cc: Switch ListContainer to use composition instead of inheritance.

cc/base/list_container.cc

Index: cc/base/list_container.cc
diff --git a/cc/base/list_container.cc b/cc/base/list_container.cc
deleted file mode 100644
index 48d2bf58ce63c78796216a26b9143dd90ab85fe0..0000000000000000000000000000000000000000
--- a/cc/base/list_container.cc
+++ /dev/null
@@ -1,576 +0,0 @@
-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "cc/base/list_container.h"
-
-#include <algorithm>
-#include <vector>
-
-#include "cc/base/scoped_ptr_vector.h"
-
-namespace {
-const size_t kDefaultNumElementTypesToReserve = 32;
-}  // namespace
-
-namespace cc {
-
-// ListContainerCharAllocator
-////////////////////////////////////////////////////
-// This class deals only with char* and void*. It does allocation and passing
-// out raw pointers, as well as memory deallocation when being destroyed.
-class ListContainerBase::ListContainerCharAllocator {
- public:
-  // ListContainerCharAllocator::InnerList
-  /////////////////////////////////////////////
-  // This class holds the raw memory chunk, as well as information about its
-  // size and availability.
-  struct InnerList {
-    scoped_ptr<char[]> data;
-    // The number of elements in total the memory can hold. The difference
-    // between capacity and size is the how many more elements this list can
-    // hold.
-    size_t capacity;
-    // The number of elements have been put into this list.
-    size_t size;
-    // The size of each element is in bytes. This is used to move from between
-    // elements' memory locations.
-    size_t step;
-
-    InnerList() : capacity(0), size(0), step(0) {}
-
-    void Erase(char* position) {
-      // Confident that destructor is called by caller of this function. Since
-      // ListContainerCharAllocator does not handle construction after
-      // allocation, it doesn't handle desctrution before deallocation.
-      DCHECK_LE(position, LastElement());
-      DCHECK_GE(position, Begin());
-      char* start = position + step;
-      std::copy(start, End(), position);
-
-      --size;
-      // Decrease capacity to avoid creating not full not last InnerList.
-      --capacity;
-    }
-
-    void InsertBefore(char** position, size_t count) {
-      DCHECK_LE(*position, LastElement() + step);
-      DCHECK_GE(*position, Begin());
-
-      // Adjust the size and capacity
-      size_t old_size = size;
-      size += count;
-      capacity = size;
-
-      // Allocate the new data and update the iterator's pointer.
-      scoped_ptr<char[]> new_data(new char[size * step]);
-      size_t position_offset = *position - Begin();
-      *position = new_data.get() + position_offset;
-
-      // Copy the data before the inserted segment
-      memcpy(new_data.get(), data.get(), position_offset);
-      // Copy the data after the inserted segment.
-      memcpy(new_data.get() + position_offset + count * step,
-             data.get() + position_offset, old_size * step - position_offset);
-      new_data.swap(data);
-    }
-
-    bool IsEmpty() const { return !size; }
-    bool IsFull() { return capacity == size; }
-    size_t NumElementsAvailable() const { return capacity - size; }
-
-    void* AddElement() {
-      DCHECK_LT(size, capacity);
-      ++size;
-      return LastElement();
-    }
-
-    void RemoveLast() {
-      DCHECK(!IsEmpty());
-      --size;
-    }
-
-    char* Begin() const { return data.get(); }
-    char* End() const { return data.get() + size * step; }
-    char* LastElement() const { return data.get() + (size - 1) * step; }
-    char* ElementAt(size_t index) const { return data.get() + index * step; }
-
-   private:
-    DISALLOW_COPY_AND_ASSIGN(InnerList);
-  };
-
-  explicit ListContainerCharAllocator(size_t element_size)
-      : element_size_(element_size),
-        size_(0),
-        last_list_index_(0),
-        last_list_(NULL) {
-    AllocateNewList(kDefaultNumElementTypesToReserve);
-    last_list_ = storage_[last_list_index_];
-  }
-
-  ListContainerCharAllocator(size_t element_size, size_t element_count)
-      : element_size_(element_size),
-        size_(0),
-        last_list_index_(0),
-        last_list_(NULL) {
-    AllocateNewList(element_count > 0 ? element_count
-                                      : kDefaultNumElementTypesToReserve);
-    last_list_ = storage_[last_list_index_];
-  }
-
-  ~ListContainerCharAllocator() {}
-
-  void* Allocate() {
-    if (last_list_->IsFull()) {
-      // Only allocate a new list if there isn't a spare one still there from
-      // previous usage.
