1 2 /* 3 * Copyright 2008 The Android Open Source Project 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 10 #ifndef SkPtrSet_DEFINED 11 #define SkPtrSet_DEFINED 12 13 #include "SkRefCnt.h" 14 #include "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 * Search for the specified ptr in the set. If it is found, return its 26 * 32bit ID [1..N], or if not found, return 0. Always returns 0 for NULL. 27 */ 28 uint32_t find(void*) const; 29 30 /** 31 * Add the specified ptr to the set, returning a unique 32bit ID for it 32 * [1...N]. Duplicate ptrs will return the same ID. 33 * 34 * If the ptr is NULL, it is not added, and 0 is returned. 35 */ 36 uint32_t add(void*); 37 38 /** 39 * Return the number of (non-null) ptrs in the set. 40 */ count()41 int count() const { return fList.count(); } 42 43 /** 44 * Copy the ptrs in the set into the specified array (allocated by the 45 * caller). The ptrs are assgined to the array based on their corresponding 46 * ID. e.g. array[ptr.ID - 1] = ptr. 47 * 48 * incPtr() and decPtr() are not called during this operation. 49 */ 50 void copyToArray(void* array[]) const; 51 52 /** 53 * Call decPtr() on each ptr in the set, and the reset the size of the set 54 * to 0. 55 */ 56 void reset(); 57 58 protected: incPtr(void * ptr)59 virtual void incPtr(void* ptr) {} decPtr(void * ptr)60 virtual void decPtr(void* ptr) {} 61 62 private: 63 struct Pair { 64 void* fPtr; // never NULL 65 uint32_t fIndex; // 1...N 66 }; 67 68 // we store the ptrs in sorted-order (using Cmp) so that we can efficiently 69 // detect duplicates when add() is called. Hence we need to store the 70 // ptr and its ID/fIndex explicitly, since the ptr's position in the array 71 // is not related to its "index". 72 SkTDArray<Pair> fList; 73 74 static int Cmp(const Pair& a, const Pair& b); 75 76 typedef SkRefCnt INHERITED; 77 }; 78 79 /** 80 * Templated wrapper for SkPtrSet, just meant to automate typecasting 81 * parameters to and from void* (which the base class expects). 82 */ 83 template <typename T> class SkTPtrSet : public SkPtrSet { 84 public: find(T ptr)85 uint32_t find(T ptr) { 86 return this->INHERITED::find((void*)ptr); 87 } add(T ptr)88 uint32_t add(T ptr) { 89 return this->INHERITED::add((void*)ptr); 90 } 91 copyToArray(T * array)92 void copyToArray(T* array) const { 93 this->INHERITED::copyToArray((void**)array); 94 } 95 96 private: 97 typedef SkPtrSet INHERITED; 98 }; 99 100 #endif 101