diff options
Diffstat (limited to 'src/qml/jsapi/qjsmanagedvalue.cpp')
| -rw-r--r-- | src/qml/jsapi/qjsmanagedvalue.cpp | 1145 |
1 files changed, 1145 insertions, 0 deletions
diff --git a/src/qml/jsapi/qjsmanagedvalue.cpp b/src/qml/jsapi/qjsmanagedvalue.cpp new file mode 100644 index 0000000000..452f991a26 --- /dev/null +++ b/src/qml/jsapi/qjsmanagedvalue.cpp @@ -0,0 +1,1145 @@ +// Copyright (C) 2020 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only + +#include <QtQml/qjsmanagedvalue.h> +#include <QtQml/qjsengine.h> +#include <QtQml/private/qv4persistent_p.h> +#include <QtQml/private/qv4engine_p.h> +#include <QtQml/private/qv4mm_p.h> +#include <QtQml/private/qjsvalue_p.h> +#include <QtQml/private/qv4runtime_p.h> +#include <QtQml/private/qv4functionobject_p.h> +#include <QtQml/private/qv4jscall_p.h> +#include <QtQml/private/qv4urlobject_p.h> +#include <QtQml/private/qv4variantobject_p.h> +#include <QtQml/private/qv4qobjectwrapper_p.h> +#include <QtQml/private/qv4qmetaobjectwrapper_p.h> +#include <QtQml/private/qv4regexpobject_p.h> +#include <QtQml/private/qv4dateobject_p.h> +#include <QtQml/private/qv4errorobject_p.h> +#include <QtQml/private/qv4identifiertable_p.h> + +#include <QtCore/qregularexpression.h> +#include <QtCore/qurl.h> +#include <QtCore/qdatetime.h> + +QT_BEGIN_NAMESPACE + +/*! + * \class QJSManagedValue + * \inmodule QtQml + * \since 6.1 + * + * \inmodule QtQml + * + * \brief QJSManagedValue represents a value on the JavaScript heap belonging to a QJSEngine. + * + * The QJSManagedValue class allows interaction with JavaScript values in most + * ways you can interact with them from JavaScript itself. You can get and set + * properties and prototypes, and you can access arrays. Additionally, you can + * transform the value into the Qt counterparts of JavaScript objects. For + * example, a Url object may be transformed into a QUrl. + * + * A QJSManagedValue is always bound to a particular QJSEngine. You cannot use + * it independently. This means that you cannot have a QJSManagedValue from one + * engine be a property or a proptotype of a QJSManagedValue from a different + * engine. + * + * In contrast to QJSValue, almost all values held by QJSManagedValue live on + * the JavaScript heap. There is no inline or unmanaged storage. Therefore, you + * can get the prototype of a primitive value, and you can get the \c length + * property of a string. + * + * Only default-constructed or moved-from QJSManagedValues do not hold a value + * on the JavaScript heap. They represent \c undefined, which doesn't have any + * properties or prototypes. + * + * Also in contrast to QJSValue, QJSManagedValue does not catch any JavaScript + * exceptions. If an operation on a QJSManagedValue causes an error, it will + * generally return an \c undefined value and QJSEngine::hasError() will return + * \c true afterwards. You can then catch the exception using + * QJSEngine::catchError(), or pass it up the stack, at your own discretion. + * + * \note As the reference to the value on the JavaScript heap has to be freed + * on destruction, you cannot move a QJSManagedValue to a different thread. + * The destruction would take place in the new thread, which would create a race + * condition with the garbage collector on the original thread. This also means + * that you cannot hold a QJSManagedValue beyond the lifespan of its engine. + * + * The recommended way of working with a QJSManagedValue is creating it + * on the stack, possibly by moving a QJSValue and adding an engine, then + * performing the necessary operations on it, and finally moving it back into a + * QJSValue for storage. Moving between QJSManagedValue and QJSValue is fast. + */ + +/*! + * \enum QJSManagedValue::Type + * + * This enum represents the JavaScript native types, as specified by + * \l{ECMA-262}. + * + * \value Undefined The \c undefined type + * \value Boolean The \c boolean type + * \value Number The \c number type + * \value String The \c string type + * \value Object The \c object type + * \value Symbol The \c symbol type + * \value Function The \c function type + * + * Note that the \c null value is not a type of itself but rather a special kind + * of object. You can query a QJSManagedValue for this condition using the + * isNull() method. Furthermore, JavaScript has no integer type, but it knows a + * special treatment of numbers in preparation for integer