-      if (last_list_index_ + 1 >= storage_.size())
-        AllocateNewList(last_list_->capacity * 2);
-
-      ++last_list_index_;
-      last_list_ = storage_[last_list_index_];
-    }
-
-    ++size_;
-    return last_list_->AddElement();
-  }
-
-  size_t element_size() const { return element_size_; }
-  size_t list_count() const { return storage_.size(); }
-  size_t size() const { return size_; }
-  bool IsEmpty() const { return size() == 0; }
-
-  size_t Capacity() const {
-    size_t capacity_sum = 0;
-    for (const auto& inner_list : storage_)
-      capacity_sum += inner_list->capacity;
-    return capacity_sum;
-  }
-
-  void Clear() {
-    // Remove all except for the first InnerList.
-    DCHECK(!storage_.empty());
-    storage_.erase(storage_.begin() + 1, storage_.end());
-    last_list_index_ = 0;
-    last_list_ = storage_[0];
-    last_list_->size = 0;
-    size_ = 0;
-  }
-
-  void RemoveLast() {
-    DCHECK(!IsEmpty());
-    last_list_->RemoveLast();
-    if (last_list_->IsEmpty() && last_list_index_ > 0) {
-      --last_list_index_;
-      last_list_ = storage_[last_list_index_];
-
-      // If there are now two empty inner lists, free one of them.
-      if (last_list_index_ + 2 < storage_.size())
-        storage_.pop_back();
-    }
-    --size_;
-  }
-
-  void Erase(PositionInListContainerCharAllocator* position) {
-    DCHECK_EQ(this, position->ptr_to_container);
-
-    // Update |position| to point to the element after the erased element.
-    InnerList* list = storage_[position->vector_index];
-    char* item_iterator = position->item_iterator;
-    if (item_iterator == list->LastElement())
-      position->Increment();
-
-    list->Erase(item_iterator);
-    // TODO(weiliangc): Free the InnerList if it is empty.
-    --size_;
-  }
-
-  void InsertBefore(ListContainerBase::Iterator* position, size_t count) {
-    if (!count)
-      return;
-
-    // If |position| is End(), then append |count| elements at the end. This
-    // will happen to not invalidate any iterators or memory.
-    if (!position->item_iterator) {
-      // Set |position| to be the first inserted element.
-      Allocate();
-      position->vector_index = storage_.size() - 1;
-      position->item_iterator = storage_[position->vector_index]->LastElement();
-      // Allocate the rest.
-      for (size_t i = 1; i < count; ++i)
-        Allocate();
-    } else {
-      storage_[position->vector_index]->InsertBefore(&position->item_iterator,
-                                                     count);
-      size_ += count;
-    }
-  }
-
-  InnerList* InnerListById(size_t id) const {
-    DCHECK_LT(id, storage_.size());
-    return storage_[id];
-  }
-
-  size_t FirstInnerListId() const {
-    // |size_| > 0 means that at least one vector in |storage_| will be
-    // non-empty.
-    DCHECK_GT(size_, 0u);
-    size_t id = 0;
-    while (storage_[id]->size == 0)
-      ++id;
-    return id;
-  }
-
-  size_t LastInnerListId() const {
-    // |size_| > 0 means that at least one vector in |storage_| will be
-    // non-empty.
