| /* |
| * Copyright (C) 2005, 2006, 2007, 2008 Apple Inc. All rights reserved. |
| * Copyright (C) 2008 David Levin <levin@chromium.org> |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Library General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Library General Public License for more details. |
| * |
| * You should have received a copy of the GNU Library General Public License |
| * along with this library; see the file COPYING.LIB. If not, write to |
| * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| * Boston, MA 02110-1301, USA. |
| * |
| */ |
| |
| #ifndef WTF_HashTable_h |
| #define WTF_HashTable_h |
| |
| #include "FastMalloc.h" |
| #include "HashTraits.h" |
| #include <wtf/Assertions.h> |
| #include <wtf/Threading.h> |
| |
| namespace WTF { |
| |
| #define DUMP_HASHTABLE_STATS 0 |
| #define CHECK_HASHTABLE_CONSISTENCY 0 |
| |
| #ifdef NDEBUG |
| #define CHECK_HASHTABLE_ITERATORS 0 |
| #define CHECK_HASHTABLE_USE_AFTER_DESTRUCTION 0 |
| #else |
| #define CHECK_HASHTABLE_ITERATORS 1 |
| #define CHECK_HASHTABLE_USE_AFTER_DESTRUCTION 1 |
| #endif |
| |
| #if DUMP_HASHTABLE_STATS |
| |
| struct HashTableStats { |
| ~HashTableStats(); |
| // All of the variables are accessed in ~HashTableStats when the static struct is destroyed. |
| |
| // The following variables are all atomically incremented when modified. |
| static int numAccesses; |
| static int numRehashes; |
| static int numRemoves; |
| static int numReinserts; |
| |
| // The following variables are only modified in the recordCollisionAtCount method within a mutex. |
| static int maxCollisions; |
| static int numCollisions; |
| static int collisionGraph[4096]; |
| |
| static void recordCollisionAtCount(int count); |
| }; |
| |
| #endif |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| class HashTable; |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| class HashTableIterator; |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| class HashTableConstIterator; |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void addIterator(const HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>*, |
| HashTableConstIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>*); |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void removeIterator(HashTableConstIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>*); |
| |
| #if !CHECK_HASHTABLE_ITERATORS |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| inline void addIterator(const HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>*, |
| HashTableConstIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>*) { } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| inline void removeIterator(HashTableConstIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>*) { } |
| |
| #endif |
| |
| typedef enum { HashItemKnownGood } HashItemKnownGoodTag; |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| class HashTableConstIterator { |
| private: |
| typedef HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits> HashTableType; |
| typedef HashTableIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits> iterator; |
| typedef HashTableConstIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits> const_iterator; |
| typedef Value ValueType; |
| typedef const ValueType& ReferenceType; |
| typedef const ValueType* PointerType; |
| |
| friend class HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>; |
| friend class HashTableIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>; |
| |
| void skipEmptyBuckets() |
| { |
| while (m_position != m_endPosition && HashTableType::isEmptyOrDeletedBucket(*m_position)) |
| ++m_position; |
| } |
| |
| HashTableConstIterator(const HashTableType* table, PointerType position, PointerType endPosition) |
| : m_position(position), m_endPosition(endPosition) |
| { |
| addIterator(table, this); |
| skipEmptyBuckets(); |
| } |
| |
| HashTableConstIterator(const HashTableType* table, PointerType position, PointerType endPosition, HashItemKnownGoodTag) |
| : m_position(position), m_endPosition(endPosition) |
| { |
| addIterator(table, this); |
| } |
| |
| public: |
| HashTableConstIterator() |
| { |
| addIterator(0, this); |
| } |
| |
| // default copy, assignment and destructor are OK if CHECK_HASHTABLE_ITERATORS is 0 |
| |
| #if CHECK_HASHTABLE_ITERATORS |
| ~HashTableConstIterator() |
| { |
| removeIterator(this); |
| } |
| |
| HashTableConstIterator(const const_iterator& other) |
| : m_position(other.m_position), m_endPosition(other.m_endPosition) |
| { |
| addIterator(other.m_table, this); |