only operations. You + * can query a QJSManagedValue to find out whether it holds the result of such a + * treatment by using the isInteger() method. + */ + +/*! + * \fn QJSManagedValue::QJSManagedValue() + * + * Creates a QJSManagedValue that represents the JavaScript \c undefined value. + * This is the only value not stored on the JavaScript heap. Calling engine() + * on a default-constructed QJSManagedValue will return nullptr. + */ + +static QV4::ExecutionEngine *v4Engine(QV4::Value *d) +{ + if (!d) + return nullptr; + + QV4::ExecutionEngine *v4 = QV4::PersistentValueStorage::getEngine(d); + Q_ASSERT(v4); + return v4; +} + +/*! + * Creates a QJSManagedValue from \a value, using the heap of \a engine. If + * \a value is itself managed and the engine it belongs to is not \a engine, + * the result is an \c undefined value, and a warning is generated. + */ +QJSManagedValue::QJSManagedValue(QJSValue value, QJSEngine *engine) +{ + QV4::ExecutionEngine *v4 = engine->handle(); + + if (QV4::Value *m = QJSValuePrivate::takeManagedValue(&value)) { + if (Q_UNLIKELY(v4Engine(m) != v4)) { + qWarning("QJSManagedValue(QJSValue, QJSEngine *) failed: " + "Value was created in different engine."); + QV4::PersistentValueStorage::free(m); + return; + } + + d = m; + return; + } + + d = v4->memoryManager->m_persistentValues->allocate(); + + if (const QString *string = QJSValuePrivate::asQString(&value)) + *d = v4->newString(*string); + else + *d = QJSValuePrivate::asReturnedValue(&value); +} + +/*! + * Creates a QJSManagedValue from \a value using the heap of \a engine. + */ +QJSManagedValue::QJSManagedValue(const QJSPrimitiveValue &value, QJSEngine *engine) : + QJSManagedValue(engine->handle()) +{ + switch (value.type()) { + case QJSPrimitiveValue::Undefined: + *d = QV4::Encode::undefined(); + return; + case QJSPrimitiveValue::Null: + *d = QV4::Encode::null(); + return; + case QJSPrimitiveValue::Boolean: + *d = QV4::Encode(value.asBoolean()); + return; + case QJSPrimitiveValue::Integer: + *d = QV4::Encode(value.asInteger()); + return; + case QJSPrimitiveValue::Double: + *d = QV4::Encode(value.asDouble()); + return; + case QJSPrimitiveValue::String: + *d = engine->handle()->newString(value.asString()); + return; + } + + Q_UNREACHABLE(); +} + +/*! + * Creates a QJSManagedValue from \a variant using the heap of \a engine. + */ +QJSManagedValue::QJSManagedValue(const QVariant &variant, QJSEngine *engine) : + QJSManagedValue(engine->handle()) +{ + *d = engine->handle()->fromVariant(variant); +} + +/*! + * Creates a QJSManagedValue from \a string using the heap of \a engine. + */ +QJSManagedValue::QJSManagedValue(const QString &string, QJSEngine *engine) : + QJSManagedValue(engine->handle()) +{ + *d = engine->handle()->newString(string); +} + +/*! + * Destroys the QJSManagedValue. + * + * \note This frees the memory slot it holds on the JavaScript heap. You must + * not destroy a QJSManagedValue from a different thread than the one + * where the QJSEngine it belongs to lives. + */ +QJSManagedValue::~QJSManagedValue() +{ + QV4::PersistentValueStorage::free(d); +} + +/*! + * Move-constructs a QJSManagedValue from \a other. This leaves \a other in + * the default-constructed state where it represents undefined and does not + * belong to any engine. + */ +QJSManagedValue::QJSManagedValue(QJSManagedValue &&other) +{ + qSwap(d, other.d); +} + +/*! + * Move-assigns a QJSManagedValue from \a other. This leaves \a other in + * the default-constructed state where it represents undefined and does not + * belong to any engine. + * + * \note This frees the memory slot this QJSManagedValue holds on the + * JavaScript heap. You must not move-assign a QJSManagedValue on a + * different thread than the one where the QJSEngine it belongs to lives. + */ +QJSManagedValue &QJSManagedValue::operator=(QJSManagedValue &&other) +{ + if (this != &other) { + QV4::PersistentValueStorage::free(d); + d = nullptr; + qSwap(d, other.d); + } + return *this; +} + +/*! + * Invokes the JavaScript '==' operator on this QJSManagedValue and \a other, + * and returns the result. + * + * \sa strictlyEquals + */ +bool QJSManagedValue::equals(const QJSManagedValue &other) const +{ + if (!d) + return !other.d || other.d->isNullOrUndefined(); + if (!other.d) + return d->isNullOrUndefined(); + + return QV4::Runtime::CompareEqual::call(*d, *other.d); +} + +/*! + * Invokes the JavaScript '===' operator on