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
   *
   *     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.trevni;
  
  import java.io.IOException;
  
  /** A column output buffer for array columns. */
  class ArrayColumnOutputBuffer extends ColumnOutputBuffer {
    private int length; // remaining in current array
  
    private static final int NONE = -1;
  
    private int runLength; // length of current run
    private int runValue = NONE; // what kind of run
  
    public ArrayColumnOutputBuffer(ColumnFileWriter writer, ColumnMetaData meta) throws IOException {
      super(writer, meta);
      assert getMeta().isArray() || getMeta().getParent() != null;
      assert !getMeta().hasIndexValues();
    }
  
    @Override
    public void writeLength(int l) throws IOException {
      assert this.length == 0;
      assert l >= 0;
      this.length = l;
      if (l == runValue) {
        runLength++; // continue a run
        return;
      }
      flushRun(); // end a run
      if (l == 1 || l == 0) {
        runLength = 1; // start a run
        runValue = l;
      } else {
        getBuffer().writeLength(l); // not a run
      }
    }
  
    @Override
    public void writeValue(Object value) throws IOException {
      assert length > 0;
      if (getMeta().getType() != ValueType.NULL) {
        flushRun();
        getBuffer().writeValue(value, getMeta().getType());
      }
      length -= 1;
    }
  
    @Override
    void flushBuffer() throws IOException {
      flushRun();
      super.flushBuffer();
    }
  
    private void flushRun() throws IOException {
      if (runLength == 0) // not in run
        return;
      else if (runLength == 1) // single value
        getBuffer().writeLength(runValue);
      else // a run
        getBuffer().writeLength((3 - runValue) - (runLength << 1));
  
      runLength = 0; // reset
      runValue = NONE;
    }
  
  }
  