chrome/browser/chromeos/timezone/timezone_request.h

   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 CHROME_BROWSER_CHROMEOS_TIMEZONE_TIMEZONE_REQUEST_H_
   6 #define CHROME_BROWSER_CHROMEOS_TIMEZONE_TIMEZONE_REQUEST_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/callback.h"
  10 #include "base/compiler_specific.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/threading/thread_checker.h"
  14 #include "base/timer/timer.h"
  15 #include "chrome/browser/chromeos/geolocation/geoposition.h"
  16 #include "net/url_request/url_fetcher.h"
  17 #include "net/url_request/url_fetcher_delegate.h"
  18 #include "url/gurl.h"
  19
  20 namespace net {
  21 class URLRequestContextGetter;
  22 }
  23
  24 namespace chromeos {
  25
  26 struct TimeZoneResponseData {
  27   enum Status {
  28     OK,
  29     INVALID_REQUEST,
  30     OVER_QUERY_LIMIT,
  31     REQUEST_DENIED,
  32     UNKNOWN_ERROR,
  33     ZERO_RESULTS,
  34     REQUEST_ERROR  // local problem
  35   };
  36
  37   TimeZoneResponseData();
  38
  39   std::string ToStringForDebug() const;
  40
  41   double dstOffset;
  42   double rawOffset;
  43   std::string timeZoneId;
  44   std::string timeZoneName;
  45   std::string error_message;
  46   Status status;
  47 };
  48
  49 // Returns default timezone service URL.
  50 GURL DefaultTimezoneProviderURL();
  51
  52 // Takes Geoposition and sends it to a server to get local timezone information.
  53 // It performs formatting of the request and interpretation of the response.
  54 // If error occurs, request is retried until timeout.
  55 // Zero timeout indicates single request.
  56 // Request is owned and destroyed by caller (usually TimeZoneProvider).
  57 // If request is destroyed while callback has not beed called yet, request
  58 // is silently cancelled.
  59 class TimeZoneRequest : private net::URLFetcherDelegate {
  60  public:
  61   // Called when a new geo timezone information is available.
  62   // The second argument indicates whether there was a server error or not.
  63   // It is true when there was a server or network error - either no response
  64   // or a 500 error code.
  65   typedef base::Callback<void(scoped_ptr<TimeZoneResponseData> /* timezone */,
  66                               bool /* server_error */)>
  67       TimeZoneResponseCallback;
  68
  69   // |url| is the server address to which the request wil be sent.
  70   // |geoposition| is the location to query timezone for.
  71   // |sensor| if this location was determined using hardware sensor.
  72   // |retry_timeout| retry request on error until timeout.
  73   TimeZoneRequest(net::URLRequestContextGetter* url_context_getter,
  74                   const GURL& service_url,
  75                   const Geoposition& geoposition,
  76                   bool sensor,
  77                   base::TimeDelta retry_timeout);
  78
  79   virtual ~TimeZoneRequest();
  80
  81   // Initiates request.
  82   // Note: if request object is destroyed before callback is called,
  83   // request will be silently cancelled.
  84   void MakeRequest(TimeZoneResponseCallback callback);
  85
  86  private:
  87   // net::URLFetcherDelegate
  88   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
  89
  90   // Start new request.
  91   void StartRequest();
  92
  93   // Schedules retry.
  94   void Retry(bool server_error);
  95
  96   scoped_refptr<net::URLRequestContextGetter> url_context_getter_;
  97   const GURL service_url_;
  98   Geoposition geoposition_;
  99   const bool sensor_;
 100
 101   TimeZoneResponseCallback callback_;
 102
 103   GURL request_url_;
 104   scoped_ptr<net::URLFetcher> url_fetcher_;
 105
 106   // When request was actually started.
 107   base::Time request_started_at_;
 108
 109   // Absolute time, when it is passed no more retry requests are allowed.
 110   base::Time retry_timeout_abs_;
 111
 112   // Pending retry.
 113   base::OneShotTimer<TimeZoneRequest> timezone_request_scheduled_;
 114
 115   // Number of retry attempts.
 116   unsigned retries_;
 117
 118   // Creation and destruction should happen on the same thread.
 119   base::ThreadChecker thread_checker_;
 120
 121   DISALLOW_COPY_AND_ASSIGN(TimeZoneRequest);
 122 };
 123
 124 }  // namespace chromeos
 125
 126 #endif  // CHROME_BROWSER_CHROMEOS_TIMEZONE_TIMEZONE_REQUEST_H_