mukesh agrawal | 46c27cc | 2013-07-10 16:39:10 -0700 | [diff] [blame] | 1 | // Copyright (c) 2013 The Chromium OS 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 SHILL_RESULT_AGGREGATOR_H_ |
| 6 | #define SHILL_RESULT_AGGREGATOR_H_ |
| 7 | |
| 8 | #include <base/basictypes.h> |
| 9 | #include <base/memory/ref_counted.h> |
| 10 | |
| 11 | #include "shill/callbacks.h" |
| 12 | #include "shill/error.h" |
| 13 | |
| 14 | namespace shill { |
| 15 | |
| 16 | // The ResultAggregator is used to aggregate the result of multiple |
| 17 | // asynchronous operations. To use: construct a ResultAggregator, and |
| 18 | // Bind its ReportResult methods to some Callbacks. |
| 19 | // |
| 20 | // When the Callbacks are destroyed, they will drop their references |
| 21 | // to the ResultAggregator. When all references to the |
| 22 | // ResultAggregator are destroyed, the ResultAggregator will invoke |
| 23 | // the |callback| with which ResultAggregator was constructed. However, |
| 24 | // if no Callbacks invoked ReportResult, then the original |callback| |
| 25 | // will not be invoked. |
| 26 | // |
| 27 | // |callback| will see Error type of Success if all Callbacks reported |
| 28 | // Success to ResultAggregator. Otherwise, |callback| will see the first |
| 29 | // of the Errors reported to ResultAggregator. |
| 30 | class ResultAggregator : public base::RefCounted<ResultAggregator> { |
| 31 | public: |
| 32 | explicit ResultAggregator(const ResultCallback &callback); |
| 33 | virtual ~ResultAggregator(); |
| 34 | |
| 35 | void ReportResult(const Error &error); |
| 36 | |
| 37 | private: |
| 38 | const ResultCallback callback_; |
| 39 | bool got_result_; |
| 40 | Error error_; |
| 41 | |
| 42 | DISALLOW_COPY_AND_ASSIGN(ResultAggregator); |
| 43 | }; |
| 44 | |
| 45 | } // namespace shill |
| 46 | |
| 47 | #endif // SHILL_RESULT_AGGREGATOR_H_ |