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Issue 1611343002: wtf reformat test Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: pydent Created 4 years, 11 months ago
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1 /* 1 /*
2 * Copyright (C) 2005, 2006, 2007, 2008, 2011, 2012 Apple Inc. All rights reserv ed. 2 * Copyright (C) 2005, 2006, 2007, 2008, 2011, 2012 Apple Inc. All rights reserv ed.
3 * 3 *
4 * This library is free software; you can redistribute it and/or 4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public 5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either 6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version. 7 * version 2 of the License, or (at your option) any later version.
8 * 8 *
9 * This library is distributed in the hope that it will be useful, 9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details. 12 * Library General Public License for more details.
13 * 13 *
14 * You should have received a copy of the GNU Library General Public License 14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB. If not, write to 15 * along with this library; see the file COPYING.LIB. If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA. 17 * Boston, MA 02110-1301, USA.
18 * 18 *
19 */ 19 */
20 20
21 #ifndef WTF_HashTraits_h 21 #ifndef WTF_HashTraits_h
22 #define WTF_HashTraits_h 22 #define WTF_HashTraits_h
23 23
24 #include "wtf/HashFunctions.h" 24 #include "wtf/HashFunctions.h"
25 #include "wtf/HashTableDeletedValueType.h" 25 #include "wtf/HashTableDeletedValueType.h"
26 #include "wtf/StdLibExtras.h" 26 #include "wtf/StdLibExtras.h"
27 #include "wtf/TypeTraits.h" 27 #include "wtf/TypeTraits.h"
28 #include <limits> 28 #include <limits>
29 #include <string.h> // For memset. 29 #include <string.h> // For memset.
30 #include <type_traits> 30 #include <type_traits>
31 #include <utility> 31 #include <utility>
32 32
33 namespace WTF { 33 namespace WTF {
34 34
35 class String; 35 class String;
36 template <bool isInteger, typename T> struct GenericHashTraitsBase; 36 template <bool isInteger, typename T>
37 template <typename T> class OwnPtr; 37 struct GenericHashTraitsBase;
38 template <typename T> class PassOwnPtr; 38 template <typename T>
39 template <typename T> struct HashTraits; 39 class OwnPtr;
40 template <typename T>
41 class PassOwnPtr;
42 template <typename T>
43 struct HashTraits;
40 44
41 enum ShouldWeakPointersBeMarkedStrongly { 45 enum ShouldWeakPointersBeMarkedStrongly {
42 WeakPointersActStrong, 46 WeakPointersActStrong,
43 WeakPointersActWeak 47 WeakPointersActWeak
44 }; 48 };
45 49
46 template <typename T> struct GenericHashTraitsBase<false, T> { 50 template <typename T>
47 // The emptyValueIsZero flag is used to optimize allocation of empty hash 51 struct GenericHashTraitsBase<false, T> {
48 // tables with zeroed memory. 52 // The emptyValueIsZero flag is used to optimize allocation of empty hash
49 static const bool emptyValueIsZero = false; 53 // tables with zeroed memory.
50 54 static const bool emptyValueIsZero = false;
51 // The hasIsEmptyValueFunction flag allows the hash table to automatically 55
52 // generate code to check for the empty value when it can be done with the 56 // The hasIsEmptyValueFunction flag allows the hash table to automatically
53 // equality operator, but allows custom functions for cases like String that 57 // generate code to check for the empty value when it can be done with the
54 // need them. 58 // equality operator, but allows custom functions for cases like String that
55 static const bool hasIsEmptyValueFunction = false; 59 // need them.
56 60 static const bool hasIsEmptyValueFunction = false;
57 // The starting table size. Can be overridden when we know beforehand that a 61
58 // hash table will have at least N entries. 62 // The starting table size. Can be overridden when we know beforehand that a
63 // hash table will have at least N entries.
