netwerk/sctp/src/LocalArray.h@ac0c01689b40 (annotated)
netwerk/sctp/src/LocalArray.h
Thu, 15 Jan 2015 15:59:08 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 15 Jan 2015 15:59:08 +0100
- branch
- TOR_BUG_9701
- changeset 10
- ac0c01689b40
- permissions
- -rw-r--r--
Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
| michael@0 | 1 | /* |
| michael@0 | 2 | * Copyright (C) 2009 The Android Open Source Project |
| michael@0 | 3 | * |
| michael@0 | 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| michael@0 | 5 | * you may not use this file except in compliance with the License. |
| michael@0 | 6 | * You may obtain a copy of the License at |
| michael@0 | 7 | * |
| michael@0 | 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| michael@0 | 9 | * |
| michael@0 | 10 | * Unless required by applicable law or agreed to in writing, software |
| michael@0 | 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| michael@0 | 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| michael@0 | 13 | * See the License for the specific language governing permissions and |
| michael@0 | 14 | * limitations under the License. |
| michael@0 | 15 | */ |
| michael@0 | 16 | |
| michael@0 | 17 | #ifndef LOCAL_ARRAY_H_included |
| michael@0 | 18 | #define LOCAL_ARRAY_H_included |
| michael@0 | 19 | |
| michael@0 | 20 | #include <cstddef> |
| michael@0 | 21 | #include <new> |
| michael@0 | 22 | |
| michael@0 | 23 | /** |
| michael@0 | 24 | * A fixed-size array with a size hint. That number of bytes will be allocated |
| michael@0 | 25 | * on the stack, and used if possible, but if more bytes are requested at |
| michael@0 | 26 | * construction time, a buffer will be allocated on the heap (and deallocated |
| michael@0 | 27 | * by the destructor). |
| michael@0 | 28 | * |
| michael@0 | 29 | * The API is intended to be a compatible subset of C++0x's std::array. |
| michael@0 | 30 | */ |
| michael@0 | 31 | template <size_t STACK_BYTE_COUNT> |
| michael@0 | 32 | class LocalArray { |
| michael@0 | 33 | public: |
| michael@0 | 34 | /** |
| michael@0 | 35 | * Allocates a new fixed-size array of the given size. If this size is |
| michael@0 | 36 | * less than or equal to the template parameter STACK_BYTE_COUNT, an |
| michael@0 | 37 | * internal on-stack buffer will be used. Otherwise a heap buffer will |
| michael@0 | 38 | * be allocated. |
| michael@0 | 39 | */ |
| michael@0 | 40 | LocalArray(size_t desiredByteCount) : mSize(desiredByteCount) { |
| michael@0 | 41 | if (desiredByteCount > STACK_BYTE_COUNT) { |
| michael@0 | 42 | mPtr = new char[mSize]; |
| michael@0 | 43 | } else { |
| michael@0 | 44 | mPtr = &mOnStackBuffer[0]; |
| michael@0 | 45 | } |
| michael@0 | 46 | } |
| michael@0 | 47 | |
| michael@0 | 48 | /** |
| michael@0 | 49 | * Frees the heap-allocated buffer, if there was one. |
| michael@0 | 50 | */ |
| michael@0 | 51 | ~LocalArray() { |
| michael@0 | 52 | if (mPtr != &mOnStackBuffer[0]) { |
| michael@0 | 53 | delete[] mPtr; |
| michael@0 | 54 | } |
| michael@0 | 55 | } |
| michael@0 | 56 | |
| michael@0 | 57 | // Capacity. |
| michael@0 | 58 | size_t size() { return mSize; } |
| michael@0 | 59 | bool empty() { return mSize == 0; } |
| michael@0 | 60 | |
| michael@0 | 61 | // Element access. |
| michael@0 | 62 | char& operator[](size_t n) { return mPtr[n]; } |
| michael@0 | 63 | const char& operator[](size_t n) const { return mPtr[n]; } |
| michael@0 | 64 | |
| michael@0 | 65 | private: |
| michael@0 | 66 | char mOnStackBuffer[STACK_BYTE_COUNT]; |
| michael@0 | 67 | char* mPtr; |
| michael@0 | 68 | size_t mSize; |
| michael@0 | 69 | |
| michael@0 | 70 | // Disallow copy and assignment. |
| michael@0 | 71 | LocalArray(const LocalArray&); |
| michael@0 | 72 | void operator=(const LocalArray&); |
| michael@0 | 73 | }; |
| michael@0 | 74 | |
| michael@0 | 75 | #endif // LOCAL_ARRAY_H_included |