| } |
| |
| const_iterator& operator=(const const_iterator& other) |
| { |
| m_position = other.m_position; |
| m_endPosition = other.m_endPosition; |
| |
| removeIterator(this); |
| addIterator(other.m_table, this); |
| |
| return *this; |
| } |
| #endif |
| |
| PointerType get() const |
| { |
| checkValidity(); |
| return m_position; |
| } |
| ReferenceType operator*() const { return *get(); } |
| PointerType operator->() const { return get(); } |
| |
| const_iterator& operator++() |
| { |
| checkValidity(); |
| ASSERT(m_position != m_endPosition); |
| ++m_position; |
| skipEmptyBuckets(); |
| return *this; |
| } |
| |
| // postfix ++ intentionally omitted |
| |
| // Comparison. |
| bool operator==(const const_iterator& other) const |
| { |
| checkValidity(other); |
| return m_position == other.m_position; |
| } |
| bool operator!=(const const_iterator& other) const |
| { |
| checkValidity(other); |
| return m_position != other.m_position; |
| } |
| |
| private: |
| void checkValidity() const |
| { |
| #if CHECK_HASHTABLE_ITERATORS |
| ASSERT(m_table); |
| #endif |
| } |
| |
| |
| #if CHECK_HASHTABLE_ITERATORS |
| void checkValidity(const const_iterator& other) const |
| { |
| ASSERT(m_table); |
| ASSERT(other.m_table); |
| ASSERT(m_table == other.m_table); |
| } |
| #else |
| void checkValidity(const const_iterator&) const { } |
| #endif |
| |
| PointerType m_position; |
| PointerType m_endPosition; |
| |
| #if CHECK_HASHTABLE_ITERATORS |
| public: |
| // Any modifications of the m_next or m_previous of an iterator that is in a linked list of a HashTable::m_iterator, |
| // should be guarded with m_table->m_mutex. |
| mutable const HashTableType* m_table; |
| mutable const_iterator* m_next; |
| mutable const_iterator* m_previous; |
| #endif |
| }; |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| class HashTableIterator { |
| private: |
| typedef HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits> HashTableType; |
| typedef HashTableIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits> iterator; |
| typedef HashTableConstIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits> const_iterator; |
| typedef Value ValueType; |
| typedef ValueType& ReferenceType; |
| typedef ValueType* PointerType; |
| |
| friend class HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>; |
| |
| HashTableIterator(HashTableType* table, PointerType pos, PointerType end) : m_iterator(table, pos, end) { } |
| HashTableIterator(HashTableType* table, PointerType pos, PointerType end, HashItemKnownGoodTag tag) : m_iterator(table, pos, end, tag) { } |
| |
| public: |
| HashTableIterator() { } |
| |
| // default copy, assignment and destructor are OK |
| |
| PointerType get() const { return const_cast<PointerType>(m_iterator.get()); } |
| ReferenceType operator*() const { return *get(); } |
| PointerType operator->() const { return get(); } |
| |
| iterator& operator++() { ++m_iterator; return *this; } |
| |
| // postfix ++ intentionally omitted |
| |
| // Comparison. |
| bool operator==(const iterator& other) const { return m_iterator == other.m_iterator; } |
| bool operator!=(const iterator& other) const { return m_iterator != other.m_iterator; } |
| |
| operator const_iterator() const { return m_iterator; } |
| |
| private: |
| const_iterator m_iterator; |
| }; |
| |
| using std::swap; |
| |
| #if !COMPILER(MSVC) |
| // Visual C++ has a swap for pairs defined. |
| |
| // swap pairs by component, in case of pair members that specialize swap |
| template<typename T, typename U> inline void swap(pair<T, U>& a, pair<T, U>& b) |
| { |
| swap(a.first, b.first); |
| swap(a.second, b.second); |
| } |
| #endif |
| |
| template<typename T, bool useSwap> struct Mover; |
| template<typename T> struct Mover<T, true> { static void move(T& from, T& to) { swap(from, to); } }; |
| template<typename T> struct Mover<T, false> { static void move(T& from, T& to) { to = from; } }; |
| |
| template<typename Key, typename Value, typename HashFunctions> class IdentityHashTranslator { |
| public: |
| static unsigned hash(const Key& key) { return HashFunctions::hash(key); } |
| static bool equal(const Key& a, const Key& b) { return HashFunctions::equal(a, b); } |
| static void translate(Value& location, const Key&, const Value& value) { location = value; } |
| }; |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| class HashTable { |
| public: |
| typedef HashTableIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits> iterator; |
| typedef HashTableConstIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits> const_iterator; |
