blob: a092c12e9afb40f6b6bb435f6fcf02fc5689a49d [file] [log] [blame]
// Copyright 2015 The Weave 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 <map>
#include <memory>
#include <queue>
#include <string>
#include <utility>
#include <vector>
#include <base/callback.h>
#include <base/macros.h>
#include <base/time/default_clock.h>
#include <base/time/time.h>
#include <weave/device.h>
#include <weave/provider/task_runner.h>
#include "src/commands/command_instance.h"
namespace weave {
class CommandQueue final {
CommandQueue(provider::TaskRunner* task_runner, base::Clock* clock);
// TODO: Remove AddCommandAddedCallback and AddCommandRemovedCallback.
using CommandCallback = base::Callback<void(Command* command)>;
// Adds notifications callback for a new command is added to the queue.
void AddCommandAddedCallback(const CommandCallback& callback);
// Adds notifications callback for a command is removed from the queue.
void AddCommandRemovedCallback(const CommandCallback& callback);
void AddCommandHandler(const std::string& component_path,
const std::string& command_name,
const Device::CommandHandlerCallback& callback);
// Checks if the command queue is empty.
bool IsEmpty() const { return map_.empty(); }
// Returns the number of commands in the queue.
size_t GetCount() const { return map_.size(); }
// Adds a new command to the queue. Each command in the queue has a unique
// ID that identifies that command instance in this queue.
// One shouldn't attempt to add a command with the same ID.
void Add(std::unique_ptr<CommandInstance> instance);
// Selects command identified by |id| ready for removal. Command will actually
// be removed after some time.
void RemoveLater(const std::string& id);
// Finds a command instance in the queue by the instance |id|. Returns
// nullptr if the command with the given |id| is not found. The returned
// pointer should not be persisted for a long period of time.
CommandInstance* Find(const std::string& id) const;
friend class CommandQueueTest;
// Removes a command identified by |id| from the queue.
bool Remove(const std::string& id);
// Removes old commands scheduled by RemoveLater() to be deleted after
// |cutoff_time|.
void Cleanup(const base::Time& cutoff_time);
// Schedule a cleanup task to be run after the specified |delay|.
void ScheduleCleanup(base::TimeDelta delay);
// Perform removal of scheduled commands (by calling Cleanup()) and scheduling
// another cleanup task if the removal queue is still not empty.
void PerformScheduledCleanup();
provider::TaskRunner* task_runner_{nullptr};
base::Clock* clock_{nullptr};
// ID-to-CommandInstance map.
std::map<std::string, std::shared_ptr<CommandInstance>> map_;
// Queue of commands to be removed, keeps them sorted by the timestamp
// (earliest first). This is done to tolerate system clock changes.
template <typename T>
using InversePriorityQueue =
std::priority_queue<T, std::vector<T>, std::greater<T>>;
InversePriorityQueue<std::pair<base::Time, std::string>> remove_queue_;
using CallbackList = std::vector<CommandCallback>;
CallbackList on_command_added_;
CallbackList on_command_removed_;
std::map<std::string, Device::CommandHandlerCallback> command_callbacks_;
Device::CommandHandlerCallback default_command_callback_;
// WeakPtr factory for controlling the lifetime of command queue cleanup
// tasks.
base::WeakPtrFactory<CommandQueue> weak_ptr_factory_{this};
} // namespace weave