this QJSManagedValue and \a other, + * and returns the result. + * + * \sa equals + */ +bool QJSManagedValue::strictlyEquals(const QJSManagedValue &other) const +{ + if (!d) + return !other.d || other.d->isUndefined(); + if (!other.d) + return d->isUndefined(); + + return QV4::RuntimeHelpers::strictEqual(*d, *other.d); +} + +/*! + * Returns the QJSEngine this QJSManagedValue belongs to. Mind that the engine + * is always valid, unless the QJSManagedValue is default-constructed or moved + * from. In the latter case a nullptr is returned. + */ +QJSEngine *QJSManagedValue::engine() const +{ + if (!d) + return nullptr; + if (QV4::ExecutionEngine *v4 = QV4::PersistentValueStorage::getEngine(d)) + return v4->jsEngine(); + return nullptr; +} + +/*! + * Returns the prototype for this QJSManagedValue. This works on any value. You + * can, for example retrieve the JavaScript \c boolean prototype from a \c boolean + * value. + */ +QJSManagedValue QJSManagedValue::prototype() const +{ + if (!d) + return QJSManagedValue(); + + QV4::ExecutionEngine *v4 = v4Engine(d); + QJSManagedValue result(v4); + + if (auto object = d->as<QV4::Object>()) + *result.d = object->getPrototypeOf(); + else if (auto managed = d->as<QV4::Managed>()) + *result.d = managed->internalClass()->prototype; + else if (d->isBoolean()) + *result.d = v4->booleanPrototype(); + else if (d->isNumber()) + *result.d = v4->numberPrototype(); + + // If the prototype appears to be undefined, then it's actually null in JS terms. + if (result.d->isUndefined()) + *result.d = QV4::Encode::null(); + + return result; +} + +/*! + * Sets the prototype of this QJSManagedValue to \a prototype. A precondition + * is that \a prototype belongs to the same QJSEngine as this QJSManagedValue + * and is an object (including null). Furthermore, this QJSManagedValue has to + * be an object (excluding null), too, and you cannot create prototype cycles. + */ +void QJSManagedValue::setPrototype(const QJSManagedValue &prototype) +{ + auto object = d ? d->as<QV4::Object>() : nullptr; + if (!object) { + qWarning("QJSManagedValue::setPrototype() failed: " + "Can only set a prototype on an object (excluding null)."); + return; + } + + // Object includes null ... + if (prototype.type() != QJSManagedValue::Object) { + qWarning("QJSManagedValue::setPrototype() failed: " + "Can only set objects (including null) as prototypes."); + return; + } + + if (Q_UNLIKELY(object->engine() != v4Engine(prototype.d))) { + qWarning("QJSManagedValue::setPrototype() failed: " + "Prototype was created in differen engine."); + return; + } + + // ... Null becomes nullptr here. That is why it appears as undefined later. + if (!object->setPrototypeOf(prototype.d->as<QV4::Object>())) { + qWarning("QJSManagedValue::setPrototype() failed: " + "Prototype cycle detected."); + } +} + +/*! + * Returns the JavaScript type of this QJSManagedValue. + */ +QJSManagedValue::Type QJSManagedValue::type() const +{ + if (!d || d->isUndefined()) + return Undefined; + if (d->isBoolean()) + return Boolean; + if (d->isNumber()) + return Number; + if (d->isString()) + return String; + if (d->isSymbol()) + return Symbol; + if (d->isFunctionObject()) + return Function; + return Object; +} + +/*! + * \fn QJSManagedValue::isUndefined() const + * + * Returns \c true if the type of this QJSManagedValue is \c undefined, + * or \c false otherwise. + */ + +/*! + * \fn QJSManagedValue::isBoolean() const + * + * Returns \c true if the type of this QJSManagedValue is \c boolean, + * or \c false otherwise. + */ + +/*! + * \fn QJSManagedValue::isNumber() const + * + * Returns \c true if the type of this QJSManagedValue is \c number, + * or \c false otherwise. + */ + +/*! + * \fn QJSManagedValue::isString() const + * + * Returns \c true if the type of this QJSManagedValue is \c string, + * or \c false otherwise. + */ + +/*! + * \fn QJSManagedValue::isSymbol() const + * + * Returns \c true if the type of this QJSManagedValue is \c symbol, + * or \c false otherwise. + */ + +/*! + * \fn QJSManagedValue::isObject() const + * + * Returns \c true if the type of this QJSManagedValue is \c object, + * or \c false otherwise. + */ + +/*! + * \fn QJSManagedValue::isFunction() const + * + * Returns \c true if the type of this QJSManagedValue is \c function, + * \c false otherwise. + */ + +/*! + * Returns \c true if this QJSManagedValue holds the JavaScript \c null value, + * or \c false