michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0:  * hash.c
michael@0:  *
michael@0:  * This is merely a couple wrappers around NSPR's PLHashTable, using
michael@0:  * the identity hash and arena-aware allocators.
michael@0:  * This is a copy of ckfw/hash.c, with modifications to use NSS types
michael@0:  * (not Cryptoki types).  Would like for this to be a single implementation,
michael@0:  * but doesn't seem like it will work.
michael@0:  */
michael@0: 
michael@0: #ifndef BASE_H
michael@0: #include "base.h"
michael@0: #endif /* BASE_H */
michael@0: 
michael@0: #include "prbit.h"
michael@0: 
michael@0: /*
michael@0:  * nssHash
michael@0:  *
michael@0:  *  nssHash_Create
michael@0:  *  nssHash_Destroy
michael@0:  *  nssHash_Add
michael@0:  *  nssHash_Remove
michael@0:  *  nssHash_Count
michael@0:  *  nssHash_Exists
michael@0:  *  nssHash_Lookup
michael@0:  *  nssHash_Iterate
michael@0:  */
michael@0: 
michael@0: struct nssHashStr {
michael@0:   NSSArena *arena;
michael@0:   PRBool i_alloced_arena;
michael@0:   PRLock *mutex;
michael@0: 
michael@0:   /*
michael@0:    * The invariant that mutex protects is:
michael@0:    *   The count accurately reflects the hashtable state.
michael@0:    */
michael@0: 
michael@0:   PLHashTable *plHashTable;
michael@0:   PRUint32 count;
michael@0: };
michael@0: 
michael@0: static PLHashNumber
michael@0: nss_identity_hash
michael@0: (
michael@0:   const void *key
michael@0: )
michael@0: {
michael@0:   PRUint32 i = (PRUint32)key;
michael@0:   PR_ASSERT(sizeof(PLHashNumber) == sizeof(PRUint32));
michael@0:   return (PLHashNumber)i;
michael@0: }
michael@0: 
michael@0: static PLHashNumber
michael@0: nss_item_hash
michael@0: (
michael@0:   const void *key
michael@0: )
michael@0: {
michael@0:   unsigned int i;
michael@0:   PLHashNumber h;
michael@0:   NSSItem *it = (NSSItem *)key;
michael@0:   h = 0;
michael@0:   for (i=0; i<it->size; i++)
michael@0:     h = PR_ROTATE_LEFT32(h, 4) ^ ((unsigned char *)it->data)[i];
michael@0:   return h;
michael@0: }
michael@0: 
michael@0: static int
michael@0: nss_compare_items(const void *v1, const void *v2)
michael@0: {
michael@0:   PRStatus ignore;
michael@0:   return (int)nssItem_Equal((NSSItem *)v1, (NSSItem *)v2, &ignore);
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * nssHash_create
michael@0:  *
michael@0:  */
michael@0: NSS_IMPLEMENT nssHash *
michael@0: nssHash_Create
michael@0: (
michael@0:   NSSArena *arenaOpt,
michael@0:   PRUint32 numBuckets,
michael@0:   PLHashFunction keyHash,
michael@0:   PLHashComparator keyCompare,
michael@0:   PLHashComparator valueCompare
michael@0: )
michael@0: {
michael@0:   nssHash *rv;
michael@0:   NSSArena *arena;
michael@0:   PRBool i_alloced;
michael@0: 
michael@0: #ifdef NSSDEBUG
michael@0:   if( arenaOpt && PR_SUCCESS != nssArena_verifyPointer(arenaOpt) ) {
michael@0:     nss_SetError(NSS_ERROR_INVALID_POINTER);
michael@0:     return (nssHash *)NULL;
michael@0:   }
michael@0: #endif /* NSSDEBUG */
michael@0: 
michael@0:   if (arenaOpt) {
michael@0:     arena = arenaOpt;
michael@0:     i_alloced = PR_FALSE;
michael@0:   } else {
michael@0:     arena = nssArena_Create();
michael@0:     i_alloced = PR_TRUE;
michael@0:   }
michael@0: 
michael@0:   rv = nss_ZNEW(arena, nssHash);
michael@0:   if( (nssHash *)NULL == rv ) {
michael@0:     goto loser;
michael@0:   }
