1// Copyright 2014 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_TRANSLATE_CORE_BROWSER_TRANSLATE_URL_FETCHER_H_
6#define COMPONENTS_TRANSLATE_CORE_BROWSER_TRANSLATE_URL_FETCHER_H_
7
8#include "base/callback.h"
9#include "base/memory/scoped_ptr.h"
10#include "net/url_request/url_fetcher_delegate.h"
11#include "url/gurl.h"
12
13namespace translate {
14
15// Downloads raw Translate data such as the Translate script and the language
16// list.
17class TranslateURLFetcher : public net::URLFetcherDelegate {
18 public:
19  // Callback type for Request().
20  typedef base::Callback<void(int, bool, const std::string&)> Callback;
21
22  // Represents internal state if the fetch is completed successfully.
23  enum State {
24    IDLE,        // No fetch request was issued.
25    REQUESTING,  // A fetch request was issued, but not finished yet.
26    COMPLETED,   // The last fetch request was finished successfully.
27    FAILED,      // The last fetch request was finished with a failure.
28  };
29
30  explicit TranslateURLFetcher(int id);
31  virtual ~TranslateURLFetcher();
32
33  int max_retry_on_5xx() {
34    return max_retry_on_5xx_;
35  }
36  void set_max_retry_on_5xx(int count) {
37    max_retry_on_5xx_ = count;
38  }
39
40  const std::string& extra_request_header() {
41    return extra_request_header_;
42  }
43  void set_extra_request_header(const std::string& header) {
44    extra_request_header_ = header;
45  }
46
47  // Requests to |url|. |callback| will be invoked when the function returns
48  // true, and the request is finished asynchronously.
49  // Returns false if the previous request is not finished, or the request
50  // is omitted due to retry limitation.
51  bool Request(const GURL& url, const Callback& callback);
52
53  // Gets internal state.
54  State state() { return state_; }
55
56  // net::URLFetcherDelegate implementation:
57  virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
58
59 private:
60  // URL to send the request.
61  GURL url_;
62
63  // ID which is assigned to the URLFetcher.
64  const int id_;
65
66  // Internal state.
67  enum State state_;
68
69  // URLFetcher instance.
70  scoped_ptr<net::URLFetcher> fetcher_;
71
72  // Callback passed at Request(). It will be invoked when an asynchronous
73  // fetch operation is finished.
74  Callback callback_;
75
76  // Counts how many times did it try to fetch the language list.
77  int retry_count_;
78
79  // Max number how many times to retry on the server error
80  int max_retry_on_5xx_;
81
82  // An extra HTTP request header
83  std::string extra_request_header_;
84
85  DISALLOW_COPY_AND_ASSIGN(TranslateURLFetcher);
86};
87
88}  // namespace translate
89
90#endif  // COMPONENTS_TRANSLATE_CORE_BROWSER_TRANSLATE_URL_FETCHER_H_
91