PlzNavigate: AppCache support.

content/browser/appcache/appcache_navigation_handle_core.cc

+// Copyright 2016 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 "content/browser/appcache/appcache_navigation_handle_core.h"
+
+#include <map>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/lazy_instance.h"
+#include "content/browser/appcache/appcache_host.h"
+#include "content/browser/appcache/appcache_navigation_handle.h"
+#include "content/browser/appcache/appcache_service_impl.h"
+#include "content/browser/appcache/chrome_appcache_service.h"
+#include "content/public/browser/browser_thread.h"
+
+namespace {
+
+// Map of AppCache host id to the AppCacheNavigationHandleCore instance.
+// Accessed on the IO thread only.
+using AppCacheHandleMap =
+    std::map <int, content::AppCacheNavigationHandleCore*>;
+base::LazyInstance<AppCacheHandleMap> g_appcache_handle_map;
+
+}  // namespace
+
+namespace content {
+
+
+AppCacheNavigationHandleCore::AppCacheNavigationHandleCore(
+    base::WeakPtr<AppCacheNavigationHandle> ui_handle,
+    ChromeAppCacheService* appcache_service,
+    int appcache_host_id)
+    : appcache_service_(appcache_service),
+      appcache_host_id_(appcache_host_id),
+      ui_handle_(ui_handle) {
+  // The AppCacheNavigationHandleCore is created on the UI thread but
+  // should only be accessed from the IO thread afterwards.
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+}
+
+AppCacheNavigationHandleCore::~AppCacheNavigationHandleCore() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  precreated_host_.reset(nullptr);
+  auto index = g_appcache_handle_map.Get().find(appcache_host_id_);

[michaeln, 2016/12/06 21:10:46]

does .erase(id) work?

[ananta, 2016/12/06 21:38:05]

Done.

+  g_appcache_handle_map.Get().erase(index);
+}
+
+void AppCacheNavigationHandleCore::Initialize() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DCHECK(precreated_host_.get() == nullptr);
+  precreated_host_.reset(
+      new AppCacheHost(appcache_host_id_, this, GetAppCacheService()));
+
+  DCHECK(g_appcache_handle_map.Get().find(appcache_host_id_) ==
+         g_appcache_handle_map.Get().end());
+  g_appcache_handle_map.Get()[appcache_host_id_] = this;
+}
+
+// static
+std::unique_ptr<AppCacheHost> AppCacheNavigationHandleCore::GetPrecreatedHost(
+    int host_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  auto index = g_appcache_handle_map.Get().find(host_id);
+  if (index != g_appcache_handle_map.Get().end()) {
+    AppCacheNavigationHandleCore* instance = index->second;
+    DCHECK(instance);
+    return std::move(instance->precreated_host_);

[michaeln, 2016/12/06 21:10:46]

ah... you leave the entry in the map but with a nullptr

[ananta, 2016/12/06 21:38:05]

Yes. The map entry will go away when the object is deleted.

+  }
+  return std::unique_ptr<AppCacheHost>();
+}
+
+AppCacheServiceImpl* AppCacheNavigationHandleCore::GetAppCacheService() {
+  return static_cast<AppCacheServiceImpl*>(appcache_service_.get());
+}
+
+void AppCacheNavigationHandleCore::OnCacheSelected(int host_id,
+                                                   const AppCacheInfo& info) {
+  DCHECK(false);
+}
+
+void AppCacheNavigationHandleCore::OnStatusChanged(
+    const std::vector<int>& host_ids,
+    AppCacheStatus status) {
+  // Should never be called.
+  DCHECK(false);
+}
+
+void AppCacheNavigationHandleCore::OnEventRaised(
+    const std::vector<int>& host_ids,
+    AppCacheEventID event_id) {
+  // Should never be called.
+  DCHECK(false);
+}
+
+void AppCacheNavigationHandleCore::OnProgressEventRaised(
+    const std::vector<int>& host_ids,
+    const GURL& url,
+    int num_total,
+    int num_complete) {
+  // Should never be called.
+  DCHECK(false);
+}
+
+void AppCacheNavigationHandleCore::OnErrorEventRaised(
+    const std::vector<int>& host_ids,
+    const AppCacheErrorDetails& details) {
+  // Should never be called.
+  DCHECK(false);
+}
+
+void AppCacheNavigationHandleCore::OnLogMessage(int host_id,
+                                                AppCacheLogLevel log_level,
+                                                const std::string& message) {
+  // Should never be called.
+  DCHECK(false);
+}
+
+void AppCacheNavigationHandleCore::OnContentBlocked(int host_id,
+                                                    const GURL& manifest_url) {
+  // Should never be called.
+  DCHECK(false);
+}
+
+}  // namespace content