components/policy/core/common/external_data_manager.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_POLICY_CORE_COMMON_EXTERNAL_DATA_MANAGER_H_
   6 #define COMPONENTS_POLICY_CORE_COMMON_EXTERNAL_DATA_MANAGER_H_
   7
   8 #include <string>
   9
  10 #include "components/policy/core/common/external_data_fetcher.h"
  11 #include "components/policy/policy_export.h"
  12
  13 namespace policy {
  14
  15 // Downloads, verifies, caches and retrieves external data referenced by
  16 // policies.
  17 // An implementation of this abstract interface should be provided for each
  18 // policy source (cloud policy, platform policy) that supports external data
  19 // references.
  20 class POLICY_EXPORT ExternalDataManager {
  21  public:
  22   // Retrieves the external data referenced by |policy| and invokes |callback|
  23   // with the result. If |policy| does not reference any external data, the
  24   // |callback| is invoked with a NULL pointer. Otherwise, the |callback| is
  25   // invoked with the referenced data once it has been successfully retrieved.
  26   // If retrieval is temporarily impossible (e.g. no network connectivity), the
  27   // |callback| will be invoked when the temporary hindrance is resolved. If
  28   // retrieval is permanently impossible (e.g. |policy| references data that
  29   // does not exist on the server), the |callback| will never be invoked.
  30   virtual void Fetch(const std::string& policy,
  31                      const ExternalDataFetcher::FetchCallback& callback) = 0;
  32 };
  33
  34 }  // namespace policy
  35
  36 #endif  // COMPONENTS_POLICY_CORE_COMMON_EXTERNAL_DATA_MANAGER_H_