QHash< Key, T > Class Template Reference

The QHash class is a template class that provides a hash-table-based dictionary. More...

#include <qdatastream.h>

Inheritance diagram for QHash< Key, T >:

Classes
class	const_iterator
	The QHash::const_iterator class provides an STL-style const iterator for QHash and QMultiHash. More...
class	iterator
	The QHash::iterator class provides an STL-style non-const iterator for QHash and QMultiHash. More...

Public Types
typedef const_iterator	ConstIterator
	Qt-style synonym for QHash::const_iterator. More...
typedef qptrdiff	difference_type
	Typedef for ptrdiff_t. More...
typedef iterator	Iterator
	Qt-style synonym for QHash::iterator. More...
typedef Key	key_type
	Typedef for Key. More...
typedef T	mapped_type
	Typedef for T. More...
typedef int	size_type
	Typedef for int. More...

Public Functions
iterator	begin ()
	Returns an STL-style iterator pointing to the first item in the hash. More...
const_iterator	begin () const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...
int	capacity () const
	Returns the number of buckets in the QHash's internal hash table. More...
void	clear ()
	Removes all items from the hash. More...
const_iterator	constBegin () const
	Returns a const STL-style iterator pointing to the first item in the hash. More...
const_iterator	constEnd () const
	Returns a const STL-style iterator pointing to the imaginary item after the last item in the hash. More...
const_iterator	constFind (const Key &key) const
	Returns an iterator pointing to the item with the key in the hash. More...
bool	contains (const Key &key) const
	Returns true if the hash contains an item with the key; otherwise returns false. More...
int	count (const Key &key) const
	Returns the number of items associated with the key. More...
int	count () const
	Same as size(). More...
void	detach ()
	Detaches this hash from any other hashes with which it may share data. More...
bool	empty () const
	This function is provided for STL compatibility. More...
iterator	end ()
	Returns an STL-style iterator pointing to the imaginary item after the last item in the hash. More...
const_iterator	end () const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...
iterator	erase (iterator it)
	Removes the (key, value) pair associated with the iterator pos from the hash, and returns an iterator to the next item in the hash. More...
iterator	find (const Key &key)
	Returns an iterator pointing to the item with the key in the hash. More...
const_iterator	find (const Key &key) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...
iterator	insert (const Key &key, const T &value)
	Inserts a new item with the key and a value of value. More...
iterator	insertMulti (const Key &key, const T &value)
	Inserts a new item with the key and a value of value. More...
bool	isDetached () const
	Returns true if the hash's internal data isn't shared with any other hash object; otherwise returns false. More...
bool	isEmpty () const
	Returns true if the hash contains no items; otherwise returns false. More...
bool	isSharedWith (const QHash< Key, T > &other) const
const Key	key (const T &value) const
	Returns the first key mapped to value. More...
const Key	key (const T &value, const Key &defaultKey) const
	Returns the first key mapped to value, or defaultKey if the hash contains no item mapped to value. More...
QList< Key >	keys () const
	Returns a list containing all the keys in the hash, in an arbitrary order. More...
QList< Key >	keys (const T &value) const
	Returns a list containing all the keys associated with value value, in an arbitrary order. More...
bool	operator!= (const QHash< Key, T > &other) const
	Returns true if other is not equal to this hash; otherwise returns false. More...
QHash< Key, T > &	operator= (const QHash< Key, T > &other)
	Assigns other to this hash and returns a reference to this hash. More...
bool	operator== (const QHash< Key, T > &other) const
	Returns true if other is equal to this hash; otherwise returns false. More...
T &	operator[] (const Key &key)
	Returns the value associated with the key as a modifiable reference. More...
const T	operator[] (const Key &key) const
	Same as value(). More...
	QHash ()
	Constructs an empty hash. More...
	QHash (const QHash< Key, T > &other)
	Constructs a copy of other. More...
int	remove (const Key &key)
	Removes all the items that have the key from the hash. More...
void	reserve (int size)
	Ensures that the QHash's internal hash table consists of at least size buckets. More...
void	setSharable (bool sharable)
int	size () const
	Returns the number of items in the hash. More...
void	squeeze ()
	Reduces the size of the QHash's internal hash table to save memory. More...
void	swap (QHash< Key, T > &other)
	Swaps hash other with this hash. More...
T	take (const Key &key)
	Removes the item with the key from the hash and returns the value associated with it. More...
QList< Key >	uniqueKeys () const
	Returns a list containing all the keys in the map. More...
QHash< Key, T > &	unite (const QHash< Key, T > &other)
	Inserts all the items in the other hash into this hash. More...
const T	value (const Key &key) const
	Returns the value associated with the key. More...
const T	value (const Key &key, const T &defaultValue) const
	If the hash contains no item with the given key, the function returns defaultValue. More...
QList< T >	values () const
	Returns a list containing all the values in the hash, in an arbitrary order. More...
QList< T >	values (const Key &key) const
	Returns a list of all the values associated with the key, from the most recently inserted to the least recently inserted. More...
	~QHash ()
	Destroys the hash. More...

Private Types
typedef QHashDummyNode< Key, T >	DummyNode
typedef QHashNode< Key, T >	Node

Private Functions
Node *	createNode (uint h, const Key &key, const T &value, Node **nextNode)
void	deleteNode (Node *node)
void	detach_helper ()
Node **	findNode (const Key &key, uint *hp=0) const
void	freeData (QHashData *d)

Static Private Functions
static int	alignOfDummyNode ()
static int	alignOfNode ()
static Node *	concrete (QHashData::Node *node)
static void	deleteNode2 (QHashData::Node *node)
static void	duplicateNode (QHashData::Node *originalNode, void *newNode)

Properties
union {
QHashData *   d
QHashNode< Key, T > *   e
};

Friends
class	const_iterator
class	iterator

Related Functions
(Note that these are not member functions.)
QDataStream &	operator<< (QDataStream &out, const QHash< Key, T > &hash)
	Writes the hash hash to stream out. More...
QDataStream &	operator>> (QDataStream &in, QHash< Key, T > &hash)
	Reads a hash from stream in into hash. More...
uint	qHash (const QPair< T1, T2 > &key)
	Returns the hash value for the key. More...
uint	qHash (char key)
	Returns the hash value for the key. More...
uint	qHash (uchar key)
	Returns the hash value for the key. More...
uint	qHash (signed char key)
	Returns the hash value for the key. More...
uint	qHash (ushort key)
	Returns the hash value for the key. More...
uint	qHash (short key)
	Returns the hash value for the key. More...
uint	qHash (uint key)
	Returns the hash value for the key. More...
uint	qHash (int key)
	Returns the hash value for the key. More...
uint	qHash (ulong key)
	Returns the hash value for the key. More...
uint	qHash (long key)
	Returns the hash value for the key. More...
uint	qHash (quint64 key)
	Returns the hash value for the key. More...
uint	qHash (qint64 key)
	Returns the hash value for the key. More...
uint	qHash (QChar key)
	Returns the hash value for the key. More...
uint	qHash (const QBitArray &key)
uint	qHash (const QString &key)
	Returns the hash value for the key. More...
uint	qHash (const T *key)
uint	qHash (const QXmlNodeModelIndex &index)
	Computes a hash key from the QXmlNodeModelIndex index, and returns it. More...

Detailed Description

template<class Key, class T>
class QHash< Key, T >

The QHash class is a template class that provides a hash-table-based dictionary.

Note

This class or function is reentrant.

QHash<Key, T> is one of Qt's generic container classes. It stores (key, value) pairs and provides very fast lookup of the value associated with a key.

QHash provides very similar functionality to QMap. The differences are:

• QHash provides faster lookups than QMap. (See Algorithmic Complexity for details.)
• When iterating over a QMap, the items are always sorted by key. With QHash, the items are arbitrarily ordered.
• The key type of a QMap must provide operator<(). The key type of a QHash must provide operator==() and a global hash function called qHash() (see the related non-member functions).

Here's an example QHash with QString keys and int values:

QHash<QString, int> hash;

To insert a (key, value) pair into the hash, you can use operator[]():

hash["one"] = 1;
hash["three"] = 3;
hash["seven"] = 7;

This inserts the following three (key, value) pairs into the QHash: ("one", 1), ("three", 3), and ("seven", 7). Another way to insert items into the hash is to use insert():

hash.insert("twelve", 12);

To look up a value, use operator[]() or value():

int num1 = hash["thirteen"];
int num2 = hash.value("thirteen");

If there is no item with the specified key in the hash, these functions return a default-constructed value.

If you want to check whether the hash contains a particular key, use contains():

int timeout = 30;
if (hash.contains("TIMEOUT"))
    timeout = hash.value("TIMEOUT");

There is also a value() overload that uses its second argument as a default value if there is no item with the specified key:

int timeout = hash.value("TIMEOUT", 30);

In general, we recommend that you use contains() and value() rather than operator[]() for looking up a key in a hash. The reason is that operator[]() silently inserts an item into the hash if no item exists with the same key (unless the hash is const). For example, the following code snippet will create 1000 items in memory:

// WRONG
QHash<int, QWidget *> hash;
...
for (int i = 0; i < 1000; ++i) {
    if (hash[i] == okButton)
        cout << "Found button at index " << i << endl;
}

To avoid this problem, replace hash[i] with hash.value(i) in the code above.

If you want to navigate through all the (key, value) pairs stored in a QHash, you can use an iterator. QHash provides both Java-style iterators (QHashIterator and QMutableHashIterator) and STL-style iterators (QHash::const_iterator and QHash::iterator). Here's how to iterate over a QHash<QString, int> using a Java-style iterator:

QHashIterator<QString, int> i(hash);
while (i.hasNext()) {
    i.next();
    cout << i.key() << ": " << i.value() << endl;
}

Here's the same code, but using an STL-style iterator:

QHash<QString, int>::const_iterator i = hash.constBegin();
while (i != hash.constEnd()) {
    cout << i.key() << ": " << i.value() << endl;
    ++i;
}

QHash is unordered, so an iterator's sequence cannot be assumed to be predictable. If ordering by key is required, use a QMap.

Normally, a QHash allows only one value per key. If you call insert() with a key that already exists in the QHash, the previous value is erased. For example:

hash.insert("plenty", 100);
hash.insert("plenty", 2000);
// hash.value("plenty") == 2000

However, you can store multiple values per key by using insertMulti() instead of insert() (or using the convenience subclass QMultiHash). If you want to retrieve all the values for a single key, you can use values(const Key &key), which returns a QList<T>:

QList<int> values = hash.values("plenty");
for (int i = 0; i < values.size(); ++i)
    cout << values.at(i) << endl;

The items that share the same key are available from most recently to least recently inserted. A more efficient approach is to call find() to get the iterator for the first item with a key and iterate from there:

QHash<QString, int>::iterator i = hash.find("plenty");
while (i != hash.end() && i.key() == "plenty") {
    cout << i.value() << endl;
    ++i;
}

If you only need to extract the values from a hash (not the keys), you can also use foreach:

QHash<QString, int> hash;
...
foreach (int value, hash)
    cout << value << endl;

Items can be removed from the hash in several ways. One way is to call remove(); this will remove any item with the given key. Another way is to use QMutableHashIterator::remove(). In addition, you can clear the entire hash using clear().

QHash's key and value data types must be assignable data types. You cannot, for example, store a QWidget as a value; instead, store a QWidget *. In addition, QHash's key type must provide operator==(), and there must also be a global qHash() function that returns a hash value for an argument of the key's type.

Here's a list of the C++ and Qt types that can serve as keys in a QHash: any integer type (char, unsigned long, etc.), any pointer type, QChar, QString, and QByteArray. For all of these, the <QHash> header defines a qHash() function that computes an adequate hash value. If you want to use other types as the key, make sure that you provide operator==() and a qHash() implementation.

Example:

#ifndef EMPLOYEE_H
#define EMPLOYEE_H

class Employee
{
public:
    Employee() {}
    Employee(const QString &name, const QDate &dateOfBirth);
    ...

private:
    QString myName;
    QDate myDateOfBirth;
};

inline bool operator==(const Employee &e1, const Employee &e2)
{
    return e1.name() == e2.name()
           && e1.dateOfBirth() == e2.dateOfBirth();
}

inline uint qHash(const Employee &key)
{
    return qHash(key.name()) ^ key.dateOfBirth().day();
}

#endif // EMPLOYEE_H

The qHash() function computes a numeric value based on a key. It can use any algorithm imaginable, as long as it always returns the same value if given the same argument. In other words, if e1 == e2, then qHash(e1) == qHash(e2) must hold as well. However, to obtain good performance, the qHash() function should attempt to return different hash values for different keys to the largest extent possible.

In the example above, we've relied on Qt's global qHash(const QString &) to give us a hash value for the employee's name, and XOR'ed this with the day they were born to help produce unique hashes for people with the same name.

Internally, QHash uses a hash table to perform lookups. Unlike Qt 3's QDict class, which needed to be initialized with a prime number, QHash's hash table automatically grows and shrinks to provide fast lookups without wasting too much memory. You can still control the size of the hash table by calling reserve() if you already know approximately how many items the QHash will contain, but this isn't necessary to obtain good performance. You can also call capacity() to retrieve the hash table's size.

See also

QHashIterator, QMutableHashIterator, QMap, QSet

Definition at line 66 of file qdatastream.h.

Typedefs

ConstIterator

template<class Key, class T>

QHash< Key, T >::ConstIterator

Qt-style synonym for QHash::const_iterator.

Definition at line 474 of file qhash.h.

difference_type

template<class Key, class T>

QHash< Key, T >::difference_type

Typedef for ptrdiff_t.

Provided for STL compatibility.

Definition at line 486 of file qhash.h.

DummyNode

template<class Key, class T>

typedef QHashDummyNode<Key, T> QHash< Key, T >::DummyNode

private

Definition at line 260 of file qhash.h.

Iterator

template<class Key, class T>

QHash< Key, T >::Iterator

Qt-style synonym for QHash::iterator.

