// Path: api/src/main/java/io/opencensus/trace/unsafe/ContextHandleUtils.java
// public class ContextHandleUtils {
// 
//   // No instance of this class.
//   private ContextHandleUtils() {}
// 
//   private static final Logger LOGGER = Logger.getLogger(ContextHandleUtils.class.getName());
//   private static final ContextManager CONTEXT_MANAGER =
//       loadContextManager(ContextManager.class.getClassLoader());
// 
//   private static ContextManager loadContextManager(@Nullable ClassLoader classLoader) {
//     try {
//       return Provider.createInstance(
//           Class.forName(
//               "io.opentelemetry.opencensusshim.OpenTelemetryContextManager",
//               /*initialize=*/ true,
//               classLoader),
//           ContextManager.class);
//     } catch (ClassNotFoundException e) {
//       LOGGER.log(
//           Level.FINE,
//           "Couldn't load full implementation for OpenTelemetry context manager, now loading "
//               + "original implementation.",
//           e);
//     }
//     return new ContextManagerImpl();
//   }
// 
//   public static ContextHandle currentContext() {
//     return CONTEXT_MANAGER.currentContext();
//   }
// 
//   /**
//    * Creates a new {@code ContextHandle} with the given value set.
//    *
//    * @param context the parent {@code ContextHandle}.
//    * @param span the value to be set.
//    * @return a new context with the given value set.
//    */
//   public static ContextHandle withValue(
//       ContextHandle context, @javax.annotation.Nullable Span span) {
//     return CONTEXT_MANAGER.withValue(context, span);
//   }
// 
//   /**
//    * Returns the value from the specified {@code ContextHandle}.
//    *
//    * @param context the specified {@code ContextHandle}.
//    * @return the value from the specified {@code ContextHandle}.
//    */
//   public static Span getValue(ContextHandle context) {
//     return CONTEXT_MANAGER.getValue(context);
//   }
// 
//   /**
//    * Attempts to pull the {@link io.grpc.Context} out of an OpenCensus {@code ContextHandle}.
//    *
//    * @return The context, or null if not a GRPC backed context handle.
//    */
//   @Nullable
//   public static Context tryExtractGrpcContext(ContextHandle handle) {
//     if (handle instanceof ContextHandleImpl) {
//       return ((ContextHandleImpl) handle).getContext();
//     }
//     // TODO: see if we can do something for the OpenTelemetry shim.
//     return null;
//   }
// }


import io.opencensus.common.Scope;
import io.opencensus.trace.unsafe.ContextHandleUtils;
import java.util.concurrent.Callable;
import javax.annotation.Nullable;
/*
 * Copyright 2017, OpenCensus Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.opencensus.trace;


/** Util methods/functionality to interact with the {@link Span} in the {@link io.grpc.Context}. */
final class CurrentSpanUtils {

  // No instance of this class.
  private CurrentSpanUtils() {}

  /**
   * Returns The {@link Span} from the current context.
   *
   * @return The {@code Span} from the current context.
   */
  @Nullable
  static Span getCurrentSpan() {
// Path: api/src/main/java/io/opencensus/trace/unsafe/ContextHandleUtils.java
// public class ContextHandleUtils {
// 
//   // No instance of this class.
//   private ContextHandleUtils() {}
// 
//   private static final Logger LOGGER = Logger.getLogger(ContextHandleUtils.class.getName());
//   private static final ContextManager CONTEXT_MANAGER =
//       loadContextManager(ContextManager.class.getClassLoader());
// 
//   private static ContextManager loadContextManager(@Nullable ClassLoader classLoader) {
//     try {
//       return Provider.createInstance(
//           Class.forName(
//               "io.opentelemetry.opencensusshim.OpenTelemetryContextManager",
//               /*initialize=*/ true,
//               classLoader),
//           ContextManager.class);
//     } catch (ClassNotFoundException e) {
//       LOGGER.log(
//           Level.FINE,
//           "Couldn't load full implementation for OpenTelemetry context manager, now loading "
//               + "original implementation.",
//           e);
//     }
//     return new ContextManagerImpl();
//   }
// 
//   public static ContextHandle currentContext() {
//     return CONTEXT_MANAGER.currentContext();
//   }
// 
//   /**
//    * Creates a new {@code ContextHandle} with the given value set.
//    *
//    * @param context the parent {@code ContextHandle}.
//    * @param span the value to be set.
//    * @return a new context with the given value set.
//    */
//   public static ContextHandle withValue(
//       ContextHandle context, @javax.annotation.Nullable Span span) {
//     return CONTEXT_MANAGER.withValue(context, span);
//   }
// 
//   /**
//    * Returns the value from the specified {@code ContextHandle}.
//    *
//    * @param context the specified {@code ContextHandle}.
//    * @return the value from the specified {@code ContextHandle}.
//    */
//   public static Span getValue(ContextHandle context) {
//     return CONTEXT_MANAGER.getValue(context);
//   }
// 
//   /**
//    * Attempts to pull the {@link io.grpc.Context} out of an OpenCensus {@code ContextHandle}.
//    *
//    * @return The context, or null if not a GRPC backed context handle.
//    */
//   @Nullable
//   public static Context tryExtractGrpcContext(ContextHandle handle) {
//     if (handle instanceof ContextHandleImpl) {
//       return ((ContextHandleImpl) handle).getContext();
//     }
//     // TODO: see if we can do something for the OpenTelemetry shim.
//     return null;
//   }
// }


// Path: api/src/main/java/io/opencensus/trace/CurrentSpanUtils.java
import io.opencensus.common.Scope;
import io.opencensus.trace.unsafe.ContextHandleUtils;
import java.util.concurrent.Callable;
import javax.annotation.Nullable;

/*
 * Copyright 2017, OpenCensus Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.opencensus.trace;


/** Util methods/functionality to interact with the {@link Span} in the {@link io.grpc.Context}. */
final class CurrentSpanUtils {

  // No instance of this class.
  private CurrentSpanUtils() {}

  /**
   * Returns The {@link Span} from the current context.
   *
   * @return The {@code Span} from the current context.
   */
  @Nullable
  static Span getCurrentSpan() {
    return ContextHandleUtils.getValue(ContextHandleUtils.currentContext());