otherwise. + */ +bool QJSManagedValue::isNull() const +{ + return d && d->isNull(); +} + +/*! + * Returns \c true if this QJSManagedValue holds an integer value, or \c false + * otherwise. The storage format of a number does not affect the result of any + * operations performed on it, but if an integer is stored, many operations are + * faster. + */ +bool QJSManagedValue::isInteger() const +{ + return d && d->isInteger(); +} + +/*! + * Returns \c true if this value represents a JavaScript regular expression + * object, or \c false otherwise. + */ +bool QJSManagedValue::isRegularExpression() const +{ + return d && d->as<QV4::RegExpObject>(); +} + +/*! + * Returns \c true if this value represents a JavaScript Array + * object, or \c false otherwise. + */ +bool QJSManagedValue::isArray() const +{ + return d && d->as<QV4::ArrayObject>(); +} + +/*! + * Returns \c true if this value represents a JavaScript Url + * object, or \c false otherwise. + */ +bool QJSManagedValue::isUrl() const +{ + return d && d->as<QV4::UrlObject>(); +} + +/*! + * Returns \c true if this value represents a QVariant managed on the JavaScript + * heap, or \c false otherwise. + */ +bool QJSManagedValue::isVariant() const +{ + return d && d->as<QV4::VariantObject>(); +} + +/*! + * Returns \c true if this value represents a QObject pointer managed on the + * JavaScript heap, or \c false otherwise. + */ +bool QJSManagedValue::isQObject() const +{ + return d && d->as<QV4::QObjectWrapper>(); +} + +/*! + * Returns \c true if this value represents a QMetaObject pointer managed on the + * JavaScript heap, or \c false otherwise. + */ +bool QJSManagedValue::isQMetaObject() const +{ + return d && d->as<QV4::QMetaObjectWrapper>(); +} + +/*! + * Returns \c true if this value represents a JavaScript Date object, or + * \c false otherwise. + */ +bool QJSManagedValue::isDate() const +{ + return d && d->as<QV4::DateObject>(); +} + +/*! + * Returns \c true if this value represents a JavaScript Error object, or + * \c false otherwise. + */ +bool QJSManagedValue::isError() const +{ + return d && d->as<QV4::ErrorObject>(); +} + +/*! + * \internal + * + * Returns \c true if this value represents a JavaScript meta type, or \c false + * otherwise. + */ +bool QJSManagedValue::isJsMetaType() const +{ + return d && d->as<QV4::InternalClass>(); +} + +/*! + * Converts the manged value to a string. If the managed value holds a string, + * that one is returned. Otherwise a string coercion by JavaScript rules is + * performed. + * + * \note Conversion of a managed value to a string can throw an exception. In + * particular, symbols cannot be coerced into strings, or a custom + * toString() method may throw. In this case the result is an empty + * string and the engine carries an error after the conversion. + */ +QString QJSManagedValue::toString() const +{ + return d ? d->toQString() : QStringLiteral("undefined"); +} + +/*! + * Converts the manged value to a number. If the managed value holds a number, + * that one is returned. Otherwise a number coercion by JavaScript rules is + * performed. + * + * \note Conversion of a managed value to a number can throw an exception. In + * particular, symbols cannot be coerced into numbers, or a custom + * valueOf() method may throw. In this case the result is 0 and the + * engine carries an error after the conversion. + */ +double QJSManagedValue::toNumber() const +{ + return d ? d->toNumber() : 0; +} + +/*! + * Converts the manged value to a boolean. If the managed value holds a boolean, + * that one is returned. Otherwise a boolean coercion by JavaScript rules is + * performed. + */ +bool QJSManagedValue::toBoolean() const +{ + return d ? d->toBoolean() : false; +} + +/*! + * Converts the manged value to an integer. This first converts the value to a + * number by the rules of toNumber(), and then clamps it into the integer range + * by the rules given for coercing the arguments to JavaScript bit shift + * operators into 32bit integers. + * + * Internally, the value may already be stored as an integer, in which case a + * fast path is taken. + * + * \note Conversion of a managed value to a number can throw an exception. In + * particular, symbols cannot be coerced into numbers, or a custom + * valueOf() method may throw. In this case the result is 0 and the + * engine carries an error after the conversion. + * + * \note The JavaScript rules for coercing