Definition at line 473 of file qhash.h.

key_type

template<class Key, class T>

QHash< Key, T >::key_type

Typedef for Key.

Provided for STL compatibility.

Definition at line 485 of file qhash.h.

mapped_type

template<class Key, class T>

QHash< Key, T >::mapped_type

Typedef for T.

Provided for STL compatibility.

Definition at line 484 of file qhash.h.

Node

template<class Key, class T>

typedef QHashNode<Key, T> QHash< Key, T >::Node

private

Definition at line 261 of file qhash.h.

size_type

template<class Key, class T>

QHash< Key, T >::size_type

Typedef for int.

Provided for STL compatibility.

Definition at line 487 of file qhash.h.

Constructors and Destructors

QHash() [1/2]

template<class Key, class T>

QHash< Key, T >::QHash ( )

inline

Constructs an empty hash.

See also

clear()

Definition at line 281 of file qhash.h.

: d(&QHashData::shared_null) { d->ref.ref(); }

QHash() [2/2]

template<class Key, class T>

QHash< Key, T >::QHash ( const QHash< Key, T > &  other )

inline

Constructs a copy of other.

This operation occurs in constant time, because QHash is implicitly shared. This makes returning a QHash from a function very fast. If a shared instance is modified, it will be copied (copy-on-write), and this takes linear time.

See also

operator=()

Definition at line 282 of file qhash.h.

: d(other.d) { d->ref.ref(); if (!d->sharable) detach(); }

~QHash()

template<class Key, class T>

QHash< Key, T >::~QHash ( )

inline

Destroys the hash.

References to the values in the hash and all iterators of this hash become invalid.

Definition at line 283 of file qhash.h.

{ if (!d->ref.deref()) freeData(d); }

Functions

alignOfDummyNode()

template<class Key, class T>

static int QHash< Key, T >::alignOfDummyNode ( )

inlinestaticprivate

Definition at line 277 of file qhash.h.

{ return 0; }

alignOfNode()

template<class Key, class T>

static int QHash< Key, T >::alignOfNode ( )

inlinestaticprivate

Definition at line 276 of file qhash.h.

{ return 0; }

begin() [1/2]

template<class Key, class T>

QHash::iterator QHash< Key, T >::begin ( )

inline

Returns an STL-style iterator pointing to the first item in the hash.

See also

constBegin(), end()

Definition at line 464 of file qhash.h.

Referenced by QScriptDebuggerCodeWidgetPrivate::_q_onScriptsChanged(), QPMCache::allPixmaps(), QStateMachinePrivate::applyProperties(), QSet< typename TokenLookupClass::NodeName >::begin(), QGLGlyphCache::cacheGlyphs(), QGLGlyphCache::cleanCache(), QSqlDatabasePrivate::cleanConnections(), QGestureManager::cleanupCachedGestures(), QNetworkAccessCache::clear(), QDeclarativeTimeLine::clear(), QDeclarativePropertyCache::clear(), QDeclarativeTypeLoader::clearCache(), QDeclarativeCompiler::compileTree(), QDeclarativePropertyCache::copy(), QDeclarativeEnginePrivate::createCache(), QPatternist::Template::createContext(), QDeclarativeVisualDataModelPrivate::createMetaData(), ModelNode::dump(), QDeclarativeVisualDataModelPrivate::ensureRoles(), QDeclarativeIntegerCache::findId(), QPMCache::flushDetachedPixmaps(), QAxScriptManager::functions(), QDeclarativeCompiler::genContextCache(), QGraphicsScenePrivate::gestureEventHandler(), QDeclarativeGridView::itemsMoved(), QDeclarativeListView::itemsMoved(), MetaObjectGenerator::metaObject(), QDBusConnectionPrivate::objectDestroyed(), operator<<(), QTextureGlyphCache::populate(), QDeclarativeImports::populateCache(), qDBusRemoveTimeout(), qPRCleanup(), QDeclarativeDebugConnectionPrivate::readyRead(), QDeclarativeTimeLine::remove(), QGraphicsScenePrivate::removeItemHelper(), QFSEventsFileSystemWatcherEngine::removePaths(), QDialogButtonBoxPrivate::retranslateStrings(), QAxScriptManager::scriptForFunction(), QAxScriptManager::scriptNames(), QTextControl::setExtraSelections(), QEventDispatcherMac::unregisterTimers(), ModelNode::updateListIndexes(), QDeclarativeGridViewPrivate::updateUnrequestedIndexes(), QDeclarativeListViewPrivate::updateUnrequestedIndexes(), QDeclarativeGridViewPrivate::updateUnrequestedPositions(), QDeclarativeListViewPrivate::updateUnrequestedPositions(), QDeclarativeWorkerScriptEnginePrivate::variantToScriptValue(), QPdfEnginePrivate::writeFonts(), QDeclarativeDataLoader::~QDeclarativeDataLoader(), QDeclarativeDebugConnection::~QDeclarativeDebugConnection(), QDeclarativeEngineDebugPrivate::~QDeclarativeEngineDebugPrivate(), QDeclarativeTimeLine::~QDeclarativeTimeLine(), QEventDispatcherMac::~QEventDispatcherMac(), QPaintBufferResource::~QPaintBufferResource(), and QPrintDialogPrivate::~QPrintDialogPrivate().

{ detach(); return iterator(d->firstNode()); }

begin() [2/2]

template<class Key, class T>

QHash::const_iterator QHash< Key, T >::begin ( ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 465 of file qhash.h.

{ return const_iterator(d->firstNode()); }

capacity()

template<class Key, class T>

int QHash< Key, T >::capacity ( ) const

inline

Returns the number of buckets in the QHash's internal hash table.

The sole purpose of this function is to provide a means of fine tuning QHash's memory usage. In general, you will rarely ever need to call this function. If you want to know how many items are in the hash, call size().

See also

reserve(), squeeze()

Definition at line 299 of file qhash.h.

Referenced by QSet< typename TokenLookupClass::NodeName >::capacity().

{ return d->numBuckets; }

clear()

template<class Key , class T >

Q_INLINE_TEMPLATE void QHash< Key, T >::clear

(

)

Removes all items from the hash.

See also

remove()

Definition at line 574 of file qhash.h.

Referenced by QGraphicsAnchorLayoutPrivate::calculateGraphs(), QStateMachinePrivate::cancelAllDelayedEvents(), QGLGlyphCache::cleanCache(), QSqlDatabasePrivate::cleanConnections(), cleanup_cmaps(), QmlJSDebugger::LiveSelectionIndicator::clear(), QDeclarativeIntegerCache::clear(), QProcessEnvironment::clear(), QSet< typename TokenLookupClass::NodeName >::clear(), QDeclarativeTypeNameCache::clear(), QNetworkAccessCache::clear(), QDeclarativeTimeLine::clear(), QDeclarativePropertyCache::clear(), ModelNode::clear(), QDeclarativeTypeLoader::clearCache(), QHeaderViewPrivate::clearCascadingSections(), QRelation::clearDictionary(), QmlJSDebugger::AbstractViewInspector::handleMessage(), QGtkStylePrivate::initGtkWidgets(), QTextDocumentLayoutPrivate::layoutTable(), operator>>(), QPatternist::XsdSchemaParser::parse(), QPatternist::NamespaceSupport::popContext(), QSvgIconEngine::read(), QStyleSheetStyle::repolish(), QJSDebuggerAgent::setBreakpoints(), QApplication::setFont(), QApplicationPrivate::setPalette_helper(), QTextDocumentWithImageResources::setText(), QIconLoader::setThemeSearchPath(), QPatternist::ParserContext::templateWithParametersHandled(), QStyleSheetStyle::unpolish(), unregWinClasses(), QPdfEnginePrivate::writeFonts(), QAxBasePrivate::~QAxBasePrivate(), QDBusConnectionManager::~QDBusConnectionManager(), QEventDispatcherMac::~QEventDispatcherMac(), and QGestureManager::~QGestureManager().

{
    *this = QHash<Key,T>();
}

concrete()

template<class Key, class T>

static Node* QHash< Key, T >::concrete ( QHashData::Node *  node )

inlinestaticprivate

Definition at line 268 of file qhash.h.

                                                      {
        return reinterpret_cast<Node *>(node);
    }

constBegin()

template<class Key, class T>

QHash::const_iterator QHash< Key, T >::constBegin ( ) const

inline

Returns a const STL-style iterator pointing to the first item in the hash.

See also

begin(), constEnd()

Definition at line 466 of file qhash.h.

Referenced by _q_dupEnvironment(), QStateMachinePrivate::applyProperties(), QPatternist::DelegatingNamespaceResolver::bindings(), QStateMachinePrivate::cancelAllDelayedEvents(), cleanup_cmaps(), QGtkStylePrivate::cleanupGtkWidgets(), QPatternist::TemplateInvoker::compress(), Graph< Vertex, EdgeData >::const_iterator::const_iterator(), QSet< typename TokenLookupClass::NodeName >::constBegin(), QPatternist::ConstructorFunctionsFactory::ConstructorFunctionsFactory(), QPSPrintEnginePrivate::emitPages(), QPatternist::TemplateInvoker::expectedOperandTypes(), QPSPrintEnginePrivate::flushPage(), QApplication::font(), QPatternist::FunctionFactory::hasSignature(), QMacPrintEnginePrivate::initialize(), QProcessEnvironmentPrivate::insert(), QXmlSimpleReaderPrivate::isExpandedEntityValueTooLarge(), QSimplexConstraint::isSatisfied(), QProcessEnvironmentPrivate::keys(), QScriptEnginePrivate::mark(), QScript::QObjectDelegate::markChildren(), Graph< Vertex, EdgeData >::const_iterator::operator++(), operator<<(), QApplication::palette(), QPatternist::PatternPlatform::parseFlags(), QPatternist::NamespaceSupport::prefix(), qt_create_commandline(), QInotifyFileSystemWatcherEngine::readFromInotify(), QEventDispatcherMac::registeredTimers(), QStateMachinePrivate::restorablesToPropertyList(), QDomDocumentTypePrivate::save(), QDomElementPrivate::save(), QSimplex::setConstraints(), QSimplex::simplifyConstraints(), QSimplex::solver(), QFont::substitutions(), QPatternist::TemplateInvoker::TemplateInvoker(), QProcessEnvironmentPrivate::toList(), QSimplexConstraint::toString(), QGraphicsScenePrivate::touchEventHandler(), QApplicationPrivate::translateRawTouchEvent(), QPatternist::CallTemplate::typeCheck(), QHash< QExplicitlySharedDataPointer, QHash >::unite(), QStateMachinePrivate::unregisterEventTransition(), unregWinClasses(), QAxScriptManager::updateScript(), QDBusConnectionManager::~QDBusConnectionManager(), and QScriptEnginePrivate::~QScriptEnginePrivate().

{ return const_iterator(d->firstNode()); }

constEnd()

template<class Key, class T>

QHash::const_iterator QHash< Key, T >::constEnd ( ) const

inline

Returns a const STL-style iterator pointing to the imaginary item after the last item in the hash.

See also

constBegin(), end()

Definition at line 469 of file qhash.h.

Referenced by _q_dupEnvironment(), QStateMachinePrivate::applyProperties(), QStyleSheetStyleSelector::attribute(), QPatternist::DelegatingNamespaceResolver::bindings(), QGLGlyphCache::cacheGlyphs(), QStateMachinePrivate::cancelAllDelayedEvents(), cleanup_cmaps(), QGtkStylePrivate::cleanupGtkWidgets(), QCoreGraphicsPaintEngine::cleanUpMacColorSpaces(), QPatternist::TemplateInvoker::compress(), QDBusConnectionPrivate::connectRelay(), QDBusConnectionPrivate::connectSignal(), Graph< Vertex, EdgeData >::const_iterator::const_iterator(), QSet< typename TokenLookupClass::NodeName >::constEnd(), QPatternist::ConstructorFunctionsFactory::ConstructorFunctionsFactory(), QMultiHash< const QGLContext *, GLProgram >::contains(), QPSPrintEnginePrivate::emitPages(), QPatternist::TemplateInvoker::expectedOperandTypes(), QDeclarativeJS::Ecma::RegExp::flagFromChar(), QPSPrintEnginePrivate::flushPage(), QApplication::font(), QDBusConnectionPrivate::getNameOwner(), QScript::QObjectDelegate::getOwnPropertyDescriptor(), QScript::QObjectDelegate::getOwnPropertySlot(), QDBusConnectionPrivate::handleSignal(), QPatternist::FunctionFactory::hasSignature(), QStyleSheetStyle::hasStyleRule(), QSortFilterProxyModelPrivate::index_to_iterator(), QMacPrintEnginePrivate::initialize(), QApplicationPrivate::initializeWidgetPaletteHash(), QProcessEnvironmentPrivate::insert(), QXmlSimpleReaderPrivate::isExpandedEntityValueTooLarge(), QSimplexConstraint::isSatisfied(), QProcessEnvironmentPrivate::keys(), QScriptEnginePrivate::mark(), QScript::QObjectDelegate::markChildren(), QDesktopServices::openUrl(), Graph< Vertex, EdgeData >::const_iterator::operator++(), operator<<(), QApplication::palette(), QPatternist::PatternPlatform::parseFlags(), QJSDebuggerAgentPrivate::positionChange(), QPatternist::NamespaceSupport::prefix(), QScript::QObjectDelegate::put(), QScriptEnginePrivate::qobjectData(), qPRCleanup(), qt_create_commandline(), qt_gl_choose_cmap(), QInotifyFileSystemWatcherEngine::readFromInotify(), QCache< QPixmapCache::Key, QPixmapCacheEntry >::relink(), QStyleSheetStyle::renderRule(), QStateMachinePrivate::restorablesToPropertyList(), QDomDocumentTypePrivate::save(), QDomElementPrivate::save(), QSimplex::setConstraints(), QSimplex::simplifyConstraints(), QDBusConnectionPrivate::socketRead(), QDBusConnectionPrivate::socketWrite(), QSimplex::solver(), QAuServerMac::stop(), QStyleSheetStyle::styleRules(), QFont::substitute(), QFont::substitutions(), QPatternist::TemplateInvoker::TemplateInvoker(), QProcessEnvironmentPrivate::toList(), QSimplexConstraint::toString(), QGraphicsScenePrivate::touchEventHandler(), QApplicationPrivate::translateRawTouchEvent(), QPatternist::CallTemplate::typeCheck(), QHash< QExplicitlySharedDataPointer, QHash >::unite(), QStateMachinePrivate::unregisterEventTransition(), unregWinClasses(), QAxScriptManager::updateScript(), QProcessEnvironment::value(), QDBusConnectionManager::~QDBusConnectionManager(), and QScriptEnginePrivate::~QScriptEnginePrivate().

