Wed, 31 Dec 2014 06:09:35 +0100
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
michael@0 | 1 | /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- |
michael@0 | 2 | * This Source Code Form is subject to the terms of the Mozilla Public |
michael@0 | 3 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
michael@0 | 4 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
michael@0 | 5 | |
michael@0 | 6 | #ifndef FRAMEPROPERTYTABLE_H_ |
michael@0 | 7 | #define FRAMEPROPERTYTABLE_H_ |
michael@0 | 8 | |
michael@0 | 9 | #include "mozilla/MemoryReporting.h" |
michael@0 | 10 | #include "nsTArray.h" |
michael@0 | 11 | #include "nsTHashtable.h" |
michael@0 | 12 | #include "nsHashKeys.h" |
michael@0 | 13 | |
michael@0 | 14 | class nsIFrame; |
michael@0 | 15 | |
michael@0 | 16 | namespace mozilla { |
michael@0 | 17 | |
michael@0 | 18 | struct FramePropertyDescriptor; |
michael@0 | 19 | |
michael@0 | 20 | typedef void (*FramePropertyDestructor)(void* aPropertyValue); |
michael@0 | 21 | typedef void (*FramePropertyDestructorWithFrame)(nsIFrame* aFrame, |
michael@0 | 22 | void* aPropertyValue); |
michael@0 | 23 | |
michael@0 | 24 | /** |
michael@0 | 25 | * A pointer to a FramePropertyDescriptor serves as a unique property ID. |
michael@0 | 26 | * The FramePropertyDescriptor stores metadata about the property. |
michael@0 | 27 | * Currently the only metadata is a destructor function. The destructor |
michael@0 | 28 | * function is called on property values when they are overwritten or |
michael@0 | 29 | * deleted. |
michael@0 | 30 | * |
michael@0 | 31 | * To use this class, declare a global (i.e., file, class or function-scope |
michael@0 | 32 | * static member) FramePropertyDescriptor and pass its address as |
michael@0 | 33 | * aProperty in the FramePropertyTable methods. |
michael@0 | 34 | */ |
michael@0 | 35 | struct FramePropertyDescriptor { |
michael@0 | 36 | /** |
michael@0 | 37 | * mDestructor will be called if it's non-null. |
michael@0 | 38 | */ |
michael@0 | 39 | FramePropertyDestructor mDestructor; |
michael@0 | 40 | /** |
michael@0 | 41 | * mDestructorWithFrame will be called if it's non-null and mDestructor |
michael@0 | 42 | * is null. WARNING: The frame passed to mDestructorWithFrame may |
michael@0 | 43 | * be a dangling frame pointer, if this is being called during |
michael@0 | 44 | * presshell teardown. Do not use it except to compare against |
michael@0 | 45 | * other frame pointers. No frame will have been allocated with |
michael@0 | 46 | * the same address yet. |
michael@0 | 47 | */ |
michael@0 | 48 | FramePropertyDestructorWithFrame mDestructorWithFrame; |
michael@0 | 49 | /** |
michael@0 | 50 | * mDestructor and mDestructorWithFrame may both be null, in which case |
michael@0 | 51 | * no value destruction is a no-op. |
michael@0 | 52 | */ |
michael@0 | 53 | }; |
michael@0 | 54 | |
michael@0 | 55 | /** |
michael@0 | 56 | * The FramePropertyTable is optimized for storing 0 or 1 properties on |
michael@0 | 57 | * a given frame. Storing very large numbers of properties on a single |
michael@0 | 58 | * frame will not be efficient. |
michael@0 | 59 | * |
michael@0 | 60 | * Property values are passed as void* but do not actually have to be |
michael@0 | 61 | * valid pointers. You can use NS_INT32_TO_PTR/NS_PTR_TO_INT32 to |
michael@0 | 62 | * store int32_t values. Null/zero values can be stored and retrieved. |
michael@0 | 63 | * Of course, the destructor function (if any) must handle such values |
michael@0 | 64 | * correctly. |
michael@0 | 65 | */ |
michael@0 | 66 | class FramePropertyTable { |
michael@0 | 67 | public: |
michael@0 | 68 | FramePropertyTable() : mLastFrame(nullptr), mLastEntry(nullptr) |
michael@0 | 69 | { |
michael@0 | 70 | } |
michael@0 | 71 | ~FramePropertyTable() |
michael@0 | 72 | { |
michael@0 | 73 | DeleteAll(); |
michael@0 | 74 | } |
michael@0 | 75 | |
michael@0 | 76 | /** |
michael@0 | 77 | * Set a property value on a frame. This requires one hashtable |
michael@0 | 78 | * lookup (using the frame as the key) and a linear search through |
michael@0 | 79 | * the properties of that frame. Any existing value for the property |
michael@0 | 80 | * is destroyed. |
michael@0 | 81 | */ |
