heron/api/src/java/com/twitter/heron/api/utils/Utils.java

// Copyright 2016 Twitter. All rights reserved.
//
// 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 com.twitter.heron.api.utils;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public final class Utils {
  public static final String DEFAULT_STREAM_ID = "default";

  private Utils() {
  }

  public static List<Object> tuple(Object... values) {
    List<Object> ret = new ArrayList<>();
    Collections.addAll(ret, values);
    return ret;
  }

  public static void sleep(long millis) {
    try {
      Thread.sleep(millis);
    } catch (InterruptedException e) {
      throw new RuntimeException(e);
    }
  }

  public static Map<String, String> readCommandLineOpts() {
    Map<String, String> ret = new HashMap<>();
    String commandOptions = System.getenv("HERON_OPTIONS");
    if (commandOptions != null) {
      commandOptions = commandOptions.replaceAll("%%%%", " ");
      String[] configs = commandOptions.split(",");
      for (String config : configs) {
        String[] options = config.split("=");
        if (options.length == 2) {
          ret.put(options[0], options[1]);
        }
      }
    }
    return ret;
  }

  public static byte[] serialize(Object obj) {
    try {
      ByteArrayOutputStream bos = new ByteArrayOutputStream();
      ObjectOutputStream oos = new ObjectOutputStream(bos);
      oos.writeObject(obj);
      oos.close();
      return bos.toByteArray();
    } catch (IOException ioe) {
      throw new RuntimeException(ioe);
    }
  }

  public static Object deserialize(byte[] serialized) {
    try {
      ByteArrayInputStream bis = new ByteArrayInputStream(serialized);
      ObjectInputStream ois = new ObjectInputStream(bis);
      Object ret = ois.readObject();
      ois.close();
      return ret;
    } catch (IOException ioe) {
      throw new RuntimeException(ioe);
    } catch (ClassNotFoundException e) {
      throw new RuntimeException(e);
    }
  }

  public static byte[] toByteArray(ByteBuffer buffer) {
    byte[] ret = new byte[buffer.remaining()];
    buffer.get(ret, 0, ret.length);
    return ret;
  }

  public static <S, T> T get(Map<S, T> m, S key, T defaultValue) {
    T ret = m.get(key);
    if (ret == null) {
      ret = defaultValue;
    }

    return ret;
  }
}