{ return const_iterator(e); }

constFind()

template<class Key, class T >

Q_INLINE_TEMPLATE QHash< Key, T >::const_iterator QHash< Key, T >::constFind

(

const Key &

key

)

const

Returns an iterator pointing to the item with the key in the hash.

Since

4.1

If the hash contains no item with the key, the function returns constEnd().

See also

find(), QMultiHash::constFind()

Definition at line 859 of file qhash.h.

Referenced by QStyleSheetStyleSelector::attribute(), QGLGlyphCache::cacheGlyphs(), QDeclarativeJS::Ecma::RegExp::flagFromChar(), QApplication::font(), QDBusConnectionPrivate::getNameOwner(), QScript::QObjectDelegate::getOwnPropertyDescriptor(), QScript::QObjectDelegate::getOwnPropertySlot(), QStyleSheetStyle::hasStyleRule(), QApplicationPrivate::initializeWidgetPaletteHash(), QDesktopServices::openUrl(), QMultiHash< const QGLContext *, GLProgram >::operator+(), QApplication::palette(), QScript::QObjectDelegate::put(), QScriptEnginePrivate::qobjectData(), qt_gl_choose_cmap(), QStyleSheetStyle::renderRule(), QAuServerMac::stop(), QStyleSheetStyle::styleRules(), QFont::substitute(), and QProcessEnvironment::value().

{
    return const_iterator(*findNode(akey));
}

contains()

template<class Key, class T >

Q_INLINE_TEMPLATE bool QHash< Key, T >::contains

(

const Key &

key

)

const

Returns true if the hash contains an item with the key; otherwise returns false.

See also

count(), QMultiHash::contains()

Definition at line 872 of file qhash.h.

Referenced by _q_dupEnvironment(), QDeclarativeIntegerCache::add(), QDeclarativeTypeNameCache::add(), QGraphicsAnchorLayoutPrivate::addAnchorMaybeParallel(), QPatternist::XsdSchema::addAnonymousType(), QSqlDatabasePrivate::addDatabase(), QPatternist::XsdSchemaParser::addFacet(), QDeclarativeCompiler::addId(), QAxScriptManager::addObject(), QWindowsFileSystemWatcherEngine::addPaths(), QWSPropertyManager::addProperty(), QPatternist::XsdValidatingInstanceReader::addSchema(), FlatListModel::addValue(), QDeclarativePropertyCache::append(), QStateMachinePrivate::applyProperties(), QPatternist::XsdInstanceReader::attribute(), QDeclarativeCompiler::buildComponent(), QDeclarativeCompiler::buildIdProperty(), callback(), QPatternist::XsdSchemaChecker::checkAttributeUseConstraints(), QPatternist::XsdSchemaChecker::checkConstrainingFacets(), QPatternist::XsdTypeChecker::checkConstrainingFacetsBinary(), QPatternist::XsdTypeChecker::checkConstrainingFacetsBoolean(), QPatternist::XsdTypeChecker::checkConstrainingFacetsDateTime(), QPatternist::XsdTypeChecker::checkConstrainingFacetsDecimal(), QPatternist::XsdTypeChecker::checkConstrainingFacetsDouble(), QPatternist::XsdTypeChecker::checkConstrainingFacetsDuration(), QPatternist::XsdTypeChecker::checkConstrainingFacetsList(), QPatternist::XsdTypeChecker::checkConstrainingFacetsNotation(), QPatternist::XsdTypeChecker::checkConstrainingFacetsQName(), QPatternist::XsdTypeChecker::checkConstrainingFacetsSignedInteger(), QPatternist::XsdTypeChecker::checkConstrainingFacetsString(), QPatternist::XsdTypeChecker::checkConstrainingFacetsUnion(), QPatternist::XsdTypeChecker::checkConstrainingFacetsUnsignedInteger(), QPatternist::XsdSchemaChecker::checkElementDuplicates(), QGtkStylePrivate::cleanupGtkWidgets(), QPatternist::ColorOutput::colorify(), QPatternist::ColoringMessageHandler::colorifyDescription(), QDeclarativeCompiler::compileAlias(), QDeclarativeCompiler::compileTree(), EGLNullWSScreen::connect(), QAxBase::connectNotify(), QProcessEnvironment::contains(), QSet< typename TokenLookupClass::NodeName >::contains(), QCache< QPixmapCache::Key, QPixmapCacheEntry >::contains(), QPatternist::Template::createContext(), QPatternist::XsdSchemaTypesFactory::createSchemaType(), QEventDispatcherWin32Private::doWsaAsyncSelect(), QSvgFont::draw(), QDeclarativePath::endpoint(), QPatternist::TypeAvailableFN::evaluateSingleton(), familyNameFromPostScriptName(), QNetworkAccessHttpBackend::fetchCacheMetaData(), QGestureManager::filterEvent(), QRegExpEngine::getEscape(), QGraphicsAnchorLayoutPrivate::getGraphParts(), QSharedNetworkSessionManager::getSession(), QApplicationPrivate::globalEventProcessor(), QTextLine::glyphs(), QStateMachinePrivate::handleFilteredEvent(), QScriptDebuggerPrivate::handleResponse(), QPatternist::XsdInstanceReader::hasAttribute(), hasDuplicatedElementsInternal(), QNetworkAccessCache::hasEntry(), QBBEngine::hasIdentifier(), QWSPropertyManager::hasProperty(), QRenderRule::hasStyleHint(), QGtkStylePrivate::initGtkWidgets(), QDeclarativePath::interpolate(), QXmlSimpleReaderPrivate::isExpandedEntityValueTooLarge(), QPatternist::XsdSchemaHelper::isValidAttributeUsesRestriction(), launchWebBrowser(), QNetworkAccessHttpBackend::loadFromCacheIfAllowed(), QFSFileEnginePrivate::longFileName(), QNetworkReplyImplPrivate::metaDataChanged(), QPatternist::XsdTypeChecker::normalizedValue(), QAxMetaObject::numParameter(), QMultiHash< const QGLContext *, GLProgram >::operator+(), QAxMetaObject::paramType(), QXmlStreamReaderPrivate::parse(), parseServerList(), QStyleSheetStyle::polish(), QTextureGlyphCache::populate(), QPatternist::XsdStateMachine< XsdSchemaToken::NodeName >::proceed(), QPatternist::NamespaceSupport::processName(), QDeclarativePath::processPath(), qt_create_commandline(), qt_mac_handleTabletEvent(), QtWndProc(), QPatternist::XSLTTokenizer::readAlternativeAttribute(), QInotifyFileSystemWatcherEngine::readFromInotify(), QDeclarativeMetaType::registerCustomStringConverter(), QEventDispatcherWin32::registerSocketNotifier(), QFreetypeFace::release(), QSqlDatabasePrivate::removeDatabase(), QDeclarativeWatcher::removeWatch(), QNetworkAccessHttpBackend::replyDownloadMetaData(), QPatternist::XsdSchemaResolver::resolveAttributeInheritance(), QPatternist::XsdSchemaResolver::resolveEnumerationFacetValues(), QHeaderViewPrivate::saveCascadingSectionSize(), QSqlRelationalTableModel::setData(), QmlJSDebugger::LiveSelectionIndicator::setItems(), ModelNode::setObjectValue(), QSimplex::simplifyConstraints(), QPatternist::XsdSchemaChecker::sourceLocation(), QPatternist::AccelTree::sourceLocation(), QPatternist::XsdSchemaResolver::sourceLocation(), FlatListModel::toString(), QFSFileEnginePrivate::unmap(), QGestureManager::unregisterGestureRecognizer(), QStyleSheetStyle::unsetPalette(), QMenuPrivate::updateActionRects(), and QPatternist::XsdValidatingInstanceReader::validateElementComplexType().

{
    return *findNode(akey) != e;
}

count() [1/2]

template<class Key, class T >

Q_OUTOFLINE_TEMPLATE int QHash< Key, T >::count

(

const Key &

key

)

const

Returns the number of items associated with the key.

See also

contains(), insertMulti()

Definition at line 719 of file qhash.h.

Referenced by _q_dupEnvironment(), QDeclarativeCompiler::addId(), FlatListModel::addValue(), QDeclarativeCompiler::buildObject(), QDeclarativeCompiler::completeComponentBuild(), QAxBase::connectNotify(), QDeclarativeIntegerCache::count(), QDeclarativeOpenMetaObject::count(), QSet< typename TokenLookupClass::NodeName >::count(), QPatternist::XSLTTokenizer::createElementDescriptions(), QDeclarativeVisualDataModelPrivate::createMetaData(), QDeclarativeCompiler::genContextCache(), QDeclarativeGridView::itemsMoved(), QDeclarativeListView::itemsMoved(), QDeclarativeOpenMetaObject::name(), QPatternist::AccelTree::printStats(), QDeclarativeBindingCompiler::program(), FlatListModel::setProperty(), and QSimplex::simplifyConstraints().

{
    int cnt = 0;
    Node *node = *findNode(akey);
    if (node != e) {
        do {
            ++cnt;
        } while ((node = node->next) != e && node->key == akey);
    }
    return cnt;
}

count() [2/2]

template<class Key, class T>

int QHash< Key, T >::count ( ) const

inline

Same as size().

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 475 of file qhash.h.

Referenced by QMultiHash< const QGLContext *, GLProgram >::operator+().

{ return d->size; }

createNode()

template<class Key, class T>

Q_INLINE_TEMPLATE QHash< Key, T >::Node * QHash< Key, T >::createNode ( uint  h, const Key &  key, const T &  value, Node **  nextNode  )

private

Definition at line 538 of file qhash.h.

{
    Node *node;

    if (QTypeInfo<T>::isDummy) {
        node = reinterpret_cast<Node *>(new (d->allocateNode(alignOfDummyNode())) DummyNode(akey));
    } else {
        node = new (d->allocateNode(alignOfNode())) Node(akey, avalue);
    }

    node->h = ah;
    node->next = *anextNode;
    *anextNode = node;
    ++d->size;
    return node;
}

deleteNode()

template<class Key , class T >

Q_INLINE_TEMPLATE void QHash< Key, T >::deleteNode ( Node *  node )

private

Definition at line 509 of file qhash.h.

{
    deleteNode2(reinterpret_cast<QHashData::Node*>(node));
    d->freeNode(node);
}

deleteNode2()

template<class Key , class T >

Q_INLINE_TEMPLATE void QHash< Key, T >::deleteNode2 ( QHashData::Node *  node )

staticprivate

Definition at line 516 of file qhash.h.

{
#ifdef Q_CC_BOR
    concrete(node)->~QHashNode<Key, T>();
#else
    concrete(node)->~Node();
#endif
}

detach()

template<class Key, class T>

void QHash< Key, T >::detach ( )

inline

Detaches this hash from any other hashes with which it may share data.

Warning

This function is not part of the public interface.

See also

isDetached()

Definition at line 303 of file qhash.h.

Referenced by QSet< typename TokenLookupClass::NodeName >::detach().

{ if (d->ref != 1) detach_helper(); }

detach_helper()

template<class Key , class T >

Q_OUTOFLINE_TEMPLATE void QHash< Key, T >::detach_helper ( )

private

Definition at line 580 of file qhash.h.

{
    QHashData *x = d->detach_helper2(duplicateNode, deleteNode2,
        QTypeInfo<T>::isDummy ? sizeof(DummyNode) : sizeof(Node),
        QTypeInfo<T>::isDummy ? alignOfDummyNode() : alignOfNode());
    if (!d->ref.deref())
        freeData(d);
    d = x;
}

duplicateNode()

template<class Key , class T >

Q_INLINE_TEMPLATE void QHash< Key, T >::duplicateNode ( QHashData::Node *  originalNode, void *  newNode  )

staticprivate

Definition at line 526 of file qhash.h.

{
    Node *concreteNode = concrete(node);
    if (QTypeInfo<T>::isDummy) {
        (void) new (newNode) DummyNode(concreteNode->key);
    } else {
        (void) new (newNode) Node(concreteNode->key, concreteNode->value);
    }
}

empty()

template<class Key, class T>

bool QHash< Key, T >::empty ( ) const

inline

This function is provided for STL compatibility.

It is equivalent to isEmpty(), returning true if the hash is empty; otherwise returns false.

Definition at line 489 of file qhash.h.

{ return isEmpty(); }

end() [1/2]

template<class Key, class T>

QHash::iterator QHash< Key, T >::end ( )

inline

Returns an STL-style iterator pointing to the imaginary item after the last item in the hash.

See also

begin(), constEnd()

Definition at line 467 of file qhash.h.

