PlzNavigate: AppCache support.

content/browser/appcache/appcache_dispatcher_host.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 "content/browser/appcache/appcache_dispatcher_host.h"
 
+#include <map>
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "content/browser/appcache/chrome_appcache_service.h"
 #include "content/browser/bad_message.h"
 #include "content/common/appcache_messages.h"
+#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/user_metrics.h"
+#include "content/public/common/browser_side_navigation_policy.h"
+
+namespace {
+
+using ProcessIdToHostMap = std::map < int, content::AppCacheDispatcherHost* >;
+base::LazyInstance<ProcessIdToHostMap> g_process_id_host_map;
+
+}  // namespace
 
 namespace content {
 
 AppCacheDispatcherHost::AppCacheDispatcherHost(
     ChromeAppCacheService* appcache_service,
     int process_id)
     : BrowserMessageFilter(AppCacheMsgStart),
       appcache_service_(appcache_service),
       frontend_proxy_(this),
       process_id_(process_id),
       weak_factory_(this) {
+  g_process_id_host_map.Get()[process_id] = this;

[michaeln, 2016/12/05 21:52:54]

ok, we have to do something about accessing this map from multiple threads,
that's going to cause problems when the ui/io threads collide

i think it'd be great if we can get rid of that map altogether, that would
eliminate thread-safety issues and also the oddness with process ids that are
reused

I was just looking at how this same problem (stashing/retrieving a ptr to the
precreated host) is handled in the sw codebase, there's no global map in that
world.  I think the same technique could be used here.

The central 'service' (context_core) object is used as a means to store/retrieve
the 'host' instance, the service contains a map of ptrs to the navhandlecores
which own the precreated hosts. At RegisterHost() time (OnProviderCreated in
sw'speak) GetNavigationHandleCore() is used to retrieve the precreated object.

Take a look at how these ServiceWorkerContextCore methods are used:

  void AddNavigationHandleCore(int service_worker_provider_id,
                               ServiceWorkerNavigationHandleCore* handle);
  void RemoveNavigationHandleCore(int service_worker_provider_id);
  ServiceWorkerNavigationHandleCore* GetNavigationHandleCore(
      int service_worker_provider_id);

wdyt?

[ananta, 2016/12/06 01:24:38]

Done. Thanks for the tip. PTAL

 }
 
 void AppCacheDispatcherHost::OnChannelConnected(int32_t peer_pid) {
-  if (appcache_service_.get()) {
-    backend_impl_.Initialize(
-        appcache_service_.get(), &frontend_proxy_, process_id_);
-    get_status_callback_ =
-        base::Bind(&AppCacheDispatcherHost::GetStatusCallback,
-                    weak_factory_.GetWeakPtr());
-    start_update_callback_ =
-        base::Bind(&AppCacheDispatcherHost::StartUpdateCallback,
-                    weak_factory_.GetWeakPtr());
-    swap_cache_callback_ =
-        base::Bind(&AppCacheDispatcherHost::SwapCacheCallback,
-                    weak_factory_.GetWeakPtr());
-  }
+  if (!appcache_service_.get())
+    return;
+
+  backend_impl_.Initialize(appcache_service_.get(), &frontend_proxy_,
+                           process_id_);
+  get_status_callback_ = base::Bind(&AppCacheDispatcherHost::GetStatusCallback,
+                                    weak_factory_.GetWeakPtr());
+  start_update_callback_ = base::Bind(
+      &AppCacheDispatcherHost::StartUpdateCallback, weak_factory_.GetWeakPtr());
+  swap_cache_callback_ = base::Bind(&AppCacheDispatcherHost::SwapCacheCallback,
+                                    weak_factory_.GetWeakPtr());
 }
 
