/*
 * 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
 *
 *     https://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.avro.io;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;

import org.apache.avro.util.Utf8;

An abstract Encoder for Avro's binary encoding. 
 To construct and configure instances, use EncoderFactory 
See Also:
EncoderFactory
BufferedBinaryEncoder
DirectBinaryEncoder
BlockingBinaryEncoder
Encoder
Decoder/**
 * An abstract {@link Encoder} for Avro's binary encoding.
 * <p/>
 * To construct and configure instances, use {@link EncoderFactory}
 *
 * @see EncoderFactory
 * @see BufferedBinaryEncoder
 * @see DirectBinaryEncoder
 * @see BlockingBinaryEncoder
 * @see Encoder
 * @see Decoder
 */
public abstract class BinaryEncoder extends Encoder {

  @Override
  public void writeNull() throws IOException {
  }

  @Override
  public void writeString(Utf8 utf8) throws IOException {
    this.writeBytes(utf8.getBytes(), 0, utf8.getByteLength());
  }

  @Override
  public void writeString(String string) throws IOException {
    if (0 == string.length()) {
      writeZero();
      return;
    }
    byte[] bytes = string.getBytes(StandardCharsets.UTF_8);
    writeInt(bytes.length);
    writeFixed(bytes, 0, bytes.length);
  }

  @Override
  public void writeBytes(ByteBuffer bytes) throws IOException {
    int len = bytes.limit() - bytes.position();
    if (0 == len) {
      writeZero();
    } else {
      writeInt(len);
      writeFixed(bytes);
    }
  }

  @Override
  public void writeBytes(byte[] bytes, int start, int len) throws IOException {
    if (0 == len) {
      writeZero();
      return;
    }
    this.writeInt(len);
    this.writeFixed(bytes, start, len);
  }

  @Override
  public void writeEnum(int e) throws IOException {
    this.writeInt(e);
  }

  @Override
  public void writeArrayStart() throws IOException {
  }

  @Override
  public void setItemCount(long itemCount) throws IOException {
    if (itemCount > 0) {
      this.writeLong(itemCount);
    }
  }

  @Override
  public void startItem() throws IOException {
  }

  @Override
  public void writeArrayEnd() throws IOException {
    writeZero();
  }

  @Override
  public void writeMapStart() throws IOException {
  }

  @Override
  public void writeMapEnd() throws IOException {
    writeZero();
  }

  @Override
  public void writeIndex(int unionIndex) throws IOException {
    writeInt(unionIndex);
  }

  
Write a zero byte to the underlying output. /** Write a zero byte to the underlying output. **/
  protected abstract void writeZero() throws IOException;

  
Returns the number of bytes currently buffered by this encoder. If this
Encoder does not buffer, this will always return zero.
 Call Flushable.flush() to empty the buffer to the underlying output. /**
   * Returns the number of bytes currently buffered by this encoder. If this
   * Encoder does not buffer, this will always return zero.
   * <p/>
   * Call {@link #flush()} to empty the buffer to the underlying output.
   */
  public abstract int bytesBuffered();

}