content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 org.apache.beam.sdk.extensions.kryo;
  
  import com.esotericsoftware.kryo.Kryo;
  import com.esotericsoftware.kryo.io.InputChunked;
  import com.esotericsoftware.kryo.io.OutputChunked;
  import com.esotericsoftware.kryo.util.DefaultInstantiatorStrategy;
  import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  import java.util.HashMap;
  import java.util.Map;
  import org.objenesis.strategy.StdInstantiatorStrategy;
  
  /** Reusable kryo instance. */
  class KryoState {
  
    private static final Storage STORAGE = new Storage();
  
    static KryoState get(KryoCoder<?> coder) {
      return STORAGE.getOrCreate(coder);
    }
  
    /** Caching thread local storage for reusable {@link KryoState}s. */
    @SuppressFBWarnings(
        value = "NP_PARAMETER_MUST_BE_NONNULL_BUT_MARKED_AS_NULLABLE",
        justification = "Spotbugs incorrectly thinks kryoStateMap is marked @Nullable")
    private static class Storage {
      /**
       * It's a known bug in checkerframework.
       * https://stackoverflow.com/questions/63049612/checker-framework-incompatible-types-in-type-argument/63078419#63078419
       */
      @SuppressWarnings("nullness")
      private final ThreadLocal<Map<String, KryoState>> kryoStateMap =
          ThreadLocal.withInitial(HashMap::new);
  
      KryoState getOrCreate(KryoCoder<?> coder) {
        return kryoStateMap
            .get()
            .computeIfAbsent(
                coder.getInstanceId(),
                k -> {
                  final Kryo kryo = new Kryo();
                  // fallback in case serialized class does not have default constructor
                  kryo.setInstantiatorStrategy(
                      new DefaultInstantiatorStrategy(new StdInstantiatorStrategy()));
                  kryo.setReferences(coder.getOptions().getReferences());
                  kryo.setRegistrationRequired(coder.getOptions().getRegistrationRequired());
  
                  ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
                  if (classLoader == null) {
                    throw new RuntimeException(
                        "Cannot detect classpath: classload is null (is it the bootstrap classloader?)");
                  }
  
                  kryo.setClassLoader(classLoader);
                  // first id of user provided class registration
                  final int firstRegistrationId = kryo.getNextRegistrationId();
                  // register user provided classes
                  for (KryoRegistrar registrar : coder.getRegistrars()) {
                    registrar.registerClasses(kryo);
                  }
                  return new KryoState(
                      kryo,
                      firstRegistrationId,
                      new InputChunked(coder.getOptions().getBufferSize()),
                      new OutputChunked(coder.getOptions().getBufferSize()));
                });
      }
    }
  
    /** The kryo instance. */
    private final Kryo kryo;
  
    /** first id of user provided class registration. */
    private final int firstRegistrationId;
  
    /** A reusable input buffer. */
    private final InputChunked inputChunked;
  
    /** A reusable output buffer. */
    private final OutputChunked outputChunked;
  
    private KryoState(
        Kryo kryo, int firstRegistrationId, InputChunked inputChunked, OutputChunked outputChunked) {
      this.kryo = kryo;
      this.firstRegistrationId = firstRegistrationId;
      this.inputChunked = inputChunked;
      this.outputChunked = outputChunked;
    }
  
    /**
     * {@link KryoState#kryo}.
     *
     * @return kryo
     */
    Kryo getKryo() {
      return kryo;
    }
  
    /**
     * {@link KryoState#firstRegistrationId}.
     *
     * @return registration id
     */
    public int getFirstRegistrationId() {
      return firstRegistrationId;
    }
  
    /**
     * {@link KryoState#inputChunked}.
     *
     * @return input buffer
     */
    InputChunked getInputChunked() {
      return inputChunked;
    }
  
    /**
     * {@link KryoState#outputChunked}.
     *
     * @return output buffer
     */
    OutputChunked getOutputChunked() {
      return outputChunked;
    }
  }
  