[Doodle] Pull time_to_live out of DoodleConfig

components/doodle/doodle_fetcher_impl.h

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_DOODLE_DOODLE_FETCHER_IMPL_H_
 #define COMPONENTS_DOODLE_DOODLE_FETCHER_IMPL_H_
 
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/optional.h"
 #include "components/doodle/doodle_fetcher.h"
 #include "components/doodle/doodle_types.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "url/gurl.h"
 
 class GoogleURLTracker;
 
 namespace base {
 class DictionaryValue;
+class TimeDelta;
 class Value;
 }
 
 namespace doodle {
 
 // This class provides information about any recent doodle.
 // It works asynchronously and calls a callback when finished fetching the
 // information from the remote enpoint.
 class DoodleFetcherImpl : public DoodleFetcher, public net::URLFetcherDelegate {
  public:
@@ skipping 17 matching lines @@
 
  private:
   // net::URLFetcherDelegate implementation.
   void OnURLFetchComplete(const net::URLFetcher* source) override;
 
   // ParseJSONCallback Success callback
   void OnJsonParsed(std::unique_ptr<base::Value> json);
   // ParseJSONCallback Failure callback
   void OnJsonParseFailed(const std::string& error_message);
 
-  base::Optional<DoodleConfig> ParseDoodle(
-      const base::DictionaryValue& ddljson) const;
+  base::Optional<DoodleConfig> ParseDoodle(const base::DictionaryValue& ddljson,
+                                           base::TimeDelta* time_to_live) const;

[mastiz, 2017/03/02 19:55:42]

Optional: wouldn't it be cleaner to return a Optional<pair<DoodleConfig,
TimeDelta>> and possibly rename to ParseDoodleConfigAndTimeToLive? 

[Marc Treib, 2017/03/03 09:35:26]

Renamed.

I don't like std::pair much - IMO it often makes things hard to read. A struct
would be an option, but TBH I don't think it's worth the hassle of
packing/unpacking and std::move'ing the DoodleConfig itself...

   bool ParseImage(const base::DictionaryValue& image_dict,
                   const std::string& image_name,
                   DoodleImage* image) const;
   void ParseBaseInformation(const base::DictionaryValue& ddljson,
-                            DoodleConfig* config) const;
+                            DoodleConfig* config,
+                            base::TimeDelta* time_to_live) const;
   GURL ParseRelativeUrl(const base::DictionaryValue& dict_value,
                         const std::string& key) const;
 
   void RespondToAllCallbacks(DoodleState state,
+                             base::TimeDelta time_to_live,
                              const base::Optional<DoodleConfig>& config);

[mastiz, 2017/03/02 19:55:42]

Ditto: perhaps a typedef or struct could also help.

[Marc Treib, 2017/03/03 09:35:26]

Same: Unless you feel strongly, I don't think it's worth it.

[mastiz, 2017/03/03 11:17:44]

I was certainly not feeling strongly, so it's fine. What I dislike about the
current signature is that it's not clear that the function returns both or
neither.

   GURL GetGoogleBaseUrl() const;
 
   // Returns whether a fetch is still in progress. A fetch begins when a
   // callback is added and ends when the last callback was called.
   bool IsFetchInProgress() const { return !callbacks_.empty(); }
 
   // Parameters set from constructor.
   scoped_refptr<net::URLRequestContextGetter> const download_context_;
   ParseJSONCallback json_parsing_callback_;
   GoogleURLTracker* google_url_tracker_;
 
   std::vector<FinishedCallback> callbacks_;
   std::unique_ptr<net::URLFetcher> fetcher_;
 
   base::WeakPtrFactory<DoodleFetcherImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DoodleFetcherImpl);
 };
 
 }  // namespace doodle
 
 #endif  // COMPONENTS_DOODLE_DOODLE_FETCHER_IMPL_H_