Port HistoryService::QueryRedirects{From,To} to CancelableTaskTracker

chrome/browser/history/history_service.cc

 // Copyright (c) 2012 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.
 
 // The history system runs on a background thread so that potentially slow
 // database operations don't delay the browser. This backend processing is
 // represented by HistoryBackend. The HistoryService's job is to dispatch to
 // that thread.
 //
 // Main thread                       History thread
@@ skipping 68 matching lines @@
     const favicon_base::FaviconRawBitmapCallback& callback,
     favicon_base::FaviconRawBitmapResult* bitmap_result) {
   callback.Run(*bitmap_result);
 }
 
 void RunWithQueryURLResult(const HistoryService::QueryURLCallback& callback,
                            const history::QueryURLResult* result) {
   callback.Run(result->success, result->row, result->visits);
 }
 
+void RunWithQueryRedirectsResult(

[droger, 2014/06/23 16:50:35]

If I understand correctly, you need this helper just because you want to use
base::Owned so that the callback owns your request.
This feels a bit strange, but I don't have a really better solution...

One way to avoid this maybe would be to have QueryRedirectsFrom return a new
QueryRedirectsResult, and then you can use PostTaskAndReplyWithResult.
It's not clear if it's better though, so feel free to keep your code as is.

[sdefresne, 2014/06/24 13:41:00]

PostTaskAndReplyWithResult does not works with CancelableTaskTracker.

+    const HistoryService::QueryRedirectsCallback& callback,
+    const GURL& url,
+    const history::QueryRedirectsResult* result) {
+  callback.Run(url, result->success, &result->redirects);
+}
+
 // Extract history::URLRows into GURLs for VisitedLinkMaster.
 class URLIteratorFromURLRows
     : public visitedlink::VisitedLinkMaster::URLIterator {
  public:
   explicit URLIteratorFromURLRows(const history::URLRows& url_rows)
       : itr_(url_rows.begin()),
         end_(url_rows.end()) {
   }
 
   virtual const GURL& NextURL() OVERRIDE {
@@ skipping 691 matching lines @@
       thread_->message_loop_proxy().get(),
       FROM_HERE,
       base::Bind(&HistoryBackend::QueryHistory,
                  history_backend_.get(),
                  text_query,
                  options,
                  base::Unretained(query_results)),
       base::Bind(callback, base::Owned(query_results)));
 }
 
-HistoryService::Handle HistoryService::QueryRedirectsFrom(
+base::CancelableTaskTracker::TaskId HistoryService::QueryRedirectsFrom(

[droger, 2014/06/23 16:50:35]

Is this function actually used? I see it only called in tests.

[sdefresne, 2014/06/24 13:41:00]

It's only called from unit tests and browser tests but I don't think it is the
job of componentization to decide whether code should be removed or not. I'll
add a ticket to track removal.

     const GURL& from_url,
-    CancelableRequestConsumerBase* consumer,
-    const QueryRedirectsCallback& callback) {
+    const QueryRedirectsCallback& callback,
+    base::CancelableTaskTracker* tracker) {
   DCHECK(thread_checker_.CalledOnValidThread());
-  return Schedule(PRIORITY_UI, &HistoryBackend::QueryRedirectsFrom, consumer,
-      new history::QueryRedirectsRequest(callback), from_url);
+  history::QueryRedirectsResult* result = new history::QueryRedirectsResult();
+  return tracker->PostTaskAndReply(
+      thread_->message_loop_proxy().get(),
+      FROM_HERE,
+      base::Bind(&HistoryBackend::QueryRedirectsFrom,
+                 history_backend_.get(),
+                 from_url,
+                 base::Unretained(result)),
+      base::Bind(&RunWithQueryRedirectsResult,
+                 callback,
+                 from_url,
+                 base::Owned(result)));
 }
 
-HistoryService::Handle HistoryService::QueryRedirectsTo(
+base::CancelableTaskTracker::TaskId HistoryService::QueryRedirectsTo(
     const GURL& to_url,
-    CancelableRequestConsumerBase* consumer,
-    const QueryRedirectsCallback& callback) {
+    const QueryRedirectsCallback& callback,
+    base::CancelableTaskTracker* tracker) {
   DCHECK(thread_checker_.CalledOnValidThread());
-  return Schedule(PRIORITY_NORMAL, &HistoryBackend::QueryRedirectsTo, consumer,
-      new history::QueryRedirectsRequest(callback), to_url);
+  history::QueryRedirectsResult* result = new history::QueryRedirectsResult();
+  return tracker->PostTaskAndReply(
+      thread_->message_loop_proxy().get(),
+      FROM_HERE,
+      base::Bind(&HistoryBackend::QueryRedirectsTo,
+                 history_backend_.get(),
+                 to_url,
+                 base::Unretained(result)),
+      base::Bind(
+          &RunWithQueryRedirectsResult, callback, to_url, base::Owned(result)));
 }
 
 HistoryService::Handle HistoryService::GetVisibleVisitCountToHost(
     const GURL& url,
     CancelableRequestConsumerBase* consumer,
     const GetVisibleVisitCountToHostCallback& callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
   return Schedule(PRIORITY_UI, &HistoryBackend::GetVisibleVisitCountToHost,
       consumer, new history::GetVisibleVisitCountToHostRequest(callback), url);
 }
@@ skipping 354 matching lines @@
   DCHECK(thread_checker_.CalledOnValidThread());
   visit_database_observers_.RemoveObserver(observer);
 }
 
 void HistoryService::NotifyVisitDBObserversOnAddVisit(
     const history::BriefVisitInfo& info) {
   DCHECK(thread_checker_.CalledOnValidThread());
   FOR_EACH_OBSERVER(history::VisitDatabaseObserver, visit_database_observers_,
                     OnAddVisit(info));
 }