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1 /*
2  * Copyright (c) 2021 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #ifndef ECMASCRIPT_TRANSITIONS_DICTIONARY_H
17 #define ECMASCRIPT_TRANSITIONS_DICTIONARY_H
18 
19 #include "ecmascript/accessor_data.h"
20 #include "ecmascript/js_symbol.h"
21 #include "ecmascript/js_tagged_number.h"
22 #include "ecmascript/tagged_hash_table.h"
23 
24 namespace panda::ecmascript {
25 class TransitionsDictionary : public TaggedHashTable<TransitionsDictionary> {
26 public:
27     using HashTableT = TaggedHashTable<TransitionsDictionary>;
IsMatch(const JSTaggedValue & key,const JSTaggedValue & otherKey)28     static inline bool IsMatch([[maybe_unused]] const JSTaggedValue &key,
29                                [[maybe_unused]] const JSTaggedValue &otherKey)
30     {
31         UNREACHABLE();
32     }
Hash(const JSTaggedValue & key)33     static inline int Hash([[maybe_unused]] const JSTaggedValue &key)
34     {
35         UNREACHABLE();
36     }
37 
IsMatch(const JSTaggedValue & key,const JSTaggedValue & metaData,const JSTaggedValue & otherKey,const JSTaggedValue & otherDetails)38     static inline bool IsMatch(const JSTaggedValue &key, const JSTaggedValue &metaData, const JSTaggedValue &otherKey,
39                                const JSTaggedValue &otherDetails)
40     {
41         return key == otherKey && metaData == otherDetails;
42     }
43 
Hash(const JSTaggedValue & key,const JSTaggedValue & metaData)44     static inline int Hash(const JSTaggedValue &key, const JSTaggedValue &metaData)
45     {
46         ASSERT(key.IsStringOrSymbol());
47 
48         uint32_t hash = 0;
49         if (key.IsString()) {
50             hash = EcmaStringAccessor(key).GetHashcode();
51         } else if (key.IsSymbol()) {
52             hash = JSSymbol::Cast(key.GetTaggedObject())->GetHashField();
53         }
54         int metaDataHash = metaData.IsInt() ? metaData.GetInt() : static_cast<int>(metaData.GetRawData());
55         return static_cast<int>(hash) + metaDataHash;
56     }
57 
GetKeyIndex(int entry)58     inline static int GetKeyIndex(int entry)
59     {
60         return HashTableT::TABLE_HEADER_SIZE + entry * GetEntrySize() + ENTRY_KEY_INDEX;
61     }
GetValueIndex(int entry)62     inline static int GetValueIndex(int entry)
63     {
64         return HashTableT::TABLE_HEADER_SIZE + entry * GetEntrySize() + ENTRY_VALUE_INDEX;
65     }
GetEntryIndex(int entry)66     inline static int GetEntryIndex(int entry)
67     {
68         return HashTableT::TABLE_HEADER_SIZE + entry * GetEntrySize();
69     }
GetEntrySize()70     inline static int GetEntrySize()
71     {
72         return ENTRY_SIZE;
73     }
74 
Cast(TaggedObject * object)75     static TransitionsDictionary *Cast(TaggedObject *object)
76     {
77         return reinterpret_cast<TransitionsDictionary *>(object);
78     }
79 
80     static constexpr int DEFAULT_ELEMENTS_NUMBER = 16;
81     static JSHandle<TransitionsDictionary> Create(const JSThread *thread,
82                                                   int numberOfElements = DEFAULT_ELEMENTS_NUMBER)
83     {
84         return HashTableT::Create(thread, numberOfElements);
85     }
86 
87     // Attempt to shrink the dictionary after deletion of key.