59 #if defined(MEMORY_SANITIZER_INITIAL_SIZE) 64 #if defined(MEMORY_SANITIZER_INITIAL_SIZE)
60 static const unsigned minimumTableSize = 1; 65 static const unsigned minimumTableSize = 1;
61 #else 66 #else
62 static const unsigned minimumTableSize = 8; 67 static const unsigned minimumTableSize = 8;
63 #endif 68 #endif
64 69
65 template <typename U = void> 70 template <typename U = void>
66 struct NeedsTracingLazily { 71 struct NeedsTracingLazily {
67 static const bool value = NeedsTracing<T>::value; 72 static const bool value = NeedsTracing<T>::value;
68 }; 73 };
69 static const WeakHandlingFlag weakHandlingFlag = IsWeak<T>::value ? WeakHand lingInCollections : NoWeakHandlingInCollections; 74 static const WeakHandlingFlag weakHandlingFlag =
75 IsWeak<T>::value ? WeakHandlingInCollections
76 : NoWeakHandlingInCollections;
70 }; 77 };
71 78
72 // Default integer traits disallow both 0 and -1 as keys (max value instead of 79 // Default integer traits disallow both 0 and -1 as keys (max value instead of
73 // -1 for unsigned). 80 // -1 for unsigned).
74 template <typename T> struct GenericHashTraitsBase<true, T> : GenericHashTraitsB ase<false, T> { 81 template <typename T>
75 static const bool emptyValueIsZero = true; 82 struct GenericHashTraitsBase<true, T> : GenericHashTraitsBase<false, T> {
76 static void constructDeletedValue(T& slot, bool) { slot = static_cast<T>(-1) ; } 83 static const bool emptyValueIsZero = true;
77 static bool isDeletedValue(T value) { return value == static_cast<T>(-1); } 84 static void constructDeletedValue(T& slot, bool) {
78 }; 85 slot = static_cast<T>(-1);
79 86 }
80 template <typename T> struct GenericHashTraits : GenericHashTraitsBase<std::is_i ntegral<T>::value, T> { 87 static bool isDeletedValue(T value) { return value == static_cast<T>(-1); }
81 typedef T TraitType; 88 };
82 typedef T EmptyValueType; 89
83 90 template <typename T>
84 static T emptyValue() { return T(); } 91 struct GenericHashTraits
85 92 : GenericHashTraitsBase<std::is_integral<T>::value, T> {
86 // Type for functions that do not take ownership, such as contains. 93 typedef T TraitType;
87 typedef const T& PeekInType; 94 typedef T EmptyValueType;
88 typedef T* IteratorGetType; 95
89 typedef const T* IteratorConstGetType; 96 static T emptyValue() { return T(); }
90 typedef T& IteratorReferenceType; 97
91 typedef const T& IteratorConstReferenceType; 98 // Type for functions that do not take ownership, such as contains.
92 static IteratorReferenceType getToReferenceConversion(IteratorGetType x) { r eturn *x; } 99 typedef const T& PeekInType;
93 static IteratorConstReferenceType getToReferenceConstConversion(IteratorCons tGetType x) { return *x; } 100 typedef T* IteratorGetType;
94 // Type for functions that take ownership, such as add. 101 typedef const T* IteratorConstGetType;
95 // The store function either not be called or called once to store something 102 typedef T& IteratorReferenceType;
96 // passed in. The value passed to the store function will be PassInType. 103 typedef const T& IteratorConstReferenceType;
97 typedef const T& PassInType; 104 static IteratorReferenceType getToReferenceConversion(IteratorGetType x) {
98 static void store(const T& value, T& storage) { storage = value; } 105 return *x;
99 106 }
100 // Type for return value of functions that transfer ownership, such as take. 107 static IteratorConstReferenceType getToReferenceConstConversion(
101 typedef T PassOutType; 108 IteratorConstGetType x) {
102 static const T& passOut(const T& value) { return value; } 109 return *x;
103 110 }
104 // Type for return value of functions that do not transfer ownership, such 111 // Type for functions that take ownership, such as add.
105 // as get. 112 // The store function either not be called or called once to store something
106 // FIXME: We could change this type to const T& for better performance if we 113 // passed in. The value passed to the store function will be PassInType.
107 // figured out a way to handle the return value from emptyValue, which is a 114 typedef const T& PassInType;
108 // temporary. 115 static void store(const T& value, T& storage) { storage = value; }
109 typedef T PeekOutType; 116
110 static const T& peek(const T& value) { return value; } 117 // Type for return value of functions that transfer ownership, such as take.