Referenced by QStateMachinePrivate::_q_animationFinished(), QScriptEnginePrivate::_q_objectDestroyed(), QScriptDebuggerCodeWidgetPrivate::_q_onScriptsChanged(), QParallelAnimationGroupPrivate::_q_uncontrolledAnimationFinished(), QDeclarativeTypeLoader::absoluteFilePath(), QDeclarativeFastProperties::accessorIndexForProperty(), QDeclarativeTimeLinePrivate::add(), QDeclarativeContextData::addImportedScript(), FlatListModel::addValue(), QPMCache::allPixmaps(), QStateMachinePrivate::applyProperties(), QGLGlyphCache::cacheGlyphs(), callback(), QMetaObject::changeGuard(), QGLGlyphCache::cleanCache(), QSqlDatabasePrivate::cleanConnections(), QGestureManager::cleanupCachedGestures(), QNetworkAccessCache::clear(), QDeclarativeTimeLine::clear(), QDeclarativePropertyCache::clear(), QDeclarativeTypeLoader::clearCache(), QObjectPrivate::clearGuards(), QDeclarativeCompiler::compileTree(), QDBusConnectionPrivate::connectSignal(), QDeclarativePropertyCache::copy(), QPersistentModelIndexData::create(), QDeclarativeEnginePrivate::createCache(), QPatternist::Template::createContext(), QDeclarativeVisualDataModelPrivate::createMetaData(), NestedListModel::data(), QScript::QObjectDelegate::deleteProperty(), QDBusConnectionPrivate::disconnectRelay(), QDBusConnectionPrivate::disconnectSignal(), QParallelAnimationGroupPrivate::disconnectUncontrolledAnimations(), ModelNode::dump(), QSet< typename TokenLookupClass::NodeName >::end(), QDeclarativeVisualDataModelPrivate::ensureRoles(), QDeclarativeIntegerCache::findId(), QPMCache::flushDetachedPixmaps(), QGLGlyphCache::fontEngineDestroyed(), QAxScriptManager::functions(), QDeclarativeCompiler::genContextCache(), QGraphicsScenePrivate::gestureEventHandler(), QWSPropertyManager::getProperty(), QTextFormatCollection::hasFormatCached(), QTextFormatCollection::indexForFormat(), QDeclarativeVisualDataModelDataMetaObject::initialValue(), QPaintBufferResource::insert(), QXmlSimpleReaderPrivate::isExpandedEntityValueTooLarge(), QDeclarativeMetaType::isModule(), QNetworkAccessCache::linkEntry(), QDeclarativeEnginePrivate::listType(), QDeclarativePixmap::load(), QTextDocumentWithImageResources::loadResource(), QReadWriteLock::lockForRead(), MetaObjectGenerator::metaObject(), QDBusConnectionPrivate::objectDestroyed(), Graph< Vertex, EdgeData >::const_iterator::operator!=(), operator<<(), QHash< QExplicitlySharedDataPointer, QHash >::operator==(), QDeclarativeOpenMetaObject::operator[](), QTextureGlyphCache::populate(), QDeclarativeImports::populateCache(), QDeclarativeVisualDataModelData::propForRole(), qDBusRealToggleWatch(), qDBusRemoveTimeout(), qDBusRemoveWatch(), QDeclarativeType::QDeclarativeType(), QDeclarativeTypeLoader::qmlDirParser(), QDeclarativeMetaType::qmlType(), QDeclarativeDebugConnectionPrivate::readyRead(), QDnotifyFileSystemWatcherEngine::refresh(), QDeclarativeBindingCompilerPrivate::registerString(), registerType(), QNetworkAccessCache::releaseEntry(), QDeclarativeTimeLine::remove(), QPaintBufferResource::remove(), QNetworkAccessCache::removeEntry(), QMetaObject::removeGuard(), QGraphicsScenePrivate::removeItemHelper(), QFSEventsFileSystemWatcherEngine::removePaths(), QWSPropertyManager::removeProperty(), QGtkStylePrivate::removeWidgetFromMap(), QNetworkAccessCache::requestEntry(), QNetworkAccessCache::requestEntryNow(), QDialogButtonBoxPrivate::retranslateStrings(), QAxScriptManager::scriptForFunction(), QAxScriptManager::scriptNames(), QDBusConnectionPrivate::serviceOwnerChangedNoLock(), QTextControl::setExtraSelections(), QWSPropertyManager::setProperty(), FlatListModel::setProperty(), ModelNode::setProperty(), QDeclarativeOpenMetaObject::setValue(), QDeclarativeBindingCompilerPrivate::subscriptionIndex(), QDeclarativeTimeLine::sync(), QReadWriteLock::tryLockForRead(), QNetworkAccessCache::unlinkEntry(), QReadWriteLock::unlock(), ModelNode::updateListIndexes(), QDeclarativeGridViewPrivate::updateUnrequestedIndexes(), QDeclarativeListViewPrivate::updateUnrequestedIndexes(), QDeclarativeGridViewPrivate::updateUnrequestedPositions(), QDeclarativeListViewPrivate::updateUnrequestedPositions(), QDeclarativeOpenMetaObject::value(), QPaintBufferResource::value(), QDeclarativeWorkerScriptEnginePrivate::variantToScriptValue(), QPdfEnginePrivate::writeFonts(), QDeclarativeDataLoader::~QDeclarativeDataLoader(), QDeclarativeDebugConnection::~QDeclarativeDebugConnection(), QDeclarativeEngineDebugPrivate::~QDeclarativeEngineDebugPrivate(), QDeclarativeTimeLine::~QDeclarativeTimeLine(), QPaintBufferResource::~QPaintBufferResource(), and QPrintDialogPrivate::~QPrintDialogPrivate().

{ detach(); return iterator(e); }

end() [2/2]

template<class Key, class T>

QHash::const_iterator QHash< Key, T >::end ( ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 468 of file qhash.h.

{ return const_iterator(e); }

erase()

template<class Key , class T >

Q_OUTOFLINE_TEMPLATE QHash< Key, T >::iterator QHash< Key, T >::erase

(

iterator

pos

)

Removes the (key, value) pair associated with the iterator pos from the hash, and returns an iterator to the next item in the hash.

Unlike remove() and take(), this function never causes QHash to rehash its internal data structure. This means that it can safely be called while iterating, and won't affect the order of items in the hash. For example:

QHash<QObject *, int> objectHash;
...
QHash<QObject *, int>::iterator i = objectHash.find(obj);
while (i != objectHash.end() && i.key() == obj) {
    if (i.value() == 0) {
        i = objectHash.erase(i);
    } else {
        ++i;
    }
}

See also

remove(), take(), find()

Definition at line 827 of file qhash.h.

Referenced by QStateMachinePrivate::_q_animationFinished(), QScriptEnginePrivate::_q_objectDestroyed(), QScriptDebuggerCodeWidgetPrivate::_q_onScriptsChanged(), QStateMachinePrivate::applyProperties(), QMetaObject::changeGuard(), QObjectPrivate::clearGuards(), QScript::QObjectDelegate::deleteProperty(), QDBusConnectionPrivate::disconnectSignal(), QSet< typename TokenLookupClass::NodeName >::erase(), QPMCache::flushDetachedPixmaps(), qDBusRemoveTimeout(), qDBusRemoveWatch(), qPRCleanup(), QDeclarativeTimeLine::remove(), QPaintBufferResource::remove(), QMetaObject::removeGuard(), QGraphicsScenePrivate::removeItemHelper(), QFSEventsFileSystemWatcherEngine::removePaths(), QGtkStylePrivate::removeWidgetFromMap(), QWindowsFileSystemWatcherEngineThread::run(), QTextControl::setExtraSelections(), QReadWriteLock::unlock(), QEventDispatcherMac::unregisterTimers(), and QPrintDialogPrivate::~QPrintDialogPrivate().

{
    if (it == iterator(e))
        return it;

    iterator ret = it;
    ++ret;

    Node *node = it;
    Node **node_ptr = reinterpret_cast<Node **>(&d->buckets[node->h % d->numBuckets]);
    while (*node_ptr != node)
        node_ptr = &(*node_ptr)->next;
    *node_ptr = node->next;
    deleteNode(node);
    --d->size;
    return ret;
}

find() [1/2]

template<class Key, class T >

Q_INLINE_TEMPLATE QHash< Key, T >::iterator QHash< Key, T >::find

(

const Key &

key

)

Returns an iterator pointing to the item with the key in the hash.

If the hash contains no item with the key, the function returns end().

If the hash contains multiple items with the key, this function returns an iterator that points to the most recently inserted value. The other values are accessible by incrementing the iterator. For example, here's some code that iterates over all the items with the same key:

QHash<QString, int> hash;
...
QHash<QString, int>::const_iterator i = hash.find("HDR");
while (i != hash.end() && i.key() == "HDR") {
    cout << i.value() << endl;
    ++i;
}

See also

value(), values(), QMultiHash::find()

Definition at line 865 of file qhash.h.

Referenced by QStateMachinePrivate::_q_animationFinished(), QScriptEnginePrivate::_q_objectDestroyed(), QDeclarativeTypeLoader::absoluteFilePath(), QDeclarativeFastProperties::accessorIndexForProperty(), QDeclarativeTimeLinePrivate::add(), QDeclarativeContextData::addImportedScript(), FlatListModel::addValue(), callback(), QDBusConnectionPrivate::connectSignal(), QPersistentModelIndexData::create(), NestedListModel::data(), QScript::QObjectDelegate::deleteProperty(), QDBusConnectionPrivate::disconnectSignal(), QSet< typename TokenLookupClass::NodeName >::find(), QGLGlyphCache::fontEngineDestroyed(), QWSPropertyManager::getProperty(), QDeclarativeVisualDataModelDataMetaObject::initialValue(), QPaintBufferResource::insert(), QXmlSimpleReaderPrivate::isExpandedEntityValueTooLarge(), QDeclarativeMetaType::isModule(), QNetworkAccessCache::linkEntry(), QDeclarativeEnginePrivate::listType(), QDeclarativePixmap::load(), QTextDocumentWithImageResources::loadResource(), QReadWriteLock::lockForRead(), QMultiHash< const QGLContext *, GLProgram >::operator+(), operator<<(), QHash< QExplicitlySharedDataPointer, QHash >::operator==(), QDeclarativeOpenMetaObject::operator[](), QDeclarativeVisualDataModelData::propForRole(), QDeclarativeType::QDeclarativeType(), QDeclarativeTypeLoader::qmlDirParser(), QDeclarativeMetaType::qmlType(), QDeclarativeDebugConnectionPrivate::readyRead(), QDnotifyFileSystemWatcherEngine::refresh(), QDeclarativeBindingCompilerPrivate::registerString(), registerType(), QNetworkAccessCache::releaseEntry(), QCache< QPixmapCache::Key, QPixmapCacheEntry >::relink(), QDeclarativeTimeLine::remove(), QPaintBufferResource::remove(), QNetworkAccessCache::removeEntry(), QWSPropertyManager::removeProperty(), QGtkStylePrivate::removeWidgetFromMap(), QNetworkAccessCache::requestEntry(), QNetworkAccessCache::requestEntryNow(), QDBusConnectionPrivate::serviceOwnerChangedNoLock(), QTextControl::setExtraSelections(), QWSPropertyManager::setProperty(), FlatListModel::setProperty(), ModelNode::setProperty(), QDeclarativeOpenMetaObject::setValue(), QDeclarativeBindingCompilerPrivate::subscriptionIndex(), QDeclarativeTimeLine::sync(), QReadWriteLock::tryLockForRead(), QNetworkAccessCache::unlinkEntry(), QReadWriteLock::unlock(), QDeclarativeOpenMetaObject::value(), and QPaintBufferResource::value().

{
    detach();
    return iterator(*findNode(akey));
}

find() [2/2]

template<class Key, class T >

Q_INLINE_TEMPLATE QHash< Key, T >::const_iterator QHash< Key, T >::find

(

const Key &

key

)

const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 853 of file qhash.h.

{
    return const_iterator(*findNode(akey));
}

findNode()

template<class Key, class T >

Q_OUTOFLINE_TEMPLATE QHash< Key, T >::Node ** QHash< Key, T >::findNode ( const Key &  key, uint *  hp = 0  ) const

private

Definition at line 878 of file qhash.h.

{
    Node **node;
    uint h = qHash(akey);

    if (d->numBuckets) {
        node = reinterpret_cast<Node **>(&d->buckets[h % d->numBuckets]);
        Q_ASSERT(*node == e || (*node)->next);
        while (*node != e && !(*node)->same_key(h, akey))
            node = &(*node)->next;
    } else {
        node = const_cast<Node **>(reinterpret_cast<const Node * const *>(&e));
    }
    if (ahp)
        *ahp = h;
    return node;
}

freeData()

template<class Key , class T >

Q_OUTOFLINE_TEMPLATE void QHash< Key, T >::freeData ( QHashData *  d )

private

Definition at line 568 of file qhash.h.

{
    x->free_helper(deleteNode2);
}

insert()

template<class Key, class T>

Q_INLINE_TEMPLATE QHash< Key, T >::iterator QHash< Key, T >::insert	(	const Key &	key,
		const T &	value
	)

Inserts a new item with the key and a value of value.

If there is already an item with the key, that item's value is replaced with value.

If there are multiple items with the key, the most recently inserted item's value is replaced with value.

See also

insertMulti()

Definition at line 753 of file qhash.h.

