tor-browser

The Tor Browser
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txStack.h (2415B)

      1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* This Source Code Form is subject to the terms of the Mozilla Public
      3 * License, v. 2.0. If a copy of the MPL was not distributed with this
      4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      5 
      6 #ifndef txStack_h___
      7 #define txStack_h___
      8 
      9 #include "nsTArray.h"
     10 
     11 class txStack : private nsTArray<void*> {
     12 public:
     13  /**
     14   * Returns the specified object from the top of this stack,
     15   * without removing it from the stack.
     16   *
     17   * @return a pointer to the object that is the top of this stack.
     18   */
     19  inline void* peek() {
     20    NS_ASSERTION(!isEmpty(), "peeking at empty stack");
     21    return !isEmpty() ? ElementAt(Length() - 1) : nullptr;
     22  }
     23 
     24  /**
     25   * Adds the specified object to the top of this stack.
     26   *
     27   * @param obj a pointer to the object that is to be added to the
     28   * top of this stack.
     29   */
     30  inline void push(void* aObject) { AppendElement(aObject); }
     31 
     32  /**
     33   * Removes and returns the specified object from the top of this
     34   * stack.
     35   *
     36   * @return a pointer to the object that was the top of this stack.
     37   */
     38  inline void* pop() {
     39    void* object = nullptr;
     40    NS_ASSERTION(!isEmpty(), "popping from empty stack");
     41    if (!isEmpty()) {
     42      object = PopLastElement();
     43    }
     44    return object;
     45  }
     46 
     47  /**
     48   * Returns true if there are no objects in the stack.
     49   *
     50   * @return true if there are no objects in the stack.
     51   */
     52  inline bool isEmpty() { return IsEmpty(); }
     53 
     54  /**
     55   * Returns the number of elements in the Stack.
     56   *
     57   * @return the number of elements in the Stack.
     58   */
     59  inline int32_t size() { return Length(); }
     60 
     61 private:
     62  friend class txStackIterator;
     63 };
     64 
     65 class txStackIterator {
     66 public:
     67  /**
     68   * Creates an iterator for the given stack.
     69   *
     70   * @param aStack the stack to create an iterator for.
     71   */
     72  inline explicit txStackIterator(txStack* aStack)
     73      : mStack(aStack), mPosition(0) {}
     74 
     75  /**
     76   * Returns true if there is more objects on the stack.
     77   *
     78   * @return .
     79   */
     80  inline bool hasNext() { return (mPosition < mStack->Length()); }
     81 
     82  /**
     83   * Returns the next object pointer from the stack.
     84   *
     85   * @return .
     86   */
     87  inline void* next() {
     88    if (mPosition == mStack->Length()) {
     89      return nullptr;
     90    }
     91    return mStack->ElementAt(mPosition++);
     92  }
     93 
     94 private:
     95  txStack* mStack;
     96  uint32_t mPosition;
     97 };
     98 
     99 #endif /* txStack_h___ */