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 "net/url_request/url_fetcher_delegate.h"
  17 #include "net/url_request/url_request_context_getter.h"
  18 #include "url/gurl.h"
  19
  20 namespace net {
  21 class URLFetcher;
  22 }
  23
  24 namespace rappor {
  25
  26 // Uploads logs from RapporService.  Logs are passed in via QueueLog(), stored
  27 // internally, and uploaded one at a time.  A queued log will be uploaded at a
  28 // fixed interval after the successful upload of the previous logs.  If an
  29 // upload fails, the uploader will keep retrying the upload with an exponential
  30 // backoff interval.
  31 class LogUploader : public net::URLFetcherDelegate {
  32  public:
  33   // Constructor takes the |server_url| that logs should be uploaded to, the
  34   // |mime_type| of the uploaded data, and |request_context| to create uploads
  35   // with.
  36   LogUploader(const GURL& server_url,
  37               const std::string& mime_type,
  38               net::URLRequestContextGetter* request_context);
  39
  40   // If the object is destroyed (or the program terminates) while logs are
  41   // queued, the logs are lost.
  42   virtual ~LogUploader();
  43
  44   // Adds an entry to the queue of logs to be uploaded to the server.  The
  45   // uploader makes no assumptions about the format of |log| and simply sends
  46   // it verbatim to the server.
  47   void QueueLog(const std::string& log);
  48
  49  protected:
  50   // Checks if an upload has been scheduled.
  51   virtual bool IsUploadScheduled() const;
  52
  53   // Schedules a future call to StartScheduledUpload if one isn't already
  54   // pending.  Can be overridden for testing.
  55   virtual void ScheduleNextUpload(base::TimeDelta interval);
  56
  57   // Starts transmission of the next log. Exposed for tests.
  58   void StartScheduledUpload();
  59
  60   // Increases the upload interval each time it's called, to handle the case
  61   // where the server is having issues. Exposed for tests.
  62   static base::TimeDelta BackOffUploadInterval(base::TimeDelta);
  63
  64  private:
  65   // Implements net::URLFetcherDelegate. Called after transmission completes
  66   // (whether successful or not).
  67   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
  68
  69   // Called when the upload is completed.
  70   void OnUploadFinished(bool server_is_healthy, bool more_logs_remaining);
  71
  72   // The server URL to upload logs to.
  73   const GURL server_url_;
  74
  75   // The mime type to specify on uploaded logs.
  76   const std::string mime_type_;
  77
  78   // The request context used to send uploads.
  79   scoped_refptr<net::URLRequestContextGetter> request_context_;
  80
  81   // The outstanding transmission that appears as a URL Fetch operation.
  82   scoped_ptr<net::URLFetcher> current_fetch_;
  83
  84   // The logs that still need to be uploaded.
  85   std::queue<std::string> queued_logs_;
  86
  87   // A timer used to delay before attempting another upload.
  88   base::OneShotTimer<LogUploader> upload_timer_;
  89
  90   // Indicates that the last triggered upload hasn't resolved yet.
  91   bool has_callback_pending_;
  92
  93   // The interval to wait after an upload's URLFetcher completion before
  94   // starting the next upload attempt.
  95   base::TimeDelta upload_interval_;
  96
  97   DISALLOW_COPY_AND_ASSIGN(LogUploader);
  98 };
  99
 100 }  // namespace rappor
 101
 102 #endif  // COMPONENTS_RAPPOR_LOG_UPLOADER_H_