Declarative content scripts: Renderer-side: per-extension shared memory regions (lazily loaded)

extensions/renderer/user_script_set_manager.cc

+// Copyright 2014 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 "extensions/renderer/user_script_set_manager.h"
+
+#include "content/public/renderer/render_thread.h"
+#include "extensions/common/extension_messages.h"
+#include "extensions/renderer/dispatcher.h"
+#include "extensions/renderer/user_script_set.h"
+#include "ipc/ipc_message.h"
+#include "ipc/ipc_message_macros.h"
+#include "third_party/WebKit/public/web/WebFrame.h"
+
+namespace extensions {
+
+UserScriptSetManager::UserScriptSetManager(const ExtensionSet* extensions)
+    : static_scripts_(extensions), extensions_(extensions) {
+  content::RenderThread::Get()->AddObserver(this);
+}
+
+UserScriptSetManager::~UserScriptSetManager() {
+}
+
+void UserScriptSetManager::AddObserver(Observer* observer) {
+  observers_.AddObserver(observer);
+}
+
+void UserScriptSetManager::RemoveObserver(Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+bool UserScriptSetManager::OnControlMessageReceived(
+    const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(UserScriptSetManager, message)
+  IPC_MESSAGE_HANDLER(ExtensionMsg_UpdateUserScripts, OnUpdateUserScripts)

[Devlin, 2014/07/28 18:15:27]

nit: Even though git cl format doesn't like it, we indent these, like so:
IPC_BEGIN...
  IPC_MESSAGE...
  IPC_MESSAGE...
IPC_END...

[Mark Dittmer, 2014/07/29 16:59:31]

Done.

+  IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+const UserScriptSet* UserScriptSetManager::ProgrammaticScripts(
+    const ExtensionId& extension_id) {
+  UserScriptSetMap::const_iterator it =
+      programmatic_scripts_.find(extension_id);
+  if (it == programmatic_scripts_.end()) {

[Devlin, 2014/07/28 18:15:28]

nit: no brackets - although I'd probably opt for a ternary here, anyway:
return it != programmatic_scripts_.end() ? it->second.get() : NULL;

[Mark Dittmer, 2014/07/29 16:59:31]

Done.

+    return NULL;
+  }
+
+  return it->second.get();
+}
+
+void UserScriptSetManager::GetAllInjections(
+    ScopedVector<ScriptInjection>* injections,
+    blink::WebFrame* web_frame,
+    int tab_id,
+    UserScript::RunLocation run_location) {
+  static_scripts_.GetInjections(injections, web_frame, tab_id, run_location);
+  for (UserScriptSetMap::iterator it = programmatic_scripts_.begin();
+       it != programmatic_scripts_.end();
+       ++it) {
+    it->second->GetInjections(injections, web_frame, tab_id, run_location);
+  }
+}
+
+void UserScriptSetManager::GetAllActiveExtensionIds(
+    std::set<std::string>* ids) const {

[Devlin, 2014/07/28 18:15:28]

Just for safety, let's throw in a DCHECK(ids) here.

[Mark Dittmer, 2014/07/29 16:59:31]

Done.

+  static_scripts_.GetActiveExtensionIds(ids);
+  for (UserScriptSetMap::const_iterator it = programmatic_scripts_.begin();
+       it != programmatic_scripts_.end();
+       ++it) {
+    it->second->GetActiveExtensionIds(ids);
+  }
+}
+
+void UserScriptSetManager::OnUpdateUserScripts(
+    base::SharedMemoryHandle shared_memory,
+    const ExtensionId& extension_id,
+    const std::set<std::string>& changed_extensions) {
+  UserScriptSet* scripts = NULL;
+  if (extension_id != "") {

[Devlin, 2014/07/28 18:15:27]

nit: if (!extension_id.empty())

[Mark Dittmer, 2014/07/29 16:59:30]

Done.

+    if (programmatic_scripts_.find(extension_id) !=

[Devlin, 2014/07/28 18:15:27]

This strikes me as wrong.
if there IS an entry, replace it
else create the default (NULL) entry.

Should this be (heavily abbreviated):
if (programmatic_scripts_.find(extension_id) == end)
  scripts = new UserScriptSet();
else
  scripts = programmatic_scripts[id]
?

[Mark Dittmer, 2014/07/29 16:59:30]

Done.

+        programmatic_scripts_.end()) {
+      scripts = new UserScriptSet(extensions_);
+      programmatic_scripts_[extension_id] = make_linked_ptr(scripts);
+    } else {
+      scripts = programmatic_scripts_[extension_id].get();
+    }
+  } else {
+    scripts = &static_scripts_;
+  }
+  if (scripts &&

[Devlin, 2014/07/28 18:15:27]

sanity check: Can |scripts| ever be NULL?  It looks like we're always doing
something for it...

[Mark Dittmer, 2014/07/29 16:59:30]

Done.

+      scripts->OnUpdateUserScripts(shared_memory, changed_extensions)) {
+    FOR_EACH_OBSERVER(
+        Observer,
+        observers_,
+        OnUserScriptsUpdated(changed_extensions, scripts->scripts_.get()));
+  }
+}
+
+}  // namespace extensions