1 /**************************************************************************** 2 ** 3 ** Copyright (C) 2018 The Qt Company Ltd. 4 ** Contact: https://www.qt.io/licensing/ 5 ** 6 ** This file is part of the QtQml module of the Qt Toolkit. 7 ** 8 ** $QT_BEGIN_LICENSE:LGPL$ 9 ** Commercial License Usage 10 ** Licensees holding valid commercial Qt licenses may use this file in 11 ** accordance with the commercial license agreement provided with the 12 ** Software or, alternatively, in accordance with the terms contained in 13 ** a written agreement between you and The Qt Company. For licensing terms 14 ** and conditions see https://www.qt.io/terms-conditions. For further 15 ** information use the contact form at https://www.qt.io/contact-us. 16 ** 17 ** GNU Lesser General Public License Usage 18 ** Alternatively, this file may be used under the terms of the GNU Lesser 19 ** General Public License version 3 as published by the Free Software 20 ** Foundation and appearing in the file LICENSE.LGPL3 included in the 21 ** packaging of this file. Please review the following information to 22 ** ensure the GNU Lesser General Public License version 3 requirements 23 ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. 24 ** 25 ** GNU General Public License Usage 26 ** Alternatively, this file may be used under the terms of the GNU 27 ** General Public License version 2.0 or (at your option) the GNU General 28 ** Public license version 3 or any later version approved by the KDE Free 29 ** Qt Foundation. The licenses are as published by the Free Software 30 ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 31 ** included in the packaging of this file. Please review the following 32 ** information to ensure the GNU General Public License requirements will 33 ** be met: https://www.gnu.org/licenses/gpl-2.0.html and 34 ** https://www.gnu.org/licenses/gpl-3.0.html. 35 ** 36 ** $QT_END_LICENSE$ 37 ** 38 ****************************************************************************/ 39 #ifndef QV4PROPERTYKEY_H 40 #define QV4PROPERTYKEY_H 41 42 // 43 // W A R N I N G 44 // ------------- 45 // 46 // This file is not part of the Qt API. It exists purely as an 47 // implementation detail. This header file may change from version to 48 // version without notice, or even be removed. 49 // 50 // We mean it. 51 // 52 53 #include <private/qv4global_p.h> 54 55 QT_BEGIN_NAMESPACE 56 57 class QString; 58 59 namespace QV4 { 60 61 struct PropertyKey 62 { 63 private: 64 // Property keys are Strings, Symbols or unsigned integers. 65 // For convenience we derive them from Values, allowing us to store them 66 // on the JS stack 67 // 68 // They do however behave somewhat different than a Value: 69 // * If the key is a String, the pointer to the string is stored in the identifier 70 // table and thus unique. 71 // * If the key is a Symbol it simply points to the referenced symbol object 72 // * if the key is an array index (a uint < UINT_MAX), it's encoded as an 73 // integer value 74 quint64 val; 75 76 // Important: Always keep this in sync with the definitions for Integers and heap objects in Value 77 static const quint64 ArrayIndexMask = 0x3800000000000ull; 78 enum { 79 IsManagedOrUndefined_Shift = 64-15, 80 }; isManagedPropertyKey81 inline bool isManaged() const { return (val >> IsManagedOrUndefined_Shift) == 0; } valuePropertyKey82 inline quint32 value() const { return val & quint64(~quint32(0)); } 83 84 #if QT_POINTER_SIZE == 8 mPropertyKey85 QML_NEARLY_ALWAYS_INLINE Heap::StringOrSymbol *m() const 86 { 87 Heap::StringOrSymbol *b; 88 memcpy(&b, &val, 8); 89 return b; 90 } setMPropertyKey91 QML_NEARLY_ALWAYS_INLINE void setM(Heap::StringOrSymbol *b) 92 { 93 memcpy(&val, &b, 8); 94 } 95 #elif QT_POINTER_SIZE == 4 mPropertyKey96 QML_NEARLY_ALWAYS_INLINE Heap::StringOrSymbol *m() const 97 { 98 Q_STATIC_ASSERT(sizeof(Heap::StringOrSymbol*) == sizeof(quint32)); 99 Heap::StringOrSymbol *b; 100 quint32 v = value(); 101 memcpy(&b, &v, 4); 102 return b; 103 } setMPropertyKey104 QML_NEARLY_ALWAYS_INLINE void setM(Heap::StringOrSymbol *b) 105 { 106 quint32 v; 107 memcpy(&v, &b, 4); 108 val = v; 109 } 110 #endif 111 112 public: invalidPropertyKey113 static PropertyKey invalid() { PropertyKey key; key.val = 0; return key; } fromArrayIndexPropertyKey114 static PropertyKey fromArrayIndex(uint idx) { PropertyKey key; key.val = ArrayIndexMask | static_cast<quint64>(idx); return key; } isStringOrSymbolPropertyKey115 bool isStringOrSymbol() const { return isManaged() && val != 0; } asArrayIndexPropertyKey116 uint asArrayIndex() const { Q_ASSERT(isArrayIndex()); return static_cast<uint>(val & 0xffffffff); } isArrayIndexPropertyKey117 uint isArrayIndex() const { return !isManaged() && val != 0; } isValidPropertyKey118 bool isValid() const { return val != 0; } fromStringOrSymbolPropertyKey119 static PropertyKey fromStringOrSymbol(Heap::StringOrSymbol *b) 120 { PropertyKey key; key.setM(b); return key; } asStringOrSymbolPropertyKey121 Heap::StringOrSymbol *asStringOrSymbol() const { 122 if (!isManaged()) 123 return nullptr; 124 return m(); 125 } 126 127 Q_QML_EXPORT bool isString() const; 128 bool isSymbol() const; 129 bool isCanonicalNumericIndexString() const; 130 131 Q_QML_EXPORT QString toQString() const; 132 Heap::StringOrSymbol *toStringOrSymbol(ExecutionEngine *e); idPropertyKey133 quint64 id() const { return val; } fromIdPropertyKey134 static PropertyKey fromId(quint64 id) { 135 PropertyKey key; key.val = id; return key; 136 } 137 138 enum FunctionNamePrefix { 139 None, 140 Getter, 141 Setter 142 }; 143 Heap::String *asFunctionName(ExecutionEngine *e, FunctionNamePrefix prefix) const; 144 145 bool operator ==(const PropertyKey &other) const { return val == other.val; } 146 bool operator !=(const PropertyKey &other) const { return val != other.val; } 147 bool operator <(const PropertyKey &other) const { return val < other.val; } 148 }; 149 150 } 151 152 QT_END_NAMESPACE 153 154 #endif 155