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
16namespace 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.
20template <typename T>
21class 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    explicit 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_
138