| typedef Traits ValueTraits; |
| typedef Key KeyType; |
| typedef Value ValueType; |
| typedef IdentityHashTranslator<Key, Value, HashFunctions> IdentityTranslatorType; |
| |
| HashTable(); |
| ~HashTable() |
| { |
| invalidateIterators(); |
| deallocateTable(m_table, m_tableSize); |
| #if CHECK_HASHTABLE_USE_AFTER_DESTRUCTION |
| m_table = (ValueType*)(uintptr_t)0xbbadbeef; |
| #endif |
| } |
| |
| HashTable(const HashTable&); |
| void swap(HashTable&); |
| HashTable& operator=(const HashTable&); |
| |
| iterator begin() { return makeIterator(m_table); } |
| iterator end() { return makeKnownGoodIterator(m_table + m_tableSize); } |
| const_iterator begin() const { return makeConstIterator(m_table); } |
| const_iterator end() const { return makeKnownGoodConstIterator(m_table + m_tableSize); } |
| |
| int size() const { return m_keyCount; } |
| int capacity() const { return m_tableSize; } |
| bool isEmpty() const { return !m_keyCount; } |
| |
| pair<iterator, bool> add(const ValueType& value) { return add<KeyType, ValueType, IdentityTranslatorType>(Extractor::extract(value), value); } |
| |
| // A special version of add() that finds the object by hashing and comparing |
| // with some other type, to avoid the cost of type conversion if the object is already |
| // in the table. |
| template<typename T, typename Extra, typename HashTranslator> pair<iterator, bool> add(const T& key, const Extra&); |
| template<typename T, typename Extra, typename HashTranslator> pair<iterator, bool> addPassingHashCode(const T& key, const Extra&); |
| |
| iterator find(const KeyType& key) { return find<KeyType, IdentityTranslatorType>(key); } |
| const_iterator find(const KeyType& key) const { return find<KeyType, IdentityTranslatorType>(key); } |
| bool contains(const KeyType& key) const { return contains<KeyType, IdentityTranslatorType>(key); } |
| |
| template <typename T, typename HashTranslator> iterator find(const T&); |
| template <typename T, typename HashTranslator> const_iterator find(const T&) const; |
| template <typename T, typename HashTranslator> bool contains(const T&) const; |
| |
| void remove(const KeyType&); |
| void remove(iterator); |
| void removeWithoutEntryConsistencyCheck(iterator); |
| void clear(); |
| |
| static bool isEmptyBucket(const ValueType& value) { return Extractor::extract(value) == KeyTraits::emptyValue(); } |
| static bool isDeletedBucket(const ValueType& value) { return KeyTraits::isDeletedValue(Extractor::extract(value)); } |
| static bool isEmptyOrDeletedBucket(const ValueType& value) { return isEmptyBucket(value) || isDeletedBucket(value); } |
| |
| ValueType* lookup(const Key& key) { return lookup<Key, IdentityTranslatorType>(key); } |
| template<typename T, typename HashTranslator> ValueType* lookup(const T&); |
| |
| #if CHECK_HASHTABLE_CONSISTENCY |
| void checkTableConsistency() const; |
| #else |
| static void checkTableConsistency() { } |
| #endif |
| |
| private: |
| static ValueType* allocateTable(int size); |
| static void deallocateTable(ValueType* table, int size); |
| |
| typedef pair<ValueType*, bool> LookupType; |
| typedef pair<LookupType, unsigned> FullLookupType; |
| |
| LookupType lookupForWriting(const Key& key) { return lookupForWriting<Key, IdentityTranslatorType>(key); }; |
| template<typename T, typename HashTranslator> FullLookupType fullLookupForWriting(const T&); |
| template<typename T, typename HashTranslator> LookupType lookupForWriting(const T&); |
| |
| template<typename T, typename HashTranslator> void checkKey(const T&); |
| |
| void removeAndInvalidateWithoutEntryConsistencyCheck(ValueType*); |
| void removeAndInvalidate(ValueType*); |
| void remove(ValueType*); |
| |
| bool shouldExpand() const { return (m_keyCount + m_deletedCount) * m_maxLoad >= m_tableSize; } |
| bool mustRehashInPlace() const { return m_keyCount * m_minLoad < m_tableSize * 2; } |
| bool shouldShrink() const { return m_keyCount * m_minLoad < m_tableSize && m_tableSize > m_minTableSize; } |
| void expand(); |
| void shrink() { rehash(m_tableSize / 2); } |
| |
| void rehash(int newTableSize); |
| void reinsert(ValueType&); |
| |
| static void initializeBucket(ValueType& bucket) { new (&bucket) ValueType(Traits::emptyValue()); } |
| static void deleteBucket(ValueType& bucket) { bucket.~ValueType(); Traits::constructDeletedValue(bucket); } |
| |
| FullLookupType makeLookupResult(ValueType* position, bool found, unsigned hash) |
| { return FullLookupType(LookupType(position, found), hash); } |
| |
