[Android] Java Bridge: handle requests from Java Script on the background thread

content/browser/android/java/gin_java_bound_object.h

 // 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.
 
 #ifndef CONTENT_BROWSER_ANDROID_JAVA_GIN_JAVA_BOUND_OBJECT_H_
 #define CONTENT_BROWSER_ANDROID_JAVA_GIN_JAVA_BOUND_OBJECT_H_
 
 #include <map>
 #include <set>
 
 #include "base/android/jni_weak_ref.h"
 #include "base/android/scoped_java_ref.h"
-#include "base/id_map.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/ref_counted.h"
-#include "base/memory/weak_ptr.h"
 #include "base/values.h"
 #include "content/browser/android/java/java_method.h"
 
 namespace content {
 
-class RenderFrameHost;
-
 class GinJavaBoundObject
     : public base::RefCountedThreadSafe<GinJavaBoundObject> {
  public:
-  // Using scoped_refptr<> as a value type is somewhat not IDMap had been
-  // designed for (it returns T* from lookups, so we have to de-ref it), but on
-  // the other hand, this allows us to manage lifetime of GinJavaBoundObject
-  // automatically.
-  typedef IDMap<scoped_refptr<GinJavaBoundObject>, IDMapOwnPointer> ObjectMap;
-  typedef ObjectMap::KeyType ObjectID;
+  typedef int32 ObjectID;
 
   static GinJavaBoundObject* CreateNamed(
       const JavaObjectWeakGlobalRef& ref,
       const base::android::JavaRef<jclass>& safe_annotation_clazz);
   static GinJavaBoundObject* CreateTransient(
       const JavaObjectWeakGlobalRef& ref,
       const base::android::JavaRef<jclass>& safe_annotation_clazz,
-      RenderFrameHost* holder);
+      int32 holder);
 
+  // The following methods can be called on any thread.
   JavaObjectWeakGlobalRef& GetWeakRef() { return ref_; }
   base::android::ScopedJavaLocalRef<jobject> GetLocalRef(JNIEnv* env) {
     return ref_.get(env);
   }
 
   bool IsNamed() { return names_count_ > 0; }
   void AddName() { ++names_count_; }
   void RemoveName() { --names_count_; }
 
   bool HasHolders() { return !holders_.empty(); }
-  void AddHolder(RenderFrameHost* holder) { holders_.insert(holder); }
-  void RemoveHolder(RenderFrameHost* holder) { holders_.erase(holder); }
+  void AddHolder(int32 holder) { holders_.insert(holder); }
+  void RemoveHolder(int32 holder) { holders_.erase(holder); }
 
   // The following methods are called on the background thread.
   std::set<std::string> GetMethodNames();
   bool HasMethod(const std::string& method_name);
   const JavaMethod* FindMethod(const std::string& method_name,
                                size_t num_parameters);
   bool IsObjectGetClassMethod(const JavaMethod* method);
   const base::android::JavaRef<jclass>& GetSafeAnnotationClass();
   base::android::ScopedJavaLocalRef<jclass> GetLocalClassRef(JNIEnv* env);
 
  private:
   friend class base::RefCountedThreadSafe<GinJavaBoundObject>;
 
   GinJavaBoundObject(
       const JavaObjectWeakGlobalRef& ref,
       const base::android::JavaRef<jclass>& safe_annotation_clazz);
   GinJavaBoundObject(
       const JavaObjectWeakGlobalRef& ref,
       const base::android::JavaRef<jclass>& safe_annotation_clazz,
-      const std::set<RenderFrameHost*> holders);
+      const std::set<int32> holders);

[Sami, 2014/12/08 18:52:31]

nit: Could this be a const reference instead of a value?

[mnaganov (inactive), 2014/12/09 10:23:55]

Done.

   ~GinJavaBoundObject();
 
   // The following methods are called on the background thread.
   void EnsureMethodsAreSetUp();
 
   JavaObjectWeakGlobalRef ref_;
 
   // An object must be kept in retained_object_set_ either if it has
   // names or if it has a non-empty holders set.
   int names_count_;
-  std::set<RenderFrameHost*> holders_;
+  std::set<int32> holders_;
 
   // The following fields are accessed on the background thread.
   typedef std::multimap<std::string, linked_ptr<JavaMethod> > JavaMethodMap;
   JavaMethodMap methods_;
   jmethodID object_get_class_method_id_;
   bool are_methods_set_up_;
   base::android::ScopedJavaGlobalRef<jclass> safe_annotation_clazz_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ANDROID_JAVA_GIN_JAVA_BOUND_OBJECT_H_