components/rappor/log_uploader.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 COMPONENTS_RAPPOR_LOG_UPLOADER_H_
   6 #define COMPONENTS_RAPPOR_LOG_UPLOADER_H_
   7
   8 #include <queue>
   9 #include <string>
  10
  11 #include "base/compiler_specific.h"
  12 #include "base/macros.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/time/time.h"
  15 #include "base/timer/timer.h"
  16 #include "components/rappor/log_uploader_interface.h"
  17 #include "net/url_request/url_fetcher_delegate.h"
  18 #include "net/url_request/url_request_context_getter.h"
  19 #include "url/gurl.h"
  20
  21 namespace net {
  22 class URLFetcher;
  23 }
  24
  25 namespace rappor {
  26
  27 // Uploads logs from RapporService.  Logs are passed in via QueueLog(), stored
  28 // internally, and uploaded one at a time.  A queued log will be uploaded at a
  29 // fixed interval after the successful upload of the previous logs.  If an
  30 // upload fails, the uploader will keep retrying the upload with an exponential
  31 // backoff interval.
  32 class LogUploader : public net::URLFetcherDelegate,
  33                     public LogUploaderInterface {
  34  public:
  35   // Constructor takes the |server_url| that logs should be uploaded to, the
  36   // |mime_type| of the uploaded data, and |request_context| to create uploads
  37   // with.
  38   LogUploader(const GURL& server_url,
  39               const std::string& mime_type,
  40               net::URLRequestContextGetter* request_context);
  41
  42   // If the object is destroyed (or the program terminates) while logs are
  43   // queued, the logs are lost.
  44   ~LogUploader() override;
  45
  46   // LogUploaderInterface:
  47   void Start() override;
  48   void Stop() override;
  49   void QueueLog(const std::string& log) override;
  50
  51  protected:
  52   // Checks if an upload has been scheduled.
  53   virtual bool IsUploadScheduled() const;
  54
  55   // Schedules a future call to StartScheduledUpload if one isn't already
  56   // pending.  Can be overridden for testing.
  57   virtual void ScheduleNextUpload(base::TimeDelta interval);
  58
  59   // Starts transmission of the next log. Exposed for tests.
  60   void StartScheduledUpload();
  61
  62   // Increases the upload interval each time it's called, to handle the case
  63   // where the server is having issues. Exposed for tests.
  64   static base::TimeDelta BackOffUploadInterval(base::TimeDelta);
  65
  66  private:
  67   // Returns true if the uploader is allowed to start another upload.
  68   bool CanStartUpload() const;
  69
  70   // Drops excess logs until we are under the size limit.
  71   void DropExcessLogs();
  72
  73   // Implements net::URLFetcherDelegate. Called after transmission completes
  74   // (whether successful or not).
  75   void OnURLFetchComplete(const net::URLFetcher* source) override;
  76
  77   // Called when the upload is completed.
  78   void OnUploadFinished(bool server_is_healthy);
  79
  80   // The server URL to upload logs to.
  81   const GURL server_url_;
  82
  83   // The mime type to specify on uploaded logs.
  84   const std::string mime_type_;
  85
  86   // The request context used to send uploads.
  87   scoped_refptr<net::URLRequestContextGetter> request_context_;
  88
  89   // True if the uploader is currently running.
  90   bool is_running_;
  91
  92   // The outstanding transmission that appears as a URL Fetch operation.
  93   scoped_ptr<net::URLFetcher> current_fetch_;
  94
  95   // The logs that still need to be uploaded.
  96   std::queue<std::string> queued_logs_;
  97
  98   // A timer used to delay before attempting another upload.
  99   base::OneShotTimer<LogUploader> upload_timer_;
 100
 101   // Indicates that the last triggered upload hasn't resolved yet.
 102   bool has_callback_pending_;
 103
 104   // The interval to wait after an upload's URLFetcher completion before
 105   // starting the next upload attempt.
 106   base::TimeDelta upload_interval_;
 107
 108   DISALLOW_COPY_AND_ASSIGN(LogUploader);
 109 };
 110
 111 }  // namespace rappor
 112
 113 #endif  // COMPONENTS_RAPPOR_LOG_UPLOADER_H_