111 }; 118 typedef T PassOutType;
112 119 static const T& passOut(const T& value) { return value; }
113 template <typename T> struct HashTraits : GenericHashTraits<T> { }; 120
114 121 // Type for return value of functions that do not transfer ownership, such
115 template <typename T> struct FloatHashTraits : GenericHashTraits<T> { 122 // as get.
116 static T emptyValue() { return std::numeric_limits<T>::infinity(); } 123 // FIXME: We could change this type to const T& for better performance if we
117 static void constructDeletedValue(T& slot, bool) { slot = -std::numeric_limi ts<T>::infinity(); } 124 // figured out a way to handle the return value from emptyValue, which is a
118 static bool isDeletedValue(T value) { return value == -std::numeric_limits<T >::infinity(); } 125 // temporary.
119 }; 126 typedef T PeekOutType;
120 127 static const T& peek(const T& value) { return value; }
121 template <> struct HashTraits<float> : FloatHashTraits<float> { }; 128 };
122 template <> struct HashTraits<double> : FloatHashTraits<double> { }; 129
130 template <typename T>
131 struct HashTraits : GenericHashTraits<T> {};
132
133 template <typename T>
134 struct FloatHashTraits : GenericHashTraits<T> {
135 static T emptyValue() { return std::numeric_limits<T>::infinity(); }
136 static void constructDeletedValue(T& slot, bool) {
137 slot = -std::numeric_limits<T>::infinity();
138 }
139 static bool isDeletedValue(T value) {
140 return value == -std::numeric_limits<T>::infinity();
141 }
142 };
143
144 template <>
145 struct HashTraits<float> : FloatHashTraits<float> {};
146 template <>
147 struct HashTraits<double> : FloatHashTraits<double> {};
123 148
124 // Default unsigned traits disallow both 0 and max as keys -- use these traits 149 // Default unsigned traits disallow both 0 and max as keys -- use these traits
125 // to allow zero and disallow max - 1. 150 // to allow zero and disallow max - 1.
126 template <typename T> struct UnsignedWithZeroKeyHashTraits : GenericHashTraits<T > { 151 template <typename T>
127 static const bool emptyValueIsZero = false; 152 struct UnsignedWithZeroKeyHashTraits : GenericHashTraits<T> {
128 static T emptyValue() { return std::numeric_limits<T>::max(); } 153 static const bool emptyValueIsZero = false;
129 static void constructDeletedValue(T& slot, bool) { slot = std::numeric_limit s<T>::max() - 1; } 154 static T emptyValue() { return std::numeric_limits<T>::max(); }
130 static bool isDeletedValue(T value) { return value == std::numeric_limits<T> ::max() - 1; } 155 static void constructDeletedValue(T& slot, bool) {
131 }; 156 slot = std::numeric_limits<T>::max() - 1;
132 157 }
133 template <typename P> struct HashTraits<P*> : GenericHashTraits<P*> { 158 static bool isDeletedValue(T value) {
134 static const bool emptyValueIsZero = true; 159 return value == std::numeric_limits<T>::max() - 1;
135 static void constructDeletedValue(P*& slot, bool) { slot = reinterpret_cast< P*>(-1); } 160 }
136 static bool isDeletedValue(P* value) { return value == reinterpret_cast<P*>( -1); } 161 };
137 }; 162
138 163 template <typename P>
139 template <typename T> struct SimpleClassHashTraits : GenericHashTraits<T> { 164 struct HashTraits<P*> : GenericHashTraits<P*> {
140 static const bool emptyValueIsZero = true; 165 static const bool emptyValueIsZero = true;
141 static void constructDeletedValue(T& slot, bool) { new (NotNull, &slot) T(Ha shTableDeletedValue); } 166 static void constructDeletedValue(P*& slot, bool) {
