Handle interface to prerenders.

chrome/browser/prerender/prerender_link_manager.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.
 
 #include "chrome/browser/prerender/prerender_link_manager.h"
 
 #include <limits>
 #include <queue>
 #include <utility>
 
 #include "chrome/browser/prerender/prerender_contents.h"
+#include "chrome/browser/prerender/prerender_handle.h"
 #include "chrome/browser/prerender/prerender_manager.h"
 #include "chrome/browser/prerender/prerender_manager_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/session_storage_namespace.h"
 #include "content/public/common/referrer.h"
 #include "googleurl/src/gurl.h"
 #include "googleurl/src/url_canon.h"
 #include "ui/gfx/size.h"
 
 using content::RenderViewHost;
 using content::SessionStorageNamespace;
 
 namespace prerender {
 
 PrerenderLinkManager::PrerenderLinkManager(PrerenderManager* manager)
     : manager_(manager) {
 }
 
 PrerenderLinkManager::~PrerenderLinkManager() {
+  for (IdPairToPrerenderHandleMap::iterator it = ids_to_handle_map_.begin();
+       it != ids_to_handle_map_.end();
+       ++it) {
+    PrerenderHandle* prerender_handle = it->second;
+    prerender_handle->OnCancel();
+    delete prerender_handle;

[mmenke, 2012/07/13 14:49:11]

Do we have a unit test that exercises this code?  Only runs when we're
destroying the PrerenderManager, too, so not much to worry about in terms of
leaks, but nice to make sure we don't DCHECK.

[gavinp, 2012/07/13 16:42:43]

In the unit test destructor, we call OnChannelClosing. Without this code, that
causes some of the tests to fail due to MANAGER_SHUTDOWN. I think that the CL
that gets profile dependency right can let us remove the OnChannelClosing, and
then we'll use this code in every unit test.

If you remove the OnChannelClosing call _and_ this code, the unit test leaks
about 32 handles.

+  }
 }
 
 bool PrerenderLinkManager::OnAddPrerender(int child_id,
                                           int prerender_id,
                                           const GURL& orig_url,
                                           const content::Referrer& referrer,
                                           const gfx::Size& size,
                                           int render_view_route_id) {
   DVLOG(2) << "OnAddPrerender, child_id = " << child_id
            << ", prerender_id = " << prerender_id
            << ", url = " << orig_url.spec();
   DVLOG(3) << "... referrer url = " << referrer.url.spec()
            << ", size = (" << size.width() << ", " << size.height() << ")"
            << ", render_view_route_id = " << render_view_route_id;
 
+  const ChildAndPrerenderIdPair child_and_prerender_id(child_id, prerender_id);
+  DCHECK_EQ(0U, ids_to_handle_map_.count(child_and_prerender_id));
+
   // TODO(gavinp): Add tests to ensure fragments work, then remove this fragment
   // clearing code.
   url_canon::Replacements<char> replacements;
   replacements.ClearRef();
   const GURL url = orig_url.ReplaceComponents(replacements);
 
-  if (!manager_->AddPrerenderFromLinkRelPrerender(
-          child_id, render_view_route_id, url, referrer, size)) {
-    return false;
+  scoped_ptr<PrerenderHandle> prerender_handle(
+      manager_->AddPrerenderFromLinkRelPrerender(
+          child_id, render_view_route_id, url, referrer, size));
+  if (prerender_handle.get()) {
+    std::pair<IdPairToPrerenderHandleMap::iterator, bool> insert_result =
+        ids_to_handle_map_.insert(IdPairToPrerenderHandleMap::value_type(
+            child_and_prerender_id, NULL));
+    DCHECK(insert_result.second);
+    delete insert_result.first->second;
+    insert_result.first->second = prerender_handle.release();
+    return true;
   }
-  const ChildAndPrerenderIdPair child_and_prerender_id(child_id, prerender_id);
-  DCHECK_EQ(0U, ids_to_url_map_.count(child_and_prerender_id));
-  ids_to_url_map_.insert(std::make_pair(child_and_prerender_id, url));
-  return true;
+  return false;
 }
 