Referenced by QDeclarativeVisualDataModel::_q_itemsInserted(), QDeclarativeVisualDataModel::_q_itemsMoved(), QDeclarativeVisualDataModel::_q_itemsRemoved(), QDeclarativeTypeLoader::absoluteFilePath(), QDeclarativeFastProperties::add(), QDeclarativeIntegerCache::add(), QDeclarativeTypeNameCache::add(), QDeclarativeTimeLinePrivate::add(), QGraphicsAnchorLayoutPrivate::addAnchorMaybeParallel(), QPatternist::XsdSchema::addAnonymousType(), QPatternist::XsdSchemaParser::addAnonymousType(), QPatternist::XsdSchemaParser::addAttribute(), QPatternist::XsdSchemaParser::addAttributeGroup(), QPatternist::GenericNamespaceResolver::addBinding(), QPatternist::DelegatingNamespaceResolver::addBinding(), MetaObjectGenerator::addChangedSignal(), QPdfEnginePrivate::addConstantAlphaObject(), QSqlDatabasePrivate::addDatabase(), QPatternist::XsdSchemaParser::addElement(), QPatternist::XsdSchemaParser::addElementGroup(), QPatternist::XsdSchemaParser::addFacet(), QSvgIconEngine::addFile(), QPatternist::AbstractFunctionFactory::addFunction(), QSvgFont::addGlyph(), QDeclarativeCompiler::addId(), QPatternist::XsdSchemaParser::addIdentityConstraint(), QPdfEnginePrivate::addImage(), QDeclarativeContextData::addImportedScript(), QGraphicsAnchorLayoutPrivate::addInternalVertex(), QPatternist::GenericStaticContext::addLocation(), QSvgTinyDocument::addNamedNode(), QSvgTinyDocument::addNamedStyle(), QPatternist::XsdSchemaParser::addNotation(), QAxScriptManager::addObject(), QInotifyFileSystemWatcherEngine::addPaths(), QKqueueFileSystemWatcherEngine::addPaths(), QWindowsFileSystemWatcherEngine::addPaths(), QSvgIconEngine::addPixmap(), QPatternist::XsdValidatingInstanceReader::addSchema(), QSvgTinyDocument::addSvgFont(), QPatternist::XsdSchema::addType(), QPatternist::XsdSchemaParser::addType(), FlatListModel::addValue(), QGtkStylePrivate::addWidgetToMap(), QDirectFbInput::addWindow(), QDeclarativePropertyCache::append(), QStateMachinePrivate::applyProperties(), QPatternist::PullBridge::attributeItems(), QPatternist::PullBridge::attributes(), QGLGlyphCache::cacheGlyphs(), QScriptObjectSnapshot::capture(), QPatternist::XQueryTokenizer::charForReference(), QPatternist::XsdSchemaChecker::checkAttributeUseConstraints(), QPatternist::XsdSchemaChecker::checkElementDuplicates(), QPatternist::ColoringMessageHandler::ColoringMessageHandler(), QAxBase::connectNotify(), QDBusConnectionPrivate::connectSignal(), GraphPath::constraint(), QGraphicsAnchorLayoutPrivate::constraintsFromSizeHints(), QPatternist::ConstructorFunctionsFactory::ConstructorFunctionsFactory(), convertWithPalette(), QPersistentModelIndexData::create(), QDialogButtonBoxPrivate::createButton(), QGraphicsAnchorLayoutPrivate::createCenterAnchors(), Graph< AnchorVertex, AnchorData >::createDirectedEdge(), QPatternist::XSLTTokenizer::createElementDescriptions(), QDeclarativeVisualDataModelPrivate::createMetaData(), QDBusMetaObject::createMetaObject(), QDeclarativeOpenMetaObjectType::createProperty(), createSlack(), QPatternist::XSLTTokenizer::createValidationAlternatives(), QDeclarativeXmlListModel::data(), NestedListModel::data(), QPatternist::GenericNamespaceResolver::defaultXQueryBindings(), QPatternist::GenericNamespaceResolver::defaultXSLTBindings(), QGestureManager::deliverEvents(), QNetworkManagerEngine::deviceAdded(), QPatternist::AccelTreeResourceLoader::deviceURIs(), QAxMetaObject::dispIDofName(), QPdfBaseEnginePrivate::drawTextItem(), QDeclarativePath::endpoint(), QDeclarativeVisualDataModelPrivate::ensureRoles(), QPatternist::FunctionAvailableFN::evaluateSingleton(), QNetworkAccessHttpBackend::fetchCacheMetaData(), flagDescriptions(), QDeclarativeListModel::flatten(), QConfFile::fromName(), QPatternist::FunctionFactoryCollection::functionSignatures(), QDeclarativeTypeLoader::get(), Maemo::GConfItemFast::getEntries(), QFreetypeFace::getFace(), QScript::QObjectDelegate::getOwnPropertyDescriptor(), QScript::QObjectDelegate::getOwnPropertySlot(), QDeclarativeTypeLoader::getQmldir(), QDeclarativeTypeLoader::getScript(), QTextLine::glyphs(), QmlJSDebugger::AbstractViewInspector::handleMessage(), hasDuplicatedElementsInternal(), QDirModelPrivate::init(), QFileSystemModelPrivate::init(), QNetworkReplyImplPrivate::initCacheSaveDevice(), initDefaultPaths(), QGtkStylePrivate::initGtkWidgets(), QNetworkManagerEngine::initialize(), QProcessEnvironment::insert(), QSet< typename TokenLookupClass::NodeName >::insert(), QPMCache::insert(), QProcessEnvironmentPrivate::insert(), QPaintBufferResource::insert(), QPatternist::ColorOutput::insertMapping(), QDeclarativeXmlQueryEngine::instance(), internalParticleLookupMap(), QDeclarativePath::interpolate(), QAxServerBase::Invoke(), QXmlSimpleReaderPrivate::isExpandedEntityValueTooLarge(), QPatternist::XsdSchemaHelper::isValidAttributeUsesExtension(), QPatternist::XsdSchemaHelper::isValidAttributeUsesRestriction(), QDeclarativeGridView::itemsMoved(), QDeclarativeListView::itemsMoved(), QDeclarativeDataLoader::load(), QTextDocumentWithImageResources::loadResource(), QReadWriteLock::lockForRead(), QMenuBarPrivate::macMenu(), QMenuPrivate::macMenu(), QPatternist::XsdTypeChecker::mergedFacetsForType(), MetaObjectGenerator::metaObject(), QPatternist::NamespaceSupport::NamespaceSupport(), QDeclarativeDataLoader::networkReplyFinished(), QDeclarativePixmapReader::networkRequestDone(), QPrintDialogPrivate::openCarbonPrintPanel(), QPatternist::Template::parametersAsHash(), QXmlStreamReaderPrivate::parse(), parseHttpOptionHeader(), QPatternist::XsdSchemaParser::parseList(), QPatternist::XsdSchemaParser::parseLocalAttribute(), QBBButtonEventNotifier::parsePPS(), QAxMetaObject::parsePrototype(), parseServerList(), QAuServerNAS::play(), QTextureGlyphCache::populate(), QJSDebuggerAgentPrivate::positionChange(), QScript::QObjectDelegate::put(), QAxScript::QAxScript(), QDBusConnectionPrivate::QDBusConnectionPrivate(), QDeclarativePackageAttached::QDeclarativePackageAttached(), QDeclarativeType::QDeclarativeType(), qmlAttachedPropertiesObjectById(), QDeclarativeTypeLoader::qmlDirParser(), QNetworkReplyPrivate::QNetworkReplyPrivate(), QScriptEnginePrivate::qobjectData(), qPRCreate(), qt_create_commandline(), qt_dispatchTabletProximityEvent(), qt_gl_choose_cmap(), qt_x11_set_fallback_font_family(), QSvgIconEngine::read(), MetaObjectGenerator::readEnumInfo(), MetaObjectGenerator::readEventInterface(), QInotifyFileSystemWatcherEngine::readFromInotify(), QNetworkReplyImplPrivate::redirectionRequested(), QDeclarativeMetaType::registerCustomStringConverter(), QDeclarativeVMEMetaObject::registerInterceptor(), registerInterface(), QEventDispatcherWin32::registerSocketNotifier(), QDeclarativeBindingCompilerPrivate::registerString(), QEventDispatcherMac::registerTimer(), registerType(), QGraphicsAnchorLayoutPrivate::removeInternalVertex(), QMultiHash< const QGLContext *, GLProgram >::replace(), QPatternist::XsdSchemaResolver::resolveAttributeInheritance(), QPatternist::XsdSchemaResolver::resolveSimpleContentComplexTypes(), QGraphicsAnchorLayoutPrivate::restoreSimplifiedConstraints(), QPatternist::AccelTreeResourceLoader::retrieveUnparsedText(), QHeaderViewPrivate::saveCascadingSectionSize(), QScriptDebuggerPrivate::scheduleCommand(), QJSDebuggerAgent::scriptLoad(), QDeclarativeWorkerScriptEnginePrivate::scriptValueToVariant(), QSqlRelationalTableModel::selectStatement(), QNetworkRequest::setAttribute(), QNetworkAccessBackend::setAttribute(), QDeclarativeListModelParser::setCustomData(), QScriptEnginePrivate::setDefaultPrototype(), QApplication::setFont(), QmlJSDebugger::LiveSelectionIndicator::setItems(), ModelNode::setObjectValue(), QAuthenticator::setOption(), QStyleSheetStyle::setPalette(), QApplicationPrivate::setPalette_helper(), QSettings::setPath(), QPatternist::NamespaceSupport::setPrefix(), QPatternist::NamespaceSupport::setPrefixes(), FlatListModel::setProperty(), ModelNode::setProperty(), QNetworkSessionPrivateImpl::setSessionProperty(), QPatternist::NamespaceSupport::setTargetNamespace(), QPatternist::XsdSchemaChecker::setupAllowedAtomicFacets(), QPatternist::XsdSchemaContext::setupBuiltinTypesFacetList(), QRegExpEngine::setupCategoriesRangeMap(), QDesktopServices::setUrlHandler(), QSimplex::simplifyConstraints(), QGraphicsAnchorLayoutPrivate::solveMinMax(), QGraphicsAnchorLayoutPrivate::solvePreferred(), QWidgetPrivate::stackUnder_sys(), QStyleSheetStyle::styleRules(), QDeclarativeBindingCompilerPrivate::subscriptionIndex(), QProcessEnvironment::systemEnvironment(), MetaObjectGenerator::tryCache(), QReadWriteLock::tryLockForRead(), QPatternist::ElementConstructor::typeCheck(), QPatternist::NamePool::unlockedAllocateLocalName(), QPatternist::NamePool::unlockedAllocateNamespace(), QPatternist::NamePool::unlockedAllocatePrefix(), QGestureManager::unregisterGestureRecognizer(), QBBEngine::updateConfiguration(), QPatternist::XsdValidatingInstanceReader::validateElementComplexType(), QSvgIconEngine::write(), and QPatternist::XsdSchemaTypesFactory::XsdSchemaTypesFactory().

{
    detach();

    uint h;
    Node **node = findNode(akey, &h);
    if (*node == e) {
        if (d->willGrow())
            node = findNode(akey, &h);
        return iterator(createNode(h, akey, avalue, node));
    }

    if (!QTypeInfo<T>::isDummy)
        (*node)->value = avalue;
    return iterator(*node);
}

insertMulti()

template<class Key, class T>

Q_INLINE_TEMPLATE QHash< Key, T >::iterator QHash< Key, T >::insertMulti	(	const Key &	key,
		const T &	value
	)

Inserts a new item with the key and a value of value.

If there is already an item with the same key in the hash, this function will simply create a new one. (This behavior is different from insert(), which overwrites the value of an existing item.)

See also

insert(), values()

Definition at line 772 of file qhash.h.

Referenced by QDeclarativeVisualDataModel::_q_itemsRemoved(), QDBusConnectionPrivate::connectSignal(), QDirModelPrivate::init(), QFileSystemModelPrivate::init(), QMultiHash< const QGLContext *, GLProgram >::insert(), QDomDocumentTypePrivate::insertAfter(), QDomDocumentTypePrivate::insertBefore(), QTextDocumentLayoutPrivate::layoutTable(), operator>>(), qDBusRealAddWatch(), QDomDocumentTypePrivate::QDomDocumentTypePrivate(), registerType(), QDomDocumentTypePrivate::replaceChild(), QJSDebuggerAgent::setBreakpoints(), and QTextControl::setExtraSelections().

{
    detach();
    d->willGrow();

    uint h;
    Node **nextNode = findNode(akey, &h);
    return iterator(createNode(h, akey, avalue, nextNode));
}

isDetached()

template<class Key, class T>

bool QHash< Key, T >::isDetached ( ) const

inline

Returns true if the hash's internal data isn't shared with any other hash object; otherwise returns false.

Warning

This function is not part of the public interface.

See also

detach()

Definition at line 304 of file qhash.h.

Referenced by QSet< typename TokenLookupClass::NodeName >::isDetached().

{ return d->ref == 1; }

isEmpty()

template<class Key, class T>

bool QHash< Key, T >::isEmpty ( ) const

inline

Returns true if the hash contains no items; otherwise returns false.

See also

size()

Definition at line 297 of file qhash.h.

Referenced by _q_dupEnvironment(), QStateMachinePrivate::applyProperties(), QPatternist::XQueryTokenizer::charForReference(), QPatternist::XsdSchemaChecker::checkConstrainingFacets(), QPatternist::XsdSchemaChecker::checkElementDuplicates(), QPatternist::XsdSchemaChecker::checkSimpleTypeConstraints(), QObjectPrivate::clearGuards(), QDeclarativeVisualDataModelPrivate::ensureRoles(), QGtkStyleFilter::eventFilter(), QCoreTextFontDatabase::fallbacksForFamily(), QDeclarativeJS::Ecma::RegExp::flagFromChar(), QRegExpEngine::getEscape(), getPath(), QTextDocumentLayoutPrivate::hitTest(), initDefaultPaths(), initFontSubst(), QApplicationPrivate::initializeWidgetPaletteHash(), QDeclarativeTimeLine::isActive(), QSet< typename TokenLookupClass::NodeName >::isEmpty(), QProcessEnvironment::isEmpty(), QCache< QPixmapCache::Key, QPixmapCacheEntry >::isEmpty(), QPatternist::XsdSchemaHelper::isSimpleDerivationOk(), QTextureGlyphCache::populate(), QPatternist::NamespaceSupport::processName(), qt_create_commandline(), qt_gl_choose_cmap(), QFreetypeFace::release(), QDeclarativeTimeLine::remove(), Graph< AnchorVertex, AnchorData >::removeDirectedEdge(), QMetaObject::removeGuard(), QKqueueFileSystemWatcherEngine::removePaths(), QWindowsFileSystemWatcherEngine::removePaths(), QWindowsFileSystemWatcherEngineThread::run(), QDomElementPrivate::save(), QSettings::setPath(), QTextDocumentWithImageResources::setText(), QSimplex::simplifyConstraints(), QGraphicsScenePrivate::touchEventHandler(), QApplicationPrivate::translateRawTouchEvent(), QDeclarativeTimeLine::updateCurrentTime(), updateWidgets(), NestedListModel::valueForNode(), and QTextDocumentWithImageResources::~QTextDocumentWithImageResources().