142 static bool isDeletedValue(const T& value) { return value.isHashTableDeleted Value(); } 167 slot = reinterpret_cast<P*>(-1);
143 }; 168 }
144 169 static bool isDeletedValue(P* value) {
145 template <typename P> struct HashTraits<OwnPtr<P>> : SimpleClassHashTraits<OwnPt r<P>> { 170 return value == reinterpret_cast<P*>(-1);
146 typedef std::nullptr_t EmptyValueType; 171 }
147 172 };
148 static EmptyValueType emptyValue() { return nullptr; } 173
149 174 template <typename T>
150 static const bool hasIsEmptyValueFunction = true; 175 struct SimpleClassHashTraits : GenericHashTraits<T> {
151 static bool isEmptyValue(const OwnPtr<P>& value) { return !value; } 176 static const bool emptyValueIsZero = true;
152 177 static void constructDeletedValue(T& slot, bool) {
153 typedef typename OwnPtr<P>::PtrType PeekInType; 178 new (NotNull, &slot) T(HashTableDeletedValue);
154 179 }
155 typedef PassOwnPtr<P> PassInType; 180 static bool isDeletedValue(const T& value) {
156 static void store(PassOwnPtr<P> value, OwnPtr<P>& storage) { storage = value ; } 181 return value.isHashTableDeletedValue();
157 182 }
158 typedef PassOwnPtr<P> PassOutType; 183 };
159 static PassOwnPtr<P> passOut(OwnPtr<P>& value) { return value.release(); } 184
160 static PassOwnPtr<P> passOut(std::nullptr_t) { return nullptr; } 185 template <typename P>
161 186 struct HashTraits<OwnPtr<P>> : SimpleClassHashTraits<OwnPtr<P>> {
162 typedef typename OwnPtr<P>::PtrType PeekOutType; 187 typedef std::nullptr_t EmptyValueType;
163 static PeekOutType peek(const OwnPtr<P>& value) { return value.get(); } 188
164 static PeekOutType peek(std::nullptr_t) { return 0; } 189 static EmptyValueType emptyValue() { return nullptr; }
165 }; 190
166 191 static const bool hasIsEmptyValueFunction = true;
167 template <typename P> struct HashTraits<RefPtr<P>> : SimpleClassHashTraits<RefPt r<P>> { 192 static bool isEmptyValue(const OwnPtr<P>& value) { return !value; }
168 typedef std::nullptr_t EmptyValueType; 193
169 static EmptyValueType emptyValue() { return nullptr; } 194 typedef typename OwnPtr<P>::PtrType PeekInType;
170 195
171 static const bool hasIsEmptyValueFunction = true; 196 typedef PassOwnPtr<P> PassInType;
172 static bool isEmptyValue(const RefPtr<P>& value) { return !value; } 197 static void store(PassOwnPtr<P> value, OwnPtr<P>& storage) {
173 198 storage = value;
174 typedef RefPtrValuePeeker<P> PeekInType; 199 }
175 typedef RefPtr<P>* IteratorGetType; 200
176 typedef const RefPtr<P>* IteratorConstGetType; 201 typedef PassOwnPtr<P> PassOutType;
177 typedef RefPtr<P>& IteratorReferenceType; 202 static PassOwnPtr<P> passOut(OwnPtr<P>& value) { return value.release(); }
178 typedef const RefPtr<P>& IteratorConstReferenceType; 203 static PassOwnPtr<P> passOut(std::nullptr_t) { return nullptr; }
179 static IteratorReferenceType getToReferenceConversion(IteratorGetType x) { r eturn *x; } 204
180 static IteratorConstReferenceType getToReferenceConstConversion(IteratorCons tGetType x) { return *x; } 205 typedef typename OwnPtr<P>::PtrType PeekOutType;
181 206 static PeekOutType peek(const OwnPtr<P>& value) { return value.get(); }
182 typedef PassRefPtr<P> PassInType; 207 static PeekOutType peek(std::nullptr_t) { return 0; }
183 static void store(PassRefPtr<P> value, RefPtr<P>& storage) { storage = value ; } 208 };
184 209
185 typedef PassRefPtr<P> PassOutType; 210 template <typename P>
186 static PassOutType passOut(RefPtr<P>& value) { return value.release(); } 211 struct HashTraits<RefPtr<P>> : SimpleClassHashTraits<RefPtr<P>> {