| iterator makeIterator(ValueType* pos) { return iterator(this, pos, m_table + m_tableSize); } |
| const_iterator makeConstIterator(ValueType* pos) const { return const_iterator(this, pos, m_table + m_tableSize); } |
| iterator makeKnownGoodIterator(ValueType* pos) { return iterator(this, pos, m_table + m_tableSize, HashItemKnownGood); } |
| const_iterator makeKnownGoodConstIterator(ValueType* pos) const { return const_iterator(this, pos, m_table + m_tableSize, HashItemKnownGood); } |
| |
| #if CHECK_HASHTABLE_CONSISTENCY |
| void checkTableConsistencyExceptSize() const; |
| #else |
| static void checkTableConsistencyExceptSize() { } |
| #endif |
| |
| #if CHECK_HASHTABLE_ITERATORS |
| void invalidateIterators(); |
| #else |
| static void invalidateIterators() { } |
| #endif |
| |
| static const int m_minTableSize = 64; |
| static const int m_maxLoad = 2; |
| static const int m_minLoad = 6; |
| |
| ValueType* m_table; |
| int m_tableSize; |
| int m_tableSizeMask; |
| int m_keyCount; |
| int m_deletedCount; |
| |
| #if CHECK_HASHTABLE_ITERATORS |
| public: |
| // All access to m_iterators should be guarded with m_mutex. |
| mutable const_iterator* m_iterators; |
| mutable Mutex m_mutex; |
| #endif |
| }; |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| inline HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::HashTable() |
| : m_table(0) |
| , m_tableSize(0) |
| , m_tableSizeMask(0) |
| , m_keyCount(0) |
| , m_deletedCount(0) |
| #if CHECK_HASHTABLE_ITERATORS |
| , m_iterators(0) |
| #endif |
| { |
| } |
| |
| static inline unsigned doubleHash(unsigned key) |
| { |
| key = ~key + (key >> 23); |
| key ^= (key << 12); |
| key ^= (key >> 7); |
| key ^= (key << 2); |
| key ^= (key >> 20); |
| return key; |
| } |
| |
| #if ASSERT_DISABLED |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| template<typename T, typename HashTranslator> |
| inline void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::checkKey(const T&) |
| { |
| } |
| |
| #else |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| template<typename T, typename HashTranslator> |
| void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::checkKey(const T& key) |
| { |
| if (!HashFunctions::safeToCompareToEmptyOrDeleted) |
| return; |
| ASSERT(!HashTranslator::equal(KeyTraits::emptyValue(), key)); |
| ValueType deletedValue = Traits::emptyValue(); |
| deletedValue.~ValueType(); |
| Traits::constructDeletedValue(deletedValue); |
| ASSERT(!HashTranslator::equal(Extractor::extract(deletedValue), key)); |
| new (&deletedValue) ValueType(Traits::emptyValue()); |
| } |
| |
| #endif |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| template<typename T, typename HashTranslator> |
| inline Value* HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::lookup(const T& key) |
| { |
| checkKey<T, HashTranslator>(key); |
| |
| int k = 0; |
| int sizeMask = m_tableSizeMask; |
| ValueType* table = m_table; |
| unsigned h = HashTranslator::hash(key); |
| int i = h & sizeMask; |
| |
| if (!table) |
| return 0; |
| |
| #if DUMP_HASHTABLE_STATS |
| atomicIncrement(&HashTableStats::numAccesses); |
| int probeCount = 0; |
| #endif |
| |
| while (1) { |
| ValueType* entry = table + i; |
| |
| // we count on the compiler to optimize out this branch |
| if (HashFunctions::safeToCompareToEmptyOrDeleted) { |
| if (HashTranslator::equal(Extractor::extract(*entry), key)) |
| return entry; |
| |
| if (isEmptyBucket(*entry)) |
| return 0; |
| } else { |
| if (isEmptyBucket(*entry)) |
| return 0; |
| |
| if (!isDeletedBucket(*entry) && HashTranslator::equal(Extractor::extract(*entry), key)) |
| return entry; |
| } |
| #if DUMP_HASHTABLE_STATS |
| ++probeCount; |
| HashTableStats::recordCollisionAtCount(probeCount); |
| #endif |
| if (k == 0) |
| k = 1 | doubleHash(h); |
| i = (i + k) & sizeMask; |
| } |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| template<typename T, typename HashTranslator> |
| inline typename HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::LookupType HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::lookupForWriting(const T& key) |
| { |
| ASSERT(m_table); |
| checkKey<T, HashTranslator>(key); |
| |
| int k = 0; |
| ValueType* table = m_table; |
| int sizeMask = m_tableSizeMask; |
| unsigned h = HashTranslator::hash(key); |
| int i = h & sizeMask; |
| |
| #if DUMP_HASHTABLE_STATS |
| atomicIncrement(&HashTableStats::numAccesses); |
| int probeCount = 0; |
| #endif |
| |
| ValueType* deletedEntry = 0; |
| |
| while (1) { |
| ValueType* entry = table + i; |
| |
