Implement IPP Get-Jobs and Get-Printer-Attributes requests.

chrome/browser/chromeos/printing/cups_print_job_manager_impl.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 CHROME_BROWSER_CHROMEOS_PRINTING_CUPS_PRINT_JOB_MANAGER_IMPL_H_
 #define CHROME_BROWSER_CHROMEOS_PRINTING_CUPS_PRINT_JOB_MANAGER_IMPL_H_
 
 #include <map>
 #include <memory>
 #include <string>
 #include <unordered_map>
 #include <vector>
 
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/chromeos/printing/cups_print_job.h"
 #include "chrome/browser/chromeos/printing/cups_print_job_manager.h"
 #include "chrome/browser/chromeos/printing/printers_manager.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "printing/backend/cups_connection.h"
 
 class Profile;
 
 namespace chromeos {
 
+struct QueryResult {
+  bool success;
+  std::vector<::printing::QueueStatus> queues;
+};
+
 class CupsPrintJobManagerImpl : public CupsPrintJobManager,
                                 public content::NotificationObserver {
  public:
   explicit CupsPrintJobManagerImpl(Profile* profile);
   ~CupsPrintJobManagerImpl() override;
 
   // CupsPrintJobManager overrides:
   bool CancelPrintJob(CupsPrintJob* job) override;
   bool SuspendPrintJob(CupsPrintJob* job) override;
   bool ResumePrintJob(CupsPrintJob* job) override;
 
   // NotificationObserver overrides:
   void Observe(int type,
                const content::NotificationSource& source,
                const content::NotificationDetails& details) override;
 
  private:
   // Begin monitoring a print job for a given |printer_name| with the given
   // |title| with the pages |total_page_number|.
   bool CreatePrintJob(const std::string& printer_name,
                       const std::string& title,
                       int job_id,
                       int total_page_number);
 
   // Schedule a query of CUPS for print job status with the default delay.
   void ScheduleQuery();
   // Schedule a query of CUPS for print job status with a delay of |delay|.
   void ScheduleQuery(const base::TimeDelta& delay);
 
-  // Query CUPS for print job status.
-  void QueryCups();
+  // Schedule the CUPS query off the UI thread. Posts results back to UI thread
+  // to UpdateJobs.
+  void PostQuery();
 
   // Process jobs from CUPS and perform notifications.
-  void UpdateJobs(const std::vector<::printing::CupsJob>& jobs);
+  void UpdateJobs(const QueryResult& results);
+
+  // Mark remaining jobs as errors and remove active jobs.
+  void PurgeJobs();
 
   // Updates the state and performs the appropriate notifications.
   void JobStateUpdated(CupsPrintJob* job, CupsPrintJob::State new_state);
 
   // Ongoing print jobs.
   std::map<std::string, std::unique_ptr<CupsPrintJob>> jobs_;
 
   // Prevents multiple queries from being scheduled simultaneously.
   bool in_query_ = false;
 
+  // Records the number of consecutive times the GetJobs query has failed.
+  int retry_count_ = 0;
+
   ::printing::CupsConnection cups_connection_;
   content::NotificationRegistrar registrar_;
   base::WeakPtrFactory<CupsPrintJobManagerImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CupsPrintJobManagerImpl);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_PRINTING_CUPS_PRINT_JOB_MANAGER_IMPL_H_