187 static PassOutType passOut(std::nullptr_t) { return nullptr; } 212 typedef std::nullptr_t EmptyValueType;
188 213 static EmptyValueType emptyValue() { return nullptr; }
189 typedef P* PeekOutType; 214
190 static PeekOutType peek(const RefPtr<P>& value) { return value.get(); } 215 static const bool hasIsEmptyValueFunction = true;
191 static PeekOutType peek(std::nullptr_t) { return 0; } 216 static bool isEmptyValue(const RefPtr<P>& value) { return !value; }
192 }; 217
193 218 typedef RefPtrValuePeeker<P> PeekInType;
194 template <typename T> struct HashTraits<RawPtr<T>> : HashTraits<T*> { }; 219 typedef RefPtr<P>* IteratorGetType;
195 220 typedef const RefPtr<P>* IteratorConstGetType;
196 template <> struct HashTraits<String> : SimpleClassHashTraits<String> { 221 typedef RefPtr<P>& IteratorReferenceType;
197 static const bool hasIsEmptyValueFunction = true; 222 typedef const RefPtr<P>& IteratorConstReferenceType;
198 static bool isEmptyValue(const String&); 223 static IteratorReferenceType getToReferenceConversion(IteratorGetType x) {
224 return *x;
225 }
226 static IteratorConstReferenceType getToReferenceConstConversion(
227 IteratorConstGetType x) {
228 return *x;
229 }
230
231 typedef PassRefPtr<P> PassInType;
232 static void store(PassRefPtr<P> value, RefPtr<P>& storage) {
233 storage = value;
234 }
235
236 typedef PassRefPtr<P> PassOutType;
237 static PassOutType passOut(RefPtr<P>& value) { return value.release(); }
238 static PassOutType passOut(std::nullptr_t) { return nullptr; }
239
240 typedef P* PeekOutType;
241 static PeekOutType peek(const RefPtr<P>& value) { return value.get(); }
242 static PeekOutType peek(std::nullptr_t) { return 0; }
243 };
244
245 template <typename T>
246 struct HashTraits<RawPtr<T>> : HashTraits<T*> {};
247
248 template <>
249 struct HashTraits<String> : SimpleClassHashTraits<String> {
250 static const bool hasIsEmptyValueFunction = true;
251 static bool isEmptyValue(const String&);
199 }; 252 };
200 253
201 // This struct template is an implementation detail of the 254 // This struct template is an implementation detail of the
202 // isHashTraitsEmptyValue function, which selects either the emptyValue function 255 // isHashTraitsEmptyValue function, which selects either the emptyValue function
203 // or the isEmptyValue function to check for empty values. 256 // or the isEmptyValue function to check for empty values.
204 template <typename Traits, bool hasEmptyValueFunction> struct HashTraitsEmptyVal ueChecker; 257 template <typename Traits, bool hasEmptyValueFunction>
205 template <typename Traits> struct HashTraitsEmptyValueChecker<Traits, true> { 258 struct HashTraitsEmptyValueChecker;
206 template <typename T> static bool isEmptyValue(const T& value) { return Trai ts::isEmptyValue(value); } 259 template <typename Traits>
207 }; 260 struct HashTraitsEmptyValueChecker<Traits, true> {
208 template <typename Traits> struct HashTraitsEmptyValueChecker<Traits, false> { 261 template <typename T>
209 template <typename T> static bool isEmptyValue(const T& value) { return valu e == Traits::emptyValue(); } 262 static bool isEmptyValue(const T& value) {
210 }; 263 return Traits::isEmptyValue(value);
211 template <typename Traits, typename T> inline bool isHashTraitsEmptyValue(const T& value) 264 }
212 { 265 };
213 return HashTraitsEmptyValueChecker<Traits, Traits::hasIsEmptyValueFunction>: :isEmptyValue(value); 266 template <typename Traits>
267 struct HashTraitsEmptyValueChecker<Traits, false> {
