1 /* 2 * Copyright 2008 The Android Open Source Project 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 9 #ifndef SkPtrSet_DEFINED 10 #define SkPtrSet_DEFINED 11 12 #include "include/core/SkFlattenable.h" 13 #include "include/core/SkRefCnt.h" 14 #include "include/private/base/SkTDArray.h" 15 16 /** 17 * Maintains a set of ptrs, assigning each a unique ID [1...N]. Duplicate ptrs 18 * return the same ID (since its a set). Subclasses can override inPtr() 19 * and decPtr(). incPtr() is called each time a unique ptr is added ot the 20 * set. decPtr() is called on each ptr when the set is destroyed or reset. 21 */ 22 class SkPtrSet : public SkRefCnt { 23 public: 24 25 26 /** 27 * Search for the specified ptr in the set. If it is found, return its 28 * 32bit ID [1..N], or if not found, return 0. Always returns 0 for nullptr. 29 */ 30 uint32_t find(void*) const; 31 32 /** 33 * Add the specified ptr to the set, returning a unique 32bit ID for it 34 * [1...N]. Duplicate ptrs will return the same ID. 35 * 36 * If the ptr is nullptr, it is not added, and 0 is returned. 37 */ 38 uint32_t add(void*); 39 40 /** 41 * Return the number of (non-null) ptrs in the set. 42 */ count()43 int count() const { return fList.size(); } 44 45 /** 46 * Copy the ptrs in the set into the specified array (allocated by the 47 * caller). The ptrs are assgined to the array based on their corresponding 48 * ID. e.g. array[ptr.ID - 1] = ptr. 49 * 50 * incPtr() and decPtr() are not called during this operation. 51 */ 52 void copyToArray(void* array[]) const; 53 54 /** 55 * Call decPtr() on each ptr in the set, and the reset the size of the set 56 * to 0. 57 */ 58 void reset(); 59 60 /** 61 * Set iterator. 62 */ 63 class Iter { 64 public: Iter(const SkPtrSet & set)65 Iter(const SkPtrSet& set) 66 : fSet(set) 67 , fIndex(0) {} 68 69 /** 70 * Return the next ptr in the set or null if the end was reached. 71 */ next()72 void* next() { 73 return fIndex < fSet.fList.size() ? fSet.fList[fIndex++].fPtr : nullptr; 74 } 75 76 private: 77 const SkPtrSet& fSet; 78 int fIndex; 79 }; 80 81 protected: incPtr(void *)82 virtual void incPtr(void*) {} decPtr(void *)83 virtual void decPtr(void*) {} 84 85 private: 86 struct Pair { 87 void* fPtr; // never nullptr 88 uint32_t fIndex; // 1...N 89 }; 90 91 // we store the ptrs in sorted-order (using Cmp) so that we can efficiently 92 // detect duplicates when add() is called. Hence we need to store the 93 // ptr and its ID/fIndex explicitly, since the ptr's position in the array 94 // is not related to its "index". 95 SkTDArray<Pair> fList; 96 97 static bool Less(const Pair& a, const Pair& b); 98 99 using INHERITED = SkRefCnt; 100 }; 101 102 /** 103 * Templated wrapper for SkPtrSet, just meant to automate typecasting 104 * parameters to and from void* (which the base class expects). 105 */ 106 template <typename T> class SkTPtrSet : public SkPtrSet { 107 public: find(T ptr)108 uint32_t find(T ptr) { 109 return this->INHERITED::find((void*)ptr); 110 } add(T ptr)111 uint32_t add(T ptr) { 112 return this->INHERITED::add((void*)ptr); 113 } 114 copyToArray(T * array)115 void copyToArray(T* array) const { 116 this->INHERITED::copyToArray((void**)array); 117 } 118 119 private: 120 using INHERITED = SkPtrSet; 121 }; 122 123 /** 124 * Subclass of SkTPtrSet specialed to call ref() and unref() when the 125 * base class's incPtr() and decPtr() are called. This makes it a valid owner 126 * of each ptr, which is released when the set is reset or destroyed. 127 */ 128 class SkRefCntSet : public SkTPtrSet<SkRefCnt*> { 129 public: 130 ~SkRefCntSet() override; 131 132 protected: 133 // overrides 134 void incPtr(void*) override; 135 void decPtr(void*) override; 136 }; 137 138 class SkFactorySet : public SkTPtrSet<SkFlattenable::Factory> {}; 139 140 /** 141 * Similar to SkFactorySet, but only allows Factorys that have registered names. 142 * Also has a function to return the next added Factory's name. 143 */ 144 class SkNamedFactorySet : public SkRefCnt { 145 public: 146 147 148 SkNamedFactorySet(); 149 150 /** 151 * Find the specified Factory in the set. If it is not already in the set, 152 * and has registered its name, add it to the set, and return its index. 153 * If the Factory has no registered name, return 0. 154 */ 155 uint32_t find(SkFlattenable::Factory); 156 157 /** 158 * If new Factorys have been added to the set, return the name of the first 159 * Factory added after the Factory name returned by the last call to this 160 * function. 161 */ 162 const char* getNextAddedFactoryName(); 163 private: 164 int fNextAddedFactory; 165 SkFactorySet fFactorySet; 166 SkTDArray<const char*> fNames; 167 168 using INHERITED = SkRefCnt; 169 }; 170 171 #endif 172