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

printing/backend/cups_jobs.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.
+
+// Implementations of IPP requests for printer queue information.
+
+#ifndef PRINTING_BACKEND_CUPS_JOBS_H_
+#define PRINTING_BACKEND_CUPS_JOBS_H_
+
+#include <cups/cups.h>
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "printing/printing_export.h"
+
+namespace printing {
+
+// Represents a print job sent to the queue.
+struct PRINTING_EXPORT CupsJob {

[Carlson, 2017/02/24 00:02:09]

Field comments please?  At least for things that are non-obvious, like
state_reasons?

[skau, 2017/02/28 00:59:59]

Done.

+  enum JobState {
+    UNKNOWN,
+    PENDING,
+    HELD,
+    COMPLETED,
+    PROCESSING,
+    STOPPED,
+    CANCELED,
+    ABORTED
+  };
+
+  int id = -1;
+  std::string printer_id;
+  JobState state = UNKNOWN;
+  int current_pages = -1;
+  std::vector<std::string> state_reasons;
+  std::string state_message;
+  int processing_started = 0;
+};
+
+// Represents the status of a printer containing the properties printer-state,
+// printer-state-reasons, and printer-state-message.
+struct PrinterStatus {
+  struct PrinterReason {
+    // Standardized reasons from RFC2911.
+    enum Reason {
+      UNKNOWN_REASON,
+      NONE,
+      MEDIA_NEEDED,
+      MEDIA_JAM,
+      MOVING_TO_PAUSED,
+      PAUSED,
+      SHUTDOWN,
+      CONNECTING_TO_DEVICE,
+      TIMED_OUT,
+      STOPPING,
+      STOPPED_PARTLY,
+      TONER_LOW,
+      TONER_EMPTY,
+      SPOOL_AREA_FULL,
+      COVER_OPEN,
+      INTERLOCK_OPEN,
+      DOOR_OPEN,
+      INPUT_TRAY_MISSING,
+      MEDIA_LOW,
+      MEDIA_EMPTY,
+      OUTPUT_TRAY_MISSING,
+      OUTPUT_AREA_ALMOST_FULL,
+      OUTPUT_AREA_FULL,
+      MARKER_SUPPLY_LOW,
+      MARKER_SUPPLY_EMPTY,
+      MARKER_WASTE_ALMOST_FULL,
+      MARKER_WASTE_FULL,
+      FUSER_OVER_TEMP,
+      FUSER_UNDER_TEMP,
+      OPC_NEAR_EOL,
+      OPC_LIFE_OVER,
+      DEVELOPER_LOW,
+      DEVELOPER_EMPTY,
+      INTERPRETER_RESOURCE_UNAVAILABLE
+    };
+
+    enum Severity { UNKNOWN_SEVERITY, REPORT, WARNING, ERROR };
+
+    Reason reason;
+    Severity severity;
+  };
+
+  ipp_pstate_t state;
+  std::vector<PrinterReason> reasons;
+  std::string message;
+};
+
+// Extracts structured job information from the |response| for |printer_id|.
+// Extracted jobs are added to |jobs|.
+void ParseJobsResponse(ipp_t* response,
+                       const std::string& printer_id,
+                       std::vector<CupsJob>* jobs);
+
+// Attempts to extract a PrinterStatus object out of |response|.
+void ParsePrinterStatus(ipp_t* response, PrinterStatus* printer_status);
+
+// Attmepts to retrieve printer status using connection |http| for |printer_id|.

[Carlson, 2017/02/24 00:02:09]

Attempts

[skau, 2017/02/28 00:59:59]

Done.

+// Returns true if succcssful and updates the fields in |printer_status| as
+// appropriate.  Returns false if the request failed.
+bool GetPrinterStatus(http_t* http,
+                      const std::string& printer_id,
+                      PrinterStatus* printer_status);
+
+// Attempts to retrieve job information using connection |http| for the printer
+// named |printer_id|.  Retrieves at most |limit| jobs.  If |completed| then
+// completed jobs are retrieved.  Otherwise, jobs that are currently in progress
+// are retrieved.  Results are added to |jobs| if the operation was successful.
+bool GetCupsJobs(http_t* http,
+                 const std::string& printer_id,
+                 int limit,
+                 bool completed,

[Carlson, 2017/02/24 00:02:09]

Suggest renaming to "include_completed"

[skau, 2017/02/28 00:59:59]

I've changed it to an enum.  It's either completed jobs xor not-completed jobs. 
include_completed would imply that if it's true, you would get both.

+                 std::vector<CupsJob>* jobs);
+
+}  // namespace printing
+
+#endif  // PRINTING_BACKEND_CUPS_JOBS_H_