{ return d->size == 0; }

isSharedWith()

template<class Key, class T>

bool QHash< Key, T >::isSharedWith ( const QHash< Key, T > &  other ) const

inline

Warning

This function is not part of the public interface.

Definition at line 306 of file qhash.h.

{ return d == other.d; }

key() [1/2]

template<class Key , class T>

Q_OUTOFLINE_TEMPLATE const Key QHash< Key, T >::key

(

const T &

value

)

const

Returns the first key mapped to value.

If the hash contains no item with the value, the function returns a default-constructed key.

This function can be slow (linear time), because QHash's internal data structure is optimized for fast lookup by key, not by value.

See also

value(), keys()

Definition at line 674 of file qhash.h.

Referenced by QParallelAnimationGroupPrivate::_q_uncontrolledAnimationFinished(), QPMCache::allPixmaps(), QStateMachinePrivate::applyProperties(), QDeclarativeVisualDataModelPrivate::createMetaData(), QParallelAnimationGroupPrivate::disconnectUncontrolledAnimations(), Graph< Vertex, EdgeData >::const_iterator::from(), QTextFormatCollection::hasFormatCached(), QTextFormatCollection::indexForFormat(), QMacPrintEnginePrivate::initialize(), QHeaderView::initializeSections(), QProcessEnvironmentPrivate::insert(), QSimplexConstraint::isSatisfied(), Graph< Vertex, EdgeData >::const_iterator::operator*(), operator<<(), QDialogButtonBoxPrivate::retranslateStrings(), QScriptDebuggerCodeWidgetPrivate::scriptId(), QSimplex::setConstraints(), QSimplex::simplifyConstraints(), QSimplex::solver(), Graph< Vertex, EdgeData >::const_iterator::to(), QSimplexConstraint::toString(), unregWinClasses(), QDeclarativeGridViewPrivate::updateUnrequestedIndexes(), QDeclarativeListViewPrivate::updateUnrequestedIndexes(), QDeclarativeGridViewPrivate::updateUnrequestedPositions(), and QDeclarativeListViewPrivate::updateUnrequestedPositions().

{
    return key(avalue, Key());
}

key() [2/2]

template<class Key, class T>

Q_OUTOFLINE_TEMPLATE const Key QHash< Key, T >::key	(	const T &	value,
		const Key &	defaultKey
	)		const

Returns the first key mapped to value, or defaultKey if the hash contains no item mapped to value.

Since

4.3 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

This function can be slow (linear time), because QHash's internal data structure is optimized for fast lookup by key, not by value.

Definition at line 680 of file qhash.h.

{
    const_iterator i = begin();
    while (i != end()) {
        if (i.value() == avalue)
            return i.key();
        ++i;
    }

    return defaultValue;
}

keys() [1/2]

template<class Key , class T >

Q_OUTOFLINE_TEMPLATE QList< Key > QHash< Key, T >::keys

(

)

const

Returns a list containing all the keys in the hash, in an arbitrary order.

Keys that occur multiple times in the hash (because items were inserted with insertMulti(), or unite() was used) also occur multiple times in the list.

To obtain a list of unique keys, where each key from the map only occurs once, use uniqueKeys().

The order is guaranteed to be the same as that used by values().

See also

uniqueKeys(), values(), key()

Definition at line 648 of file qhash.h.

Referenced by Graph< AnchorVertex, AnchorData >::adjacentVertices(), QDeclarativeDebugConnectionPrivate::advertisePlugins(), QDeclarativeDebugServerPrivate::advertisePlugins(), QPatternist::XsdInstanceReader::attributeNames(), QPatternist::XsdSchemaChecker::checkConstrainingFacets(), NestedListModel::checkRoles(), QGLGlyphCache::cleanupContext(), QGestureManager::cleanupGesturesForRemovedRecognizer(), QDeclarativeDebugConnectionPrivate::connected(), QGestureManager::getGestureTargets(), QGraphicsAnchorLayoutPrivate::getGraphParts(), getVariables(), QCache< QPixmapCache::Key, QPixmapCacheEntry >::keys(), printHelp(), QDeclarativePropertyCache::propertyNames(), qDBusRealAddTimeout(), QDeclarativeMetaType::qmlTypeNames(), QSvgIconEngine::read(), QStyleSheetStyle::repolish(), FlatListModel::roles(), QNetworkManagerEngine::sessionStateForId(), QStyleSheetStyle::setProperties(), QGestureManager::unregisterGestureRecognizer(), QSvgIconEngine::write(), and QGestureManager::~QGestureManager().

{
    QList<Key> res;
    res.reserve(size());
    const_iterator i = begin();
    while (i != end()) {
        res.append(i.key());
        ++i;
    }
    return res;
}

keys() [2/2]

template<class Key , class T>

Q_OUTOFLINE_TEMPLATE QList< Key > QHash< Key, T >::keys

(

const T &

value

)

const

Returns a list containing all the keys associated with value value, in an arbitrary order.

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

This function can be slow (linear time), because QHash's internal data structure is optimized for fast lookup by key, not by value.

Definition at line 661 of file qhash.h.

{
    QList<Key> res;
    const_iterator i = begin();
    while (i != end()) {
        if (i.value() == avalue)
            res.append(i.key());
        ++i;
    }
    return res;
}

operator!=()

template<class Key, class T>

bool QHash< Key, T >::operator!= ( const QHash< Key, T > &  other ) const

inline

Returns true if other is not equal to this hash; otherwise returns false.

Two hashes are considered equal if they contain the same (key, value) pairs.

This function requires the value type to implement operator==().

See also

operator==()

Definition at line 293 of file qhash.h.

{ return !(*this == other); }

operator=()

template<class Key, class T>

Q_INLINE_TEMPLATE QHash< Key, T > & QHash< Key, T >::operator=

(

const QHash< Key, T > &

other

)

Assigns other to this hash and returns a reference to this hash.

Definition at line 591 of file qhash.h.

{
    if (d != other.d) {
        QHashData *o = other.d;
        o->ref.ref();
        if (!d->ref.deref())
            freeData(d);
        d = o;
        if (!d->sharable)
            detach_helper();
    }
    return *this;
}

operator==()

template<class Key, class T>

Q_OUTOFLINE_TEMPLATE bool QHash< Key, T >::operator==

(

const QHash< Key, T > &

other

)

const

Returns true if other is equal to this hash; otherwise returns false.

Two hashes are considered equal if they contain the same (key, value) pairs.

This function requires the value type to implement operator==().

See also

operator!=()

Definition at line 898 of file qhash.h.

{
    if (size() != other.size())
        return false;
    if (d == other.d)
        return true;

    const_iterator it = begin();

    while (it != end()) {
        const Key &akey = it.key();

        const_iterator it2 = other.find(akey);
        do {
            if (it2 == other.end() || !(it2.key() == akey))
                return false;
            if (!QTypeInfo<T>::isDummy && !(it.value() == it2.value()))
                return false;
            ++it;
            ++it2;
        } while (it != end() && it.key() == akey);
    }
    return true;
}

operator[]() [1/2]

template<class Key, class T >

Q_INLINE_TEMPLATE T & QHash< Key, T >::operator[]

(

const Key &

key

)

Returns the value associated with the key as a modifiable reference.

If the hash contains no item with the key, the function inserts a default-constructed value into the hash with the key, and returns a reference to it. If the hash contains multiple items with the key, this function returns a reference to the most recently inserted value.

See also

insert(), value()

Definition at line 738 of file qhash.h.

{
    detach();

    uint h;
    Node **node = findNode(akey, &h);
    if (*node == e) {
        if (d->willGrow())
            node = findNode(akey, &h);
        return createNode(h, akey, T(), node)->value;
    }
    return (*node)->value;
}

operator[]() [2/2]

template<class Key, class T >

Q_INLINE_TEMPLATE const T QHash< Key, T >::operator[]

(

const Key &

key

)

const

Same as value().

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 732 of file qhash.h.

{
    return value(akey);
}

remove()

template<class Key, class T >

Q_OUTOFLINE_TEMPLATE int QHash< Key, T >::remove

(

const Key &

key

)

Removes all the items that have the key from the hash.

Returns the number of items removed which is usually 1 but will be 0 if the key isn't in the hash, or greater than 1 if insertMulti() has been used with the key.

See also

clear(), take(), QMultiHash::remove()

Definition at line 784 of file qhash.h.

Referenced by QPatternist::GenericNamespaceResolver::addBinding(), QPatternist::DelegatingNamespaceResolver::addBinding(), QStateMachinePrivate::applyProperties(), QGestureManager::cleanupCachedGestures(), QGestureManager::cleanupGesturesForRemovedRecognizer(), QCoreGraphicsPaintEngine::clearColorSpace(), QPrintDialogPrivate::closeCarbonPrintPanel(), QGestureManager::filterEventThroughContexts(), QPMCache::insert(), QFSFileEnginePrivate::longFileName(), QDeclarativeEngineDebugPrivate::message(), QPMCache::object(), QMultiHash< const QGLContext *, GLProgram >::operator+(), QStyleSheetStyle::polish(), qt_dispatchTabletProximityEvent(), qt_x11_set_fallback_font_family(), QInotifyFileSystemWatcherEngine::readFromInotify(), QDeclarativeEngineDebugPrivate::remove(), QProcessEnvironment::remove(), QSet< typename TokenLookupClass::NodeName >::remove(), QPMCache::remove(), QDomDocumentTypePrivate::removeChild(), QBBEngine::removeConfiguration(), Graph< AnchorVertex, AnchorData >::removeDirectedEdge(), QNetworkAccessCache::removeEntry(), QGraphicsAnchorLayoutPrivate::removeInternalVertex(), QGraphicsScenePrivate::removeItemHelper(), QWindowsFileSystemWatcherEngine::removePaths(), QWSPropertyManager::removeProperties(), QWSPropertyManager::removeProperty(), QFont::removeSubstitution(), QDirectFbInput::removeWindow(), QDomDocumentTypePrivate::replaceChild(), QGraphicsAnchorLayoutPrivate::restoreSimplifiedConstraints(), QKqueueFileSystemWatcherEngine::run(), QWindowsFileSystemWatcherEngineThread::run(), QJSDebuggerAgent::scriptUnload(), QNetworkRequest::setAttribute(), QNetworkAccessBackend::setAttribute(), QAuServerNAS::setDone(), QNetworkSessionPrivateImpl::setSessionProperty(), QDesktopServices::setUrlHandler(), QAuServerNAS::soundDestroyed(), QNetworkAccessCache::timerEvent(), QCache< QPixmapCache::Key, QPixmapCacheEntry >::unlink(), QFSFileEnginePrivate::unmap(), QStyleSheetStyle::unpolish(), QStateMachinePrivate::unregisterEventTransition(), QGestureManager::unregisterGestureRecognizer(), QStateMachinePrivate::unregisterSignalTransition(), QEventDispatcherWin32::unregisterSocketNotifier(), QStyleSheetStyle::unsetPalette(), updateWidgets(), QConfFileSettingsPrivate::~QConfFileSettingsPrivate(), QDeclarativePackageAttached::~QDeclarativePackageAttached(), QDeclarativePixmapReader::~QDeclarativePixmapReader(), QDeclarativeXmlQueryEngine::~QDeclarativeXmlQueryEngine(), and QMenuPrivate::QMacMenuPrivate::~QMacMenuPrivate().

{
    if (isEmpty()) // prevents detaching shared null
        return 0;
    detach();

    int oldSize = d->size;
    Node **node = findNode(akey);
    if (*node != e) {
        bool deleteNext = true;
        do {
            Node *next = (*node)->next;
            deleteNext = (next != e && next->key == (*node)->key);
            deleteNode(*node);
            *node = next;
            --d->size;
        } while (deleteNext);
        d->hasShrunk();
    }
    return oldSize - d->size;
}

reserve()

template<class Key , class T >

Q_INLINE_TEMPLATE void QHash< Key, T >::reserve

(

int

size

)

Ensures that the QHash's internal hash table consists of at least size buckets.

This function is useful for code that needs to build a huge hash and wants to avoid repeated reallocation. For example:

QHash<QString, int> hash;
hash.reserve(20000);
for (int i = 0; i < 20000; ++i)
    hash.insert(keys[i], values[i]);

Ideally, size should be slightly more than the maximum number of items expected in the hash. size doesn't have to be prime, because QHash will use a prime number internally anyway. If size is an underestimate, the worst that will happen is that the QHash will be a bit slower.

In general, you will rarely ever need to call this function. QHash's internal hash table automatically shrinks or grows to provide good performance without wasting too much memory.

See also

squeeze(), capacity()

Definition at line 846 of file qhash.h.

Referenced by QPatternist::AccelTree::AccelTree(), QPatternist::BasicTypesFactory::BasicTypesFactory(), QPatternist::XQueryTokenizer::charForReference(), QPatternist::XSLTTokenizer::createElementDescriptions(), QPatternist::GenericStaticContext::GenericStaticContext(), QPatternist::NamePool::NamePool(), QXmlSerializerPrivate::QXmlSerializerPrivate(), QSet< typename TokenLookupClass::NodeName >::reserve(), and QPatternist::XsdSchemaTypesFactory::XsdSchemaTypesFactory().

{
    detach();
    d->rehash(-qMax(asize, 1));
}

setSharable()

template<class Key, class T>

void QHash< Key, T >::setSharable ( bool  sharable )

inline

Warning

This function is not part of the public interface.

Definition at line 305 of file qhash.h.

Referenced by QSet< typename TokenLookupClass::NodeName >::setSharable().

{ if (!sharable) detach(); d->sharable = sharable; }

size()

template<class Key, class T>

int QHash< Key, T >::size ( ) const

inline

Returns the number of items in the hash.

