Add a method to query IPP printers for attributes.

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 <string>
+#include <utility>
 #include <vector>
 
 #include "printing/printing_export.h"
 
+// This file contains a collection of functions used to query IPP printers or
+// print servers and the related code to parse these responses.  All Get*
+// operations block on the network request and cannot be run on the UI thread.

[Carlson, 2017/05/30 17:36:42]

Can you add assertions to the relevant functions about not
running on the UI thread?  I'm sure someone's going to do it anyways by
accident.  :)

[skau, 2017/05/31 00:01:20]

I'm looking into it.  There's a migration away from thread assertions in favor
of using the TaskScheduler.

+
 namespace printing {
 
 // Represents a print job sent to the queue.
 struct PRINTING_EXPORT CupsJob {
   // Corresponds to job-state from RFC2911.
   enum JobState {
     UNKNOWN,
     PENDING,  // waiting to be processed
     HELD,  // the job has not begun printing and will not without intervention
     COMPLETED,
@@ skipping 76 matching lines @@
   ~PrinterStatus();
 
   // printer-state
   ipp_pstate_t state;
   // printer-state-reasons
   std::vector<PrinterReason> reasons;
   // printer-state-message
   std::string message;
 };
 
+struct PRINTING_EXPORT PrinterInfo {
+  PrinterInfo();
+  PrinterInfo(const PrinterInfo& info);
+
+  ~PrinterInfo();
+
+  // printer-make-and-model
+  std::string make_and_model;
+
+  // document-format-supported
+  // MIME types for supported formats.
+  std::vector<std::string> document_formats;
+
+  // ipp-versions-supported
+  // A collection of major, minor pairs.
+  std::vector<std::pair<int, int>> ipp_versions;
+
+  // Does ipp-features-supported contain 'ipp-everywhere'.
+  bool ipp_everywhere = false;
+};
+
 // Specifies classes of jobs.
 enum JobCompletionState {
   COMPLETED,  // only completed jobs
   PROCESSING  // only jobs that are being processed
 };
 
 // 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);
 
+// Queries the printer at |address| on |port| with a Get-Printer-Attributes
+// request to populate |printer_info|.  Returns false if the request failed.
+bool PRINTING_EXPORT GetPrinterInfo(const std::string& address,
+                                    const int port,
+                                    const std::string& resource,
+                                    PrinterInfo* printer_info);
+
 // Attempts to retrieve printer status using connection |http| for |printer_id|.
 // 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,
                  JobCompletionState completed,
                  std::vector<CupsJob>* jobs);
 
 }  // namespace printing
 
 #endif  // PRINTING_BACKEND_CUPS_JOBS_H_