Add more of the server-side plumbing for extension APIs. Also

chrome/browser/extensions/extension_function_dispatcher.cc

+// Copyright (c) 2009 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/extensions/extension_function_dispatcher.h"
+
+#include "base/json_reader.h"
+#include "base/json_writer.h"
+#include "base/singleton.h"
+#include "base/values.h"
+#include "chrome/browser/extensions/extension_function.h"
+#include "chrome/browser/extensions/extension_tabs_module.h"
+#include "chrome/browser/renderer_host/render_view_host.h"
+
+// FactoryRegistry -------------------------------------------------------------
+
+namespace {
+
+// A pointer to a function that create an instance of an ExtensionFunction.
+typedef ExtensionFunction* (*ExtensionFunctionFactory)();
+
+// Contains a list of all known extension functions and allows clients to create
+// instances of them.
+class FactoryRegistry {
+ public:
+  static FactoryRegistry* instance();
+  FactoryRegistry();
+  void GetAllNames(std::vector<std::string>* names);
+  ExtensionFunction* NewFunction(const std::string& name);
+
+ private:
+  typedef std::map<std::string, ExtensionFunctionFactory> FactoryMap;
+  FactoryMap factories_;
+};
+
+// Template for defining ExtensionFunctionFactory.
+template<class T>
+ExtensionFunction* NewExtensionFunction() {
+  return new T();
+}
+
+FactoryRegistry* FactoryRegistry::instance() {
+  return Singleton<FactoryRegistry>::get();
+}
+
+FactoryRegistry::FactoryRegistry() {
+  // Register all functions here.
+  factories_["GetTabsForWindow"] =
+      &NewExtensionFunction<GetTabsForWindowFunction>;
+  factories_["CreateTab"] = &NewExtensionFunction<CreateTabFunction>;
+}
+
+void FactoryRegistry::GetAllNames(
+    std::vector<std::string>* names) {
+  for (FactoryMap::iterator iter = factories_.begin(); iter != factories_.end();
+       ++iter) {
+    names->push_back(iter->first);
+  }
+}
+
+ExtensionFunction* FactoryRegistry::NewFunction(const std::string& name) {
+  FactoryMap::iterator iter = factories_.find(name);
+  DCHECK(iter != factories_.end());
+  return iter->second();
+}
+
+};
+
+
+// ExtensionFunctionDispatcher -------------------------------------------------
+
+void ExtensionFunctionDispatcher::GetAllFunctionNames(
+    std::vector<std::string>* names) {
+  FactoryRegistry::instance()->GetAllNames(names);
+}
+
+ExtensionFunctionDispatcher::ExtensionFunctionDispatcher(
+    RenderViewHost* render_view_host)
+  : render_view_host_(render_view_host) {}
+
+void ExtensionFunctionDispatcher::HandleRequest(const std::string& name,
+                                                const std::string& args,
+                                                int callback_id) {
+  scoped_ptr<Value> value;
+  if (!args.empty()) {
+    JSONReader reader;
+    value.reset(reader.JsonToValue(args, false, false));
+
+    // Since we do the serialization in the v8 extension, we should always get
+    // valid JSON.
+    if (!value.get()) {
+      DCHECK(false);
+      return;
+    }
+  }
+
+  // TODO(aa): This will get a bit more complicated when we support functions
+  // that live longer than the stack frame.
+  scoped_ptr<ExtensionFunction> function(
+      FactoryRegistry::instance()->NewFunction(name));
+  function->set_dispatcher(this);
+  function->set_args(value.get());
+  function->set_callback_id(callback_id);
+  function->Run();
+}
+
+void ExtensionFunctionDispatcher::SendResponse(ExtensionFunction* function) {
+  std::string json;
+
+  // Some functions might not need to return any results.
+  if (function->result())
+    JSONWriter::Write(function->result(), false, &json);
+
+  render_view_host_->SendExtensionResponse(function->callback_id(), json);
+}