Index: net/base/priority_queue.h |
diff --git a/net/base/priority_queue.h b/net/base/priority_queue.h |
deleted file mode 100644 |
index 9b17d61b21e6ef6c8690b62e2edd9c63cf830e02..0000000000000000000000000000000000000000 |
--- a/net/base/priority_queue.h |
+++ /dev/null |
@@ -1,311 +0,0 @@ |
-// Copyright (c) 2012 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. |
- |
-#ifndef NET_BASE_PRIORITY_QUEUE_H_ |
-#define NET_BASE_PRIORITY_QUEUE_H_ |
- |
-#include <list> |
-#include <vector> |
- |
-#include "base/basictypes.h" |
-#include "base/logging.h" |
-#include "base/threading/non_thread_safe.h" |
-#include "net/base/net_export.h" |
- |
-#if !defined(NDEBUG) |
-#include "base/containers/hash_tables.h" |
-#endif |
- |
-namespace net { |
- |
-// A simple priority queue. The order of values is by priority and then FIFO. |
-// Unlike the std::priority_queue, this implementation allows erasing elements |
-// from the queue, and all operations are O(p) time for p priority levels. |
-// The queue is agnostic to priority ordering (whether 0 precedes 1). |
-// If the highest priority is 0, FirstMin() returns the first in order. |
-// |
-// In debug-mode, the internal queues store (id, value) pairs where id is used |
-// to validate Pointers. |
-// |
-template<typename T> |
-class PriorityQueue : public base::NonThreadSafe { |
- private: |
- // This section is up-front for Pointer only. |
-#if !defined(NDEBUG) |
- typedef std::list<std::pair<unsigned, T> > List; |
-#else |
- typedef std::list<T> List; |
-#endif |
- |
- public: |
- typedef uint32 Priority; |
- |
- // A pointer to a value stored in the queue. The pointer becomes invalid |
- // when the queue is destroyed or cleared, or the value is erased. |
- class Pointer { |
- public: |
- // Constructs a null pointer. |
- Pointer() : priority_(kNullPriority) { |
-#if !defined(NDEBUG) |
- id_ = static_cast<unsigned>(-1); |
-#endif |
- // TODO(syzm) |
- // An uninitialized iterator behaves like an uninitialized pointer as per |
- // the STL docs. The fix below is ugly and should possibly be replaced |
- // with a better approach. |
- iterator_ = dummy_empty_list_.end(); |
- } |
- |
- Pointer(const Pointer& p) |
- : priority_(p.priority_), |
- iterator_(p.iterator_) { |
-#if !defined(NDEBUG) |
- id_ = p.id_; |
-#endif |
- } |
- |
- Pointer& operator=(const Pointer& p) { |
- // Self-assignment is benign. |
- priority_ = p.priority_; |
- iterator_ = p.iterator_; |
-#if !defined(NDEBUG) |
- id_ = p.id_; |
-#endif |
- return *this; |
- } |
- |
- bool is_null() const { return priority_ == kNullPriority; } |
- |
- Priority priority() const { return priority_; } |
- |
-#if !defined(NDEBUG) |
- const T& value() const { return iterator_->second; } |
-#else |
- const T& value() const { return *iterator_; } |
-#endif |
- |
- // Comparing to Pointer from a different PriorityQueue is undefined. |
- bool Equals(const Pointer& other) const { |
- return (priority_ == other.priority_) && (iterator_ == other.iterator_); |
- } |
- |
- void Reset() { |
- *this = Pointer(); |
- } |
- |
- private: |
- friend class PriorityQueue; |
- |
- // Note that we need iterator and not const_iterator to pass to |
- // List::erase. When C++11 is turned on for Chromium, this could |
- // be changed to const_iterator and the const_casts in the rest of |
- // the file can be removed. |
- typedef typename PriorityQueue::List::iterator ListIterator; |
- |
- static const Priority kNullPriority = static_cast<Priority>(-1); |
- |
- // It is guaranteed that Pointer will treat |iterator| as a |
- // const_iterator. |
- Pointer(Priority priority, const ListIterator& iterator) |
- : priority_(priority), iterator_(iterator) { |
-#if !defined(NDEBUG) |
- id_ = iterator_->first; |
-#endif |
- } |
- |
- Priority priority_; |
- ListIterator iterator_; |
- // The STL iterators when uninitialized are like uninitialized pointers |
- // which cause crashes when assigned to other iterators. We need to |
- // initialize a NULL iterator to the end of a valid list. |
- List dummy_empty_list_; |
- |
-#if !defined(NDEBUG) |
- // Used by the queue to check if a Pointer is valid. |
- unsigned id_; |
-#endif |
- }; |
- |
- // Creates a new queue for |num_priorities|. |
- explicit PriorityQueue(Priority num_priorities) |
- : lists_(num_priorities), size_(0) { |
-#if !defined(NDEBUG) |
- next_id_ = 0; |
-#endif |
- } |
- |
- // Adds |value| with |priority| to the queue. Returns a pointer to the |
- // created element. |
- Pointer Insert(const T& value, Priority priority) { |
- DCHECK(CalledOnValidThread()); |
- DCHECK_LT(priority, lists_.size()); |
- ++size_; |
- List& list = lists_[priority]; |
-#if !defined(NDEBUG) |
- unsigned id = next_id_; |
- valid_ids_.insert(id); |