See also

isEmpty(), count()

Definition at line 295 of file qhash.h.

Referenced by QCache< QPixmapCache::Key, QPixmapCacheEntry >::count(), QApplication::font(), QTextFormatCollection::indexForFormat(), QProcessEnvironmentPrivate::keys(), operator<<(), QHash< QExplicitlySharedDataPointer, QHash >::operator==(), QApplication::palette(), qPRCleanup(), QApplication::setFont(), QApplicationPrivate::setPalette_helper(), QSet< typename TokenLookupClass::NodeName >::size(), QCache< QPixmapCache::Key, QPixmapCacheEntry >::size(), and QProcessEnvironmentPrivate::toList().

{ return d->size; }

squeeze()

template<class Key, class T>

void QHash< Key, T >::squeeze ( )

inline

Reduces the size of the QHash's internal hash table to save memory.

The sole purpose of this function is to provide a means of fine tuning QHash's memory usage. In general, you will rarely ever need to call this function.

See also

reserve(), capacity()

Definition at line 301 of file qhash.h.

Referenced by QSet< typename TokenLookupClass::NodeName >::squeeze().

{ reserve(1); }

swap()

template<class Key, class T>

void QHash< Key, T >::swap ( QHash< Key, T > &  other )

inline

Swaps hash other with this hash.

Since

4.8

This operation is very fast and never fails.

Definition at line 290 of file qhash.h.

Referenced by QSet< typename TokenLookupClass::NodeName >::swap(), and QMultiHash< const QGLContext *, GLProgram >::swap().

{ qSwap(d, other.d); }

take()

template<class Key, class T >

Q_OUTOFLINE_TEMPLATE T QHash< Key, T >::take

(

const Key &

key

)

Removes the item with the key from the hash and returns the value associated with it.

If the item does not exist in the hash, the function simply returns a default-constructed value. If there are multiple items for key in the hash, only the most recently inserted one is removed.

If you don't use the return value, remove() is more efficient.

See also

remove()

Definition at line 807 of file qhash.h.

Referenced by QStateMachinePrivate::_q_animationFinished(), QGraphicsAnchorLayoutPrivate::addAnchorMaybeParallel(), QSqlDatabasePrivate::addDatabase(), QStateMachinePrivate::applyProperties(), QGLGlyphCache::cleanupContext(), QNetworkManagerEngine::deviceRemoved(), QGLGlyphCache::fontEngineDestroyed(), QScriptDebuggerPrivate::handleResponse(), QDeclarativeGridView::itemsMoved(), QDeclarativeListView::itemsMoved(), QDeclarativeDataLoader::networkReplyFinished(), QDeclarativePixmapReader::networkRequestDone(), QAxScriptManager::objectDestroyed(), QFreetypeFace::release(), QDBusConnectionManager::removeConnection(), QSqlDatabasePrivate::removeDatabase(), QInotifyFileSystemWatcherEngine::removePaths(), QKqueueFileSystemWatcherEngine::removePaths(), QDeclarativeWatcher::removeWatch(), QSimplex::simplifyConstraints(), and QEventDispatcherMac::unregisterTimer().

{
    if (isEmpty()) // prevents detaching shared null
        return T();
    detach();

    Node **node = findNode(akey);
    if (*node != e) {
        T t = (*node)->value;
        Node *next = (*node)->next;
        deleteNode(*node);
        *node = next;
        --d->size;
        d->hasShrunk();
        return t;
    }
    return T();
}

uniqueKeys()

template<class Key , class T >

Q_OUTOFLINE_TEMPLATE QList< Key > QHash< Key, T >::uniqueKeys

(

)

const

Returns a list containing all the keys in the map.

Since

4.2

Keys that occur multiple times in the map (because items were inserted with insertMulti(), or unite() was used) occur only once in the returned list.

See also

keys(), values()

Definition at line 628 of file qhash.h.

{
    QList<Key> res;
    res.reserve(size()); // May be too much, but assume short lifetime
    const_iterator i = begin();
    if (i != end()) {
        for (;;) {
            const Key &aKey = i.key();
            res.append(aKey);
            do {
                if (++i == end())
                    goto break_out_of_outer_loop;
            } while (aKey == i.key());
        }
    }
break_out_of_outer_loop:
    return res;
}

unite()

template<class Key, class T>

Q_INLINE_TEMPLATE QHash< Key, T > & QHash< Key, T >::unite

(

const QHash< Key, T > &

other

)

Inserts all the items in the other hash into this hash.

If a key is common to both hashes, the resulting hash will contain the key multiple times.

See also

insertMulti()

Definition at line 556 of file qhash.h.

Referenced by QPatternist::XsdSchemaChecker::addComponentLocationHash(), QPatternist::XsdSchemaResolver::addComponentLocationHash(), and QPatternist::XsdParticleChecker::subsumes().

{
    QHash<Key, T> copy(other);
    const_iterator it = copy.constEnd();
    while (it != copy.constBegin()) {
        --it;
        insertMulti(it.key(), it.value());
    }
    return *this;
}

value() [1/2]

template<class Key, class T >

Q_INLINE_TEMPLATE const T QHash< Key, T >::value

(

const Key &

key

)

const

Returns the value associated with the key.

If the hash contains no item with the key, the function returns a default-constructed value. If there are multiple items for the key in the hash, the value of the most recently inserted one is returned.

See also

key(), values(), contains(), operator[]()

Definition at line 606 of file qhash.h.

Referenced by QStateMachinePrivate::_q_animationFinished(), QNetworkReplyImplPrivate::_q_copyReadyRead(), QScriptDebuggerCodeWidgetPrivate::_q_onBreakpointsAboutToBeRemoved(), QScriptDebuggerCodeWidgetPrivate::_q_onBreakpointsDataChanged(), QScriptDebuggerCodeWidgetPrivate::_q_onBreakpointsInserted(), QParallelAnimationGroupPrivate::_q_uncontrolledAnimationFinished(), QEventDispatcherMacPrivate::activateTimer(), QNetworkManagerEngine::activeConnectionPropertiesChanged(), QSvgIconEngine::actualSize(), QMenuPrivate::QMacMenuPrivate::addAction(), MetaObjectGenerator::addChangedSignal(), QPdfEnginePrivate::addConstantAlphaObject(), QPdfEnginePrivate::addImage(), QGraphicsAnchorLayoutPrivate::addInternalVertex(), QWindowsFileSystemWatcherEngine::addPaths(), FlatListModel::addValue(), Graph< AnchorVertex, AnchorData >::adjacentVertices(), QPMCache::allPixmaps(), QNetworkReplyImplPrivate::appendDownstreamDataSignalEmissions(), QStateMachinePrivate::applyProperties(), QScriptEngineAgentPrivate::atStatement(), QDeclarativeMetaType::attachedPropertiesFuncId(), QNetworkRequest::attribute(), QPatternist::XsdInstanceReader::attribute(), QStyleSheetStyleSelector::attribute(), QDeclarativePath::attributeAt(), QPatternist::XsdInstanceReader::attributeItem(), QGraphicsAnchorLayoutPrivate::calculateGraphs(), QGestureManager::cancelGesturesForChildren(), QPatternist::XQueryTokenizer::charForReference(), QPatternist::XsdSchemaChecker::checkAttributeUseConstraints(), QPatternist::XsdSchemaChecker::checkConstrainingFacets(), QPatternist::XsdTypeChecker::checkConstrainingFacetsBinary(), QPatternist::XsdTypeChecker::checkConstrainingFacetsBoolean(), QPatternist::XsdTypeChecker::checkConstrainingFacetsDateTime(), QPatternist::XsdTypeChecker::checkConstrainingFacetsDecimal(), QPatternist::XsdTypeChecker::checkConstrainingFacetsDouble(), QPatternist::XsdTypeChecker::checkConstrainingFacetsDuration(), QPatternist::XsdTypeChecker::checkConstrainingFacetsList(), QPatternist::XsdTypeChecker::checkConstrainingFacetsNotation(), QPatternist::XsdTypeChecker::checkConstrainingFacetsQName(), QPatternist::XsdTypeChecker::checkConstrainingFacetsSignedInteger(), QPatternist::XsdTypeChecker::checkConstrainingFacetsString(), QPatternist::XsdTypeChecker::checkConstrainingFacetsUnion(), QPatternist::XsdTypeChecker::checkConstrainingFacetsUnsignedInteger(), QPatternist::XsdSchemaChecker::checkElementDuplicates(), QGestureManager::cleanupGesturesForRemovedRecognizer(), QGtkStylePrivate::cleanupGtkWidgets(), QCoreGraphicsPaintEngine::cleanUpMacColorSpaces(), QPatternist::ColorOutput::colorify(), QPatternist::ColoringMessageHandler::colorifyDescription(), EGLNullWSScreen::connect(), QDBusConnectionManager::connection(), QScriptEnginePrivate::convertValue(), convertWithPalette(), QScriptEnginePrivate::create(), Graph< AnchorVertex, AnchorData >::createDirectedEdge(), QDBusMetaObject::createMetaObject(), QPatternist::XsdSchemaTypesFactory::createSchemaType(), QPatternist::BasicTypesFactory::createSchemaType(), QDeclarativeMetaType::customStringConverter(), QDeclarativeTypeNameCache::data(), QSqlDatabasePrivate::database(), QScriptEnginePrivate::defaultPrototype(), QScriptDebuggerAgent::deleteBreakpoint(), QGestureManager::deliverEvents(), derivedTermValid(), QScriptEngineAgentPrivate::didReachBreakpoint(), QAuthenticatorPrivate::digestMd5Response(), QAxMetaObject::dispIDofName(), QMacStyle::drawControl(), QPdfBaseEnginePrivate::drawTextItem(), Graph< AnchorVertex, AnchorData >::edgeData(), QPatternist::AccelTree::elementById(), QDeclarativePath::endpoint(), QPatternist::XsdStateMachine< XsdSchemaToken::NodeName >::epsilonClosure(), familyNameFromPostScriptName(), QNetworkAccessHttpBackend::fetchCacheMetaData(), QWSPropertyManager::Data::find(), QWidget::find(), QDBusConnectionPrivate::findMetaObject(), QAxScript::findObject(), QGraphicsAnchorLayoutPrivate::findPaths(), QNetworkReplyImplPrivate::finished(), QPMCache::flushDetachedPixmaps(), QApplication::font(), QConfFile::fromName(), QGraphicsScenePrivate::gestureEventHandler(), QDeclarativeTypeLoader::get(), QRegExpEngine::getEscape(), QFreetypeFace::getFace(), QGestureManager::getGestureTargets(), QBBEngine::getInterfaceFromId(), QScript::QObjectDelegate::getOwnPropertyDescriptor(), QScript::QObjectDelegate::getOwnPropertySlot(), getPath(), QWSPropertyManager::getProperty(), QDeclarativeTypeLoader::getQmldir(), QDeclarativeTypeLoader::getScript(), QSharedNetworkSessionManager::getSession(), QGestureManager::getState(), QComboMenuDelegate::getStyleOption(), QGtkStylePrivate::gtkWidget(), QDirectFbInput::handleEnterLeaveEvents(), QStateMachinePrivate::handleFilteredEvent(), QDirectFbInput::handleKeyEvents(), QDirectFbInput::handleMouseEvents(), QDBusConnectionPrivate::handleSignal(), QDirectFbInput::handleWheelEvent(), hasDuplicatedElementsInternal(), QTextFormatCollection::hasFormatCached(), QSqlResult::hasOutValues(), QDeclarativePackage::hasPart(), QWSPropertyManager::hasProperty(), QStyleSheetStyle::hasStyleRule(), QNetworkRequest::header(), QmlJSDebugger::AbstractViewInspector::idStringForObject(), QTextFormatCollection::indexForFormat(), QMacPrintEnginePrivate::initialize(), QPMCache::insert(), QProcessEnvironmentPrivate::insert(), QDeclarativeXmlQueryEngine::instance(), QDeclarativeMetaType::interfaceIId(), QDeclarativePath::interpolate(), QSimplexConstraint::invert(), QAxServerBase::Invoke(), QXmlSimpleReaderPrivate::isExpandedEntityValueTooLarge(), QSimplexConstraint::isSatisfied(), QPatternist::XsdParticleChecker::isUPAConform(), QPatternist::XsdSchemaHelper::isValidAttributeUsesRestriction(), QDeclarativeMetaType::listType(), QPatternist::GenericDynamicContext::locationFor(), QPatternist::GenericStaticContext::locationFor(), QReadWriteLock::lockForRead(), QPatternist::GenericNamespaceResolver::lookupNamespaceURI(), QPatternist::DelegatingNamespaceResolver::lookupNamespaceURI(), QScript::QObjectDelegate::markChildren(), QMenuPrivate::QMacMenuPrivate::merged(), QDeclarativeEngineDebugPrivate::message(), QDeclarativeVMEMetaObject::metaCall(), QNetworkReplyImplPrivate::metaDataChanged(), QPatternist::XsdStateMachine< XsdSchemaToken::NodeName >::move(), QSvgTinyDocument::namedNode(), QSvgTinyDocument::namedStyle(), QPatternist::AccelTree::namespaceBindings(), QDeclarativeDataLoader::networkReplyProgress(), QPatternist::XsdTypeChecker::normalizedValue(), QAxMetaObject::numParameter(), QPMCache::object(), QPatternist::AccelTreeResourceLoader::openUnparsedText(), operator<<(), QHash< QExplicitlySharedDataPointer, QHash >::operator[](), QAuthenticator::option(), QAxMetaObject::paramType(), QAuthenticatorPrivate::parseDigestAuthenticationChallenge(), QPatternist::PatternPlatform::parseFlags(), QAuthenticatorPrivate::parseHttpResponse(), parseServerList(), QDeclarativePackage::part(), QSvgIconEngine::pixmap(), QJSDebuggerAgentPrivate::positionChange(), QPrintDialogPrivate::printDialogSheetDoneCallback(), QPatternist::AccelTree::printStats(), QPatternist::XsdStateMachine< XsdSchemaToken::NodeName >::proceed(), QPatternist::NamespaceSupport::processName(), QDeclarativePath::processPath(), FlatListScriptClass::property(), QDeclarativePropertyCache::property(), QScript::QObjectDelegate::put(), qDBusRemoveWatch(), qmlAttachedPropertiesObjectById(), QDeclarativeMetaType::qmlType(), qPRFindWidget(), qt_aqua_get_known_size(), qt_fallback_font_family(), qt_internal_proc(), qt_mac_handleTabletEvent(), qt_mac_set_modal_state(), qt_mac_socket_callback(), QAxServerBase::qt_metacall(), QtWndProc(), QSvgIconEngine::read(), MetaObjectGenerator::readEnumInfo(), MetaObjectGenerator::readEventInfo(), MetaObjectGenerator::readEventInterface(), QInotifyFileSystemWatcherEngine::readFromInotify(), QGestureManager::recycle(), QPMCache::remove(), QGraphicsAnchorLayoutPrivate::removeAnchor(), Graph< AnchorVertex, AnchorData >::removeDirectedEdge(), QGraphicsAnchorLayoutPrivate::removeInternalVertex(), QWindowsFileSystemWatcherEngine::removePaths(), QPatternist::XsdSchemaResolver::resolveEnumerationFacetValues(), QPatternist::XsdSchemaResolver::resolveSimpleContentComplexTypes(), QDialogButtonBoxPrivate::retranslateStrings(), QPatternist::ConstructorFunctionsFactory::retrieveFunctionSignature(), QPatternist::FunctionFactoryCollection::retrieveFunctionSignature(), QKqueueFileSystemWatcherEngine::run(), QWindowsFileSystemWatcherEngineThread::run(), QAxScriptManager::script(), QMenuPrivate::scrollMenu(), QSqlRelationalTableModel::selectStatement(), QNetworkAccessCacheBackend::sendCacheContents(), QNetworkAccessHttpBackend::sendCacheContents(), QPatternist::AccelTree::sendNamespaces(), QEventDispatcherWin32Private::sendTimerEvent(), QNetworkSessionPrivateImpl::sessionProperty(), QNetworkManagerEngine::sessionStateForId(), QSimplex::setConstraints(), QMenuPrivate::setCurrentAction(), QScriptEnginePrivate::setDefaultPrototype(), QTextControl::setExtraSelections(), ModelNode::setObjectValue(), QWSPropertyManager::setProperty(), FlatListScriptClass::setProperty(), QSimplex::simplifyConstraints(), QSimplex::solver(), QPatternist::XsdSchemaChecker::sourceLocation(), QPatternist::AccelTree::sourceLocation(), QPatternist::XsdSchemaResolver::sourceLocation(), QPatternist::AccelTree::stringValue(), QRenderRule::styleHint(), QStyleSheetStyle::styleRules(), QMacStyle::subControlRect(), QStyleSheetStyle::subControlRect(), QFont::substitutes(), QPatternist::XsdParticleChecker::subsumes(), QDBusConnectionPrivate::timerEvent(), QDockWidgetLayout::titleHeight(), QSimplexConstraint::toString(), MetaObjectGenerator::tryCache(), QReadWriteLock::tryLockForRead(), QPatternist::XsdSchema::type(), QReadWriteLock::unlock(), QPatternist::NamePool::unlockedAllocateLocalName(), QPatternist::NamePool::unlockedAllocateNamespace(), QPatternist::NamePool::unlockedAllocatePrefix(), QFSFileEnginePrivate::unmap(), QStateMachinePrivate::unregisterEventTransition(), QGestureManager::unregisterGestureRecognizer(), QEventDispatcherWin32::unregisterSocketNotifier(), QStyleSheetStyle::unsetPalette(), QMenuPrivate::updateActionRects(), QBBButtonEventNotifier::updateButtonStates(), QPatternist::NamespaceSupport::uri(), QPatternist::XsdValidatingInstanceReader::validateElementComplexType(), QDeclarativeIntegerCache::value(), QSvgIconEngine::write(), and QGestureManager::~QGestureManager().