| // we count on the compiler to optimize out this branch |
| if (HashFunctions::safeToCompareToEmptyOrDeleted) { |
| if (isEmptyBucket(*entry)) |
| return LookupType(deletedEntry ? deletedEntry : entry, false); |
| |
| if (HashTranslator::equal(Extractor::extract(*entry), key)) |
| return LookupType(entry, true); |
| |
| if (isDeletedBucket(*entry)) |
| deletedEntry = entry; |
| } else { |
| if (isEmptyBucket(*entry)) |
| return LookupType(deletedEntry ? deletedEntry : entry, false); |
| |
| if (isDeletedBucket(*entry)) |
| deletedEntry = entry; |
| else if (HashTranslator::equal(Extractor::extract(*entry), key)) |
| return LookupType(entry, true); |
| } |
| #if DUMP_HASHTABLE_STATS |
| ++probeCount; |
| HashTableStats::recordCollisionAtCount(probeCount); |
| #endif |
| if (k == 0) |
| k = 1 | doubleHash(h); |
| i = (i + k) & sizeMask; |
| } |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| template<typename T, typename HashTranslator> |
| inline typename HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::FullLookupType HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::fullLookupForWriting(const T& key) |
| { |
| ASSERT(m_table); |
| checkKey<T, HashTranslator>(key); |
| |
| int k = 0; |
| ValueType* table = m_table; |
| int sizeMask = m_tableSizeMask; |
| unsigned h = HashTranslator::hash(key); |
| int i = h & sizeMask; |
| |
| #if DUMP_HASHTABLE_STATS |
| atomicIncrement(&HashTableStats::numAccesses); |
| int probeCount = 0; |
| #endif |
| |
| ValueType* deletedEntry = 0; |
| |
| while (1) { |
| ValueType* entry = table + i; |
| |
| // we count on the compiler to optimize out this branch |
| if (HashFunctions::safeToCompareToEmptyOrDeleted) { |
| if (isEmptyBucket(*entry)) |
| return makeLookupResult(deletedEntry ? deletedEntry : entry, false, h); |
| |
| if (HashTranslator::equal(Extractor::extract(*entry), key)) |
| return makeLookupResult(entry, true, h); |
| |
| if (isDeletedBucket(*entry)) |
| deletedEntry = entry; |
| } else { |
| if (isEmptyBucket(*entry)) |
| return makeLookupResult(deletedEntry ? deletedEntry : entry, false, h); |
| |
| if (isDeletedBucket(*entry)) |
| deletedEntry = entry; |
| else if (HashTranslator::equal(Extractor::extract(*entry), key)) |
| return makeLookupResult(entry, true, h); |
| } |
| #if DUMP_HASHTABLE_STATS |
| ++probeCount; |
| HashTableStats::recordCollisionAtCount(probeCount); |
| #endif |
| if (k == 0) |
| k = 1 | doubleHash(h); |
| i = (i + k) & sizeMask; |
| } |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| template<typename T, typename Extra, typename HashTranslator> |
| inline pair<typename HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::iterator, bool> HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::add(const T& key, const Extra& extra) |
| { |
| checkKey<T, HashTranslator>(key); |
| |
| invalidateIterators(); |
| |
| if (!m_table) |
| expand(); |
| |
| checkTableConsistency(); |
| |
| ASSERT(m_table); |
| |
| int k = 0; |
| ValueType* table = m_table; |
| int sizeMask = m_tableSizeMask; |
| unsigned h = HashTranslator::hash(key); |
| int i = h & sizeMask; |
| |
| #if DUMP_HASHTABLE_STATS |
| atomicIncrement(&HashTableStats::numAccesses); |
| int probeCount = 0; |
| #endif |
| |
| ValueType* deletedEntry = 0; |
| ValueType* entry; |
| while (1) { |
| entry = table + i; |
| |
| // we count on the compiler to optimize out this branch |
| if (HashFunctions::safeToCompareToEmptyOrDeleted) { |
| if (isEmptyBucket(*entry)) |
| break; |
| |
| if (HashTranslator::equal(Extractor::extract(*entry), key)) |
| return std::make_pair(makeKnownGoodIterator(entry), false); |
| |
| if (isDeletedBucket(*entry)) |
| deletedEntry = entry; |
| } else { |
| if (isEmptyBucket(*entry)) |
| break; |
| |
| if (isDeletedBucket(*entry)) |
| deletedEntry = entry; |
| else if (HashTranslator::equal(Extractor::extract(*entry), key)) |
| return std::make_pair(makeKnownGoodIterator(entry), false); |
| } |
| #if DUMP_HASHTABLE_STATS |
| ++probeCount; |
| HashTableStats::recordCollisionAtCount(probeCount); |
| #endif |
| if (k == 0) |
| k = 1 | doubleHash(h); |
| i = (i + k) & sizeMask; |
| } |
| |
| if (deletedEntry) { |
| initializeBucket(*deletedEntry); |
| entry = deletedEntry; |
| --m_deletedCount; |
| } |
| |
| HashTranslator::translate(*entry, key, extra); |
| |
| ++m_keyCount; |
| |
| if (shouldExpand()) { |
| // FIXME: This makes an extra copy on expand. Probably not that bad since |
| // expand is rare, but would be better to have a version of expand that can |
| // follow a pivot entry and return the new position. |