- ++next_id_; |
- return Pointer(priority, list.insert(list.end(), |
- std::make_pair(id, value))); |
-#else |
- return Pointer(priority, list.insert(list.end(), value)); |
-#endif |
- } |
- |
- // Adds |value| with |priority| to the queue. Returns a pointer to the |
- // created element. |
- Pointer InsertAtFront(const T& value, Priority priority) { |
- DCHECK(CalledOnValidThread()); |
- DCHECK_LT(priority, lists_.size()); |
- ++size_; |
- List& list = lists_[priority]; |
-#if !defined(NDEBUG) |
- unsigned id = next_id_; |
- valid_ids_.insert(id); |
- ++next_id_; |
- return Pointer(priority, list.insert(list.begin(), |
- std::make_pair(id, value))); |
-#else |
- return Pointer(priority, list.insert(list.begin(), value)); |
-#endif |
- } |
- |
- // Removes the value pointed by |pointer| from the queue. All pointers to this |
- // value including |pointer| become invalid. |
- void Erase(const Pointer& pointer) { |
- DCHECK(CalledOnValidThread()); |
- DCHECK_LT(pointer.priority_, lists_.size()); |
- DCHECK_GT(size_, 0u); |
- |
-#if !defined(NDEBUG) |
- DCHECK_EQ(1u, valid_ids_.erase(pointer.id_)); |
- DCHECK_EQ(pointer.iterator_->first, pointer.id_); |
-#endif |
- |
- --size_; |
- lists_[pointer.priority_].erase(pointer.iterator_); |
- } |
- |
- // Returns a pointer to the first value of minimum priority or a null-pointer |
- // if empty. |
- Pointer FirstMin() const { |
- DCHECK(CalledOnValidThread()); |
- for (size_t i = 0; i < lists_.size(); ++i) { |
- List* list = const_cast<List*>(&lists_[i]); |
- if (!list->empty()) |
- return Pointer(i, list->begin()); |
- } |
- return Pointer(); |
- } |
- |
- // Returns a pointer to the last value of minimum priority or a null-pointer |
- // if empty. |
- Pointer LastMin() const { |
- DCHECK(CalledOnValidThread()); |
- for (size_t i = 0; i < lists_.size(); ++i) { |
- List* list = const_cast<List*>(&lists_[i]); |
- if (!list->empty()) |
- return Pointer(i, --list->end()); |
- } |
- return Pointer(); |
- } |
- |
- // Returns a pointer to the first value of maximum priority or a null-pointer |
- // if empty. |
- Pointer FirstMax() const { |
- DCHECK(CalledOnValidThread()); |
- for (size_t i = lists_.size(); i > 0; --i) { |
- size_t index = i - 1; |
- List* list = const_cast<List*>(&lists_[index]); |
- if (!list->empty()) |
- return Pointer(index, list->begin()); |
- } |
- return Pointer(); |
- } |
- |
- // Returns a pointer to the last value of maximum priority or a null-pointer |
- // if empty. |
- Pointer LastMax() const { |
- DCHECK(CalledOnValidThread()); |
- for (size_t i = lists_.size(); i > 0; --i) { |
- size_t index = i - 1; |
- List* list = const_cast<List*>(&lists_[index]); |
- if (!list->empty()) |
- return Pointer(index, --list->end()); |
- } |
- return Pointer(); |
- } |
- |
- // Given an ordering of the values in this queue by decreasing |
- // priority and then FIFO, returns a pointer to the value following |
- // the value of the given pointer (which must be non-NULL). |
- // |
- // (One could also implement GetNextTowardsFirstMin() [decreasing |
- // priority, then reverse FIFO] as well as |
- // GetNextTowards{First,Last}Max() [increasing priority, then |
- // {,reverse} FIFO].) |
- Pointer GetNextTowardsLastMin(const Pointer& pointer) const { |
- DCHECK(CalledOnValidThread()); |
- DCHECK(!pointer.is_null()); |
- DCHECK_LT(pointer.priority_, lists_.size()); |
- |
- typename Pointer::ListIterator it = pointer.iterator_; |
- Priority priority = pointer.priority_; |
- DCHECK(it != lists_[priority].end()); |
- ++it; |
- while (it == lists_[priority].end()) { |
- if (priority == 0u) |
- return Pointer(); |
- --priority; |
- it = const_cast<List*>(&lists_[priority])->begin(); |
- } |
- return Pointer(priority, it); |
- } |
- |
- // Empties the queue. All pointers become invalid. |
- void Clear() { |
- DCHECK(CalledOnValidThread()); |
- for (size_t i = 0; i < lists_.size(); ++i) { |
- lists_[i].clear(); |
- } |
-#if !defined(NDEBUG) |
- valid_ids_.clear(); |
-#endif |
- size_ = 0u; |
- } |
- |
- // Returns the number of priorities the queue supports. |
- size_t num_priorities() const { |
- DCHECK(CalledOnValidThread()); |
- return lists_.size(); |
- } |
- |
- bool empty() const { |
- DCHECK(CalledOnValidThread()); |
- return size_ == 0; |
- } |
- |
- // Returns number of queued values. |
- size_t size() const { |
- DCHECK(CalledOnValidThread()); |
- return size_; |
- } |
- |
- private: |
- typedef std::vector<List> ListVector; |
- |
-#if !defined(NDEBUG) |
- unsigned next_id_; |
- base::hash_set<unsigned> valid_ids_; |
-#endif |
- |
- ListVector lists_; |
- size_t size_; |
- |
- DISALLOW_COPY_AND_ASSIGN(PriorityQueue); |
-}; |
- |
-} // namespace net |
- |
-#endif // NET_BASE_PRIORITY_QUEUE_H_ |