michael@0 | 82 | void Set(nsIFrame* aFrame, const FramePropertyDescriptor* aProperty, |
michael@0 | 83 | void* aValue); |
michael@0 | 84 | /** |
michael@0 | 85 | * Get a property value for a frame. This requires one hashtable |
michael@0 | 86 | * lookup (using the frame as the key) and a linear search through |
michael@0 | 87 | * the properties of that frame. If the frame has no such property, |
michael@0 | 88 | * returns null. |
michael@0 | 89 | * @param aFoundResult if non-null, receives a value 'true' iff |
michael@0 | 90 | * the frame has a value for the property. This lets callers |
michael@0 | 91 | * disambiguate a null result, which can mean 'no such property' or |
michael@0 | 92 | * 'property value is null'. |
michael@0 | 93 | */ |
michael@0 | 94 | void* Get(const nsIFrame* aFrame, const FramePropertyDescriptor* aProperty, |
michael@0 | 95 | bool* aFoundResult = nullptr); |
michael@0 | 96 | /** |
michael@0 | 97 | * Remove a property value for a frame. This requires one hashtable |
michael@0 | 98 | * lookup (using the frame as the key) and a linear search through |
michael@0 | 99 | * the properties of that frame. The old property value is returned |
michael@0 | 100 | * (and not destroyed). If the frame has no such property, |
michael@0 | 101 | * returns null. |
michael@0 | 102 | * @param aFoundResult if non-null, receives a value 'true' iff |
michael@0 | 103 | * the frame had a value for the property. This lets callers |
michael@0 | 104 | * disambiguate a null result, which can mean 'no such property' or |
michael@0 | 105 | * 'property value is null'. |
michael@0 | 106 | */ |
michael@0 | 107 | void* Remove(nsIFrame* aFrame, const FramePropertyDescriptor* aProperty, |
michael@0 | 108 | bool* aFoundResult = nullptr); |
michael@0 | 109 | /** |
michael@0 | 110 | * Remove and destroy a property value for a frame. This requires one |
michael@0 | 111 | * hashtable lookup (using the frame as the key) and a linear search |
michael@0 | 112 | * through the properties of that frame. If the frame has no such |
michael@0 | 113 | * property, nothing happens. |
michael@0 | 114 | */ |
michael@0 | 115 | void Delete(nsIFrame* aFrame, const FramePropertyDescriptor* aProperty); |
michael@0 | 116 | /** |
michael@0 | 117 | * Remove and destroy all property values for a frame. This requires one |
michael@0 | 118 | * hashtable lookup (using the frame as the key). |
michael@0 | 119 | */ |
michael@0 | 120 | void DeleteAllFor(nsIFrame* aFrame); |
michael@0 | 121 | /** |
michael@0 | 122 | * Remove and destroy all property values for all frames. |
michael@0 | 123 | */ |
michael@0 | 124 | void DeleteAll(); |
michael@0 | 125 | |
michael@0 | 126 | size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const; |
michael@0 | 127 | |
michael@0 | 128 | protected: |
michael@0 | 129 | /** |
michael@0 | 130 | * Stores a property descriptor/value pair. It can also be used to |
michael@0 | 131 | * store an nsTArray of PropertyValues. |
michael@0 | 132 | */ |
michael@0 | 133 | struct PropertyValue { |
michael@0 | 134 | PropertyValue() : mProperty(nullptr), mValue(nullptr) {} |
michael@0 | 135 | PropertyValue(const FramePropertyDescriptor* aProperty, void* aValue) |
michael@0 | 136 | : mProperty(aProperty), mValue(aValue) {} |
michael@0 | 137 | |
michael@0 | 138 | bool IsArray() { return !mProperty && mValue; } |
michael@0 | 139 | nsTArray<PropertyValue>* ToArray() |
michael@0 | 140 | { |
michael@0 | 141 | NS_ASSERTION(IsArray(), "Must be array"); |
michael@0 | 142 | return reinterpret_cast<nsTArray<PropertyValue>*>(&mValue); |
michael@0 | 143 | } |
michael@0 | 144 | |
michael@0 | 145 | void DestroyValueFor(nsIFrame* aFrame) { |
michael@0 | 146 | if (mProperty->mDestructor) { |
michael@0 | 147 | mProperty->mDestructor(mValue); |
michael@0 | 148 | } else if (mProperty->mDestructorWithFrame) { |
michael@0 | 149 | mProperty->mDestructorWithFrame(aFrame, mValue); |
michael@0 | 150 | } |
michael@0 | 151 | } |
michael@0 | 152 | |
michael@0 | 153 | size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) { |
michael@0 | 154 | size_t n = 0; |
michael@0 | 155 | // We don't need to measure mProperty because it always points to static |
michael@0 | 156 | // memory. As for mValue: if it's a single value we can't measure it, |