268 template <typename T>
269 static bool isEmptyValue(const T& value) {
270 return value == Traits::emptyValue();
271 }
272 };
273 template <typename Traits, typename T>
274 inline bool isHashTraitsEmptyValue(const T& value) {
275 return HashTraitsEmptyValueChecker<
276 Traits, Traits::hasIsEmptyValueFunction>::isEmptyValue(value);
214 } 277 }
215 278
216 template <typename FirstTraitsArg, typename SecondTraitsArg> 279 template <typename FirstTraitsArg, typename SecondTraitsArg>
217 struct PairHashTraits : GenericHashTraits<std::pair<typename FirstTraitsArg::Tra itType, typename SecondTraitsArg::TraitType>> { 280 struct PairHashTraits
218 typedef FirstTraitsArg FirstTraits; 281 : GenericHashTraits<std::pair<typename FirstTraitsArg::TraitType,
219 typedef SecondTraitsArg SecondTraits; 282 typename SecondTraitsArg::TraitType>> {
220 typedef std::pair<typename FirstTraits::TraitType, typename SecondTraits::Tr aitType> TraitType; 283 typedef FirstTraitsArg FirstTraits;
221 typedef std::pair<typename FirstTraits::EmptyValueType, typename SecondTrait s::EmptyValueType> EmptyValueType; 284 typedef SecondTraitsArg SecondTraits;
222 285 typedef std::pair<typename FirstTraits::TraitType,
223 static const bool emptyValueIsZero = FirstTraits::emptyValueIsZero && Second Traits::emptyValueIsZero; 286 typename SecondTraits::TraitType>
224 static EmptyValueType emptyValue() { return std::make_pair(FirstTraits::empt yValue(), SecondTraits::emptyValue()); } 287 TraitType;
225 288 typedef std::pair<typename FirstTraits::EmptyValueType,
226 static const unsigned minimumTableSize = FirstTraits::minimumTableSize; 289 typename SecondTraits::EmptyValueType>
227 290 EmptyValueType;
228 static void constructDeletedValue(TraitType& slot, bool zeroValue) 291
229 { 292 static const bool emptyValueIsZero =
230 FirstTraits::constructDeletedValue(slot.first, zeroValue); 293 FirstTraits::emptyValueIsZero && SecondTraits::emptyValueIsZero;
231 // For GC collections the memory for the backing is zeroed when it is 294 static EmptyValueType emptyValue() {
232 // allocated, and the constructors may take advantage of that, 295 return std::make_pair(FirstTraits::emptyValue(),
233 // especially if a GC occurs during insertion of an entry into the 296 SecondTraits::emptyValue());
234 // table. This slot is being marked deleted, but If the slot is reused 297 }
235 // at a later point, the same assumptions around memory zeroing must 298
236 // hold as they did at the initial allocation. Therefore we zero the 299 static const unsigned minimumTableSize = FirstTraits::minimumTableSize;
237 // value part of the slot here for GC collections. 300
238 if (zeroValue) 301 static void constructDeletedValue(TraitType& slot, bool zeroValue) {
239 memset(reinterpret_cast<void*>(&slot.second), 0, sizeof(slot.second) ); 302 FirstTraits::constructDeletedValue(slot.first, zeroValue);
240 } 303 // For GC collections the memory for the backing is zeroed when it is
241 static bool isDeletedValue(const TraitType& value) { return FirstTraits::isD eletedValue(value.first); } 304 // allocated, and the constructors may take advantage of that,
305 // especially if a GC occurs during insertion of an entry into the
306 // table. This slot is being marked deleted, but If the slot is reused
307 // at a later point, the same assumptions around memory zeroing must
308 // hold as they did at the initial allocation. Therefore we zero the
309 // value part of the slot here for GC collections.