numbers into 32bit integers are + * unintuitive. + */ +int QJSManagedValue::toInteger() const +{ + return d ? d->toInt32() : 0; +} + +/*! + * Converts the manged value to a QJSPrimitiveValue. If the managed value holds + * a type supported by QJSPrimitiveValue, the value is copied. Otherwise the + * value is converted to a string, and the string is stored in + * QJSPrimitiveValue. + * + * \note Conversion of a managed value to a string can throw an exception. In + * particular, symbols cannot be coerced into strings, or a custom + * toString() method may throw. In this case the result is the undefined + * value and the engine carries an error after the conversion. + */ +QJSPrimitiveValue QJSManagedValue::toPrimitive() const +{ + if (!d || d->isUndefined()) + return QJSPrimitiveUndefined(); + if (d->isNull()) + return QJSPrimitiveNull(); + if (d->isBoolean()) + return d->booleanValue(); + if (d->isInteger()) + return d->integerValue(); + if (d->isNumber()) + return d->doubleValue(); + + bool ok; + const QString result = d->toQString(&ok); + return ok ? QJSPrimitiveValue(result) : QJSPrimitiveValue(QJSPrimitiveUndefined()); +} + +/*! + * Copies this QJSManagedValue into a new QJSValue. This is less efficient than + * move-constructing a QJSValue from a QJSManagedValue, but retains the + * QJSManagedValue. + */ +QJSValue QJSManagedValue::toJSValue() const +{ + return d ? QJSValuePrivate::fromReturnedValue(d->asReturnedValue()) : QJSValue(); +} + +/*! + * Copies this QJSManagedValue into a new QVariant. This also creates a useful + * QVariant if QJSManagedValue::isVariant() returns false. QVariant can hold all + * types supported by QJSManagedValue. + */ +QVariant QJSManagedValue::toVariant() const +{ + if (!d || d->isUndefined()) + return QVariant(); + if (d->isNull()) + return QVariant(QMetaType::fromType<std::nullptr_t>(), nullptr); + if (d->isBoolean()) + return QVariant(d->booleanValue()); + if (d->isInteger()) + return QVariant(d->integerValue()); + if (d->isNumber()) + return QVariant(d->doubleValue()); + if (d->isString()) + return QVariant(d->toQString()); + if (d->as<QV4::Managed>()) + return QV4::ExecutionEngine::toVariant(*d, QMetaType{}, true); + + Q_UNREACHABLE_RETURN(QVariant()); +} + +/*! + * If this QJSManagedValue holds a JavaScript regular expression object, returns + * an equivalent QRegularExpression. Otherwise returns an invalid one. + */ +QRegularExpression QJSManagedValue::toRegularExpression() const +{ + if (const auto *r = d ? d->as<QV4::RegExpObject>() : nullptr) + return r->toQRegularExpression(); + return {}; +} + +/*! + * If this QJSManagedValue holds a JavaScript Url object, returns + * an equivalent QUrl. Otherwise returns an invalid one. + */ +QUrl QJSManagedValue::toUrl() const +{ + if (const auto *u = d ? d->as<QV4::UrlObject>() : nullptr) + return u->toQUrl(); + return {}; +} + +/*! + * If this QJSManagedValue holds a QObject pointer, returns it. Otherwise + * returns nullptr. + */ +QObject *QJSManagedValue::toQObject() const +{ + if (const auto *o = d ? d->as<QV4::QObjectWrapper>() : nullptr) + return o->object(); + return {}; +} + +/*! + * If this QJSManagedValue holds a QMetaObject pointer, returns it. + * Otherwise returns nullptr. + */ +const QMetaObject *QJSManagedValue::toQMetaObject() const +{ + if (const auto *m = d ? d->as<QV4::QMetaObjectWrapper>() : nullptr) + return m->metaObject(); + return {}; +} + +/*! + * If this QJSManagedValue holds a JavaScript Date object, returns an equivalent + * QDateTime. Otherwise returns an invalid one. + */ +QDateTime QJSManagedValue::toDateTime() const +{ + if (const auto *t = d ? d->as<QV4::DateObject>() : nullptr) + return t->toQDateTime(); + return {}; +} + +/*! + * Returns \c true if this QJSManagedValue has a property \a name, otherwise + * returns \c false. The properties of the prototype chain are considered. + */ +bool QJSManagedValue::hasProperty(const QString &name) const +{ + if (!d || d->isNullOrUndefined()) + return false; + + if (d->isString() && name == QStringLiteral("length")) + return true; + + if (QV4::Object *obj = d->as<QV4::Object>()) { + QV4::Scope scope(obj->engine()); + QV4::ScopedPropertyKey key(scope, scope.engine->identifierTable->asPropertyKey(name)); + return obj->hasProperty(key); + } + + return prototype().hasProperty(name); +} + +/*! + * Returns \c true if this QJSManagedValue has a property \a name, otherwise + * returns \c