Android: lazy initialization for method id.

base/android/jni_android.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 "base/android/jni_android.h"
 
 #include <map>
 
 #include "base/android/build_info.h"
+#include "base/android/jni_method_id.h"
 #include "base/android/jni_string.h"
-#include "base/atomicops.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/threading/platform_thread.h"
 
 namespace {
 using base::android::GetClass;
 using base::android::GetMethodID;
 using base::android::ScopedJavaLocalRef;
 
 struct MethodIdentifier {
@@ skipping 68 matching lines @@
 
   // Call ByteArrayOutputStream.toString()
   ScopedJavaLocalRef<jstring> exception_string(
       env, static_cast<jstring>(
           env->CallObjectMethod(bytearray_output_stream.obj(),
                                 bytearray_output_stream_tostring)));
 
   return ConvertJavaStringToUTF8(exception_string);
 }
 
-enum MethodType {
-  METHODTYPE_STATIC,
-  METHODTYPE_NORMAL,
-};
-
-enum ExceptionCheck {
-  EXCEPTIONCHECK_YES,
-  EXCEPTIONCHECK_NO,
-};
-
-template<MethodType method_type, ExceptionCheck exception_check>
-jmethodID GetMethodIDInternal(JNIEnv* env,
-                              jclass clazz,
-                              const char* method_name,
-                              const char* jni_signature) {
-  jmethodID method_id = method_type == METHODTYPE_STATIC ?
-      env->GetStaticMethodID(clazz, method_name, jni_signature) :
-      env->GetMethodID(clazz, method_name, jni_signature);
-  if (exception_check == EXCEPTIONCHECK_YES) {
-    CHECK(!base::android::ClearException(env) && method_id) <<
-      "Failed to find " <<
-      (method_type == METHODTYPE_STATIC ? "static " : "") <<
-      "method " << method_name << " " << jni_signature;
-  } else if (base::android::HasException(env)) {
-    env->ExceptionClear();
-  }
-  return method_id;
-}
-
 }  // namespace
 
 namespace base {
 namespace android {
 
 JNIEnv* AttachCurrentThread() {
   if (!g_jvm)
     return NULL;
   JNIEnv* env = NULL;
   jint ret = g_jvm->AttachCurrentThread(&env, NULL);
@@ skipping 49 matching lines @@
                       const char* method_name,
                       const char* jni_signature) {
   // clazz.env() can not be used as that may be from a different thread.
   return GetMethodID(env, clazz.obj(), method_name, jni_signature);
 }
 
 jmethodID GetMethodID(JNIEnv* env,
                       jclass clazz,
                       const char* method_name,
                       const char* jni_signature) {
-  return GetMethodIDInternal<METHODTYPE_NORMAL, EXCEPTIONCHECK_YES>(
+  return MethodID::Get<MethodID::METHODTYPE_NORMAL,
+                       MethodID::EXCEPTIONCHECK_YES>(
       env, clazz, method_name, jni_signature);
 }
 
 jmethodID GetMethodIDOrNull(JNIEnv* env,
                             jclass clazz,
                             const char* method_name,
                             const char* jni_signature) {
-  return GetMethodIDInternal<METHODTYPE_NORMAL, EXCEPTIONCHECK_NO>(
+  return MethodID::Get<MethodID::METHODTYPE_NORMAL,
+                       MethodID::EXCEPTIONCHECK_NO>(
       env, clazz, method_name, jni_signature);
 }
 
 jmethodID GetStaticMethodID(JNIEnv* env,
                             const JavaRef<jclass>& clazz,
                             const char* method_name,
                             const char* jni_signature) {
   return GetStaticMethodID(env, clazz.obj(), method_name,
       jni_signature);
 }
 
 jmethodID GetStaticMethodID(JNIEnv* env,
                             jclass clazz,
                             const char* method_name,
                             const char* jni_signature) {
-  return GetMethodIDInternal<METHODTYPE_STATIC, EXCEPTIONCHECK_YES>(
+  return MethodID::Get<MethodID::METHODTYPE_STATIC,
+                       MethodID::EXCEPTIONCHECK_YES>(
       env, clazz, method_name, jni_signature);
 }
 
-jmethodID GetStaticMethodIDOrNull(JNIEnv* env,
-                                  jclass clazz,
-                                  const char* method_name,
-                                  const char* jni_signature) {
-  return GetMethodIDInternal<METHODTYPE_STATIC, EXCEPTIONCHECK_NO>(
-      env, clazz, method_name, jni_signature);
-}
-
 bool HasMethod(JNIEnv* env,
                const JavaRef<jclass>& clazz,
                const char* method_name,
                const char* jni_signature) {
   jmethodID method_id =
       env->GetMethodID(clazz.obj(), method_name, jni_signature);
   if (!method_id) {
     ClearException(env);
     return false;
   }
@@ skipping 111 matching lines @@
   // RVO should avoid any extra copies of the exception string.
   base::android::BuildInfo::GetInstance()->set_java_exception_info(
       GetJavaExceptionInfo(env, java_throwable));
 
   // Now, feel good about it and die.
   CHECK(false);
 }
 
 }  // namespace android
 }  // namespace base