michael@0: 
michael@0:   rv->mutex = PZ_NewLock(nssILockOther);
michael@0:   if( (PZLock *)NULL == rv->mutex ) {
michael@0:     goto loser;
michael@0:   }
michael@0: 
michael@0:   rv->plHashTable = PL_NewHashTable(numBuckets, 
michael@0:                                     keyHash, keyCompare, valueCompare,
michael@0:                                     &nssArenaHashAllocOps, arena);
michael@0:   if( (PLHashTable *)NULL == rv->plHashTable ) {
michael@0:     (void)PZ_DestroyLock(rv->mutex);
michael@0:     goto loser;
michael@0:   }
michael@0: 
michael@0:   rv->count = 0;
michael@0:   rv->arena = arena;
michael@0:   rv->i_alloced_arena = i_alloced;
michael@0: 
michael@0:   return rv;
michael@0: loser:
michael@0:   (void)nss_ZFreeIf(rv);
michael@0:   return (nssHash *)NULL;
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * nssHash_CreatePointer
michael@0:  *
michael@0:  */
michael@0: NSS_IMPLEMENT nssHash *
michael@0: nssHash_CreatePointer
michael@0: (
michael@0:   NSSArena *arenaOpt,
michael@0:   PRUint32 numBuckets
michael@0: )
michael@0: {
michael@0:   return nssHash_Create(arenaOpt, numBuckets, 
michael@0:                         nss_identity_hash, PL_CompareValues, PL_CompareValues);
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * nssHash_CreateString
michael@0:  *
michael@0:  */
michael@0: NSS_IMPLEMENT nssHash *
michael@0: nssHash_CreateString
michael@0: (
michael@0:   NSSArena *arenaOpt,
michael@0:   PRUint32 numBuckets
michael@0: )
michael@0: {
michael@0:   return nssHash_Create(arenaOpt, numBuckets, 
michael@0:                         PL_HashString, PL_CompareStrings, PL_CompareStrings);
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * nssHash_CreateItem
michael@0:  *
michael@0:  */
michael@0: NSS_IMPLEMENT nssHash *
michael@0: nssHash_CreateItem
michael@0: (
michael@0:   NSSArena *arenaOpt,
michael@0:   PRUint32 numBuckets
michael@0: )
michael@0: {
michael@0:   return nssHash_Create(arenaOpt, numBuckets, 
michael@0:                         nss_item_hash, nss_compare_items, PL_CompareValues);
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * nssHash_Destroy
michael@0:  *
michael@0:  */
michael@0: NSS_IMPLEMENT void
michael@0: nssHash_Destroy
michael@0: (
michael@0:   nssHash *hash
michael@0: )
michael@0: {
michael@0:   (void)PZ_DestroyLock(hash->mutex);
michael@0:   PL_HashTableDestroy(hash->plHashTable);
michael@0:   if (hash->i_alloced_arena) {
michael@0:     nssArena_Destroy(hash->arena);
michael@0:   } else {
michael@0:     nss_ZFreeIf(hash);
michael@0:   }
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * nssHash_Add
michael@0:  *
michael@0:  */
michael@0: NSS_IMPLEMENT PRStatus
michael@0: nssHash_Add
michael@0: (
michael@0:   nssHash *hash,
michael@0:   const void *key,
michael@0:   const void *value
michael@0: )
michael@0: {
michael@0:   PRStatus error = PR_FAILURE;
michael@0:   PLHashEntry *he;
michael@0: 
michael@0:   PZ_Lock(hash->mutex);
michael@0:   
michael@0:   he = PL_HashTableAdd(hash->plHashTable, key, (void *)value);
michael@0:   if( (PLHashEntry *)NULL == he ) {
michael@0:     nss_SetError(NSS_ERROR_NO_MEMORY);
michael@0:   } else if (he->value != value) {
michael@0:     nss_SetError(NSS_ERROR_HASH_COLLISION);
michael@0:   } else {
michael@0:     hash->count++;
michael@0:     error = PR_SUCCESS;
michael@0:   }
michael@0: 