false. The properties of the prototype chain are not considered. + */ +bool QJSManagedValue::hasOwnProperty(const QString &name) const +{ + if (!d || d->isNullOrUndefined()) + return false; + + if (d->isString() && name == QStringLiteral("length")) + return true; + + if (QV4::Object *obj = d->as<QV4::Object>()) { + QV4::Scope scope(obj->engine()); + QV4::ScopedPropertyKey key(scope, scope.engine->identifierTable->asPropertyKey(name)); + return obj->getOwnProperty(key) != QV4::Attr_Invalid; + } + + return false; +} + +/*! + * Returns the property \a name of this QJSManagedValue. The prototype chain + * is searched if the property is not found on the actual object. + */ +QJSValue QJSManagedValue::property(const QString &name) const +{ + if (!d) + return QJSValue(); + + if (d->isNullOrUndefined()) { + QV4::ExecutionEngine *e = v4Engine(d); + e->throwTypeError(QStringLiteral("Cannot read property '%1' of null").arg(name)); + return QJSValue(); + } + + if (QV4::String *string = d->as<QV4::String>()) { + if (name == QStringLiteral("length")) + return QJSValue(string->d()->length()); + } + + if (QV4::Object *obj = d->as<QV4::Object>()) { + QV4::Scope scope(obj->engine()); + QV4::ScopedPropertyKey key(scope, scope.engine->identifierTable->asPropertyKey(name)); + return QJSValuePrivate::fromReturnedValue(obj->get(key)); + } + + return prototype().property(name); +} + +/*! + * Sets the property \a name to \a value on this QJSManagedValue. This can only + * be done on JavaScript values of type \c object. Furhermore, \a value has to be + * either a primitive or belong to the same engine as this value. + */ +void QJSManagedValue::setProperty(const QString &name, const QJSValue &value) +{ + if (!d) + return; + + if (d->isNullOrUndefined()) { + v4Engine(d)->throwTypeError( + QStringLiteral("Value is null and could not be converted to an object")); + } + + if (QV4::Object *obj = d->as<QV4::Object>()) { + QV4::Scope scope(obj->engine()); + QV4::ExecutionEngine *v4 = QJSValuePrivate::engine(&value); + if (Q_UNLIKELY(v4 && v4 != scope.engine)) { + qWarning("QJSManagedValue::setProperty() failed: " + "Value was created in different engine."); + return; + } + QV4::ScopedPropertyKey key(scope, scope.engine->identifierTable->asPropertyKey(name)); + obj->put(key, QJSValuePrivate::convertToReturnedValue(scope.engine, value)); + } +} + +/*! + * Deletes the property \a name from this QJSManagedValue. Returns \c true if + * the deletion succeeded, or \c false otherwise. + */ +bool QJSManagedValue::deleteProperty(const QString &name) +{ + if (!d) + return false; + + if (QV4::Object *obj = d->as<QV4::Object>()) { + QV4::Scope scope(obj->engine()); + QV4::ScopedPropertyKey key(scope, scope.engine->identifierTable->asPropertyKey(name)); + return obj->deleteProperty(key); + } + + return false; +} + +/*! + * Returns \c true if this QJSManagedValue has an array index \a arrayIndex, + * otherwise returns \c false. The properties of the prototype chain are + * considered. + */ +bool QJSManagedValue::hasProperty(quint32 arrayIndex) const +{ + if (!d || d->isNullOrUndefined()) + return false; + + if (QV4::String *string = d->as<QV4::String>()) + return arrayIndex < quint32(string->d()->length()); + + if (QV4::Object *obj = d->as<QV4::Object>()) { + bool hasProperty = false; + if (arrayIndex == std::numeric_limits<quint32>::max()) + obj->get(obj->engine()->id_uintMax(), &hasProperty); + else + obj->get(arrayIndex, &hasProperty); + return hasProperty; + } + + return prototype().hasProperty(arrayIndex); +} + +/*! + * Returns \c true if this QJSManagedValue has an array index \a arrayIndex, + * otherwise returns \c false. The properties of the prototype chain are not + * considered. + */ +bool QJSManagedValue::hasOwnProperty(quint32 arrayIndex) const +{ + if (!d || d->isNullOrUndefined()) + return false; + + if (QV4::String *string = d->as<QV4::String>()) + return arrayIndex < quint32(string->d()->length()); + + if (QV4::Object *obj = d->as<QV4::Object>()) { + if (arrayIndex == std::numeric_limits<quint32>::max()) { + return obj->getOwnProperty(obj->engine()->id_uintMax()->toPropertyKey()) + != QV4::Attr_Invalid; + } else { + return obj->getOwnProperty(QV4::PropertyKey::fromArrayIndex(arrayIndex)) + != QV4::Attr_Invalid; + } + } + + return false; +} + +/*! + * Returns the property stored at \a arrayIndex of this QJSManagedValue. The + * prototype chain is searched if the