The Tor Browser: media/omx-plugin/include/ics/utils/List.h@b8a032363ba2 (annotated)

media/omx-plugin/include/ics/utils/List.h@b8a032363ba2 (annotated)

media/omx-plugin/include/ics/utils/List.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /*
  * Copyright (C) 2005 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 //
 // Templated list class.  Normally we'd use STL, but we don't have that.
 // This class mimics STL's interfaces.
 //
 // Objects are copied into the list with the '=' operator or with copy-
 // construction, so if the compiler's auto-generated versions won't work for
 // you, define your own.
 //
 // The only class you want to use from here is "List".
 //
 #ifndef _LIBS_UTILS_LIST_H
 #define _LIBS_UTILS_LIST_H
 #include <stddef.h>
 #include <stdint.h>
 namespace android {
 /*
  * Doubly-linked list.  Instantiate with "List<MyClass> myList".
  *
  * Objects added to the list are copied using the assignment operator,
  * so this must be defined.
  */
 template<typename T>
 class List
 {
 protected:
     /*
      * One element in the list.
      */
     class _Node {
     public:
         explicit _Node(const T& val) : mVal(val) {}
         ~_Node() {}
         inline T& getRef() { return mVal; }
         inline const T& getRef() const { return mVal; }
         inline _Node* getPrev() const { return mpPrev; }
         inline _Node* getNext() const { return mpNext; }
         inline void setVal(const T& val) { mVal = val; }
         inline void setPrev(_Node* ptr) { mpPrev = ptr; }
         inline void setNext(_Node* ptr) { mpNext = ptr; }
     private:
         friend class List;
         friend class _ListIterator;
         T           mVal;
         _Node*      mpPrev;
         _Node*      mpNext;
     };
     /*
      * Iterator for walking through the list.
      */
     template <typename TYPE>
     struct CONST_ITERATOR {
         typedef _Node const * NodePtr;
         typedef const TYPE Type;
     };
     template <typename TYPE>
     struct NON_CONST_ITERATOR {
         typedef _Node* NodePtr;
         typedef TYPE Type;
     };
     template<
         typename U,
         template <class> class Constness
     >
     class _ListIterator {
         typedef _ListIterator<U, Constness>     _Iter;
         typedef typename Constness<U>::NodePtr  _NodePtr;
         typedef typename Constness<U>::Type     _Type;
         explicit _ListIterator(_NodePtr ptr) : mpNode(ptr) {}
     public:
         _ListIterator() {}
         _ListIterator(const _Iter& rhs) : mpNode(rhs.mpNode) {}
         ~_ListIterator() {}
         // this will handle conversions from iterator to const_iterator
         // (and also all convertible iterators)
         // Here, in this implementation, the iterators can be converted
         // if the nodes can be converted
         template<typename V> explicit
         _ListIterator(const V& rhs) : mpNode(rhs.mpNode) {}
         /*
          * Dereference operator.  Used to get at the juicy insides.
          */
         _Type& operator*() const { return mpNode->getRef(); }
         _Type* operator->() const { return &(mpNode->getRef()); }
         /*
          * Iterator comparison.
          */
         inline bool operator==(const _Iter& right) const {
             return mpNode == right.mpNode; }
         inline bool operator!=(const _Iter& right) const {
             return mpNode != right.mpNode; }
         /*
          * handle comparisons between iterator and const_iterator
          */
         template<typename OTHER>
         inline bool operator==(const OTHER& right) const {
             return mpNode == right.mpNode; }
         template<typename OTHER>
         inline bool operator!=(const OTHER& right) const {
             return mpNode != right.mpNode; }
         /*
          * Incr/decr, used to move through the list.
          */
         inline _Iter& operator++() {     // pre-increment
             mpNode = mpNode->getNext();
             return *this;
         }
         const _Iter operator++(int) {    // post-increment
             _Iter tmp(*this);
             mpNode = mpNode->getNext();
             return tmp;
         }
         inline _Iter& operator--() {     // pre-increment
             mpNode = mpNode->getPrev();
             return *this;
         }
         const _Iter operator--(int) {   // post-increment
             _Iter tmp(*this);
             mpNode = mpNode->getPrev();
             return tmp;
         }
         inline _NodePtr getNode() const { return mpNode; }
         _NodePtr mpNode;    /* should be private, but older gcc fails */
     private:
         friend class List;
     };
 public:
     List() {
         prep();
     }
     List(const List<T>& src) {      // copy-constructor
         prep();
         insert(begin(), src.begin(), src.end());
     }
     virtual ~List() {
         clear();
         delete[] (unsigned char*) mpMiddle;
     }
     typedef _ListIterator<T, NON_CONST_ITERATOR> iterator;
     typedef _ListIterator<T, CONST_ITERATOR> const_iterator;
     List<T>& operator=(const List<T>& right);
     /* returns true if the list is empty */
