| 1 | // Copyright (C) 2018 The Qt Company Ltd. |
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| 2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
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| 3 | #ifndef QV4PROPERTYKEY_H |
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| 4 | #define QV4PROPERTYKEY_H |
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| 5 | |
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| 6 | // |
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| 7 | // W A R N I N G |
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| 8 | // ------------- |
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| 9 | // |
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| 10 | // This file is not part of the Qt API. It exists purely as an |
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| 11 | // implementation detail. This header file may change from version to |
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| 12 | // version without notice, or even be removed. |
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| 13 | // |
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| 14 | // We mean it. |
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| 15 | // |
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| 16 | |
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| 17 | #include <private/qv4writebarrier_p.h> |
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| 18 | #include <private/qv4global_p.h> |
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| 19 | #include <private/qv4staticvalue_p.h> |
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| 20 | #include <QtCore/qhashfunctions.h> |
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| 21 | |
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| 22 | QT_BEGIN_NAMESPACE |
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| 23 | |
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| 24 | class QString; |
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| 25 | |
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| 26 | namespace QV4 { |
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| 27 | |
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| 28 | struct PropertyKey |
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| 29 | { |
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| 30 | private: |
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| 31 | // Property keys are Strings, Symbols or unsigned integers. |
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| 32 | // For convenience we derive them from Values, allowing us to store them |
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| 33 | // on the JS stack |
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| 34 | // |
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| 35 | // They do however behave somewhat different than a Value: |
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| 36 | // * If the key is a String, the pointer to the string is stored in the identifier |
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| 37 | // table and thus unique. |
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| 38 | // * If the key is a Symbol it simply points to the referenced symbol object |
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| 39 | // * if the key is an array index (a uint < UINT_MAX), it's encoded as an |
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| 40 | // integer value |
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| 41 | QV4::StaticValue val; |
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| 42 | |
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| 43 | inline bool isManaged() const { return val.isManaged(); } |
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| 44 | inline quint32 value() const { return val.value(); } |
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| 45 | |
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| 46 | public: |
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| 47 | static PropertyKey invalid() |
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| 48 | { |
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| 49 | PropertyKey key; |
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| 50 | key.val = StaticValue::undefinedValue(); |
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| 51 | return key; |
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| 52 | } |
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| 53 | |
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| 54 | static PropertyKey fromArrayIndex(uint idx) |
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| 55 | { |
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| 56 | PropertyKey key; |
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| 57 | key.val.setInt_32(idx); |
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| 58 | return key; |
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| 59 | } |
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| 60 | |
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| 61 | bool isStringOrSymbol() const { return isManaged(); } |
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| 62 | uint asArrayIndex() const |
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| 63 | { |
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| 64 | Q_ASSERT(isArrayIndex()); |
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| 65 | return value(); |
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| 66 | } |
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| 67 | |
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| 68 | bool isArrayIndex() const { return val.isInteger(); } |
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| 69 | bool isValid() const { return !val.isUndefined(); } |
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| 70 | |
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| 71 | // We cannot #include the declaration of Heap::StringOrSymbol here. |
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| 72 | // Therefore we do some gymnastics to enforce the type safety. |
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| 73 | |
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| 74 | template<typename StringOrSymbol = Heap::StringOrSymbol, typename Engine = QV4::EngineBase> |
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| 75 | static PropertyKey fromStringOrSymbol(Engine *engine, StringOrSymbol *b) |
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| 76 | { |
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| 77 | static_assert(std::is_base_of_v<Heap::StringOrSymbol, StringOrSymbol>); |
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| 78 | PropertyKey key; |
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| 79 | QV4::WriteBarrier::markCustom(engine, [&](QV4::MarkStack *stack) { |
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| 80 | if constexpr (QV4::WriteBarrier::isInsertionBarrier) { |
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| 81 | // treat this as an insertion - the StringOrSymbol becomes reachable |
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| 82 | // via the propertykey, so we consequently need to mark it durnig gc |
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| 83 | b->mark(stack); |
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| 84 | } |
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| 85 | }); |
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| 86 | key.val.setM(b); |
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| 87 | Q_ASSERT(key.isManaged()); |
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| 88 | return key; |
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| 89 | } |
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| 90 | |
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| 91 | template<typename StringOrSymbol = Heap::StringOrSymbol> |
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| 92 | StringOrSymbol *asStringOrSymbol() const |
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| 93 | { |
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| 94 | static_assert(std::is_base_of_v<Heap::StringOrSymbol, StringOrSymbol>); |
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| 95 | if (!isManaged()) |
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| 96 | return nullptr; |
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| 97 | return static_cast<StringOrSymbol *>(val.m()); |
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| 98 | } |
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| 99 | |
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| 100 | Q_QML_EXPORT bool isString() const; |
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| 101 | Q_QML_EXPORT bool isSymbol() const; |
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| 102 | bool isCanonicalNumericIndexString() const; |
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| 103 | |
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| 104 | Q_QML_EXPORT QString toQString() const; |
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| 105 | Heap::StringOrSymbol *toStringOrSymbol(ExecutionEngine *e); |
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| 106 | quint64 id() const { return val._val; } |
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| 107 | static PropertyKey fromId(quint64 id) { |
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| 108 | PropertyKey key; key.val._val = id; return key; |
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| 109 | } |
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| 110 | |
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| 111 | enum FunctionNamePrefix { |
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| 112 | None, |
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| 113 | Getter, |
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| 114 | Setter |
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| 115 | }; |
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| 116 | Heap::String *asFunctionName(ExecutionEngine *e, FunctionNamePrefix prefix) const; |
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| 117 | |
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| 118 | bool operator ==(const PropertyKey &other) const { return val._val == other.val._val; } |
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| 119 | bool operator !=(const PropertyKey &other) const { return val._val != other.val._val; } |
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| 120 | bool operator <(const PropertyKey &other) const { return val._val < other.val._val; } |
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| 121 | friend size_t qHash(const PropertyKey &key, size_t seed = 0) { return qHash(key: key.val._val, seed); } |
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| 122 | }; |
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| 123 | |
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| 124 | } |
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| 125 | |
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| 126 | QT_END_NAMESPACE |
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| 127 | |
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| 128 | #endif |
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| 129 | |
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