1 // Copyright 2011 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28 #ifndef V8_SMART_ARRAY_POINTER_H_ 29 #define V8_SMART_ARRAY_POINTER_H_ 30 31 namespace v8 { 32 namespace internal { 33 34 35 // A 'scoped array pointer' that calls DeleteArray on its pointer when the 36 // destructor is called. 37 template<typename T> 38 class SmartArrayPointer { 39 public: 40 // Default constructor. Constructs an empty scoped pointer. 41 inline SmartArrayPointer() : p_(NULL) {} 42 43 // Constructs a scoped pointer from a plain one. 44 explicit inline SmartArrayPointer(T* ptr) : p_(ptr) {} 45 46 // Copy constructor removes the pointer from the original to avoid double 47 // freeing. 48 inline SmartArrayPointer(const SmartArrayPointer<T>& rhs) : p_(rhs.p_) { 49 const_cast<SmartArrayPointer<T>&>(rhs).p_ = NULL; 50 } 51 52 // When the destructor of the scoped pointer is executed the plain pointer 53 // is deleted using DeleteArray. This implies that you must allocate with 54 // NewArray. 55 inline ~SmartArrayPointer() { if (p_) DeleteArray(p_); } 56 57 inline T* operator->() const { return p_; } 58 59 // You can get the underlying pointer out with the * operator. 60 inline T* operator*() { return p_; } 61 62 // You can use [n] to index as if it was a plain pointer 63 inline T& operator[](size_t i) { 64 return p_[i]; 65 } 66 67 // We don't have implicit conversion to a T* since that hinders migration: 68 // You would not be able to change a method from returning a T* to 69 // returning an SmartArrayPointer<T> and then get errors wherever it is used. 70 71 72 // If you want to take out the plain pointer and don't want it automatically 73 // deleted then call Detach(). Afterwards, the smart pointer is empty 74 // (NULL). 75 inline T* Detach() { 76 T* temp = p_; 77 p_ = NULL; 78 return temp; 79 } 80 81 // Assignment requires an empty (NULL) SmartArrayPointer as the receiver. Like 82 // the copy constructor it removes the pointer in the original to avoid 83 // double freeing. 84 inline SmartArrayPointer& operator=(const SmartArrayPointer<T>& rhs) { 85 ASSERT(is_empty()); 86 T* tmp = rhs.p_; // swap to handle self-assignment 87 const_cast<SmartArrayPointer<T>&>(rhs).p_ = NULL; 88 p_ = tmp; 89 return *this; 90 } 91 92 inline bool is_empty() { return p_ == NULL; } 93 94 private: 95 T* p_; 96 }; 97 98 } } // namespace v8::internal 99 100 #endif // V8_SMART_ARRAY_POINTER_H_ 101
