Add initial Controller to DownloadService

components/download/internal/controller_impl.h

+// Copyright 2017 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 COMPONENTS_DOWNLOAD_INTERNAL_CONTROLLER_IMPL_H_
+#define COMPONENTS_DOWNLOAD_INTERNAL_CONTROLLER_IMPL_H_
+
+#include <map>
+#include <memory>
+
+#include "base/macros.h"
+#include "base/optional.h"
+#include "components/download/internal/controller.h"
+#include "components/download/internal/download_driver.h"
+#include "components/download/internal/model.h"
+#include "components/download/internal/startup_status.h"
+#include "components/download/public/download_params.h"
+
+namespace download {
+
+class ClientSet;
+class DownloadDriver;
+class Model;
+
+struct Configuration;
+struct SchedulingParams;
+
+// The internal Controller implementation.  This class does all of the heavy
+// lifting for the DownloadService.
+class ControllerImpl : public Controller,
+                       public DownloadDriver::Client,
+                       public Model::Client {
+ public:
+  // |clients| is externally owned and must be guaranteed to outlive this class.
+  ControllerImpl(std::unique_ptr<ClientSet> clients,
+                 std::unique_ptr<Configuration> config,
+                 std::unique_ptr<DownloadDriver> driver,
+                 std::unique_ptr<Model> model);
+  ~ControllerImpl() override;
+
+  // Controller implementation.
+  void Initialize() override;
+  const StartupStatus& GetStartupStatus() override;
+  void StartDownload(const DownloadParams& params) override;
+  void PauseDownload(const std::string& guid) override;
+  void ResumeDownload(const std::string& guid) override;
+  void CancelDownload(const std::string& guid) override;
+  void ChangeDownloadCriteria(const std::string& guid,
+                              const SchedulingParams& params) override;
+  DownloadClient GetOwnerOfDownload(const std::string& guid) override;
+
+ private:
+  // DownloadDriver::Client implementation.
+  void OnDriverReady(bool success) override;
+  void OnDownloadCreated(const DriverEntry& download) override;
+  void OnDownloadFailed(const DriverEntry& download, int reason) override;
+  void OnDownloadSucceeded(const DriverEntry& download,
+                           const base::FilePath& path) override;
+  void OnDownloadUpdated(const DriverEntry& download) override;
+
+  // Model::Client implementation.
+  void OnModelReady(bool success) override;
+  void OnItemAdded(bool success,
+                   DownloadClient client,
+                   const std::string& guid) override;
+  void OnItemUpdated(bool success,
+                     DownloadClient client,
+                     const std::string& guid) override;
+  void OnItemRemoved(bool success,
+                     DownloadClient client,
+                     const std::string& guid) override;
+
+  // Checks if initialization is complete and successful.  If so, completes the
+  // internal state initialization.
+  void AttemptToFinalizeSetup();
+
+  // Cancels and cleans upany requests that are no longer associated with a
+  // Client in |clients_|.
+  void CancelOrphanedRequests();
+
+  // Fixes any discrepencies in state between |model_| and |driver_|.  Meant to
+  // resolve state issues during startup.
+  void ResolveInitialRequestStates();
+
+  // Notifies all Client in |clients_| that this controller is initialized and
+  // lets them know which download requests we are aware of for their
+  // DownloadClient.
+  void NotifyClientsOfStartup();
+
+  // Pulls the current state of requests from |model_| and |driver_| and sets
+  // the other internal states appropriately.
+  void PullCurrentRequestStatus();
+
+  void HandleStartDownloadResponse(DownloadClient client,
+                                   const std::string& guid,
+                                   DownloadParams::StartResult result);
+  void HandleStartDownloadResponse(
+      DownloadClient client,
+      const std::string& guid,
+      DownloadParams::StartResult result,
+      const DownloadParams::StartCallback& callback);
+
+  std::unique_ptr<ClientSet> clients_;
+  std::unique_ptr<Configuration> config_;
+
+  // Owned Dependencies.
+  std::unique_ptr<DownloadDriver> driver_;
+  std::unique_ptr<Model> model_;
+
+  // Internal state.
+  StartupStatus startup_status_;
+  std::map<std::string, DownloadParams::StartCallback> start_callbacks_;
+
+  DISALLOW_COPY_AND_ASSIGN(ControllerImpl);
+};
+
+}  // namespace download
+
+#endif  // COMPONENTS_DOWNLOAD_INTERNAL_CONTROLLER_IMPL_H_