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Diffstat (limited to 'nsprpub/lib/ds/plhash.h')
| -rw-r--r-- | nsprpub/lib/ds/plhash.h | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/nsprpub/lib/ds/plhash.h b/nsprpub/lib/ds/plhash.h new file mode 100644 index 000000000..2c221aed7 --- /dev/null +++ b/nsprpub/lib/ds/plhash.h @@ -0,0 +1,126 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef plhash_h___ +#define plhash_h___ +/* + * API to portable hash table code. + */ +#include <stdio.h> +#include "prtypes.h" + +PR_BEGIN_EXTERN_C + +typedef struct PLHashEntry PLHashEntry; +typedef struct PLHashTable PLHashTable; +typedef PRUint32 PLHashNumber; +#define PL_HASH_BITS 32 /* Number of bits in PLHashNumber */ +typedef PLHashNumber (PR_CALLBACK *PLHashFunction)(const void *key); +typedef PRIntn (PR_CALLBACK *PLHashComparator)(const void *v1, const void *v2); + +typedef PRIntn (PR_CALLBACK *PLHashEnumerator)(PLHashEntry *he, PRIntn i, void *arg); + +/* Flag bits in PLHashEnumerator's return value */ +#define HT_ENUMERATE_NEXT 0 /* continue enumerating entries */ +#define HT_ENUMERATE_STOP 1 /* stop enumerating entries */ +#define HT_ENUMERATE_REMOVE 2 /* remove and free the current entry */ +#define HT_ENUMERATE_UNHASH 4 /* just unhash the current entry */ + +typedef struct PLHashAllocOps { + void * (PR_CALLBACK *allocTable)(void *pool, PRSize size); + void (PR_CALLBACK *freeTable)(void *pool, void *item); + PLHashEntry * (PR_CALLBACK *allocEntry)(void *pool, const void *key); + void (PR_CALLBACK *freeEntry)(void *pool, PLHashEntry *he, PRUintn flag); +} PLHashAllocOps; + +#define HT_FREE_VALUE 0 /* just free the entry's value */ +#define HT_FREE_ENTRY 1 /* free value and entire entry */ + +struct PLHashEntry { + PLHashEntry *next; /* hash chain linkage */ + PLHashNumber keyHash; /* key hash function result */ + const void *key; /* ptr to opaque key */ + void *value; /* ptr to opaque value */ +}; + +struct PLHashTable { + PLHashEntry **buckets; /* vector of hash buckets */ + PRUint32 nentries; /* number of entries in table */ + PRUint32 shift; /* multiplicative hash shift */ + PLHashFunction keyHash; /* key hash function */ + PLHashComparator keyCompare; /* key comparison function */ + PLHashComparator valueCompare; /* value comparison function */ + const PLHashAllocOps *allocOps; /* allocation operations */ + void *allocPriv; /* allocation private data */ +#ifdef HASHMETER + PRUint32 nlookups; /* total number of lookups */ + PRUint32 nsteps; /* number of hash chains traversed */ + PRUint32 ngrows; /* number of table expansions */ + PRUint32 nshrinks; /* number of table contractions */ +#endif +}; + +/* + * Create a new hash table. + * If allocOps is null, use default allocator ops built on top of malloc(). + */ +PR_EXTERN(PLHashTable *) +PL_NewHashTable(PRUint32 numBuckets, PLHashFunction keyHash, + PLHashComparator keyCompare, PLHashComparator valueCompare, + const PLHashAllocOps *allocOps, void *allocPriv); + +PR_EXTERN(void) +PL_HashTableDestroy(PLHashTable *ht); + +/* Higher level access methods */ +PR_EXTERN(PLHashEntry *) +PL_HashTableAdd(PLHashTable *ht, const void *key, void *value); + +PR_EXTERN(PRBool) +PL_HashTableRemove(PLHashTable *ht, const void *key); + +PR_EXTERN(void *) +PL_HashTableLookup(PLHashTable *ht, const void *key); + +PR_EXTERN(void *) +PL_HashTableLookupConst(PLHashTable *ht, const void *key); + +PR_EXTERN(PRIntn) +PL_HashTableEnumerateEntries(PLHashTable *ht, PLHashEnumerator f, void *arg); + +/* General-purpose C string hash function. */ +PR_EXTERN(PLHashNumber) +PL_HashString(const void *key); + +/* Compare strings using strcmp(), return true if equal. */ +PR_EXTERN(PRIntn) +PL_CompareStrings(const void *v1, const void *v2); + +/* Stub function just returns v1 == v2 */ +PR_EXTERN(PRIntn) +PL_CompareValues(const void *v1, const void *v2); + +/* Low level access methods */ +PR_EXTERN(PLHashEntry **) +PL_HashTableRawLookup(PLHashTable *ht, PLHashNumber keyHash, const void *key); + +PR_EXTERN(PLHashEntry **) +PL_HashTableRawLookupConst(PLHashTable *ht, PLHashNumber keyHash, + const void *key); + +PR_EXTERN(PLHashEntry *) +PL_HashTableRawAdd(PLHashTable *ht, PLHashEntry **hep, PLHashNumber keyHash, + const void *key, void *value); + +PR_EXTERN(void) +PL_HashTableRawRemove(PLHashTable *ht, PLHashEntry **hep, PLHashEntry *he); + +/* This can be trivially implemented using PL_HashTableEnumerateEntries. */ +PR_EXTERN(PRIntn) +PL_HashTableDump(PLHashTable *ht, PLHashEnumerator dump, FILE *fp); + +PR_END_EXTERN_C + +#endif /* plhash_h___ */ |