michael@0:   (void)PZ_Unlock(hash->mutex);
michael@0: 
michael@0:   return error;
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * nssHash_Remove
michael@0:  *
michael@0:  */
michael@0: NSS_IMPLEMENT void
michael@0: nssHash_Remove
michael@0: (
michael@0:   nssHash *hash,
michael@0:   const void *it
michael@0: )
michael@0: {
michael@0:   PRBool found;
michael@0: 
michael@0:   PZ_Lock(hash->mutex);
michael@0: 
michael@0:   found = PL_HashTableRemove(hash->plHashTable, it);
michael@0:   if( found ) {
michael@0:     hash->count--;
michael@0:   }
michael@0: 
michael@0:   (void)PZ_Unlock(hash->mutex);
michael@0:   return;
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * nssHash_Count
michael@0:  *
michael@0:  */
michael@0: NSS_IMPLEMENT PRUint32
michael@0: nssHash_Count
michael@0: (
michael@0:   nssHash *hash
michael@0: )
michael@0: {
michael@0:   PRUint32 count;
michael@0: 
michael@0:   PZ_Lock(hash->mutex);
michael@0: 
michael@0:   count = hash->count;
michael@0: 
michael@0:   (void)PZ_Unlock(hash->mutex);
michael@0: 
michael@0:   return count;
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * nssHash_Exists
michael@0:  *
michael@0:  */
michael@0: NSS_IMPLEMENT PRBool
michael@0: nssHash_Exists
michael@0: (
michael@0:   nssHash *hash,
michael@0:   const void *it
michael@0: )
michael@0: {
michael@0:   void *value;
michael@0: 
michael@0:   PZ_Lock(hash->mutex);
michael@0: 
michael@0:   value = PL_HashTableLookup(hash->plHashTable, it);
michael@0: 
michael@0:   (void)PZ_Unlock(hash->mutex);
michael@0: 
michael@0:   if( (void *)NULL == value ) {
michael@0:     return PR_FALSE;
michael@0:   } else {
michael@0:     return PR_TRUE;
michael@0:   }
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * nssHash_Lookup
michael@0:  *
michael@0:  */
michael@0: NSS_IMPLEMENT void *
michael@0: nssHash_Lookup
michael@0: (
michael@0:   nssHash *hash,
michael@0:   const void *it
michael@0: )
michael@0: {
michael@0:   void *rv;
michael@0: 
michael@0:   PZ_Lock(hash->mutex);
michael@0: 
michael@0:   rv = PL_HashTableLookup(hash->plHashTable, it);
michael@0: 
michael@0:   (void)PZ_Unlock(hash->mutex);
michael@0: 
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: struct arg_str {
michael@0:   nssHashIterator fcn;
michael@0:   void *closure;
michael@0: };
michael@0: 
michael@0: static PRIntn
michael@0: nss_hash_enumerator
michael@0: (
michael@0:   PLHashEntry *he,
michael@0:   PRIntn index,
michael@0:   void *arg
michael@0: )
michael@0: {
michael@0:   struct arg_str *as = (struct arg_str *)arg;
michael@0:   as->fcn(he->key, he->value, as->closure);
michael@0:   return HT_ENUMERATE_NEXT;
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * nssHash_Iterate
michael@0:  *
michael@0:  * NOTE that the iteration function will be called with the hashtable locked.
michael@0:  */
michael@0: NSS_IMPLEMENT void
michael@0: nssHash_Iterate
michael@0: (
michael@0:   nssHash *hash,
michael@0:   nssHashIterator fcn,
michael@0:   void *closure
michael@0: )
michael@0: {
michael@0:   struct arg_str as;
michael@0:   as.fcn = fcn;
michael@0:   as.closure = closure;
michael@0: 
michael@0:   PZ_Lock(hash->mutex);
michael@0: 
michael@0:   PL_HashTableEnumerateEntries(hash->plHashTable, nss_hash_enumerator, &as);
michael@0: 
michael@0:   (void)PZ_Unlock(hash->mutex);
michael@0: 
michael@0:   return;
michael@0: }