| KeyType enteredKey = Extractor::extract(*entry); |
| expand(); |
| pair<iterator, bool> p = std::make_pair(find(enteredKey), true); |
| ASSERT(p.first != end()); |
| return p; |
| } |
| |
| checkTableConsistency(); |
| |
| return std::make_pair(makeKnownGoodIterator(entry), true); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| template<typename T, typename Extra, typename HashTranslator> |
| inline pair<typename HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::iterator, bool> HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::addPassingHashCode(const T& key, const Extra& extra) |
| { |
| checkKey<T, HashTranslator>(key); |
| |
| invalidateIterators(); |
| |
| if (!m_table) |
| expand(); |
| |
| checkTableConsistency(); |
| |
| FullLookupType lookupResult = fullLookupForWriting<T, HashTranslator>(key); |
| |
| ValueType* entry = lookupResult.first.first; |
| bool found = lookupResult.first.second; |
| unsigned h = lookupResult.second; |
| |
| if (found) |
| return std::make_pair(makeKnownGoodIterator(entry), false); |
| |
| if (isDeletedBucket(*entry)) { |
| initializeBucket(*entry); |
| --m_deletedCount; |
| } |
| |
| HashTranslator::translate(*entry, key, extra, h); |
| ++m_keyCount; |
| if (shouldExpand()) { |
| // FIXME: This makes an extra copy on expand. Probably not that bad since |
| // expand is rare, but would be better to have a version of expand that can |
| // follow a pivot entry and return the new position. |
| KeyType enteredKey = Extractor::extract(*entry); |
| expand(); |
| pair<iterator, bool> p = std::make_pair(find(enteredKey), true); |
| ASSERT(p.first != end()); |
| return p; |
| } |
| |
| checkTableConsistency(); |
| |
| return std::make_pair(makeKnownGoodIterator(entry), true); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| inline void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::reinsert(ValueType& entry) |
| { |
| ASSERT(m_table); |
| ASSERT(!lookupForWriting(Extractor::extract(entry)).second); |
| ASSERT(!isDeletedBucket(*(lookupForWriting(Extractor::extract(entry)).first))); |
| #if DUMP_HASHTABLE_STATS |
| atomicIncrement(&HashTableStats::numReinserts); |
| #endif |
| |
| Mover<ValueType, Traits::needsDestruction>::move(entry, *lookupForWriting(Extractor::extract(entry)).first); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| template <typename T, typename HashTranslator> |
| typename HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::iterator HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::find(const T& key) |
| { |
| if (!m_table) |
| return end(); |
| |
| ValueType* entry = lookup<T, HashTranslator>(key); |
| if (!entry) |
| return end(); |
| |
| return makeKnownGoodIterator(entry); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| template <typename T, typename HashTranslator> |
| typename HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::const_iterator HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::find(const T& key) const |
| { |
| if (!m_table) |
| return end(); |
| |
| ValueType* entry = const_cast<HashTable*>(this)->lookup<T, HashTranslator>(key); |
| if (!entry) |
| return end(); |
| |
| return makeKnownGoodConstIterator(entry); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| template <typename T, typename HashTranslator> |
| bool HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::contains(const T& key) const |
| { |
| if (!m_table) |
| return false; |
| |
| return const_cast<HashTable*>(this)->lookup<T, HashTranslator>(key); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::removeAndInvalidateWithoutEntryConsistencyCheck(ValueType* pos) |
| { |
| invalidateIterators(); |
| remove(pos); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::removeAndInvalidate(ValueType* pos) |
| { |
| invalidateIterators(); |
| checkTableConsistency(); |
| remove(pos); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::remove(ValueType* pos) |
| { |
| #if DUMP_HASHTABLE_STATS |
| atomicIncrement(&HashTableStats::numRemoves); |
| #endif |
| |
| deleteBucket(*pos); |
| ++m_deletedCount; |
| --m_keyCount; |
| |
| if (shouldShrink()) |
| shrink(); |
| |
| checkTableConsistency(); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| inline void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::remove(iterator it) |
| { |
| if (it == end()) |
| return; |
| |
| removeAndInvalidate(const_cast<ValueType*>(it.m_iterator.m_position)); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| inline void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::removeWithoutEntryConsistencyCheck(iterator it) |