michael@0 | 157 | // because the type is opaque; if it's an array, we measure the array |
michael@0 | 158 | // storage, but we can't measure the individual values, again because |
michael@0 | 159 | // their types are opaque. |
michael@0 | 160 | if (IsArray()) { |
michael@0 | 161 | nsTArray<PropertyValue>* array = ToArray(); |
michael@0 | 162 | n += array->SizeOfExcludingThis(aMallocSizeOf); |
michael@0 | 163 | } |
michael@0 | 164 | return n; |
michael@0 | 165 | } |
michael@0 | 166 | |
michael@0 | 167 | const FramePropertyDescriptor* mProperty; |
michael@0 | 168 | void* mValue; |
michael@0 | 169 | }; |
michael@0 | 170 | |
michael@0 | 171 | /** |
michael@0 | 172 | * Used with an array of PropertyValues to allow lookups that compare |
michael@0 | 173 | * only on the FramePropertyDescriptor. |
michael@0 | 174 | */ |
michael@0 | 175 | class PropertyComparator { |
michael@0 | 176 | public: |
michael@0 | 177 | bool Equals(const PropertyValue& a, const PropertyValue& b) const { |
michael@0 | 178 | return a.mProperty == b.mProperty; |
michael@0 | 179 | } |
michael@0 | 180 | bool Equals(const FramePropertyDescriptor* a, const PropertyValue& b) const { |
michael@0 | 181 | return a == b.mProperty; |
michael@0 | 182 | } |
michael@0 | 183 | bool Equals(const PropertyValue& a, const FramePropertyDescriptor* b) const { |
michael@0 | 184 | return a.mProperty == b; |
michael@0 | 185 | } |
michael@0 | 186 | }; |
michael@0 | 187 | |
michael@0 | 188 | /** |
michael@0 | 189 | * Our hashtable entry. The key is an nsIFrame*, the value is a |
michael@0 | 190 | * PropertyValue representing one or more property/value pairs. |
michael@0 | 191 | */ |
michael@0 | 192 | class Entry : public nsPtrHashKey<nsIFrame> |
michael@0 | 193 | { |
michael@0 | 194 | public: |
michael@0 | 195 | Entry(KeyTypePointer aKey) : nsPtrHashKey<nsIFrame>(aKey) {} |
michael@0 | 196 | Entry(const Entry &toCopy) : |
michael@0 | 197 | nsPtrHashKey<nsIFrame>(toCopy), mProp(toCopy.mProp) {} |
michael@0 | 198 | |
michael@0 | 199 | PropertyValue mProp; |
michael@0 | 200 | }; |
michael@0 | 201 | |
michael@0 | 202 | static void DeleteAllForEntry(Entry* aEntry); |
michael@0 | 203 | static PLDHashOperator DeleteEnumerator(Entry* aEntry, void* aArg); |
michael@0 | 204 | |
michael@0 | 205 | static size_t SizeOfPropertyTableEntryExcludingThis(Entry* aEntry, |
michael@0 | 206 | mozilla::MallocSizeOf aMallocSizeOf, void *); |
michael@0 | 207 | |
michael@0 | 208 | nsTHashtable<Entry> mEntries; |
michael@0 | 209 | nsIFrame* mLastFrame; |
michael@0 | 210 | Entry* mLastEntry; |
michael@0 | 211 | }; |
michael@0 | 212 | |
michael@0 | 213 | /** |
michael@0 | 214 | * This class encapsulates the properties of a frame. |
michael@0 | 215 | */ |
michael@0 | 216 | class FrameProperties { |
michael@0 | 217 | public: |
michael@0 | 218 | FrameProperties(FramePropertyTable* aTable, nsIFrame* aFrame) |
michael@0 | 219 | : mTable(aTable), mFrame(aFrame) {} |
michael@0 | 220 | FrameProperties(FramePropertyTable* aTable, const nsIFrame* aFrame) |
michael@0 | 221 | : mTable(aTable), mFrame(const_cast<nsIFrame*>(aFrame)) {} |
michael@0 | 222 | |
michael@0 | 223 | void Set(const FramePropertyDescriptor* aProperty, void* aValue) const |
michael@0 | 224 | { |
michael@0 | 225 | mTable->Set(mFrame, aProperty, aValue); |
michael@0 | 226 | } |
michael@0 | 227 | void* Get(const FramePropertyDescriptor* aProperty, |
michael@0 | 228 | bool* aFoundResult = nullptr) const |
michael@0 | 229 | { |
michael@0 | 230 | return mTable->Get(mFrame, aProperty, aFoundResult); |
michael@0 | 231 | } |
michael@0 | 232 | void* Remove(const FramePropertyDescriptor* aProperty, |
michael@0 | 233 | bool* aFoundResult = nullptr) const |
michael@0 | 234 | { |
michael@0 | 235 | return mTable->Remove(mFrame, aProperty, aFoundResult); |
michael@0 | 236 | } |
michael@0 | 237 | void Delete(const FramePropertyDescriptor* aProperty) |
michael@0 | 238 | { |
michael@0 | 239 | mTable->Delete(mFrame, aProperty); |
michael@0 | 240 | } |
michael@0 | 241 | |
michael@0 | 242 | private: |
michael@0 | 243 | FramePropertyTable* mTable; |
michael@0 | 244 | nsIFrame* mFrame; |
michael@0 | 245 | }; |
michael@0 | 246 | |
michael@0 | 247 | } |
michael@0 | 248 | |
michael@0 | 249 | #endif /* FRAMEPROPERTYTABLE_H_ */ |