 bool AppCacheDispatcherHost::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(AppCacheDispatcherHost, message)
     IPC_MESSAGE_HANDLER(AppCacheHostMsg_RegisterHost, OnRegisterHost)
     IPC_MESSAGE_HANDLER(AppCacheHostMsg_UnregisterHost, OnUnregisterHost)
     IPC_MESSAGE_HANDLER(AppCacheHostMsg_SetSpawningHostId, OnSetSpawningHostId)
     IPC_MESSAGE_HANDLER(AppCacheHostMsg_GetResourceList, OnGetResourceList)
     IPC_MESSAGE_HANDLER(AppCacheHostMsg_SelectCache, OnSelectCache)
     IPC_MESSAGE_HANDLER(AppCacheHostMsg_SelectCacheForWorker,
                         OnSelectCacheForWorker)
     IPC_MESSAGE_HANDLER(AppCacheHostMsg_SelectCacheForSharedWorker,
                         OnSelectCacheForSharedWorker)
     IPC_MESSAGE_HANDLER(AppCacheHostMsg_MarkAsForeignEntry,
                         OnMarkAsForeignEntry)
     IPC_MESSAGE_HANDLER_DELAY_REPLY(AppCacheHostMsg_GetStatus, OnGetStatus)
     IPC_MESSAGE_HANDLER_DELAY_REPLY(AppCacheHostMsg_StartUpdate, OnStartUpdate)
     IPC_MESSAGE_HANDLER_DELAY_REPLY(AppCacheHostMsg_SwapCache, OnSwapCache)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
   return handled;
 }
 
-AppCacheDispatcherHost::~AppCacheDispatcherHost() {}
+AppCacheDispatcherHost::~AppCacheDispatcherHost() {
+  ProcessIdToHostMap::iterator index =
+      g_process_id_host_map.Get().find(process_id_);
+  if ((index != g_process_id_host_map.Get().end()) && index->second == this)
+    g_process_id_host_map.Get().erase(index);
+}
+
+void AppCacheDispatcherHost::RegisterPrecreatedHost(
+    std::unique_ptr<AppCacheHost> host) {
+  DCHECK(host.get());
+  DCHECK(IsBrowserSideNavigationEnabled());
+  backend_impl_.RegisterPrecreatedHost(std::move(host));
+}
 
 void AppCacheDispatcherHost::OnRegisterHost(int host_id) {
   if (appcache_service_.get()) {
     if (!backend_impl_.RegisterHost(host_id)) {
       bad_message::ReceivedBadMessage(this, bad_message::ACDH_REGISTER);
     }
   }
 }
 
 void AppCacheDispatcherHost::OnUnregisterHost(int host_id) {
@@ skipping 11 matching lines @@
       bad_message::ReceivedBadMessage(this, bad_message::ACDH_SET_SPAWNING);
   }
 }
 
 void AppCacheDispatcherHost::OnSelectCache(
     int host_id,
     const GURL& document_url,
     int64_t cache_document_was_loaded_from,
     const GURL& opt_manifest_url) {
   if (appcache_service_.get()) {
-    if (!backend_impl_.SelectCache(host_id,
-                                   document_url,
+    if (!backend_impl_.SelectCache(host_id, document_url,
                                    cache_document_was_loaded_from,
                                    opt_manifest_url)) {
       bad_message::ReceivedBadMessage(this, bad_message::ACDH_SELECT_CACHE);
     }
   } else {
     frontend_proxy_.OnCacheSelected(host_id, AppCacheInfo());
   }
 }
 
 void AppCacheDispatcherHost::OnSelectCacheForWorker(
     int host_id, int parent_process_id, int parent_host_id) {
   if (appcache_service_.get()) {
-    if (!backend_impl_.SelectCacheForWorker(
-            host_id, parent_process_id, parent_host_id)) {
+    if (!backend_impl_.SelectCacheForWorker(host_id, parent_process_id,
+                                            parent_host_id)) {
       bad_message::ReceivedBadMessage(
           this, bad_message::ACDH_SELECT_CACHE_FOR_WORKER);
     }
   } else {
     frontend_proxy_.OnCacheSelected(host_id, AppCacheInfo());
   }
 }
 
 void AppCacheDispatcherHost::OnSelectCacheForSharedWorker(int host_id,
                                                           int64_t appcache_id) {
   if (appcache_service_.get()) {
     if (!backend_impl_.SelectCacheForSharedWorker(host_id, appcache_id))
       bad_message::ReceivedBadMessage(
           this, bad_message::ACDH_SELECT_CACHE_FOR_SHARED_WORKER);
   } else {
     frontend_proxy_.OnCacheSelected(host_id, AppCacheInfo());
   }
 }
 
