Move most of ChromeV8Context to a base ScriptContext

chrome/renderer/extensions/module_system.h

-// 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.
-
-#ifndef CHROME_RENDERER_EXTENSIONS_MODULE_SYSTEM_H_
-#define CHROME_RENDERER_EXTENSIONS_MODULE_SYSTEM_H_
-
-#include "base/compiler_specific.h"
-#include "base/memory/linked_ptr.h"
-#include "base/memory/scoped_ptr.h"
-#include "chrome/renderer/extensions/object_backed_native_handler.h"
-#include "extensions/renderer/native_handler.h"
-#include "v8/include/v8.h"
-
-#include <map>
-#include <set>
-#include <string>
-#include <vector>
-
-namespace extensions {
-
-class ChromeV8Context;
-
-// A module system for JS similar to node.js' require() function.
-// Each module has three variables in the global scope:
-//   - exports, an object returned to dependencies who require() this
-//     module.
-//   - require, a function that takes a module name as an argument and returns
-//     that module's exports object.
-//   - requireNative, a function that takes the name of a registered
-//     NativeHandler and returns an object that contains the functions the
-//     NativeHandler defines.
-//
-// Each module in a ModuleSystem is executed at most once and its exports
-// object cached.
-//
-// Note that a ModuleSystem must be used only in conjunction with a single
-// v8::Context.
-// TODO(koz): Rename this to JavaScriptModuleSystem.
-class ModuleSystem : public ObjectBackedNativeHandler {
- public:
-  class SourceMap {
-   public:
-    virtual ~SourceMap() {}
-    virtual v8::Handle<v8::Value> GetSource(v8::Isolate* isolate,
-                                            const std::string& name) = 0;
-    virtual bool Contains(const std::string& name) = 0;
-  };
-
-  class ExceptionHandler {
-   public:
-    virtual ~ExceptionHandler() {}
-    virtual void HandleUncaughtException(const v8::TryCatch& try_catch) = 0;
-
-   protected:
-    // Formats |try_catch| as a nice string.
-    std::string CreateExceptionString(const v8::TryCatch& try_catch);
-  };
-
-  // Enables native bindings for the duration of its lifetime.
-  class NativesEnabledScope {
-   public:
-    explicit NativesEnabledScope(ModuleSystem* module_system);
-    ~NativesEnabledScope();
-
-   private:
-    ModuleSystem* module_system_;
-    DISALLOW_COPY_AND_ASSIGN(NativesEnabledScope);
-  };
-
-  // |source_map| is a weak pointer.
-  ModuleSystem(ChromeV8Context* context, SourceMap* source_map);
-  virtual ~ModuleSystem();
-
-  // Require the specified module. This is the equivalent of calling
-  // require('module_name') from the loaded JS files.
-  v8::Handle<v8::Value> Require(const std::string& module_name);
-  void Require(const v8::FunctionCallbackInfo<v8::Value>& args);
-
-  // Run |code| in the current context with the name |name| used for stack
-  // traces.
-  v8::Handle<v8::Value> RunString(v8::Handle<v8::String> code,
-                                  v8::Handle<v8::String> name);
-
-  // Calls the specified method exported by the specified module. This is
-  // equivalent to calling require('module_name').method_name() from JS.
-  v8::Local<v8::Value> CallModuleMethod(const std::string& module_name,
-                                        const std::string& method_name);
-  v8::Local<v8::Value> CallModuleMethod(
-      const std::string& module_name,
-      const std::string& method_name,
-      std::vector<v8::Handle<v8::Value> >* args);
-  v8::Local<v8::Value> CallModuleMethod(
-      const std::string& module_name,
-      const std::string& method_name,
-      int argc,
-      v8::Handle<v8::Value> argv[]);
-
-  // Register |native_handler| as a potential target for requireNative(), so
-  // calls to requireNative(|name|) from JS will return a new object created by
-  // |native_handler|.
-  void RegisterNativeHandler(const std::string& name,
-                             scoped_ptr<NativeHandler> native_handler);
-
-  // Causes requireNative(|name|) to look for its module in |source_map_|
-  // instead of using a registered native handler. This can be used in unit
-  // tests to mock out native modules.
-  void OverrideNativeHandlerForTest(const std::string& name);
-
-  // Executes |code| in the current context with |name| as the filename.
-  void RunString(const std::string& code, const std::string& name);
-
-  // Make |object|.|field| lazily evaluate to the result of
-  // require(|module_name|)[|module_field|].
