Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 1 | // Copyright 2011 the V8 project authors. All rights reserved. |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 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, |
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| 22 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 26 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 28 | #ifndef V8_SMART_ARRAY_POINTER_H_ |
| 29 | #define V8_SMART_ARRAY_POINTER_H_ |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 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> |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 38 | class SmartArrayPointer { |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 39 | public: |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 40 | // Default constructor. Constructs an empty scoped pointer. |
| 41 | inline SmartArrayPointer() : p_(NULL) {} |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 42 | |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 43 | // Constructs a scoped pointer from a plain one. |
| 44 | explicit inline SmartArrayPointer(T* ptr) : p_(ptr) {} |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 45 | |
| 46 | // Copy constructor removes the pointer from the original to avoid double |
| 47 | // freeing. |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 48 | inline SmartArrayPointer(const SmartArrayPointer<T>& rhs) : p_(rhs.p_) { |
| 49 | const_cast<SmartArrayPointer<T>&>(rhs).p_ = NULL; |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 50 | } |
| 51 | |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 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. |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 55 | inline ~SmartArrayPointer() { if (p_) DeleteArray(p_); } |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 56 | |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 57 | inline T* operator->() const { return p_; } |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 58 | |
| 59 | // You can get the underlying pointer out with the * operator. |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 60 | inline T* operator*() { return p_; } |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 61 | |
| 62 | // You can use [n] to index as if it was a plain pointer |
| 63 | inline T& operator[](size_t i) { |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 64 | return p_[i]; |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 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 |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 69 | // returning an SmartArrayPointer<T> and then get errors wherever it is used. |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 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() { |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 76 | T* temp = p_; |
| 77 | p_ = NULL; |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 78 | return temp; |
| 79 | } |
| 80 | |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 81 | // Assignment requires an empty (NULL) SmartArrayPointer as the receiver. Like |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 82 | // the copy constructor it removes the pointer in the original to avoid |
| 83 | // double freeing. |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 84 | inline SmartArrayPointer& operator=(const SmartArrayPointer<T>& rhs) { |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 85 | ASSERT(is_empty()); |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 86 | T* tmp = rhs.p_; // swap to handle self-assignment |
| 87 | const_cast<SmartArrayPointer<T>&>(rhs).p_ = NULL; |
| 88 | p_ = tmp; |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 89 | return *this; |
| 90 | } |
| 91 | |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 92 | inline bool is_empty() { return p_ == NULL; } |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 93 | |
| 94 | private: |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 95 | T* p_; |
Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 96 | }; |
| 97 | |
| 98 | } } // namespace v8::internal |
| 99 | |
Ben Murdoch | 589d697 | 2011-11-30 16:04:58 +0000 | [diff] [blame] | 100 | #endif // V8_SMART_ARRAY_POINTER_H_ |