 // TODO(gavinp): Once an observer interface is provided down to the WebKit
 // layer, we should add DCHECK_NE(0L, ids_to_url_map_.count(...)) to both
 // OnCancelPrerender and OnAbandonPrerender. We can't do this now, since
 // the WebKit layer isn't even aware if we didn't add the prerender to the map
 // in OnAddPrerender above.
 void PrerenderLinkManager::OnCancelPrerender(int child_id, int prerender_id) {
   DVLOG(2) << "OnCancelPrerender, child_id = " << child_id
            << ", prerender_id = " << prerender_id;
   const ChildAndPrerenderIdPair child_and_prerender_id(child_id, prerender_id);
-  IdPairToUrlMap::iterator id_url_iter =
-      ids_to_url_map_.find(child_and_prerender_id);
-  if (id_url_iter == ids_to_url_map_.end()) {
+  IdPairToPrerenderHandleMap::iterator id_to_handle_iter =
+      ids_to_handle_map_.find(child_and_prerender_id);
+  if (id_to_handle_iter == ids_to_handle_map_.end()) {
     DVLOG(5) << "... canceling a prerender that doesn't exist.";
     return;
   }
-  const GURL url = id_url_iter->second;
-  ids_to_url_map_.erase(id_url_iter);
-  manager_->MaybeCancelPrerender(url);
+  PrerenderHandle* prerender_handle = id_to_handle_iter->second;
+  prerender_handle->OnCancel();
+  RemovePrerender(id_to_handle_iter);
 }
 
 void PrerenderLinkManager::OnAbandonPrerender(int child_id, int prerender_id) {
   DVLOG(2) << "OnAbandonPrerender, child_id = " << child_id
            << ", prerender_id = " << prerender_id;
-  // TODO(gavinp,cbentzel): Implement reasonable behaviour for
-  // navigation away from launcher.
   const ChildAndPrerenderIdPair child_and_prerender_id(child_id, prerender_id);
-  ids_to_url_map_.erase(child_and_prerender_id);
+  IdPairToPrerenderHandleMap::iterator id_to_handle_iter =
+      ids_to_handle_map_.find(child_and_prerender_id);
+  if (id_to_handle_iter == ids_to_handle_map_.end())
+    return;
+  PrerenderHandle* prerender_handle = id_to_handle_iter->second;
+  prerender_handle->OnNavigateAway();
+  RemovePrerender(id_to_handle_iter);
 }
 
 void PrerenderLinkManager::OnChannelClosing(int child_id) {
   DVLOG(2) << "OnChannelClosing, child id = " << child_id;
   const ChildAndPrerenderIdPair child_and_minimum_prerender_id(
       child_id, std::numeric_limits<int>::min());
   const ChildAndPrerenderIdPair child_and_maximum_prerender_id(
       child_id, std::numeric_limits<int>::max());
   std::queue<int> prerender_ids_to_abandon;
-  for (IdPairToUrlMap::iterator
-           i = ids_to_url_map_.lower_bound(child_and_minimum_prerender_id),
-           e = ids_to_url_map_.upper_bound(child_and_maximum_prerender_id);
+  for (IdPairToPrerenderHandleMap::iterator
+           i = ids_to_handle_map_.lower_bound(child_and_minimum_prerender_id),
+           e = ids_to_handle_map_.upper_bound(child_and_maximum_prerender_id);
        i != e; ++i) {
     prerender_ids_to_abandon.push(i->first.second);
   }
   while (!prerender_ids_to_abandon.empty()) {
     DVLOG(4) << "---> abandon prerender_id = "
              << prerender_ids_to_abandon.front();
     OnAbandonPrerender(child_id, prerender_ids_to_abandon.front());
     prerender_ids_to_abandon.pop();
   }
 }
 
 bool PrerenderLinkManager::IsEmpty() const {
-  return ids_to_url_map_.empty();
+  return ids_to_handle_map_.empty();
+}
+
+void PrerenderLinkManager::RemovePrerender(
+    const IdPairToPrerenderHandleMap::iterator& id_to_handle_iter) {
+  PrerenderHandle* prerender_handle = id_to_handle_iter->second;
+  delete prerender_handle;
+  ids_to_handle_map_.erase(id_to_handle_iter);
 }
 
 }  // namespace prerender
-