 void AppCacheDispatcherHost::OnMarkAsForeignEntry(
     int host_id,
     const GURL& document_url,
     int64_t cache_document_was_loaded_from) {
   if (appcache_service_.get()) {
-    if (!backend_impl_.MarkAsForeignEntry(
-            host_id, document_url, cache_document_was_loaded_from)) {
+    if (!backend_impl_.MarkAsForeignEntry(host_id, document_url,
+                                          cache_document_was_loaded_from)) {
       bad_message::ReceivedBadMessage(this,
                                       bad_message::ACDH_MARK_AS_FOREIGN_ENTRY);
     }
   }
 }
 
 void AppCacheDispatcherHost::OnGetResourceList(
     int host_id, std::vector<AppCacheResourceInfo>* params) {
   if (appcache_service_.get())
     backend_impl_.GetResourceList(host_id, params);
 }
 
 void AppCacheDispatcherHost::OnGetStatus(int host_id, IPC::Message* reply_msg) {
   if (pending_reply_msg_) {
     bad_message::ReceivedBadMessage(
         this, bad_message::ACDH_PENDING_REPLY_IN_GET_STATUS);
     delete reply_msg;
     return;
   }
 
   pending_reply_msg_.reset(reply_msg);
   if (appcache_service_.get()) {
-    if (!backend_impl_.GetStatusWithCallback(
-            host_id, get_status_callback_, reply_msg)) {
+    if (!backend_impl_.GetStatusWithCallback(host_id, get_status_callback_,
+                                             reply_msg)) {
       bad_message::ReceivedBadMessage(this, bad_message::ACDH_GET_STATUS);
     }
     return;
   }
 
   GetStatusCallback(APPCACHE_STATUS_UNCACHED, reply_msg);
 }
 
 void AppCacheDispatcherHost::OnStartUpdate(int host_id,
                                            IPC::Message* reply_msg) {
   if (pending_reply_msg_) {
     bad_message::ReceivedBadMessage(
         this, bad_message::ACDH_PENDING_REPLY_IN_START_UPDATE);
     delete reply_msg;
     return;
   }
 
   pending_reply_msg_.reset(reply_msg);
   if (appcache_service_.get()) {
-    if (!backend_impl_.StartUpdateWithCallback(
-            host_id, start_update_callback_, reply_msg)) {
+    if (!backend_impl_.StartUpdateWithCallback(host_id, start_update_callback_,
+                                               reply_msg)) {
       bad_message::ReceivedBadMessage(this, bad_message::ACDH_START_UPDATE);
     }
     return;
   }
 
   StartUpdateCallback(false, reply_msg);
 }
 
 void AppCacheDispatcherHost::OnSwapCache(int host_id, IPC::Message* reply_msg) {
   if (pending_reply_msg_) {
     bad_message::ReceivedBadMessage(
         this, bad_message::ACDH_PENDING_REPLY_IN_SWAP_CACHE);
     delete reply_msg;
     return;
   }
 
   pending_reply_msg_.reset(reply_msg);
   if (appcache_service_.get()) {
-    if (!backend_impl_.SwapCacheWithCallback(
-            host_id, swap_cache_callback_, reply_msg)) {
+    if (!backend_impl_.SwapCacheWithCallback(host_id, swap_cache_callback_,
+                                             reply_msg)) {
       bad_message::ReceivedBadMessage(this, bad_message::ACDH_SWAP_CACHE);
     }
     return;
   }
 
   SwapCacheCallback(false, reply_msg);
 }
 
 void AppCacheDispatcherHost::GetStatusCallback(
     AppCacheStatus status, void* param) {
@@ skipping 10 matching lines @@
   Send(pending_reply_msg_.release());
 }
 
 void AppCacheDispatcherHost::SwapCacheCallback(bool result, void* param) {
   IPC::Message* reply_msg = reinterpret_cast<IPC::Message*>(param);
   DCHECK_EQ(pending_reply_msg_.get(), reply_msg);
   AppCacheHostMsg_SwapCache::WriteReplyParams(reply_msg, result);
   Send(pending_reply_msg_.release());
 }
 
+// static
+scoped_refptr<AppCacheDispatcherHost> AppCacheDispatcherHost::GetHostForProcess(
+    int process_id) {
+  ProcessIdToHostMap::iterator index =
+      g_process_id_host_map.Get().find(process_id);
+  if (index == g_process_id_host_map.Get().end())
+    return scoped_refptr<AppCacheDispatcherHost>();
+  return index->second;
+}
+
 }  // namespace content