Making CUPS calls non-blocking.

BUG=none
TEST=Verify proxy is not blocked on CUPS calls.

Review URL: http://codereview.chromium.org/5846001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@69357 0039d316-1c4b-4281-b951-d872f2087c98

chrome/service/cloud_print/print_system_cups.cc

@@ -31,13 +31,13 @@
 #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;
@@ -380,7 +380,10 @@ void PrintSystemCUPS::AddPrintServer(const std::string& url) {
 
   // 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 =
@@ -622,6 +625,7 @@ int PrintSystemCUPS::PrintFile(const GURL& url, const char* name,
     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);
   }
@@ -633,6 +637,7 @@ int PrintSystemCUPS::GetJobs(cups_job_t** jobs, const GURL& url,
     return cupsGetJobs(jobs, name, myjobs, whichjobs);
   } else {
     printing::HttpConnectionCUPS http(url);
+    http.SetBlocking(false);
     return cupsGetJobs2(http.http(), jobs, name, myjobs, whichjobs);
   }
 }

printing/backend/print_backend_consts.cc

@@ -8,3 +8,7 @@
 
 const char kLocationTagName[] = "location";
 const char kDriverNameTagName[] = "drivername";
+const char kCUPSPrintServerURL[] = "print_server_url";
+const char kCUPSBlocking[] = "cups_blocking";
+const char kValueTrue[] = "true";
+const char kValueFalse[] = "false";

printing/backend/print_backend_consts.h

@@ -8,5 +8,9 @@
 
 extern const char kLocationTagName[];
 extern const char kDriverNameTagName[];
+extern const char kCUPSPrintServerURL[];
+extern const char kCUPSBlocking[];
+extern const char kValueTrue[];
+extern const char kValueFalse[];
 
 #endif  // PRINTING_BACKEND_PRINT_BACKEND_CONSTS_H_

printing/backend/print_backend_cups.cc

@@ -19,6 +19,7 @@
 #include "base/values.h"
 #include "googleurl/src/gurl.h"
 #include "printing/backend/cups_helper.h"
+#include "printing/backend/print_backend_consts.h"
 
 #if !defined(OS_MACOSX)
 GCRY_THREAD_OPTION_PTHREAD_IMPL;
@@ -76,11 +77,10 @@ namespace printing {
 
 static const char kCUPSPrinterInfoOpt[] = "printer-info";
 static const char kCUPSPrinterStateOpt[] = "printer-state";
-static const char kCUPSPrintServerURL[] = "print_server_url";
 
 class PrintBackendCUPS : public PrintBackend {
  public:
-  explicit PrintBackendCUPS(const GURL& print_server_url);
+  PrintBackendCUPS(const GURL& print_server_url, bool blocking);
   virtual ~PrintBackendCUPS() {}
 
   // PrintBackend implementation.
@@ -100,10 +100,11 @@ class PrintBackendCUPS : public PrintBackend {
   FilePath GetPPD(const char* name);
 
   GURL print_server_url_;
+  bool blocking_;
 };
 
-PrintBackendCUPS::PrintBackendCUPS(const GURL& print_server_url)
-    : print_server_url_(print_server_url) {
+PrintBackendCUPS::PrintBackendCUPS(const GURL& print_server_url, bool blocking)
+    : print_server_url_(print_server_url), blocking_(blocking) {
 }
 
 void PrintBackendCUPS::EnumeratePrinters(PrinterList* printer_list) {
@@ -194,20 +195,24 @@ scoped_refptr<PrintBackend> PrintBackend::CreateInstance(
   g_gcrypt_initializer.Get();
 #endif
 
-  std::string print_server_url_str;
+  std::string print_server_url_str, cups_blocking;
   if (print_backend_settings) {
     print_backend_settings->GetString(kCUPSPrintServerURL,
                                       &print_server_url_str);
+
+    print_backend_settings->GetString(kCUPSBlocking,
+                                      &cups_blocking);
   }
   GURL print_server_url(print_server_url_str.c_str());
-  return new PrintBackendCUPS(print_server_url);
+  return new PrintBackendCUPS(print_server_url, cups_blocking == kValueTrue);
 }
 
 int PrintBackendCUPS::GetDests(cups_dest_t** dests) {
   if (print_server_url_.is_empty()) {  // Use default (local) print server.
     return cupsGetDests(dests);
   } else {
     HttpConnectionCUPS http(print_server_url_);
+    http.SetBlocking(blocking_);
     return cupsGetDests2(http.http(), dests);
   }
 }
@@ -233,7 +238,7 @@ FilePath PrintBackendCUPS::GetPPD(const char* name) {
     // To distinguish error case from the normal return, will check result file
     // size agains content length.
     HttpConnectionCUPS http(print_server_url_);
-    http.SetBlocking(false);
+    http.SetBlocking(blocking_);
     ppd_file_path = cupsGetPPD2(http.http(), name);
     // Check if the get full PPD, since non-blocking call may simply return
     // normally after timeout expired.