New link rel=prerender api, using WebKit::WebPrerenderingPlatform

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_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() {
+}
+
+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) << "... render_view_route_id = " << render_view_route_id

[cbentzel, 2012/05/04 15:32:25]

May as well DVLOG(3) the size. 

[gavinp, 2012/05/04 23:10:51]

Done.

+           << ", referrer url = " << referrer.url.spec();
+  // 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;
+  }
+  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;
+}
+
+// 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()) {
+    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);
+}
+
+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);
+}
+
+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);
+       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();
+}
+
+}  // namespace prerender
+