property is not found on the actual + * object. + */ +QJSValue QJSManagedValue::property(quint32 arrayIndex) const +{ + if (!d || d->isNullOrUndefined()) + return QJSValue(); + + if (QV4::String *string = d->as<QV4::String>()) { + const QString qString = string->toQString(); + if (arrayIndex < quint32(qString.size())) + return qString.sliced(arrayIndex, 1); + return QJSValue(); + } + + if (QV4::Object *obj = d->as<QV4::Object>()) { + if (arrayIndex == std::numeric_limits<quint32>::max()) + return QJSValuePrivate::fromReturnedValue(obj->get(obj->engine()->id_uintMax())); + else + return QJSValuePrivate::fromReturnedValue(obj->get(arrayIndex)); + } + + return prototype().property(arrayIndex); +} + +/*! + * Stores the \a value at \a arrayIndex in this QJSManagedValue. This can only + * be done on JavaScript values of type \c object, and it's not recommended if the + * value is not an array. Furhermore, \a value has to be either a primitive or + * belong to the same engine as this value. + */ +void QJSManagedValue::setProperty(quint32 arrayIndex, const QJSValue &value) +{ + if (!d) + return; + + if (QV4::Object *obj = d->as<QV4::Object>()) { + QV4::ExecutionEngine *v4 = QJSValuePrivate::engine(&value); + if (Q_UNLIKELY(v4 && v4 != obj->engine())) { + qWarning("QJSManagedValue::setProperty() failed: " + "Value was created in different engine."); + return; + } + obj->put(arrayIndex, QJSValuePrivate::convertToReturnedValue(v4, value)); + } +} + +/*! + * Deletes the value stored at \a arrayIndex from this QJSManagedValue. Returns + * \c true if the deletion succeeded, or \c false otherwise. + */ +bool QJSManagedValue::deleteProperty(quint32 arrayIndex) +{ + if (!d) + return false; + + if (QV4::Object *obj = d->as<QV4::Object>()) + return obj->deleteProperty(QV4::PropertyKey::fromArrayIndex(arrayIndex)); + + return false; +} + +static const QV4::FunctionObject *functionObjectForCall(QV4::Value *d) +{ + if (Q_UNLIKELY(!d)) { + qWarning("QJSManagedValue: Calling a default-constructed or moved-from managed value" + "should throw an exception, but there is no engine to receive it."); + return nullptr; + } + + if (const QV4::FunctionObject *f = d->as<QV4::FunctionObject>()) + return f; + + v4Engine(d)->throwTypeError(QStringLiteral("Value is not a function")); + return nullptr; +} + +/*! + * If this QJSManagedValue represents a JavaScript FunctionObject, calls it with + * the given \a arguments, and returns the result. Otherwise returns a + * JavaScript \c undefined value. + * + * The \a arguments have to be either primitive values or belong to the same + * QJSEngine as this QJSManagedValue. Otherwise the call is not carried + * out and a JavaScript \c undefined value is returned. + */ +QJSValue QJSManagedValue::call(const QJSValueList &arguments) const +{ + const QV4::FunctionObject *f = functionObjectForCall(d); + if (!f) + return QJSValue(); + + QV4::ExecutionEngine *engine = f->engine(); + + QV4::Scope scope(engine); + QV4::JSCallArguments jsCallData(scope, arguments.size()); + *jsCallData.thisObject = engine->globalObject; + int i = 0; + for (const QJSValue &arg : arguments) { + if (Q_UNLIKELY(!QJSValuePrivate::checkEngine(engine, arg))) { + qWarning("QJSManagedValue::call() failed: Argument was created in different engine."); + return QJSValue(); + } + jsCallData.args[i++] = QJSValuePrivate::convertToReturnedValue(engine, arg); + } + + return QJSValuePrivate::fromReturnedValue(f->call(jsCallData)); +} + +/*! + * If this QJSManagedValue represents a JavaScript FunctionObject, calls it on + * \a instance with the given \a arguments, and returns the result. Otherwise + * returns a JavaScript \c undefined value. + * + * The \a arguments and the \a instance have to be either primitive values or + * belong to the same QJSEngine as this QJSManagedValue. Otherwise the call is + * not carried out and a JavaScript \c undefined value is returned. + */ +QJSValue QJSManagedValue::callWithInstance(const QJSValue &instance, + const QJSValueList &arguments) const +{ + const QV4::FunctionObject *f = functionObjectForCall(d); + if (!f) + return QJSValue(); + + QV4::ExecutionEngine *engine = f->engine(); + + if (Q_UNLIKELY(!QJSValuePrivate::checkEngine(engine, instance))) { + qWarning("QJSManagedValue::callWithInstance() failed: " + "Instance was created in different engine."); + return QJSValue(); + } + + QV4::Scope scope(engine); + QV4::JSCallArguments