-    DCHECK_GT(size_, 0u);
-    size_t id = storage_.size() - 1;
-    while (storage_[id]->size == 0)
-      --id;
-    return id;
-  }
-
-  size_t NumAvailableElementsInLastList() const {
-    return last_list_->NumElementsAvailable();
-  }
-
- private:
-  void AllocateNewList(size_t list_size) {
-    scoped_ptr<InnerList> new_list(new InnerList);
-    new_list->capacity = list_size;
-    new_list->size = 0;
-    new_list->step = element_size_;
-    new_list->data.reset(new char[list_size * element_size_]);
-    storage_.push_back(new_list.Pass());
-  }
-
-  ScopedPtrVector<InnerList> storage_;
-  const size_t element_size_;
-
-  // The number of elements in the list.
-  size_t size_;
-
-  // The index of the last list to have had elements added to it, or the only
-  // list if the container has not had elements added since being cleared.
-  size_t last_list_index_;
-
-  // This is equivalent to |storage_[last_list_index_]|.
-  InnerList* last_list_;
-
-  DISALLOW_COPY_AND_ASSIGN(ListContainerCharAllocator);
-};
-
-// PositionInListContainerCharAllocator
-//////////////////////////////////////////////////////
-ListContainerBase::PositionInListContainerCharAllocator::
-    PositionInListContainerCharAllocator(
-        const ListContainerBase::PositionInListContainerCharAllocator& other)
-    : ptr_to_container(other.ptr_to_container),
-      vector_index(other.vector_index),
-      item_iterator(other.item_iterator) {
-}
-
-ListContainerBase::PositionInListContainerCharAllocator::
-    PositionInListContainerCharAllocator(
-        ListContainerBase::ListContainerCharAllocator* container,
-        size_t vector_ind,
-        char* item_iter)
-    : ptr_to_container(container),
-      vector_index(vector_ind),
-      item_iterator(item_iter) {
-}
-
-bool ListContainerBase::PositionInListContainerCharAllocator::operator==(
-    const ListContainerBase::PositionInListContainerCharAllocator& other)
-    const {
-  DCHECK_EQ(ptr_to_container, other.ptr_to_container);
-  return vector_index == other.vector_index &&
-         item_iterator == other.item_iterator;
-}
-
-bool ListContainerBase::PositionInListContainerCharAllocator::operator!=(
-    const ListContainerBase::PositionInListContainerCharAllocator& other)
-    const {
-  return !(*this == other);
-}
-
-ListContainerBase::PositionInListContainerCharAllocator
-ListContainerBase::PositionInListContainerCharAllocator::Increment() {
-  ListContainerCharAllocator::InnerList* list =
-      ptr_to_container->InnerListById(vector_index);
-  if (item_iterator == list->LastElement()) {
-    ++vector_index;
-    while (vector_index < ptr_to_container->list_count()) {
-      if (ptr_to_container->InnerListById(vector_index)->size != 0)
-        break;
-      ++vector_index;
-    }
-    if (vector_index < ptr_to_container->list_count())
-      item_iterator = ptr_to_container->InnerListById(vector_index)->Begin();
-    else
-      item_iterator = NULL;
-  } else {
-    item_iterator += list->step;
-  }
-  return *this;
-}
-
-ListContainerBase::PositionInListContainerCharAllocator
-ListContainerBase::PositionInListContainerCharAllocator::ReverseIncrement() {
-  ListContainerCharAllocator::InnerList* list =
-      ptr_to_container->InnerListById(vector_index);
-  if (item_iterator == list->Begin()) {
-    --vector_index;
-    // Since |vector_index| is unsigned, we compare < list_count() instead of
-    // comparing >= 0, as the variable will wrap around when it goes out of
-    // range (below 0).