-  //
-  // TODO(kalman): All targets for this method are ObjectBackedNativeHandlers,
-  //               move this logic into those classes (in fact, the chrome
-  //               object is the only client, only that needs to implement it).
-  void SetLazyField(v8::Handle<v8::Object> object,
-                    const std::string& field,
-                    const std::string& module_name,
-                    const std::string& module_field);
-
-  void SetLazyField(v8::Handle<v8::Object> object,
-                    const std::string& field,
-                    const std::string& module_name,
-                    const std::string& module_field,
-                    v8::AccessorGetterCallback getter);
-
-  // Make |object|.|field| lazily evaluate to the result of
-  // requireNative(|module_name|)[|module_field|].
-  // TODO(kalman): Same as above.
-  void SetNativeLazyField(v8::Handle<v8::Object> object,
-                          const std::string& field,
-                          const std::string& module_name,
-                          const std::string& module_field);
-
-  // Passes exceptions to |handler| rather than console::Fatal.
-  void SetExceptionHandlerForTest(scoped_ptr<ExceptionHandler> handler) {
-    exception_handler_ = handler.Pass();
-  }
-
- protected:
-  friend class ChromeV8Context;
-  virtual void Invalidate() OVERRIDE;
-
- private:
-  typedef std::map<std::string, linked_ptr<NativeHandler> > NativeHandlerMap;
-
-  // Retrieves the lazily defined field specified by |property|.
-  static void LazyFieldGetter(v8::Local<v8::String> property,
-                              const v8::PropertyCallbackInfo<v8::Value>& info);
-  // Retrieves the lazily defined field specified by |property| on a native
-  // object.
-  static void NativeLazyFieldGetter(
-      v8::Local<v8::String> property,
-      const v8::PropertyCallbackInfo<v8::Value>& info);
-
-  // Called when an exception is thrown but not caught.
-  void HandleException(const v8::TryCatch& try_catch);
-
-  // Ensure that require_ has been evaluated from require.js.
-  void EnsureRequireLoaded();
-
-  void RequireForJs(const v8::FunctionCallbackInfo<v8::Value>& args);
-  v8::Local<v8::Value> RequireForJsInner(v8::Handle<v8::String> module_name);
-
-  typedef v8::Handle<v8::Value> (ModuleSystem::*RequireFunction)(
-      const std::string&);
-  // Base implementation of a LazyFieldGetter which uses |require_fn| to require
-  // modules.
-  static void LazyFieldGetterInner(
-      v8::Local<v8::String> property,
-      const v8::PropertyCallbackInfo<v8::Value>& info,
-      RequireFunction require_function);
-
-  // Return the named source file stored in the source map.
-  // |args[0]| - the name of a source file in source_map_.
-  v8::Handle<v8::Value> GetSource(const std::string& module_name);
-
-  // Return an object that contains the native methods defined by the named
-  // NativeHandler.
-  // |args[0]| - the name of a native handler object.
-  v8::Handle<v8::Value> RequireNativeFromString(const std::string& native_name);
-  void RequireNative(const v8::FunctionCallbackInfo<v8::Value>& args);
-
-  // Wraps |source| in a (function(require, requireNative, exports) {...}).
-  v8::Handle<v8::String> WrapSource(v8::Handle<v8::String> source);
-
-  // NativeHandler implementation which returns the private area of an Object.
-  void Private(const v8::FunctionCallbackInfo<v8::Value>& args);
-
-  // NativeHandler implementation which returns a function wrapper for a
-  // provided function.
-  void CreateFunctionWrapper(const v8::FunctionCallbackInfo<v8::Value>& args);
-
-  ChromeV8Context* context_;
-
-  // A map from module names to the JS source for that module. GetSource()
-  // performs a lookup on this map.
-  SourceMap* source_map_;
-
-  // A map from native handler names to native handlers.
-  NativeHandlerMap native_handler_map_;
-
-  // When 0, natives are disabled, otherwise indicates how many callers have
-  // pinned natives as enabled.
-  int natives_enabled_;
-
-  // Called when an exception is thrown but not caught in JS. Overridable by
-  // tests.
-  scoped_ptr<ExceptionHandler> exception_handler_;
-
-  std::set<std::string> overridden_native_handlers_;
-
-  DISALLOW_COPY_AND_ASSIGN(ModuleSystem);
-};
-
-}  // namespace extensions
-
-#endif  // CHROME_RENDERER_EXTENSIONS_MODULE_SYSTEM_H_