Quirks Client for downloading and providing display profiles

components/quirks/quirks_client.h

+// Copyright 2016 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_QUIRKS_QUIRKS_CLIENT_H_
+#define COMPONENTS_QUIRKS_QUIRKS_CLIENT_H_
+
+#include "base/files/file_path.h"
+#include "base/macros.h"
+#include "base/timer/timer.h"
+#include "net/base/backoff_entry.h"
+#include "net/url_request/url_fetcher_delegate.h"
+
+namespace quirks {
+
+class QuirksManager;
+
+using DownloadFinishedCallback = base::Callback<void(const base::FilePath&)>;
+
+// Handles providing data from icc and other display data files.  This may
+// involve downloading and storing files from the Quirks Server, or serving
+// these files from local, writable storage.
+class QuirksClient : public net::URLFetcherDelegate {
+ public:
+  enum RequestReason {
+    FIRST,  // Device's first server request.
+    RETRY,  // Has server file been added since last check?
+    UPDATE  // Has server file been updated since last check?
+  };
+
+  QuirksClient(int64_t product_id,
+               const DownloadFinishedCallback& on_download_finished,
+               QuirksManager* manager);
+  ~QuirksClient() override;
+
+  void StartDownload();
+
+ private:
+  // Send callback and self delete when done.
+  void Shutdown(bool success);
+
+  // Schedules retry.
+  void Retry();
+
+  // net::URLFetcherDelegate:
+  void OnURLFetchComplete(const net::URLFetcher* source) override;
+
+  // Write |data| to |file_path|.
+  static bool WriteIccFile(const base::FilePath file_path,
+                           const std::string& data);
+
+  // Translate json with base64-encoded data (|result|) into raw |data|.
+  bool ParseResult(const std::string& result, std::string* data);
+
+  // ID of display to request from Quirks Server.
+  const int64_t product_id_;
+
+  // Callback supplied by caller.
+  const DownloadFinishedCallback on_download_finished_;
+
+  QuirksManager* manager_;

[stevenjb, 2016/02/16 20:07:51]

Add a comment that this is a weak pointer guaranteed to outlive this class.

[Greg Levin, 2016/02/17 23:01:51]

Done.

+
+  // Full path to icc file.
+  const base::FilePath icc_path_;
+
+  // This fetcher is used to download icc file.
+  scoped_ptr<net::URLFetcher> url_fetcher_;
+
+  // Why are we making this server call?

[stevenjb, 2016/02/16 20:07:51]

Don't phrase the comment as a question. 'Reason for this server call.'

[Greg Levin, 2016/02/17 23:01:51]

Done.

+  RequestReason request_reason_;
+
+  // Pending retry.
+  base::OneShotTimer request_scheduled_;
+
+  // Controls exponential backoff of time between server checks.
+  net::BackoffEntry backoff_entry_;
+
+  // Factory for callbacks.
+  base::WeakPtrFactory<QuirksClient> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(QuirksClient);
+};
+
+}  // namespace chromeos
+
+#endif  // COMPONENTS_QUIRKS_QUIRKS_CLIENT_H_