PLHashComparator    keyCompare;     /* key comparison function */
  90     PLHashComparator    valueCompare;   /* value comparison function */
  91     const PLHashAllocOps *allocOps;     /* allocation operations */
  92     void                *allocPriv;     /* allocation private data */
  93 #ifdef HASHMETER
  94     PRUint32              nlookups;       /* total number of lookups */
  95     PRUint32              nsteps;         /* number of hash chains traversed */
  96     PRUint32              ngrows;         /* number of table expansions */
  97     PRUint32              nshrinks;       /* number of table contractions */
  98 #endif
  99 };
 100
 101 /*
 102  * Create a new hash table.
 103  * If allocOps is null, use default allocator ops built on top of malloc().
 104  */
 105 PR_EXTERN(PLHashTable *)
 106 PL_NewHashTable(PRUint32 numBuckets, PLHashFunction keyHash,
 107                 PLHashComparator keyCompare, PLHashComparator valueCompare,
 108                 const PLHashAllocOps *allocOps, void *allocPriv);
 109
 110 PR_EXTERN(void)
 111 PL_HashTableDestroy(PLHashTable *ht);
 112
 113 /* Higher level access methods */
 114 PR_EXTERN(PLHashEntry *)
 115 PL_HashTableAdd(PLHashTable *ht, const void *key, void *value);
 116
 117 PR_EXTERN(unsigned char)
 118 PL_HashTableRemove(PLHashTable *ht, const void *key);
 119
 120 PR_EXTERN(void *)
 121 PL_HashTableLookup(PLHashTable *ht, const void *key);
 122
 123 PR_EXTERN(void *)
 124 PL_HashTableLookupConst(PLHashTable *ht, const void *key);
 125
 126 PR_EXTERN(PRIntn)
 127 PL_HashTableEnumerateEntries(PLHashTable *ht, PLHashEnumerator f, void *arg);
 128
 129 /* General-purpose C string hash function. */
 130 PR_EXTERN(PLHashNumber)
 131 PL_HashString(const void *key);
 132
 133 /* Compare strings using strcmp(), return true if equal. */
 134 PR_EXTERN(PRIntn)
 135 PL_CompareStrings(const void *v1, const void *v2);
 136
 137 /* Stub function just returns v1 == v2 */
 138 PR_EXTERN(PRIntn)
 139 PL_CompareValues(const void *v1, const void *v2);
 140
 141 /* Low level access methods */
 142 PR_EXTERN(PLHashEntry **)
 143 PL_HashTableRawLookup(PLHashTable *ht, PLHashNumber keyHash, const void *key);
 144
 145 PR_EXTERN(PLHashEntry **)
 146 PL_HashTableRawLookupConst(PLHashTable *ht, PLHashNumber keyHash,
 147                            const void *key);
 148
 149 PR_EXTERN(PLHashEntry *)
 150 PL_HashTableRawAdd(PLHashTable *ht, PLHashEntry **hep, PLHashNumber keyHash,
 151                    const void *key, void *value);
 152
 153 PR_EXTERN(void)
 154 PL_HashTableRawRemove(PLHashTable *ht, PLHashEntry **hep, PLHashEntry *he);
 155
 156 /* This can be trivially implemented using PL_HashTableEnumerateEntries. */
 157 PR_EXTERN(PRIntn)
 158 PL_HashTableDump(PLHashTable *ht, PLHashEnumerator dump, FILE *fp);
 159
 160 PR_END_EXTERN_C
 161
 162 #endif /* plhash_h___ */