/*
* 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 "ValueCheck.h"
#include <wtf/Assertions.h>
#include <wtf/Threading.h>
namespace WTF {
#define DUMP_HASHTABLE_STATS 0
// Enables internal WTF consistency checks that are invoked automatically. Non-WTF callers can call checkTableConsistency() even if internal checks are disabled.
#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_UNUSED(other, 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;
// Work around MSVC's standard library, whose swap for pairs does not swap by component.
template<typename T> inline void hashTableSwap(T& a, T& b)
{
swap(a, b);
}
// Swap pairs by component, in case of pair members that specialize swap.
template<typename T, typename U> inline void hashTableSwap(pair<T, U>& a, pair<T, U>& b)
{
swap(a.first, b.first);
swap(a.second, b.second);
}
template<typename T, bool useSwap> struct Mover;
template<typename T> struct Mover<T, true> { static void move(T& from, T& to) { hashTableSwap(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 removeWithoutEntryConsistencyCheck(const_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 !ASSERT_DISABLED
void checkTableConsistency() const;
#else
static void checkTableConsistency() { }
#endif
#if CHECK_HASHTABLE_CONSISTENCY
void internalCheckTableConsistency() const { checkTableConsistency(); }
void internalCheckTableConsistencyExceptSize() const { checkTableConsistencyExceptSize(); }
#else
static void internalCheckTableConsistencyExceptSize() { }
static void internalCheckTableConsistency() { }
#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 !ASSERT_DISABLED
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();
internalCheckTableConsistency();
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;
}
internalCheckTableConsistency();
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();
internalCheckTableConsistency();
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;
}
internalCheckTableConsistency();
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();
internalCheckTableConsistency();
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();
internalCheckTableConsistency();
}
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>::removeWithoutEntryConsistencyCheck(const_iterator it)
{
if (it == end())
return;
removeAndInvalidateWithoutEntryConsistencyCheck(const_cast<ValueType*>(it.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)
{
internalCheckTableConsistencyExceptSize();
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);
internalCheckTableConsistency();
}
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 !ASSERT_DISABLED
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(!m_table || !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;
ValueCheck<Key>::checkConsistency(it->first);
}
ASSERT(count == m_keyCount);
ASSERT(deletedCount == m_deletedCount);
ASSERT(m_tableSize >= m_minTableSize);
ASSERT(m_tableSizeMask);
ASSERT(m_tableSize == m_tableSizeMask + 1);
}
#endif // ASSERT_DISABLED
#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