-    while (vector_index < ptr_to_container->list_count()) {
-      if (ptr_to_container->InnerListById(vector_index)->size != 0)
-        break;
-      --vector_index;
-    }
-    if (vector_index < ptr_to_container->list_count()) {
-      item_iterator =
-          ptr_to_container->InnerListById(vector_index)->LastElement();
-    } else {
-      item_iterator = NULL;
-    }
-  } else {
-    item_iterator -= list->step;
-  }
-  return *this;
-}
-
-// ListContainerBase
-////////////////////////////////////////////
-ListContainerBase::ListContainerBase(size_t max_size_for_derived_class)
-    : data_(new ListContainerCharAllocator(max_size_for_derived_class)) {
-}
-
-ListContainerBase::ListContainerBase(size_t max_size_for_derived_class,
-                                     size_t num_of_elements_to_reserve_for)
-    : data_(new ListContainerCharAllocator(max_size_for_derived_class,
-                                           num_of_elements_to_reserve_for)) {
-}
-
-ListContainerBase::~ListContainerBase() {
-}
-
-void ListContainerBase::RemoveLast() {
-  data_->RemoveLast();
-}
-
-void ListContainerBase::EraseAndInvalidateAllPointers(
-    ListContainerBase::Iterator* position) {
-  data_->Erase(position);
-}
-
-void ListContainerBase::InsertBeforeAndInvalidateAllPointers(
-    ListContainerBase::Iterator* position,
-    size_t count) {
-  data_->InsertBefore(position, count);
-}
-
-ListContainerBase::ConstReverseIterator ListContainerBase::crbegin() const {
-  if (data_->IsEmpty())
-    return crend();
-
-  size_t id = data_->LastInnerListId();
-  return ConstReverseIterator(data_.get(), id,
-                              data_->InnerListById(id)->LastElement(), 0);
-}
-
-ListContainerBase::ConstReverseIterator ListContainerBase::crend() const {
-  return ConstReverseIterator(data_.get(), static_cast<size_t>(-1), NULL,
-                              size());
-}
-
-ListContainerBase::ReverseIterator ListContainerBase::rbegin() {
-  if (data_->IsEmpty())
-    return rend();
-
-  size_t id = data_->LastInnerListId();
-  return ReverseIterator(data_.get(), id,
-                         data_->InnerListById(id)->LastElement(), 0);
-}
-
-ListContainerBase::ReverseIterator ListContainerBase::rend() {
-  return ReverseIterator(data_.get(), static_cast<size_t>(-1), NULL, size());
-}
-
-ListContainerBase::ConstIterator ListContainerBase::cbegin() const {
-  if (data_->IsEmpty())
-    return cend();
-
-  size_t id = data_->FirstInnerListId();
-  return ConstIterator(data_.get(), id, data_->InnerListById(id)->Begin(), 0);
-}
-
-ListContainerBase::ConstIterator ListContainerBase::cend() const {
-  if (data_->IsEmpty())
-    return ConstIterator(data_.get(), 0, NULL, size());
-
-  size_t id = data_->list_count();
-  return ConstIterator(data_.get(), id, NULL, size());
-}
-
-ListContainerBase::Iterator ListContainerBase::begin() {
-  if (data_->IsEmpty())
-    return end();
-
-  size_t id = data_->FirstInnerListId();
-  return Iterator(data_.get(), id, data_->InnerListById(id)->Begin(), 0);
-}
-
-ListContainerBase::Iterator ListContainerBase::end() {
-  if (data_->IsEmpty())
-    return Iterator(data_.get(), 0, NULL, size());
-
-  size_t id = data_->list_count();
-  return Iterator(data_.get(), id, NULL, size());
-}
-
-ListContainerBase::ConstIterator ListContainerBase::IteratorAt(
-    size_t index) const {
-  DCHECK_LT(index, size());
-  size_t original_index = index;
-  size_t list_index;
-  for (list_index = 0; list_index < data_->list_count(); ++list_index) {
-    size_t current_size = data_->InnerListById(list_index)->size;
-    if (index < current_size)
-      break;
-    index -= current_size;
-  }
-  return ConstIterator(data_.get(), list_index,
-                       data_->InnerListById(list_index)->ElementAt(index),