{
    Node *node;
    if (d->size == 0 || (node = *findNode(akey)) == e) {
        return T();
    } else {
        return node->value;
    }
}

value() [2/2]

template<class Key, class T>

Q_INLINE_TEMPLATE const T QHash< Key, T >::value	(	const Key &	key,
		const T &	defaultValue
	)		const

If the hash contains no item with the given key, the function returns defaultValue.

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 617 of file qhash.h.

{
    Node *node;
    if (d->size == 0 || (node = *findNode(akey)) == e) {
        return adefaultValue;
    } else {
        return node->value;
    }
}

values() [1/2]

template<class Key , class T >

Q_OUTOFLINE_TEMPLATE QList< T > QHash< Key, T >::values

(

)

const

Returns a list containing all the values in the hash, in an arbitrary order.

If a key is associated multiple values, all of its values will be in the list, and not just the most recently inserted one.

The order is guaranteed to be the same as that used by keys().

See also

keys(), value()

Definition at line 693 of file qhash.h.

Referenced by QPatternist::XsdSchema::anonymousTypes(), QStateMachinePrivate::applyProperties(), ModelNode::clear(), QPatternist::XsdSchema::complexTypes(), QGraphicsAnchorLayoutPrivate::constraintsFromPaths(), QIcdEngine::doRequestUpdate(), QTextDocumentLayoutPrivate::drawTableCell(), QTextLine::glyphs(), QTextDocumentLayoutPrivate::hitTest(), QTextDocumentLayoutPrivate::layoutCell(), QDeclarativeMetaType::qmlType(), QDeclarativeMetaType::qmlTypes(), shiftConstraints(), QPatternist::XsdSchema::simpleTypes(), QPatternist::XsdSchema::types(), QDeclarativeSmoothedAnimationPrivate::updateRunningAnimations(), QPatternist::XsdSchemaResolver::XsdSchemaResolver(), and QDeclarativePixmapReader::~QDeclarativePixmapReader().

{
    QList<T> res;
    res.reserve(size());
    const_iterator i = begin();
    while (i != end()) {
        res.append(i.value());
        ++i;
    }
    return res;
}

values() [2/2]

template<class Key, class T >

Q_OUTOFLINE_TEMPLATE QList< T > QHash< Key, T >::values

(

const Key &

key

)

const

Returns a list of all the values associated with the key, from the most recently inserted to the least recently inserted.

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

See also

count(), insertMulti()

Definition at line 706 of file qhash.h.

{
    QList<T> res;
    Node *node = *findNode(akey);
    if (node != e) {
        do {
            res.append(node->value);
        } while ((node = node->next) != e && node->key == akey);
    }
    return res;
}

Friends and Related Functions

const_iterator

template<class Key, class T>

friend class const_iterator

friend

Definition at line 461 of file qhash.h.

iterator

template<class Key, class T>

friend class iterator

friend

Definition at line 393 of file qhash.h.

operator<<()

template<class Key, class T>

QDataStream & operator<< ( QDataStream &  out, const QHash< Key, T > &  hash  )

related

Writes the hash hash to stream out.

This function requires the key and value types to implement operator<<().

See also

{Serializing Qt Data Types}

Definition at line 376 of file qdatastream.h.

{
    out << quint32(hash.size());
    typename QHash<Key, T>::ConstIterator it = hash.end();
    typename QHash<Key, T>::ConstIterator begin = hash.begin();
    while (it != begin) {
        --it;
        out << it.key() << it.value();
    }
    return out;
}

operator>>()

template<class Key, class T>

QDataStream & operator>> ( QDataStream &  in, QHash< Key, T > &  hash  )

related

Reads a hash from stream in into hash.

This function requires the key and value types to implement operator>>().

See also

{Serializing Qt Data Types}

Definition at line 349 of file qdatastream.h.

{
    QDataStream::Status oldStatus = in.status();
    in.resetStatus();
    hash.clear();

    quint32 n;
    in >> n;

    for (quint32 i = 0; i < n; ++i) {
        if (in.status() != QDataStream::Ok)
            break;

        Key k;
        T t;
        in >> k >> t;
        hash.insertMulti(k, t);
    }

    if (in.status() != QDataStream::Ok)
        hash.clear();
    if (oldStatus != QDataStream::Ok)
        in.setStatus(oldStatus);
    return in;
}

qHash() [1/17]

template<class Key, class T>

uint qHash ( const QPair< T1, T2 > &  key )

related

Returns the hash value for the key.

Since

4.3

Types T1 and T2 must be supported by qHash().

Definition at line 105 of file qhash.h.

{
    uint h1 = qHash(key.first);
    uint h2 = qHash(key.second);
    return ((h1 << 16) | (h1 >> 16)) ^ h2;
}

qHash() [2/17]

template<class Key, class T>

uint qHash ( char  key )

related

Returns the hash value for the key.

Definition at line 62 of file qhash.h.

{ return uint(key); }

qHash() [3/17]

template<class Key, class T>

uint qHash ( uchar  key )

related

Returns the hash value for the key.

Definition at line 63 of file qhash.h.

{ return uint(key); }

qHash() [4/17]

template<class Key, class T>

uint qHash ( signed char  key )

related

Returns the hash value for the key.

Definition at line 64 of file qhash.h.

{ return uint(key); }

qHash() [5/17]

template<class Key, class T>

uint qHash ( ushort  key )

related

Returns the hash value for the key.

Definition at line 65 of file qhash.h.

{ return uint(key); }

qHash() [6/17]

template<class Key, class T>

uint qHash ( short  key )

related

Returns the hash value for the key.

Definition at line 66 of file qhash.h.

{ return uint(key); }

qHash() [7/17]

template<class Key, class T>

uint qHash ( uint  key )

related

Returns the hash value for the key.

Definition at line 67 of file qhash.h.

{ return key; }

qHash() [8/17]

template<class Key, class T>

uint qHash ( int  key )

related

Returns the hash value for the key.

Definition at line 68 of file qhash.h.

{ return uint(key); }

qHash() [9/17]

template<class Key, class T>

uint qHash ( ulong  key )

related

Returns the hash value for the key.

Definition at line 69 of file qhash.h.

{
    if (sizeof(ulong) > sizeof(uint)) {
        return uint(((key >> (8 * sizeof(uint) - 1)) ^ key) & (~0U));
    } else {
        return uint(key & (~0U));
    }
}

qHash() [10/17]

template<class Key, class T>

uint qHash ( long  key )

related

Returns the hash value for the key.

Definition at line 77 of file qhash.h.

{ return qHash(ulong(key)); }

qHash() [11/17]

template<class Key, class T>

uint qHash ( quint64  key )

related

Returns the hash value for the key.

Definition at line 78 of file qhash.h.

{
    if (sizeof(quint64) > sizeof(uint)) {
        return uint(((key >> (8 * sizeof(uint) - 1)) ^ key) & (~0U));
    } else {
        return uint(key & (~0U));
    }
}

qHash() [12/17]

template<class Key, class T>

uint qHash ( qint64  key )

related

Returns the hash value for the key.

Definition at line 86 of file qhash.h.

{ return qHash(quint64(key)); }

qHash() [13/17]

template<class Key, class T>

uint qHash ( QChar  key )

related

Returns the hash value for the key.

Definition at line 87 of file qhash.h.

{ return qHash(key.unicode()); }

qHash() [14/17]

template<class Key, class T>

uint qHash ( const QBitArray &  key )

related

Definition at line 107 of file qhash.cpp.

{
    int m = bitArray.d.size() - 1;
    uint result = hash(reinterpret_cast<const uchar *>(bitArray.d.constData()), qMax(0, m));

    // deal with the last 0 to 7 bits manually, because we can't trust that
    // the padding is initialized to 0 in bitArray.d
    int n = bitArray.size();
    if (n & 0x7)
        result = ((result << 4) + bitArray.d.at(m)) & ((1 << n) - 1);
    return result;
}

qHash() [15/17]

template<class Key, class T>

uint qHash ( const QString &  key )

related

Returns the hash value for the key.

Definition at line 97 of file qhash.cpp.

{
    return hash(key.unicode(), key.size());
}

qHash() [16/17]

template<class Key, class T>

uint qHash ( const T *  key )

related

Returns the hash value for the key.

Definition at line 97 of file qhash.h.

{
    return qHash(reinterpret_cast<quintptr>(key));
}

qHash() [17/17]

template<class Key, class T>

uint qHash ( const QXmlNodeModelIndex &  index )

related

Computes a hash key from the QXmlNodeModelIndex index, and returns it.

Since

4.4

This function would be used by QHash if you wanted to build a hash table for instances of QXmlNodeModelIndex.

The hash is computed on QXmlNodeModelIndex::data(), QXmlNodeModelIndex::additionalData(), and QXmlNodeModelIndex::model(). This means the hash key can be used for node indexes from different node models.

Definition at line 1447 of file qabstractxmlnodemodel.cpp.

{
    return uint(index.data() + index.additionalData() + quintptr(index.model()));
}

Properties

@55

union { ... }

d

template<class Key, class T>

QHashData* QHash< Key, T >::d

Definition at line 264 of file qhash.h.

Referenced by QHash< QExplicitlySharedDataPointer, QHash >::isSharedWith(), QHash< QExplicitlySharedDataPointer, QHash >::operator=(), QHash< QExplicitlySharedDataPointer, QHash >::operator==(), qt_create_commandline(), QHash< QExplicitlySharedDataPointer, QHash >::swap(), and QHash< QExplicitlySharedDataPointer, QHash >::~QHash().

e

template<class Key, class T>

QHashNode<Key, T>* QHash< Key, T >::e

Definition at line 265 of file qhash.h.

---

The documentation for this class was generated from the following files:

• /src/corelib/io/qdatastream.h
• /src/corelib/tools/qhash.h
• /src/corelib/tools/qhash.cpp
• /src/xmlpatterns/api/qabstractxmlnodemodel.cpp