Make NSSCertDatabase::ListCerts work async on a worker thread.

net/cert/nss_cert_database.h

 // Copyright (c) 2012 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 NET_CERT_NSS_CERT_DATABASE_H_
 #define NET_CERT_NSS_CERT_DATABASE_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/callback_forward.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/string16.h"
 #include "crypto/scoped_nss_types.h"
 #include "net/base/net_export.h"
 #include "net/cert/cert_type.h"
 #include "net/cert/x509_certificate.h"
 
 namespace base {
 template <typename T> struct DefaultLazyInstanceTraits;
+class TaskRunner;
 }
 template <class ObserverType> class ObserverListThreadSafe;
 
 namespace net {
 
 class CryptoModule;
 typedef std::vector<scoped_refptr<CryptoModule> > CryptoModuleList;
 
 // Provides functions to manipulate the NSS certificate stores.
 class NET_EXPORT NSSCertDatabase {
@@ skipping 53 matching lines @@
   enum {
     TRUST_DEFAULT         =      0,
     TRUSTED_SSL           = 1 << 0,
     TRUSTED_EMAIL         = 1 << 1,
     TRUSTED_OBJ_SIGN      = 1 << 2,
     DISTRUSTED_SSL        = 1 << 3,
     DISTRUSTED_EMAIL      = 1 << 4,
     DISTRUSTED_OBJ_SIGN   = 1 << 5,
   };
 
+  typedef base::Callback<void(scoped_ptr<CertificateList> certs)>
+      ListCertsCallback;
+
   // DEPRECATED: See http://crbug.com/329735.
   static NSSCertDatabase* GetInstance();
 
   // Get a list of unique certificates in the certificate database (one
   // instance of all certificates).
-  virtual void ListCerts(CertificateList* certs);
+  // DEPRECATED by |ListCerts|. See http://crbug.com/340460.
+  virtual void ListCertsSync(CertificateList* certs);
+
+  // Asynchronously get a list of unique certificates in the certificate
+  // database (one instance of all certificates). Note that the callback may be
+  // run even after the database is deleted.
+  virtual void ListCerts(const ListCertsCallback& callback);
 
   // Get the default slot for public key data.
   virtual crypto::ScopedPK11Slot GetPublicSlot() const;
 
   // Get the default slot for private key or mixed private/public key data.
   virtual crypto::ScopedPK11Slot GetPrivateSlot() const;
 
   // Get the default module for public key data.
   // The returned pointer must be stored in a scoped_refptr<CryptoModule>.
   // DEPRECATED: use GetPublicSlot instead.
@@ skipping 92 matching lines @@
   // NOTE: CertDatabase::AddObserver should be preferred. Observers registered
   // here will only recieve notifications generated directly through the
   // NSSCertDatabase, but not those from the CertDatabase. The CertDatabase
   // observers will recieve both.
   void AddObserver(Observer* observer);
 
   // Unregisters |observer| from receiving notifications.  This must be called
   // on the same thread on which AddObserver() was called.
   void RemoveObserver(Observer* observer);
 
+  // Overrides task runner that's used for running slow tasks.
+  void SetSlowTaskRunnerForTest(
+      const scoped_refptr<base::TaskRunner>& task_runner);
+
  protected:
   NSSCertDatabase();
   virtual ~NSSCertDatabase();
 
+  // Certificate listing implementation used by |ListCerts| and |ListCertsSync|.
+  // Static so it may safely be used on the worker thread.
+  static void ListCertsImpl(CertificateList* certs);
+
+  // Gets task runner that should be used for slow tasks like certificate
+  // listing. Defaults to a base::WorkerPool runner, but may be overriden
+  // in tests (see SetSlowTaskRunnerForTest).
+  scoped_refptr<base::TaskRunner> GetSlowTaskRunner() const;
+
  private:
   friend struct base::DefaultLazyInstanceTraits<NSSCertDatabase>;
 
   // Broadcasts notifications to all registered observers.
   void NotifyObserversOfCertAdded(const X509Certificate* cert);
   void NotifyObserversOfCertRemoved(const X509Certificate* cert);
   void NotifyObserversOfCACertChanged(const X509Certificate* cert);
 
+  // Task runner that should be used in tests if set.
+  scoped_refptr<base::TaskRunner> slow_task_runner_for_test_;
+
   const scoped_refptr<ObserverListThreadSafe<Observer> > observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(NSSCertDatabase);
 };
 
 }  // namespace net
 
 #endif  // NET_CERT_NSS_CERT_DATABASE_H_