parquet-column/src/main/java/parquet/column/values/ValuesWriter.java

/**
 * Copyright 2012 Twitter, Inc.
 *
 * 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 parquet.column.values;

import parquet.bytes.BytesInput;
import parquet.column.Encoding;
import parquet.column.page.DictionaryPage;
import parquet.io.api.Binary;

/**
 * base class to implement an encoding for a given column
 *
 * @author Julien Le Dem
 *
 */
public abstract class ValuesWriter {

  /**
   * used to decide if we want to work to the next page
   * @return the size of the currently buffered data
   */
  public abstract long getBufferedSize();


  // TODO: maybe consolidate into a getPage
  /**
   * @return the bytes buffered so far to write to the current page
   */
  public abstract BytesInput getBytes();

  /**
   * called after getBytes() and before reset()
   * @return the encoding that was used to encode the bytes
   */
  public abstract Encoding getEncoding();

  /**
   * called after getBytes() to reset the current buffer and start writing the next page
   */
  public abstract void reset();

  /**
   * @return the dictionary page or null if not dictionary based
   */
  public DictionaryPage createDictionaryPage() {
    return null;
  }

  /**
   * reset the dictionary when a new block starts
   */
  public void resetDictionary() {
  }

  /**
   *
   * @return the allocated size of the buffer
   * ( > {@link #getBufferedMemorySize()() )
   */
  abstract public long getAllocatedSize();

  /**
   * @param value the value to encode
   */
  public void writeByte(int value) {
    throw new UnsupportedOperationException(getClass().getName());
  }

  /**
   * @param value the value to encode
   */
  public void writeBoolean(boolean v) {
    throw new UnsupportedOperationException(getClass().getName());
  }

  /**
   * @param value the value to encode
   */
  public void writeBytes(Binary v) {
    throw new UnsupportedOperationException(getClass().getName());
  }

  /**
   * @param value the value to encode
   */
  public void writeInteger(int v) {
    throw new UnsupportedOperationException(getClass().getName());
  }

  /**
   * @param value the value to encode
   */
  public void writeLong(long v) {
    throw new UnsupportedOperationException(getClass().getName());
  }

  /**
   * @param value the value to encode
   */
  public void writeDouble(double v) {
    throw new UnsupportedOperationException(getClass().getName());
  }

  /**
   * @param value the value to encode
   */
  public void writeFloat(float v) {
    throw new UnsupportedOperationException(getClass().getName());
  }

  abstract public String memUsageString(String prefix);

}