/*
    * 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.hadoop.hbase.io.encoding;
  
  import java.io.DataOutputStream;
  import java.io.IOException;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.KeyValue;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.io.ByteArrayOutputStream;
  
  @InterfaceAudience.Private
  public class RowIndexEncoderV1 {
    private static final Log LOG = LogFactory.getLog(RowIndexEncoderV1.class);
  
    /** The Cell previously appended. */
    private Cell lastCell = null;
  
    private DataOutputStream out;
    private NoneEncoder encoder;
    private int startOffset = -1;
    private ByteArrayOutputStream rowsOffsetBAOS = new ByteArrayOutputStream(
        64 * 4);
  
    public RowIndexEncoderV1(DataOutputStream out,
        HFileBlockDefaultEncodingContext encodingCtx) {
      this.out = out;
      this.encoder = new NoneEncoder(out, encodingCtx);
    }
  
    public int write(Cell cell) throws IOException {
      // checkKey uses comparator to check we are writing in order.
      if (!checkRow(cell)) {
        if (startOffset < 0) {
          startOffset = out.size();
        }
        rowsOffsetBAOS.writeInt(out.size() - startOffset);
      }
      lastCell = cell;
      return encoder.write(cell);
    }
  
    protected boolean checkRow(final Cell cell) throws IOException {
      boolean isDuplicateRow = false;
      if (cell == null) {
        throw new IOException("Key cannot be null or empty");
      }
      if (lastCell != null) {
        int keyComp = KeyValue.COMPARATOR.compareRows(lastCell, cell);
        if (keyComp > 0) {
          throw new IOException("Added a key not lexically larger than"
              + " previous. Current cell = " + cell + ", lastCell = " + lastCell);
        } else if (keyComp == 0) {
          isDuplicateRow = true;
        }
      }
      return isDuplicateRow;
    }
  
    public void flush() throws IOException {
      int onDiskDataSize = 0;
      if (startOffset >= 0) {
        onDiskDataSize = out.size() - startOffset;
      }
      // rowsOffsetBAOS.size() / 4
      out.writeInt(rowsOffsetBAOS.size() >> 2);
      if (rowsOffsetBAOS.size() > 0) {
        out.write(rowsOffsetBAOS.getBuffer(), 0, rowsOffsetBAOS.size());
      }
      out.writeInt(onDiskDataSize);
      if (LOG.isTraceEnabled()) {
        LOG.trace("RowNumber: " + (rowsOffsetBAOS.size() >> 2)
            + ", onDiskDataSize: " + onDiskDataSize + ", totalOnDiskSize: "
            + (out.size() - startOffset));
      }
    }
  
  }