chrome/browser/chromeos/file_system_provider/request_manager.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_FILE_SYSTEM_PROVIDER_REQUEST_MANAGER_H_
   6 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_REQUEST_MANAGER_H_
   7
   8 #include <map>
   9 #include <string>
  10
  11 #include "base/callback.h"
  12 #include "base/files/file.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/memory/weak_ptr.h"
  15 #include "base/time/time.h"
  16 #include "base/timer/timer.h"
  17 #include "chrome/browser/chromeos/file_system_provider/provided_file_system_info.h"
  18 #include "chrome/browser/chromeos/file_system_provider/request_value.h"
  19
  20 namespace chromeos {
  21 namespace file_system_provider {
  22
  23 // Manages requests between the service, async utils and the providing
  24 // extensions.
  25 class RequestManager {
  26  public:
  27   class HandlerInterface {
  28    public:
  29     virtual ~HandlerInterface() {}
  30
  31     // Called when the request is created. Executes the request implementation.
  32     // Returns false in case of a execution failure.
  33     virtual bool Execute(int request_id) = 0;
  34
  35     // Success callback invoked by the providing extension in response to
  36     // Execute(). It may be called more than once, until |has_next| is set to
  37     // false.
  38     virtual void OnSuccess(int request_id,
  39                            scoped_ptr<RequestValue> result,
  40                            bool has_next) = 0;
  41
  42     // Error callback invoked by the providing extension in response to
  43     // Execute(). It can be called at most once. It can be also called if the
  44     // request is aborted due to a timeout.
  45     virtual void OnError(int request_id, base::File::Error error) = 0;
  46   };
  47
  48   RequestManager();
  49   virtual ~RequestManager();
  50
  51   // Creates a request and returns its request id (greater than 0). Returns 0 in
  52   // case of an error (eg. too many requests).
  53   int CreateRequest(scoped_ptr<HandlerInterface> handler);
  54
  55   // Handles successful response for the |request_id|. If |has_next| is false,
  56   // then the request is disposed, after handling the |response|. On error,
  57   // returns false, and the request is disposed.
  58   bool FulfillRequest(int request_id,
  59                       scoped_ptr<RequestValue> response,
  60                       bool has_next);
  61
  62   // Handles error response for the |request_id|. If handling the error fails,
  63   // returns false. Always disposes the request.
  64   bool RejectRequest(int request_id, base::File::Error error);
  65
  66   // Sets a custom timeout for tests. The new timeout value will be applied to
  67   // new requests
  68   void SetTimeoutForTests(const base::TimeDelta& timeout);
  69
  70  private:
  71   struct Request {
  72     Request();
  73     ~Request();
  74
  75     // Timer for discarding the request during a timeout.
  76     base::OneShotTimer<RequestManager> timeout_timer;
  77
  78     // Handler tied to this request.
  79     scoped_ptr<HandlerInterface> handler;
  80
  81    private:
  82     DISALLOW_COPY_AND_ASSIGN(Request);
  83   };
  84
  85   typedef std::map<int, Request*> RequestMap;
  86
  87   // Called when a request with |request_id| timeouts.
  88   void OnRequestTimeout(int request_id);
  89
  90   RequestMap requests_;
  91   int next_id_;
  92   base::TimeDelta timeout_;
  93   base::WeakPtrFactory<RequestManager> weak_ptr_factory_;
  94
  95   DISALLOW_COPY_AND_ASSIGN(RequestManager);
  96 };
  97
  98 }  // namespace file_system_provider
  99 }  // namespace chromeos
 100
 101 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_REQUEST_MANAGER_H_