// Copyright 2014 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_UPDATE_CLIENT_BACKGROUND_DOWNLOADER_WIN_H_ #define COMPONENTS_UPDATE_CLIENT_BACKGROUND_DOWNLOADER_WIN_H_ #include #include #include #include #include "base/memory/ref_counted.h" #include "base/sequence_checker.h" #include "base/time/time.h" #include "base/timer/timer.h" #include "components/update_client/crx_downloader.h" namespace base { class FilePath; class SequencedTaskRunner; } namespace update_client { // Implements a downloader in terms of the BITS service. The public interface // of this class and the CrxDownloader overrides are expected to be called // from the main sequence. The rest of the class code runs on a sequenced // task runner. The task runner must initialize COM. // // This class manages a COM client for Windows BITS. The client uses polling, // triggered by an one-shot timer, to get state updates from BITS. Since the // timer has sequence afinity, the callbacks from the timer are delegated to // a sequenced task runner, which handles all client COM interaction with // the BITS service. class BackgroundDownloader : public CrxDownloader { public: explicit BackgroundDownloader(scoped_refptr successor); private: // Overrides for CrxDownloader. ~BackgroundDownloader() override; void DoStartDownload(const GURL& url) override; // Called asynchronously on the |com_task_runner_| at different stages during // the download. |OnDownloading| can be called multiple times. // |EndDownload| switches the execution flow from the |com_task_runner_| to // the main sequence. void BeginDownload(const GURL& url); void OnDownloading(); void EndDownload(HRESULT hr); HRESULT BeginDownloadHelper(const GURL& url); // Handles the job state transitions to a final state. Returns true always // since the download has reached a final state and no further processing for // this download is needed. bool OnStateTransferred(); bool OnStateError(); bool OnStateCancelled(); bool OnStateAcknowledged(); // Handles the transition to a transient state where the job is in the // queue but not actively transferring data. Returns true if the download has // been in this state for too long and it will be abandoned, or false, if // further processing for this download is needed. bool OnStateQueued(); // Handles the job state transition to a transient error state, which may or // may not be considered final, depending on the error. Returns true if // the state is final, or false, if the download is allowed to continue. bool OnStateTransientError(); // Handles the job state corresponding to transferring data. Returns false // always since this is never a final state. bool OnStateTransferring(); void StartTimer(); void OnTimer(); // Creates or opens a job for the given url and queues it up. Returns S_OK if // a new job was created or S_FALSE if an existing job for the |url| was found // in the BITS queue. HRESULT QueueBitsJob(const GURL& url, Microsoft::WRL::ComPtr* job); HRESULT CreateOrOpenJob(const GURL& url, Microsoft::WRL::ComPtr* job); HRESULT InitializeNewJob( const Microsoft::WRL::ComPtr& job, const GURL& url); // Returns true if at the time of the call, it appears that the job // has not been making progress toward completion. bool IsStuck(); // Makes the downloaded file available to the caller by renaming the // temporary file to its destination and removing it from the BITS queue. HRESULT CompleteJob(); // Revokes the interface pointers from GIT. HRESULT ClearGit(); // Updates the BITS interface pointers so that the COM functions of these // interfaces can be called in this COM STA apartment. HRESULT UpdateInterfacePointers(); // Resets the BITS interface pointers. void ResetInterfacePointers(); // Returns the number of jobs in the BITS queue which were created by this // downloader. HRESULT GetBackgroundDownloaderJobCount(size_t* num_jobs); // Cleans up incompleted jobs that are too old. void CleanupStaleJobs(); // This sequence checker is bound to the main sequence. SEQUENCE_CHECKER(sequence_checker_); // Executes blocking COM calls to BITS. scoped_refptr com_task_runner_; // The timer has sequence affinity. This member is created and destroyed // on the main task runner. std::unique_ptr timer_; DWORD git_cookie_bits_manager_; DWORD git_cookie_job_; // COM interface pointers are valid for the thread that called // |UpdateInterfacePointers| to get pointers to COM proxies, which are valid // for that thread only. Microsoft::WRL::ComPtr bits_manager_; Microsoft::WRL::ComPtr job_; // Contains the time when the download of the current url has started. base::TimeTicks download_start_time_; // Contains the time when the BITS job is last seen making progress. base::TimeTicks job_stuck_begin_time_; // Contains the path of the downloaded file if the download was successful. base::FilePath response_; }; } // namespace update_client #endif // COMPONENTS_UPDATE_CLIENT_BACKGROUND_DOWNLOADER_WIN_H_