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1 // Copyright (c) 2012 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 CHROME_BROWSER_CHROMEOS_SYSTEM_LOGS_SYSTEM_LOGS_FETCHER_H_ | |
6 #define CHROME_BROWSER_CHROMEOS_SYSTEM_LOGS_SYSTEM_LOGS_FETCHER_H_ | |
7 | |
8 #include <map> | |
9 #include <string> | |
10 | |
11 #include "base/callback.h" | |
12 #include "base/memory/scoped_vector.h" | |
13 #include "base/memory/weak_ptr.h" | |
14 | |
15 namespace chromeos { | |
16 | |
17 typedef std::map<std::string, std::string> SystemLogsResponse; | |
18 | |
19 // Callback that the data sources use to return data. | |
20 typedef base::Callback<void(SystemLogsResponse* response)> | |
21 SysLogsSourceCallback; | |
22 | |
23 // Callback that the SystemLogsFetcher uses to return data. | |
24 typedef base::Callback<void(scoped_ptr<SystemLogsResponse> response)> | |
25 SysLogsFetcherCallback; | |
26 | |
27 // The SystemLogsSource provides a interface for the data sources that | |
28 // the SystemLogsFetcher class uses to fetch logs and other | |
29 // information. | |
30 class SystemLogsSource { | |
31 public: | |
32 // Fetches data and passes it by to the callback | |
33 virtual void Fetch(const SysLogsSourceCallback& callback) = 0; | |
34 virtual ~SystemLogsSource() {} | |
35 }; | |
36 | |
37 // The SystemLogsFetcher creates a list of data sources which must be | |
38 // classes that implement the SystemLogsSource. It's Fetch function | |
39 // receives as a parameter a callback that takes only one parameter | |
40 // SystemLogsResponse that is a map of keys and values. | |
41 // Each data source also returns a SystemLogsResponse. If two data sources | |
42 // return the same key, only the first one will be stored. | |
43 // The class runs on the UI thread. | |
44 // | |
45 // EXAMPLE: | |
46 // class Example { | |
47 // public: | |
48 // void ProcessLogs(SystemLogsResponse* response) { | |
49 // //do something with the logs | |
50 // } | |
51 // void GetLogs() { | |
52 // SystemLogsFetcher* fetcher = new SystemLogsFetcher(); | |
53 // fetcher->Fetch(base::Bind(&Example::ProcessLogs, this)); | |
54 // } | |
55 class SystemLogsFetcher { | |
56 public: | |
57 SystemLogsFetcher(); | |
58 ~SystemLogsFetcher(); | |
59 | |
60 void Fetch(const SysLogsFetcherCallback& callback); | |
61 | |
62 private: | |
63 // Callback passed to all the data sources. It merges the |data| it recieves | |
64 // into response_. When all the data sources have responded, it deletes their | |
65 // objects and returns the response to the callback_. After this it | |
66 // deletes this instance of the object. | |
67 void AddResponse(SystemLogsResponse* response); | |
68 | |
69 ScopedVector<SystemLogsSource> data_sources_; | |
70 SysLogsFetcherCallback callback_; | |
71 | |
72 scoped_ptr<SystemLogsResponse> response_; // The actual response data. | |
73 size_t num_pending_requests_; // The number of callbacks it should get. | |
74 | |
75 base::WeakPtrFactory<SystemLogsFetcher> weak_ptr_factory_; | |
76 | |
77 DISALLOW_COPY_AND_ASSIGN(SystemLogsFetcher); | |
78 }; | |
79 | |
80 } // namespace chromeos | |
81 | |
82 #endif // CHROME_BROWSER_CHROMEOS_SYSTEM_LOGS_SYSTEM_LOGS_FETCHER_H_ | |
83 | |
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