Initial RemoteCommandService

components/policy/core/common/remote_commands/remote_commands_service.h

Index: components/policy/core/common/remote_commands/remote_commands_service.h
diff --git a/components/policy/core/common/remote_commands/remote_commands_service.h b/components/policy/core/common/remote_commands/remote_commands_service.h
new file mode 100644
index 0000000000000000000000000000000000000000..6308ef8f386ae4fa139b9f5c3e3980c8125b1cdd
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+++ b/components/policy/core/common/remote_commands/remote_commands_service.h
@@ -0,0 +1,106 @@
+// Copyright 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 COMPONENTS_POLICY_CORE_COMMON_REMOTE_COMMANDS_REMOTE_COMMANDS_SERVICE_H_
+#define COMPONENTS_POLICY_CORE_COMMON_REMOTE_COMMANDS_REMOTE_COMMANDS_SERVICE_H_
+
+#include <deque>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "components/policy/core/common/cloud/cloud_policy_constants.h"
+#include "components/policy/core/common/remote_commands/remote_command_job.h"
+#include "components/policy/core/common/remote_commands/remote_commands_queue.h"
+#include "components/policy/policy_export.h"
+#include "policy/proto/device_management_backend.pb.h"
+
+namespace base {
+class Clock;
+}  // namespace base
+
+namespace policy {
+
+class CloudPolicyClient;
+class RemoteCommandsFactory;
+
+// Service class which will connect to a CloudPolicyClient in order to fetch
+// remote commands from DMServer and send results for executed commands
+// back to the server.
+class POLICY_EXPORT RemoteCommandsService
+    : public RemoteCommandsQueue::Observer {
+ public:
+  RemoteCommandsService(scoped_ptr<RemoteCommandsFactory> factory,
+                        CloudPolicyClient* client);
+  ~RemoteCommandsService() override;
+
+  // Attempts to fetch remote commands, mainly supposed to be called by
+  // invalidation service. Note that there will be at most one ongoing fetch
+  // request and all other fetch request will be enqueued if another fetch
+  // request is in-progress. And in such a case, another request will be made
+  // immediately after the current ongoing request finishes.
+  // Returns true if the new request was started immediately. Returns false if
+  // another request was in progress already and the new request got enqueued.
+  bool FetchRemoteCommands();
+
+  // Returns whether a command fetch request is in progress or not.
+  bool IsCommandFetchInProgressForTesting() const {
+    return command_fetch_in_progress_;
+  }
+
+  // Set an alternative clock for testing.
+  void SetClockForTesting(scoped_ptr<base::Clock> clock);
+
+ private:
+  // Helper function to enqueue a command which we get from server.
+  void EnqueueCommand(const enterprise_management::RemoteCommand& command);
+
+  // RemoteCommandsQueue::Observer:
+  void OnJobStarted(RemoteCommandJob* command) override;
+  void OnJobFinished(RemoteCommandJob* command) override;
+
+  // Callback to handle commands we get from the server.
+  void OnRemoteCommandsFetched(
+      DeviceManagementStatus status,
+      const std::vector<enterprise_management::RemoteCommand>& commands);
+
+  // Whether there is a command fetch on going or not.
+  bool command_fetch_in_progress_ = false;
+
+  // Whether there is an enqueued fetch request, which indicates there were
+  // additional FetchRemoteCommands() calls while a fetch request was ongoing.
+  bool has_enqueued_fetch_request_ = false;
+
+  // Command results that have not been sent back to the server yet.
+  std::vector<enterprise_management::RemoteCommandResult> unsent_results_;
+
+  // Whether an command exists or not.

[bartfab (slow), 2015/03/17 14:01:22]

You changed this comment from "Whether an executed command exists or not," which
was ambiguous, to "Whether an command exists or not," which is even more
ambiguous. Based on the member name, it should probably be:

// Whether at least one command has finished executing.

[binjin, 2015/03/18 10:09:38]

Done.

+  bool has_finished_command_ = false;
+
+  // ID of the latest command which has finished execution if
+  // |has_finished_command_| is true. We will acknowledge this ID to the
+  // server so that we can re-fetch commands that have not been executed yet
+  // after a crash or browser restart.
+  RemoteCommandJob::UniqueIDType lastest_finished_command_id_;
+
+  // Collects the IDs of all fetched commands. We need this since the command ID
+  // is opaque.
+  // IDs will be stored in the order that they are fetched from the server,
+  // and acknowledging a command will discard its ID from
+  // |fetched_command_ids_|, as well as IDs of every command before it.

[bartfab (slow), 2015/03/17 14:01:22]

Nit: s/IDs/the IDs/

[binjin, 2015/03/18 10:09:38]

Done.

+  std::deque<RemoteCommandJob::UniqueIDType> fetched_command_ids_;
+
+  RemoteCommandsQueue queue_;
+  scoped_ptr<RemoteCommandsFactory> factory_;
+  CloudPolicyClient* const client_;
+
+  base::WeakPtrFactory<RemoteCommandsService> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(RemoteCommandsService);
+};
+
+}  // namespace policy
+
+#endif  // COMPONENTS_POLICY_CORE_COMMON_REMOTE_COMMANDS_REMOTE_COMMANDS_SERVICE_H_