Added system log uploader.

chrome/browser/chromeos/policy/system_log_uploader.h

+// Copyright (c) 2015 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 CHROME_BROWSER_CHROMEOS_POLICY_SYSTEM_LOG_UPLOADER_H_
+#define CHROME_BROWSER_CHROMEOS_POLICY_SYSTEM_LOG_UPLOADER_H_
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/ref_counted_memory.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "base/time/time.h"
+#include "chrome/browser/chromeos/policy/upload_job.h"
+
+namespace base {
+class SequencedTaskRunner;
+}
+
+namespace policy {
+
+// Class responsible for periodically uploading system logs, it handles the
+// server responses by UploadJob:Delegate callbacks.
+class SystemLogUploader : public UploadJob::Delegate {
+ public:
+  // A delegate interface used by SystemLogUploader to read the system logs
+  // from the disk and create an upload job.
+  class Delegate {
+   public:
+    // Structure that stores the system log files as pairs: (file name, loaded
+    // from the disk binary file data).
+    typedef std::vector<std::pair<std::string, std::string>> SystemLogs;
+
+    typedef base::Callback<void(const SystemLogs* system_logs)>
+        LogUploadCallback;
+
+    virtual ~Delegate() {}
+
+    // Loads system logs and invokes |upload_callback|.
+    virtual void LoadSystemLogs(const LogUploadCallback& upload_callback) = 0;
+
+    // Creates a new fully configured instance of an UploadJob. This method
+    // should be only called once per every scheduled system log upload.

[Andrew T Wilson (Slow), 2015/07/31 12:07:13]

Not "should be" but "will be called exactly once per every scheduled system log
upload".

BTW, what if the upload fails and we have to retry - will we create a new
UploadJob in that case, or re-use the existing one? If the former, then we
should get rid of the word "scheduled" in the comment, and say "once per every
system log upload". If we re-use the existing one on a retry, then we should
explicitly say that.

[Polina Bondarenko, 2015/07/31 13:52:03]

Fixed, we create new upload job for every upload attempt.

+    virtual scoped_ptr<UploadJob> CreateUploadJob(
+        const GURL& upload_url,
+        UploadJob::Delegate* delegate) = 0;
+  };
+
+  explicit SystemLogUploader(
+      scoped_ptr<Delegate> syslog_delegate,
+      const scoped_refptr<base::SequencedTaskRunner>& task_runner);
+
+  ~SystemLogUploader() override;
+
+  // Returns the time of the last upload attempt, or Time(0) if no upload has
+  // ever happened.
+  base::Time last_upload_attempt() const { return last_upload_attempt_; }
+
+  // UploadJob::Delegate:
+  // Callbacks handle success and failure results of upload, destroy the
+  // upload job.
+  void OnSuccess() override;
+  void OnFailure(UploadJob::ErrorCode error_code) override;
+
+ private:
+  // Starts the system log loading process.
+  void StartLogUpload();
+
+  // Starts the system log upload.
+  void UploadSystemLogs(const Delegate::SystemLogs* system_logs);
+
+  // Helper method that figures out when the next system log upload should
+  // be scheduled.
+  void ScheduleNextSystemLogUpload(base::TimeDelta frequency);
+
+  // The number of consequent retries after the failed uploads.
+  int retry_count_;
+
+  // How long to wait between system log uploads.
+  base::TimeDelta upload_frequency_;
+
+  // The time the last upload attempt was performed.
+  base::Time last_upload_attempt_;
+
+  // TaskRunner used for scheduling upload tasks.
+  const scoped_refptr<base::SequencedTaskRunner> task_runner_;
+
+  // The upload job that is re-created on every system log upload.
+  scoped_ptr<UploadJob> upload_job_;
+
+  // The Delegate is used to load system logs and create UploadJobs.
+  scoped_ptr<Delegate> syslog_delegate_;
+
+  base::ThreadChecker thread_checker_;
+
+  // Note: This should remain the last member so it'll be destroyed and
+  // invalidate the weak pointers before any other members are destroyed.
+  base::WeakPtrFactory<SystemLogUploader> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(SystemLogUploader);
+};
+
+}  // namespace policy
+
+#endif  // CHROME_BROWSER_CHROMEOS_POLICY_SYSTEM_LOG_UPLOADER_H_