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.bookkeeper.common.coder;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.ByteBufInputStream;
  import io.netty.buffer.ByteBufOutputStream;
  import java.io.IOException;
  import org.apache.bookkeeper.common.util.VarInt;
  
  /**
   * A {@link Coder} that encodes {@link Integer Integers} using between 1 and 5 bytes. Negative
   * numbers always take 5 bytes.
   */
  public class VarIntCoder implements Coder<Integer> {
  
      private static final long serialVersionUID = 465214482437322885L;
  
      public static VarIntCoder of() {
          return INSTANCE;
      }
  
      private static final VarIntCoder INSTANCE = new VarIntCoder();
  
      private VarIntCoder() {
      }
  
      @Override
      public void encode(Integer value, ByteBuf buf) {
          checkNotNull(value, "Can not encode a null integer value");
          checkNotNull(buf, "Can not encode into a null output buffer");
  
          ByteBufOutputStream output = new ByteBufOutputStream(buf);
  
          try {
              VarInt.encode(value, output);
          } catch (IOException e) {
              throw new IllegalStateException("Failed to encode integer '" + value + "' into the provided buffer", e);
          }
      }
  
      @Override
      public int getSerializedSize(Integer value) {
          return VarInt.getLength(value);
      }
  
      @Override
      public Integer decode(ByteBuf buf) {
          checkNotNull(buf, "Can not decode into a null input buffer");
  
          ByteBufInputStream input = new ByteBufInputStream(buf);
  
          try {
              return VarInt.decodeInt(input);
          } catch (IOException e) {
              throw new IllegalStateException("Failed to decode an integration from the provided buffer");
          }
      }
  
  }
  