| { |
| if (it == end()) |
| return; |
| |
| removeAndInvalidateWithoutEntryConsistencyCheck(const_cast<ValueType*>(it.m_iterator.m_position)); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| inline void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::remove(const KeyType& key) |
| { |
| remove(find(key)); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| Value* HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::allocateTable(int size) |
| { |
| // would use a template member function with explicit specializations here, but |
| // gcc doesn't appear to support that |
| if (Traits::emptyValueIsZero) |
| return static_cast<ValueType*>(fastZeroedMalloc(size * sizeof(ValueType))); |
| ValueType* result = static_cast<ValueType*>(fastMalloc(size * sizeof(ValueType))); |
| for (int i = 0; i < size; i++) |
| initializeBucket(result[i]); |
| return result; |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::deallocateTable(ValueType* table, int size) |
| { |
| if (Traits::needsDestruction) { |
| for (int i = 0; i < size; ++i) { |
| if (!isDeletedBucket(table[i])) |
| table[i].~ValueType(); |
| } |
| } |
| fastFree(table); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::expand() |
| { |
| int newSize; |
| if (m_tableSize == 0) |
| newSize = m_minTableSize; |
| else if (mustRehashInPlace()) |
| newSize = m_tableSize; |
| else |
| newSize = m_tableSize * 2; |
| |
| rehash(newSize); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::rehash(int newTableSize) |
| { |
| checkTableConsistencyExceptSize(); |
| |
| int oldTableSize = m_tableSize; |
| ValueType* oldTable = m_table; |
| |
| #if DUMP_HASHTABLE_STATS |
| if (oldTableSize != 0) |
| atomicIncrement(&HashTableStats::numRehashes); |
| #endif |
| |
| m_tableSize = newTableSize; |
| m_tableSizeMask = newTableSize - 1; |
| m_table = allocateTable(newTableSize); |
| |
| for (int i = 0; i != oldTableSize; ++i) |
| if (!isEmptyOrDeletedBucket(oldTable[i])) |
| reinsert(oldTable[i]); |
| |
| m_deletedCount = 0; |
| |
| deallocateTable(oldTable, oldTableSize); |
| |
| checkTableConsistency(); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::clear() |
| { |
| invalidateIterators(); |
| deallocateTable(m_table, m_tableSize); |
| m_table = 0; |
| m_tableSize = 0; |
| m_tableSizeMask = 0; |
| m_keyCount = 0; |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::HashTable(const HashTable& other) |
| : m_table(0) |
| , m_tableSize(0) |
| , m_tableSizeMask(0) |
| , m_keyCount(0) |
| , m_deletedCount(0) |
| #if CHECK_HASHTABLE_ITERATORS |
| , m_iterators(0) |
| #endif |
| { |
| // Copy the hash table the dumb way, by adding each element to the new table. |
| // It might be more efficient to copy the table slots, but it's not clear that efficiency is needed. |
| const_iterator end = other.end(); |
| for (const_iterator it = other.begin(); it != end; ++it) |
| add(*it); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::swap(HashTable& other) |
| { |
| invalidateIterators(); |
| other.invalidateIterators(); |
| |
| ValueType* tmp_table = m_table; |
| m_table = other.m_table; |
| other.m_table = tmp_table; |
| |
| int tmp_tableSize = m_tableSize; |
| m_tableSize = other.m_tableSize; |
| other.m_tableSize = tmp_tableSize; |
| |
| int tmp_tableSizeMask = m_tableSizeMask; |
| m_tableSizeMask = other.m_tableSizeMask; |
| other.m_tableSizeMask = tmp_tableSizeMask; |
| |
| int tmp_keyCount = m_keyCount; |
| m_keyCount = other.m_keyCount; |
| other.m_keyCount = tmp_keyCount; |
| |
| int tmp_deletedCount = m_deletedCount; |
| m_deletedCount = other.m_deletedCount; |
| other.m_deletedCount = tmp_deletedCount; |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>& HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::operator=(const HashTable& other) |
| { |
| HashTable tmp(other); |
| swap(tmp); |
| return *this; |
| } |
| |
| #if CHECK_HASHTABLE_CONSISTENCY |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::checkTableConsistency() const |
| { |
| checkTableConsistencyExceptSize(); |
| ASSERT(!shouldExpand()); |
| ASSERT(!shouldShrink()); |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::checkTableConsistencyExceptSize() const |
| { |
| if (!m_table) |
| return; |
| |
| int count = 0; |
| int deletedCount = 0; |
| for (int j = 0; j < m_tableSize; ++j) { |
| ValueType* entry = m_table + j; |
| if (isEmptyBucket(*entry)) |
| continue; |
| |
| if (isDeletedBucket(*entry)) { |
| ++deletedCount; |
| continue; |
| } |
| |
| const_iterator it = find(Extractor::extract(*entry)); |
