Making CUPS calls non-blocking....

chrome/service/cloud_print/print_system_cups.cc

 // Copyright (c) 2010 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.
 
 #include "chrome/service/cloud_print/print_system.h"
 
 #include <cups/cups.h>
 #include <dlfcn.h>
 #include <errno.h>
 #include <pthread.h>
@@ skipping 13 matching lines @@
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/task.h"
 #include "base/values.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/service/cloud_print/cloud_print_consts.h"
 #include "chrome/service/cloud_print/cloud_print_helpers.h"
 #include "googleurl/src/gurl.h"
 #include "printing/backend/cups_helper.h"
 #include "printing/backend/print_backend.h"
+#include "printing/backend/print_backend_consts.h"
 
 namespace {
 static const char kCUPSPrinterInfoOpt[] = "printer-info";
 static const char kCUPSPrinterStateOpt[] = "printer-state";
 static const char kCUPSPrintServerURLs[] = "print_server_urls";
 static const char kCUPSUpdateTimeoutMs[] = "update_timeout_ms";
-static const char kCUPSPrintBackendServerURL[] = "print_server_url";
 
 // Default port for IPP print servers.
 static const int kDefaultIPPServerPort = 631;
 
 // Time interval to check for printer's updates.
 const int kCheckForPrinterUpdatesMs = 6*60*60*1000;
 
 // Job update timeput
 const int kJobUpdateTimeoutMs = 5000;
 
@@ skipping 322 matching lines @@
   if (print_servers_.empty())
     AddPrintServer(std::string());
 }
 
 void PrintSystemCUPS::AddPrintServer(const std::string& url) {
   if (url.empty())
     LOG(WARNING) << "No print server specified. Using default print server.";
 
   // Get Print backend for the specific print server.
   DictionaryValue backend_settings;
-  backend_settings.SetString(kCUPSPrintBackendServerURL, url);
+  backend_settings.SetString(kCUPSPrintServerURL, url);
+
+  // Make CUPS requests non-blocking.
+  backend_settings.SetString(kCUPSBlocking, kValueFalse);
 
   PrintServerInfoCUPS print_server;
   print_server.backend =
     printing::PrintBackend::CreateInstance(&backend_settings);
   print_server.url = GURL(url.c_str());
 
   print_servers_.push_back(print_server);
 }
 
 void PrintSystemCUPS::Init() {
@@ skipping 221 matching lines @@
   return new PrintSystemCUPS(print_system_settings);
 }
 
 int PrintSystemCUPS::PrintFile(const GURL& url, const char* name,
                                const char* filename, const char* title,
                                int num_options, cups_option_t* options) {
   if (url.is_empty()) {  // Use default (local) print server.
     return cupsPrintFile(name, filename, title, num_options, options);
   } else {
     printing::HttpConnectionCUPS http(url);
+    http.SetBlocking(false);
     return cupsPrintFile2(http.http(), name, filename,
                           title, num_options, options);
   }
 }
 
 int PrintSystemCUPS::GetJobs(cups_job_t** jobs, const GURL& url,
                              const char* name, int myjobs, int whichjobs) {
   if (url.is_empty()) {  // Use default (local) print server.
     return cupsGetJobs(jobs, name, myjobs, whichjobs);
   } else {
     printing::HttpConnectionCUPS http(url);
+    http.SetBlocking(false);
     return cupsGetJobs2(http.http(), jobs, name, myjobs, whichjobs);
   }
 }
 
 PlatformJobId PrintSystemCUPS::SpoolPrintJob(
     const std::string& print_ticket,
     const FilePath& print_data_file_path,
     const std::string& print_data_mime_type,
     const std::string& printer_name,
     const std::string& job_title,
@@ skipping 80 matching lines @@
       *short_printer_name = full_printer_name.substr(separator + 1);
       return &(*it);
     }
   }
 
   LOG(WARNING) << "Server not found for printer: " << full_printer_name;
   return NULL;
 }
 
 }  // namespace cloud_print