jsCallData(scope, arguments.size()); + *jsCallData.thisObject = QJSValuePrivate::convertToReturnedValue(engine, instance); + int i = 0; + for (const QJSValue &arg : arguments) { + if (Q_UNLIKELY(!QJSValuePrivate::checkEngine(engine, arg))) { + qWarning("QJSManagedValue::callWithInstance() failed: " + "Argument was created in different engine."); + return QJSValue(); + } + jsCallData.args[i++] = QJSValuePrivate::convertToReturnedValue(engine, arg); + } + + return QJSValuePrivate::fromReturnedValue(f->call(jsCallData)); +} + +/*! + * If this QJSManagedValue represents a JavaScript FunctionObject, calls it as + * constructor with the given \a arguments, and returns the result. Otherwise + * returns a JavaScript \c undefined value. + * + * The \a arguments have to be either primitive values or belong to the same + * QJSEngine as this QJSManagedValue. Otherwise the call is not carried + * out and a JavaScript \c undefined value is returned. + */ +QJSValue QJSManagedValue::callAsConstructor(const QJSValueList &arguments) const +{ + const QV4::FunctionObject *f = functionObjectForCall(d); + if (!f) + return QJSValue(); + + QV4::ExecutionEngine *engine = f->engine(); + + QV4::Scope scope(engine); + QV4::JSCallArguments jsCallData(scope, arguments.size()); + int i = 0; + for (const QJSValue &arg : arguments) { + if (Q_UNLIKELY(!QJSValuePrivate::checkEngine(engine, arg))) { + qWarning("QJSManagedValue::callAsConstructor() failed: " + "Argument was created in different engine."); + return QJSValue(); + } + jsCallData.args[i++] = QJSValuePrivate::convertToReturnedValue(engine, arg); + } + + return QJSValuePrivate::fromReturnedValue(f->callAsConstructor(jsCallData)); +} + +/*! + * \internal + * + * Retrieves the JavaScript meta type of this value. The JavaScript meta type + * represents the layout of members in an object. Instantiating a meta type is + * faster than re-constructing the same object using a sequence of setProperty() + * calls on a new object. + * + * \sa members(), instantiate() + */ +QJSManagedValue QJSManagedValue::jsMetaType() const +{ + if (!d) + return QJSManagedValue(); + + QJSManagedValue result(v4Engine(d)); + if (QV4::Managed *m = d->as<QV4::Managed>()) + *result.d = m->internalClass(); + + return result; +} + +/*! + * \internal + * + * If this value is a JavaScript meta type, retrieves the names of its members + * The ordering of the names corresponds to the ordering of the values to be + * passed to instantiate(). + * + * If the value is not a meta type, an empty list is returned. + * + * \sa isMetaType(), metaType(), instantiate() + */ +QStringList QJSManagedValue::jsMetaMembers() const +{ + if (!d) + return {}; + + if (QV4::InternalClass *c = d->as<QV4::InternalClass>()) { + const auto heapClass = c->d(); + const int size = heapClass->size; + QStringList result; + result.reserve(size); + QV4::Scope scope(c->engine()); + for (int i = 0; i < size; ++i) { + QV4::ScopedValue key(scope, heapClass->keyAt(i)); + result.append(key->toQString()); + } + return result; + } + + return {}; +} + +/*! + * \internal + * + * If this value is a JavaScript meta type, instantiates it using the + * \a values, and returns the result. Otherwise returns undefined. + * + * The values are expected in the same order as the keys in the return value of + * members(), and that is the order in which properties were added to the object + * this meta type originally belongs to. + * + * \sa members(), metaType(), isMetaType(). + */ +QJSManagedValue QJSManagedValue::jsMetaInstantiate(const QJSValueList &values) const +{ + if (!d) + return {}; + + if (QV4::InternalClass *c = d->as<QV4::InternalClass>()) { + QV4::ExecutionEngine *engine = c->engine(); + QJSManagedValue result(engine); + *result.d = c->engine()->newObject(c->d()); + QV4::Object *o = result.d->as<QV4::Object>(); + + for (uint i = 0, end = qMin(qsizetype(c->d()->size), values.size()); i < end; ++i) { + const QJSValue &arg = values[i]; + if (Q_UNLIKELY(!QJSValuePrivate::checkEngine(engine, arg))) { + qWarning("QJSManagedValue::instantiate() failed: " + "Argument was created in different engine."); + return QJSManagedValue(); + } + o->setProperty(i, QJSValuePrivate::convertToReturnedValue(engine, arg)); + } + + return result; + } + + return {}; +} + +QJSManagedValue::QJSManagedValue(QV4::ExecutionEngine *engine) : + d(engine->memoryManager->m_persistentValues->allocate()) +{ +} + +QT_END_NAMESPACE |