     inline bool empty() const { return mpMiddle->getNext() == mpMiddle; }
     /* return #of elements in list */
     size_t size() const {
         return size_t(distance(begin(), end()));
     }
     /*
      * Return the first element or one past the last element.  The
      * _Node* we're returning is converted to an "iterator" by a
      * constructor in _ListIterator.
      */
     inline iterator begin() {
         return iterator(mpMiddle->getNext());
     }
     inline const_iterator begin() const {
         return const_iterator(const_cast<_Node const*>(mpMiddle->getNext()));
     }
     inline iterator end() {
         return iterator(mpMiddle);
     }
     inline const_iterator end() const {
         return const_iterator(const_cast<_Node const*>(mpMiddle));
     }
     /* add the object to the head or tail of the list */
     void push_front(const T& val) { insert(begin(), val); }
     void push_back(const T& val) { insert(end(), val); }
     /* insert before the current node; returns iterator at new node */
     iterator insert(iterator posn, const T& val)
     {
         _Node* newNode = new _Node(val);        // alloc & copy-construct
         newNode->setNext(posn.getNode());
         newNode->setPrev(posn.getNode()->getPrev());
         posn.getNode()->getPrev()->setNext(newNode);
         posn.getNode()->setPrev(newNode);
         return iterator(newNode);
     }
     /* insert a range of elements before the current node */
     void insert(iterator posn, const_iterator first, const_iterator last) {
         for ( ; first != last; ++first)
             insert(posn, *first);
     }
     /* remove one entry; returns iterator at next node */
     iterator erase(iterator posn) {
         _Node* pNext = posn.getNode()->getNext();
         _Node* pPrev = posn.getNode()->getPrev();
         pPrev->setNext(pNext);
         pNext->setPrev(pPrev);
         delete posn.getNode();
         return iterator(pNext);
     }
     /* remove a range of elements */
     iterator erase(iterator first, iterator last) {
         while (first != last)
             erase(first++);     // don't erase than incr later!
         return iterator(last);
     }
     /* remove all contents of the list */
     void clear() {
         _Node* pCurrent = mpMiddle->getNext();
         _Node* pNext;
         while (pCurrent != mpMiddle) {
             pNext = pCurrent->getNext();
             delete pCurrent;
             pCurrent = pNext;
         }
         mpMiddle->setPrev(mpMiddle);
         mpMiddle->setNext(mpMiddle);
     }
     /*
      * Measure the distance between two iterators.  On exist, "first"
      * will be equal to "last".  The iterators must refer to the same
      * list.
      *
      * FIXME: This is actually a generic iterator function. It should be a
      * template function at the top-level with specializations for things like
      * vector<>, which can just do pointer math). Here we limit it to
      * _ListIterator of the same type but different constness.
      */
     template<
         typename U,
         template <class> class CL,
         template <class> class CR
     >
     ptrdiff_t distance(
             _ListIterator<U, CL> first, _ListIterator<U, CR> last) const
     {
         ptrdiff_t count = 0;
         while (first != last) {
             ++first;
             ++count;
         }
         return count;
     }
 private:
     /*
      * I want a _Node but don't need it to hold valid data.  More
      * to the point, I don't want T's constructor to fire, since it
      * might have side-effects or require arguments.  So, we do this
      * slightly uncouth storage alloc.
      */
     void prep() {
         mpMiddle = (_Node*) new unsigned char[sizeof(_Node)];
         mpMiddle->setPrev(mpMiddle);
         mpMiddle->setNext(mpMiddle);
     }
     /*
      * This node plays the role of "pointer to head" and "pointer to tail".
      * It sits in the middle of a circular list of nodes.  The iterator
      * runs around the circle until it encounters this one.
      */
     _Node*      mpMiddle;
 };
 /*
  * Assignment operator.
  *
  * The simplest way to do this would be to clear out the target list and
  * fill it with the source.  However, we can speed things along by
  * re-using existing elements.
  */
 template<class T>
 List<T>& List<T>::operator=(const List<T>& right)
 {
     if (this == &right)
         return *this;       // self-assignment
     iterator firstDst = begin();
     iterator lastDst = end();
     const_iterator firstSrc = right.begin();
     const_iterator lastSrc = right.end();
     while (firstSrc != lastSrc && firstDst != lastDst)
         *firstDst++ = *firstSrc++;
     if (firstSrc == lastSrc)        // ran out of elements in source?
         erase(firstDst, lastDst);   // yes, erase any extras
     else
         insert(lastDst, firstSrc, lastSrc);     // copy remaining over
     return *this;
 }
 }; // namespace android
 #endif // _LIBS_UTILS_LIST_H

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media/omx-plugin/include/ics/utils/List.h@b8a032363ba2 (annotated)

media/omx-plugin/include/ics/utils/List.h