cc/base/scoped_ptr_deque.h

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CC_BASE_SCOPED_PTR_DEQUE_H_
   6 #define CC_BASE_SCOPED_PTR_DEQUE_H_
   7
   8 #include <algorithm>
   9 #include <deque>
  10
  11 #include "base/basictypes.h"
  12 #include "base/logging.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/stl_util.h"
  15
  16 namespace cc {
  17
  18 // This type acts like a deque<scoped_ptr> based on top of std::deque. The
  19 // ScopedPtrDeque has ownership of all elements in the deque.
  20 template <typename T>
  21 class ScopedPtrDeque {
  22  public:
  23   typedef typename std::deque<T*>::const_iterator const_iterator;
  24   typedef typename std::deque<T*>::reverse_iterator reverse_iterator;
  25   typedef typename std::deque<T*>::const_reverse_iterator
  26       const_reverse_iterator;
  27
  28 #if defined(OS_ANDROID)
  29   // On Android the iterator is not a class, so we can't block assignment.
  30   typedef typename std::deque<T*>::iterator iterator;
  31 #else
  32   // Ban setting values on the iterator directly. New pointers must be passed
  33   // to methods on the ScopedPtrDeque class to appear in the deque.
  34   class iterator : public std::deque<T*>::iterator {
  35    public:
  36     iterator(const typename std::deque<T*>::iterator& other)
  37         : std::deque<T*>::iterator(other) {}
  38     T* const& operator*() { return std::deque<T*>::iterator::operator*(); }
  39   };
  40 #endif
  41
  42   ScopedPtrDeque() {}
  43
  44   ~ScopedPtrDeque() { clear(); }
  45
  46   size_t size() const {
  47     return data_.size();
  48   }
  49
  50   T* at(size_t index) const {
  51     DCHECK(index < size());
  52     return data_[index];
  53   }
  54
  55   T* operator[](size_t index) const {
  56     return at(index);
  57   }
  58
  59   T* front() const {
  60     DCHECK(!empty());
  61     return at(0);
  62   }
  63
  64   T* back() const {
  65     DCHECK(!empty());
  66     return at(size() - 1);
  67   }
  68
  69   bool empty() const {
  70     return data_.empty();
  71   }
  72
  73   scoped_ptr<T> take_front() {
  74     scoped_ptr<T> ret(front());
  75     data_.pop_front();
  76     return ret.Pass();
  77   }
  78
  79   scoped_ptr<T> take_back() {
  80     scoped_ptr<T> ret(back());
  81     data_.pop_back();
  82     return ret.Pass();
  83   }
  84
  85   void clear() {
  86     STLDeleteElements(&data_);
  87   }
  88
  89   void push_front(scoped_ptr<T> item) {
  90     data_.push_front(item.release());
  91   }
  92
  93   void push_back(scoped_ptr<T> item) {
  94     data_.push_back(item.release());
  95   }
  96
  97   void insert(iterator position, scoped_ptr<T> item) {
  98     DCHECK(position <= end());
  99     data_.insert(position, item.release());
 100   }
 101
 102   scoped_ptr<T> take(iterator position) {
 103     DCHECK(position < end());
 104     scoped_ptr<T> ret(*position);
 105     data_.erase(position);
 106     return ret.Pass();
 107   }
 108
 109   void swap(iterator a, iterator b) {
 110     DCHECK(a < end());
 111     DCHECK(b < end());
 112     if (a == end() || b == end() || a == b)
 113       return;
 114     typename std::deque<T*>::iterator writable_a = a;
 115     typename std::deque<T*>::iterator writable_b = b;
 116     std::swap(*writable_a, *writable_b);
 117   }
 118
 119   iterator begin() { return static_cast<iterator>(data_.begin()); }
 120   const_iterator begin() const { return data_.begin(); }
 121   iterator end() { return static_cast<iterator>(data_.end()); }
 122   const_iterator end() const { return data_.end(); }
 123
 124   reverse_iterator rbegin() { return data_.rbegin(); }
 125   const_reverse_iterator rbegin() const { return data_.rbegin(); }
 126   reverse_iterator rend() { return data_.rend(); }
 127   const_reverse_iterator rend() const { return data_.rend(); }
 128
 129  private:
 130   std::deque<T*> data_;
 131
 132   DISALLOW_COPY_AND_ASSIGN(ScopedPtrDeque);
 133 };
 134
 135 }  // namespace cc
 136
 137 #endif  // CC_BASE_SCOPED_PTR_DEQUE_H_