| ASSERT(entry == it.m_position); |
| ++count; |
| } |
| |
| ASSERT(count == m_keyCount); |
| ASSERT(deletedCount == m_deletedCount); |
| ASSERT(m_tableSize >= m_minTableSize); |
| ASSERT(m_tableSizeMask); |
| ASSERT(m_tableSize == m_tableSizeMask + 1); |
| } |
| |
| #endif // CHECK_HASHTABLE_CONSISTENCY |
| |
| #if CHECK_HASHTABLE_ITERATORS |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::invalidateIterators() |
| { |
| MutexLocker lock(m_mutex); |
| const_iterator* next; |
| for (const_iterator* p = m_iterators; p; p = next) { |
| next = p->m_next; |
| p->m_table = 0; |
| p->m_next = 0; |
| p->m_previous = 0; |
| } |
| m_iterators = 0; |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void addIterator(const HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>* table, |
| HashTableConstIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>* it) |
| { |
| it->m_table = table; |
| it->m_previous = 0; |
| |
| // Insert iterator at head of doubly-linked list of iterators. |
| if (!table) { |
| it->m_next = 0; |
| } else { |
| MutexLocker lock(table->m_mutex); |
| ASSERT(table->m_iterators != it); |
| it->m_next = table->m_iterators; |
| table->m_iterators = it; |
| if (it->m_next) { |
| ASSERT(!it->m_next->m_previous); |
| it->m_next->m_previous = it; |
| } |
| } |
| } |
| |
| template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits> |
| void removeIterator(HashTableConstIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>* it) |
| { |
| typedef HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits> HashTableType; |
| typedef HashTableConstIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits> const_iterator; |
| |
| // Delete iterator from doubly-linked list of iterators. |
| if (!it->m_table) { |
| ASSERT(!it->m_next); |
| ASSERT(!it->m_previous); |
| } else { |
| MutexLocker lock(it->m_table->m_mutex); |
| if (it->m_next) { |
| ASSERT(it->m_next->m_previous == it); |
| it->m_next->m_previous = it->m_previous; |
| } |
| if (it->m_previous) { |
| ASSERT(it->m_table->m_iterators != it); |
| ASSERT(it->m_previous->m_next == it); |
| it->m_previous->m_next = it->m_next; |
| } else { |
| ASSERT(it->m_table->m_iterators == it); |
| it->m_table->m_iterators = it->m_next; |
| } |
| } |
| |
| it->m_table = 0; |
| it->m_next = 0; |
| it->m_previous = 0; |
| } |
| |
| #endif // CHECK_HASHTABLE_ITERATORS |
| |
| // iterator adapters |
| |
| template<typename HashTableType, typename ValueType> struct HashTableConstIteratorAdapter { |
| HashTableConstIteratorAdapter(const typename HashTableType::const_iterator& impl) : m_impl(impl) {} |
| |
| const ValueType* get() const { return (const ValueType*)m_impl.get(); } |
| const ValueType& operator*() const { return *get(); } |
| const ValueType* operator->() const { return get(); } |
| |
| HashTableConstIteratorAdapter& operator++() { ++m_impl; return *this; } |
| // postfix ++ intentionally omitted |
| |
| typename HashTableType::const_iterator m_impl; |
| }; |
| |
| template<typename HashTableType, typename ValueType> struct HashTableIteratorAdapter { |
| HashTableIteratorAdapter(const typename HashTableType::iterator& impl) : m_impl(impl) {} |
| |
| ValueType* get() const { return (ValueType*)m_impl.get(); } |
| ValueType& operator*() const { return *get(); } |
| ValueType* operator->() const { return get(); } |
| |
| HashTableIteratorAdapter& operator++() { ++m_impl; return *this; } |
| // postfix ++ intentionally omitted |
| |
| operator HashTableConstIteratorAdapter<HashTableType, ValueType>() { |
| typename HashTableType::const_iterator i = m_impl; |
| return i; |
| } |
| |
| typename HashTableType::iterator m_impl; |
| }; |
| |
| template<typename T, typename U> |
| inline bool operator==(const HashTableConstIteratorAdapter<T, U>& a, const HashTableConstIteratorAdapter<T, U>& b) |
| { |
| return a.m_impl == b.m_impl; |
| } |
| |
| template<typename T, typename U> |
| inline bool operator!=(const HashTableConstIteratorAdapter<T, U>& a, const HashTableConstIteratorAdapter<T, U>& b) |
| { |
| return a.m_impl != b.m_impl; |
| } |
| |
| template<typename T, typename U> |
| inline bool operator==(const HashTableIteratorAdapter<T, U>& a, const HashTableIteratorAdapter<T, U>& b) |
| { |
| return a.m_impl == b.m_impl; |
| } |
| |
| template<typename T, typename U> |
| inline bool operator!=(const HashTableIteratorAdapter<T, U>& a, const HashTableIteratorAdapter<T, U>& b) |
| { |
| return a.m_impl != b.m_impl; |
| } |
| |
| } // namespace WTF |
| |
| #include "HashIterators.h" |
| |
| #endif // WTF_HashTable_h |