310 if (zeroValue)
311 memset(reinterpret_cast<void*>(&slot.second), 0, sizeof(slot.second));
312 }
313 static bool isDeletedValue(const TraitType& value) {
314 return FirstTraits::isDeletedValue(value.first);
315 }
242 }; 316 };
243 317
244 template <typename First, typename Second> 318 template <typename First, typename Second>
245 struct HashTraits<std::pair<First, Second>> : public PairHashTraits<HashTraits<F irst>, HashTraits<Second>> { }; 319 struct HashTraits<std::pair<First, Second>>
320 : public PairHashTraits<HashTraits<First>, HashTraits<Second>> {};
246 321
247 template <typename KeyTypeArg, typename ValueTypeArg> 322 template <typename KeyTypeArg, typename ValueTypeArg>
248 struct KeyValuePair { 323 struct KeyValuePair {
249 typedef KeyTypeArg KeyType; 324 typedef KeyTypeArg KeyType;
250 325
251 KeyValuePair(const KeyTypeArg& _key, const ValueTypeArg& _value) 326 KeyValuePair(const KeyTypeArg& _key, const ValueTypeArg& _value)
252 : key(_key) 327 : key(_key), value(_value) {}
253 , value(_value) 328
254 { 329 template <typename OtherKeyType, typename OtherValueType>
255 } 330 KeyValuePair(const KeyValuePair<OtherKeyType, OtherValueType>& other)
256 331 : key(other.key), value(other.value) {}
257 template <typename OtherKeyType, typename OtherValueType> 332
258 KeyValuePair(const KeyValuePair<OtherKeyType, OtherValueType>& other) 333 KeyTypeArg key;
259 : key(other.key) 334 ValueTypeArg value;
260 , value(other.value)
261 {
262 }
263
264 KeyTypeArg key;
265 ValueTypeArg value;
266 }; 335 };
267 336
268 template <typename KeyTraitsArg, typename ValueTraitsArg> 337 template <typename KeyTraitsArg, typename ValueTraitsArg>
269 struct KeyValuePairHashTraits : GenericHashTraits<KeyValuePair<typename KeyTrait sArg::TraitType, typename ValueTraitsArg::TraitType>> { 338 struct KeyValuePairHashTraits
270 typedef KeyTraitsArg KeyTraits; 339 : GenericHashTraits<KeyValuePair<typename KeyTraitsArg::TraitType,
271 typedef ValueTraitsArg ValueTraits; 340 typename ValueTraitsArg::TraitType>> {
272 typedef KeyValuePair<typename KeyTraits::TraitType, typename ValueTraits::Tr aitType> TraitType; 341 typedef KeyTraitsArg KeyTraits;
273 typedef KeyValuePair<typename KeyTraits::EmptyValueType, typename ValueTrait s::EmptyValueType> EmptyValueType; 342 typedef ValueTraitsArg ValueTraits;
274 343 typedef KeyValuePair<typename KeyTraits::TraitType,
275 static const bool emptyValueIsZero = KeyTraits::emptyValueIsZero && ValueTra its::emptyValueIsZero; 344 typename ValueTraits::TraitType>
276 static EmptyValueType emptyValue() { return KeyValuePair<typename KeyTraits: :EmptyValueType, typename ValueTraits::EmptyValueType>(KeyTraits::emptyValue(), ValueTraits::emptyValue()); } 345 TraitType;
277 346 typedef KeyValuePair<typename KeyTraits::EmptyValueType,
278 template <typename U = void> 347 typename ValueTraits::EmptyValueType>
279 struct NeedsTracingLazily { 348 EmptyValueType;
280 static const bool value = NeedsTracingTrait<KeyTraits>::value || NeedsTr acingTrait<ValueTraits>::value; 349
281 }; 350 static const bool emptyValueIsZero =
282 static const WeakHandlingFlag weakHandlingFlag = (KeyTraits::weakHandlingFla g == WeakHandlingInCollections || ValueTraits::weakHandlingFlag == WeakHandlingI nCollections) ? WeakHandlingInCollections : NoWeakHandlingInCollections; 351 KeyTraits::emptyValueIsZero && ValueTraits::emptyValueIsZero;
283 352 static EmptyValueType emptyValue() {
284 static const unsigned minimumTableSize = KeyTraits::minimumTableSize; 353 return KeyValuePair<typename KeyTraits::EmptyValueType,
285 354 typename ValueTraits::EmptyValueType>(
286 static void constructDeletedValue(TraitType& slot, bool zeroValue) 355 KeyTraits::emptyValue(), ValueTraits::emptyValue());
287 { 356 }
288 KeyTraits::constructDeletedValue(slot.key, zeroValue); 357
289 // See similar code in this file for why we need to do this. 358 template <typename U = void>
290 if (zeroValue) 359 struct NeedsTracingLazily {
291 memset(reinterpret_cast<void*>(&slot.value), 0, sizeof(slot.value)); 360 static const bool value = NeedsTracingTrait<KeyTraits>::value ||
292 } 361 NeedsTracingTrait<ValueTraits>::value;
293 static bool isDeletedValue(const TraitType& value) { return KeyTraits::isDel etedValue(value.key); } 362 };
363 static const WeakHandlingFlag weakHandlingFlag =
364 (KeyTraits::weakHandlingFlag == WeakHandlingInCollections ||
365 ValueTraits::weakHandlingFlag == WeakHandlingInCollections)
366 ? WeakHandlingInCollections
367 : NoWeakHandlingInCollections;
368
369 static const unsigned minimumTableSize = KeyTraits::minimumTableSize;
370
371 static void constructDeletedValue(TraitType& slot, bool zeroValue) {
372 KeyTraits::constructDeletedValue(slot.key, zeroValue);
373 // See similar code in this file for why we need to do this.