Shrink(const JSThread * thread,const JSHandle<TransitionsDictionary> & dictionary)88     inline static JSHandle<TransitionsDictionary> Shrink(const JSThread *thread,
89                                                          const JSHandle<TransitionsDictionary> &dictionary)
90     {
91         return HashTableT::Shrink(thread, dictionary, 0);
92     }
93 
GetAttributes(int entry)94     inline JSTaggedValue GetAttributes(int entry) const
95     {
96         int index = GetEntryIndex(entry) + ENTRY_DETAILS_INDEX;
97         return HashTableT::Get(index);
98     }
99 
SetAttributes(const JSThread * thread,int entry,JSTaggedValue metaData)100     inline void SetAttributes(const JSThread *thread, int entry, JSTaggedValue metaData)
101     {
102         int index = GetEntryIndex(entry) + ENTRY_DETAILS_INDEX;
103         HashTableT::Set(thread, index, metaData);
104     }
105 
SetEntry(const JSThread * thread,int entry,const JSTaggedValue & key,const JSTaggedValue & value,const JSTaggedValue & metaData)106     inline void SetEntry(const JSThread *thread, int entry, const JSTaggedValue &key, const JSTaggedValue &value,
107                          const JSTaggedValue &metaData)
108     {
109         SetKey(thread, entry, key);
110         JSTaggedValue weakValue = JSTaggedValue(value.CreateAndGetWeakRef());
111         SetValue(thread, entry, weakValue);
112         if (!metaData.IsHeapObject()) {
113             SetAttributes(thread, entry, metaData);
114             return;
115         }
116         JSTaggedValue weakMetaData = JSTaggedValue(metaData.CreateAndGetWeakRef());
117         SetAttributes(thread, entry, weakMetaData);
118     }
119 
RemoveElement(const JSThread * thread,int entry)120     inline void RemoveElement(const JSThread *thread, int entry)
121     {
122         SetKey(thread, entry, JSTaggedValue::Hole());
123         SetValue(thread, entry, JSTaggedValue::Hole());
124         SetAttributes(thread, entry, JSTaggedValue::Hole());
125         IncreaseHoleEntriesCount(thread);
126     }
127 
128     int FindEntry(const JSTaggedValue &key, const JSTaggedValue &metaData);
129     static JSHandle<TransitionsDictionary> PutIfAbsent(const JSThread *thread,
130                                                        const JSHandle<TransitionsDictionary> &dictionary,
131                                                        const JSHandle<JSTaggedValue> &key,
132                                                        const JSHandle<JSTaggedValue> &value,
133                                                        const JSHandle<JSTaggedValue> &metaData);
134     static JSHandle<TransitionsDictionary> Remove(const JSThread *thread, const JSHandle<TransitionsDictionary> &table,
135                                                   const JSHandle<JSTaggedValue> &key, const JSTaggedValue &metaData);
136     void Rehash(const JSThread *thread, TransitionsDictionary *newTable);
137 
CheckWeakExist(const JSTaggedValue & value)138     static bool CheckWeakExist(const JSTaggedValue &value)
139     {
140         if (value == JSTaggedValue::Undefined()) {
141             return false;
142         }
143         return true;
144     }
145 
ComputeCompactSize(const JSHandle<TransitionsDictionary> & table,int computeHashTableSize,int tableSize,int addedElements)146     static int ComputeCompactSize(const JSHandle<TransitionsDictionary> &table, int computeHashTableSize,
147         int tableSize, int addedElements)
148     {
149         int realEntryCount = 0;
150         for (int i = 0; i < tableSize; i++) {
151             // value is weak reference, if not use will be set undefined.
152             if (TransitionsDictionary::CheckWeakExist(table->GetValue(i))) {
153                 realEntryCount++;
154             }
155         }
156         return std::min(computeHashTableSize,
157             static_cast<int>(helpers::math::GetPowerOfTwoValue32(realEntryCount + addedElements) * HASH_TABLE_BUFFER));
158     }
159 
160     static constexpr int ENTRY_SIZE = 3;
161     static constexpr int ENTRY_KEY_INDEX = 0;
162     static constexpr int ENTRY_VALUE_INDEX = 1;
163     static constexpr int ENTRY_DETAILS_INDEX = 2;
164     static constexpr int HASH_TABLE_BUFFER = 2;
165     DECL_DUMP()
166 };
167 }  // namespace panda::ecmascript
168 #endif
169