-                       original_index);
-}
-
-ListContainerBase::Iterator ListContainerBase::IteratorAt(size_t index) {
-  DCHECK_LT(index, size());
-  size_t original_index = index;
-  size_t list_index;
-  for (list_index = 0; list_index < data_->list_count(); ++list_index) {
-    size_t current_size = data_->InnerListById(list_index)->size;
-    if (index < current_size)
-      break;
-    index -= current_size;
-  }
-  return Iterator(data_.get(), list_index,
-                  data_->InnerListById(list_index)->ElementAt(index),
-                  original_index);
-}
-
-void* ListContainerBase::Allocate(size_t size_of_actual_element_in_bytes) {
-  DCHECK_LE(size_of_actual_element_in_bytes, data_->element_size());
-  return data_->Allocate();
-}
-
-size_t ListContainerBase::size() const {
-  return data_->size();
-}
-
-bool ListContainerBase::empty() const {
-  return data_->IsEmpty();
-}
-
-size_t ListContainerBase::MaxSizeForDerivedClass() const {
-  return data_->element_size();
-}
-
-size_t ListContainerBase::GetCapacityInBytes() const {
-  return data_->Capacity() * data_->element_size();
-}
-
-void ListContainerBase::clear() {
-  data_->Clear();
-}
-
-size_t ListContainerBase::AvailableSizeWithoutAnotherAllocationForTesting()
-    const {
-  return data_->NumAvailableElementsInLastList();
-}
-
-// ListContainerBase::Iterator
-/////////////////////////////////////////////////
-ListContainerBase::Iterator::Iterator(ListContainerCharAllocator* container,
-                                      size_t vector_ind,
-                                      char* item_iter,
-                                      size_t index)
-    : PositionInListContainerCharAllocator(container, vector_ind, item_iter),
-      index_(index) {
-}
-
-ListContainerBase::Iterator::~Iterator() {
-}
-
-size_t ListContainerBase::Iterator::index() const {
-  return index_;
-}
-
-// ListContainerBase::ConstIterator
-/////////////////////////////////////////////////
-ListContainerBase::ConstIterator::ConstIterator(
-    const ListContainerBase::Iterator& other)
-    : PositionInListContainerCharAllocator(other), index_(other.index()) {
-}
-
-ListContainerBase::ConstIterator::ConstIterator(
-    ListContainerCharAllocator* container,
-    size_t vector_ind,
-    char* item_iter,
-    size_t index)
-    : PositionInListContainerCharAllocator(container, vector_ind, item_iter),
-      index_(index) {
-}
-
-ListContainerBase::ConstIterator::~ConstIterator() {
-}
-
-size_t ListContainerBase::ConstIterator::index() const {
-  return index_;
-}
-
-// ListContainerBase::ReverseIterator
-/////////////////////////////////////////////////
-ListContainerBase::ReverseIterator::ReverseIterator(
-    ListContainerCharAllocator* container,
-    size_t vector_ind,
-    char* item_iter,
-    size_t index)
-    : PositionInListContainerCharAllocator(container, vector_ind, item_iter),
-      index_(index) {
-}
-
-ListContainerBase::ReverseIterator::~ReverseIterator() {
-}
-
-size_t ListContainerBase::ReverseIterator::index() const {
-  return index_;
-}
-
-// ListContainerBase::ConstReverseIterator
-/////////////////////////////////////////////////
-ListContainerBase::ConstReverseIterator::ConstReverseIterator(
-    const ListContainerBase::ReverseIterator& other)
-    : PositionInListContainerCharAllocator(other), index_(other.index()) {
-}
-
-ListContainerBase::ConstReverseIterator::ConstReverseIterator(
-    ListContainerCharAllocator* container,
-    size_t vector_ind,
-    char* item_iter,
-    size_t index)
-    : PositionInListContainerCharAllocator(container, vector_ind, item_iter),
-      index_(index) {
-}
-
-ListContainerBase::ConstReverseIterator::~ConstReverseIterator() {
-}
-
-size_t ListContainerBase::ConstReverseIterator::index() const {
-  return index_;
-}
-
-}  // namespace cc