374 if (zeroValue)
375 memset(reinterpret_cast<void*>(&slot.value), 0, sizeof(slot.value));
376 }
377 static bool isDeletedValue(const TraitType& value) {
378 return KeyTraits::isDeletedValue(value.key);
379 }
294 }; 380 };
295 381
296 template <typename Key, typename Value> 382 template <typename Key, typename Value>
297 struct HashTraits<KeyValuePair<Key, Value>> : public KeyValuePairHashTraits<Hash Traits<Key>, HashTraits<Value>> { }; 383 struct HashTraits<KeyValuePair<Key, Value>>
384 : public KeyValuePairHashTraits<HashTraits<Key>, HashTraits<Value>> {};
298 385
299 template <typename T> 386 template <typename T>
300 struct NullableHashTraits : public HashTraits<T> { 387 struct NullableHashTraits : public HashTraits<T> {
301 static const bool emptyValueIsZero = false; 388 static const bool emptyValueIsZero = false;
302 static T emptyValue() { return reinterpret_cast<T>(1); } 389 static T emptyValue() { return reinterpret_cast<T>(1); }
303 }; 390 };
304 391
305 // This is for tracing inside collections that have special support for weak 392 // This is for tracing inside collections that have special support for weak
306 // pointers. The trait has a trace method which returns true if there are weak 393 // pointers. The trait has a trace method which returns true if there are weak
307 // pointers to things that have not (yet) been marked live. Returning true 394 // pointers to things that have not (yet) been marked live. Returning true
308 // indicates that the entry in the collection may yet be removed by weak 395 // indicates that the entry in the collection may yet be removed by weak
309 // handling. Default implementation for non-weak types is to use the regular 396 // handling. Default implementation for non-weak types is to use the regular
310 // non-weak TraceTrait. Default implementation for types with weakness is to 397 // non-weak TraceTrait. Default implementation for types with weakness is to
311 // call traceInCollection on the type's trait. 398 // call traceInCollection on the type's trait.
312 template <WeakHandlingFlag weakHandlingFlag, ShouldWeakPointersBeMarkedStrongly strongify, typename T, typename Traits> 399 template <WeakHandlingFlag weakHandlingFlag,
400 ShouldWeakPointersBeMarkedStrongly strongify,
401 typename T,
402 typename Traits>
313 struct TraceInCollectionTrait; 403 struct TraceInCollectionTrait;
314 404
315 } // namespace WTF 405 } // namespace WTF
316 406
317 using WTF::HashTraits; 407 using WTF::HashTraits;
318 using WTF::PairHashTraits; 408 using WTF::PairHashTraits;
319 using WTF::NullableHashTraits; 409 using WTF::NullableHashTraits;
320 using WTF::SimpleClassHashTraits; 410 using WTF::SimpleClassHashTraits;
321 411
322 #endif // WTF_HashTraits_h 412 #endif // WTF_HashTraits_h
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