Make PrerenderHandle an observer of PrerenderContents.

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 "chrome/common/prerender_messages.h"
+#include "content/public/browser/render_process_host.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 "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();
+    DCHECK(!prerender_handle->IsValid());
     delete prerender_handle;
   }
 }
 
 bool PrerenderLinkManager::OnAddPrerender(int child_id,
                                           int prerender_id,
                                           const GURL& 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 = " << 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));
+  DCHECK_EQ(0u, ids_to_handle_map_.count(child_and_prerender_id));
 
-  scoped_ptr<PrerenderHandle> prerender_handle(
-      manager_->AddPrerenderFromLinkRelPrerender(
-          child_id, render_view_route_id, url, referrer, size));
-  if (prerender_handle.get()) {
+  if (PrerenderHandle* prerender_handle = manager_->
+          AddPrerenderFromLinkRelPrerender(child_id, render_view_route_id,
+                                           url, referrer, size)) {
     std::pair<IdPairToPrerenderHandleMap::iterator, bool> insert_result =
-        ids_to_handle_map_.insert(std::make_pair(
-            child_and_prerender_id, static_cast<PrerenderHandle*>(NULL)));
+        ids_to_handle_map_.insert(std::make_pair(child_and_prerender_id,
+                                                 prerender_handle));
     DCHECK(insert_result.second);
-    delete insert_result.first->second;
-    insert_result.first->second = prerender_handle.release();
+    // If we are given a prerender that is already prerendering, we have missed
+    // the start event.
+    if (prerender_handle->IsPrerendering())
+      OnPrerenderStart(prerender_handle);
+    prerender_handle->AddObserver(this);
     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);
   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;
   }
   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;
   const ChildAndPrerenderIdPair child_and_prerender_id(child_id, 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 (IdPairToPrerenderHandleMap::iterator
@@ skipping 14 matching lines @@
   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);
 }
 
+PrerenderLinkManager::IdPairToPrerenderHandleMap::iterator
+PrerenderLinkManager::FindPrerenderHandle(
+    PrerenderHandle* prerender_handle) {
+  for (IdPairToPrerenderHandleMap::iterator it = ids_to_handle_map_.begin();
+       it != ids_to_handle_map_.end(); ++it) {
+    if (it->second == prerender_handle)
+      return it;
+  }
+  NOTREACHED();
+  return ids_to_handle_map_.end();
+}
+
+void PrerenderLinkManager::OnPrerenderStart(
+    PrerenderHandle* prerender_handle) {

[mmenke, 2012/12/07 17:59:29]

Think it's worth mentioning that this is called from
PrerenderLinkManager::OnAddPrerender, except from pending prerenders, where the
handle calls OnAddPrerender in AdoptPrerenderDataFrom.

[gavinp, 2012/12/10 17:55:10]

Done.

I'm not super happy about this either; perhaps the PrerenderManager::Add() and
PrerenderContents::Start... should take a PrerenderContents/PrerenderHandle
observer argument?

+  ChildAndPrerenderIdPair child_and_prerender_id_pair =
+      FindPrerenderHandle(prerender_handle)->first;
+  const int child_id = child_and_prerender_id_pair.first;
+  const int prerender_id = child_and_prerender_id_pair.second;
+
+  if (content::RenderProcessHost* render_process_host =
+              content::RenderProcessHost::FromID(child_id)) {
+    render_process_host->Send(new PrerenderMsg_OnPrerenderStart(prerender_id));
+  }
+}
+
+void PrerenderLinkManager::OnPrerenderAddAlias(
+    PrerenderHandle* prerender_handle,
+    const GURL& alias_url) {
+  ChildAndPrerenderIdPair child_and_prerender_id_pair =
+      FindPrerenderHandle(prerender_handle)->first;
+  const int child_id = child_and_prerender_id_pair.first;
+  const int prerender_id = child_and_prerender_id_pair.second;
+
+  if (content::RenderProcessHost* render_process_host =
+              content::RenderProcessHost::FromID(child_id)) {
+    render_process_host->Send(new PrerenderMsg_OnPrerenderAddAlias(prerender_id,
+                                                                   alias_url));
+  }
+}
+
+void PrerenderLinkManager::OnPrerenderStop(
+    PrerenderHandle* prerender_handle) {
+  IdPairToPrerenderHandleMap::iterator
+      it = FindPrerenderHandle(prerender_handle);
+  ChildAndPrerenderIdPair child_and_prerender_id_pair = it->first;
+  const int child_id = child_and_prerender_id_pair.first;
+  const int prerender_id = child_and_prerender_id_pair.second;
+
+  if (content::RenderProcessHost* render_process_host =
+              content::RenderProcessHost::FromID(child_id)) {
+    render_process_host->Send(new PrerenderMsg_OnPrerenderStop(prerender_id));
+  }
+  RemovePrerender(it);
+}
+
 }  // namespace prerender