Download driver for components/download.

components/download/internal/download_driver.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_DOWNLOAD_DRIVER_H_
+#define COMPONENTS_DOWNLOAD_INTERNAL_DOWNLOAD_DRIVER_H_
+
+#include <string>
+
+#include "base/optional.h"
+#include "components/download/internal/driver_entry.h"
+
+namespace base {
+class FilePath;
+}  // namespace base
+
+namespace download {
+
+struct DownloadParams;
+
+// The interface that includes all the operations to interact with low level
+// download library functionalities.
+class DownloadDriver {
+ public:
+  // The client to receive updates from content download library.
+  // The update events for all downloads will pass through, so it's the
+  // client's responsibility to filter the events it needs to handle.
+  class Client {
+   public:
+    // Called when the low level download library is ready. |success| is true
+    // when the low level download library is ready.
+    virtual void OnDriverReady(bool success) = 0;
+
+    // Called when any download is created.
+    virtual void OnDownloadCreated(const DriverEntry& download) = 0;
+
+    // Called when any download is failed. |reason| is propagated from low level
+    // download library.
+    virtual void OnDownloadFailed(const DriverEntry& download, int reason) = 0;
+
+    // Called when any download is successfully completed.
+    virtual void OnDownloadSucceeded(const DriverEntry& download,
+                                     const base::FilePath& path) = 0;
+
+    // Called when any download is updated.
+    virtual void OnDownloadUpdated(const DriverEntry& download) = 0;
+  };
+
+  // Initialize the driver to receive download updates.
+  virtual void Initialize(Client* client) = 0;
+
+  // Returns if the driver is ready. Returns false when the driver is not
+  // initialized by the client, or low level download library has been shut
+  // down.
+  virtual bool IsReady() const = 0;
+
+  // Starts a new download.
+  virtual void Start(const DownloadParams& params) = 0;
+
+  // Cancels an existing download, all data associated with this download should
+  // be removed.
+  virtual void Cancel(const std::string& guid) = 0;
+
+  // Pauses the download.
+  virtual void Pause(const std::string& guid) = 0;
+
+  // Resumes the download
+  virtual void Resume(const std::string& guid) = 0;
+
+  // Find a download record from low level download library.
+  virtual base::Optional<DriverEntry> Find(const std::string& guid) = 0;
+};
+
+}  // namespace download
+
+#endif  // COMPONENTS_DOWNLOAD_INTERNAL_DOWNLOAD_DRIVER_H_