package org.apache.lucene.analysis.ja.util;
   
   /*
    * 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.
   */
  
  import java.io.BufferedOutputStream;
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  
  import org.apache.lucene.analysis.ja.dict.ConnectionCosts;
  
  import org.apache.lucene.codecs.CodecUtil;
  import org.apache.lucene.store.DataOutput;
  import org.apache.lucene.store.OutputStreamDataOutput;
  import org.apache.lucene.util.BitUtil;
  
  public final class ConnectionCostsWriter {
    
    private final short[][] costs; // array is backward IDs first since get is called using the same backward ID consecutively. maybe doesn't matter.
    private final int forwardSize;
    private final int backwardSize;
    /**
     * Constructor for building. TODO: remove write access
     */
    public ConnectionCostsWriter(int forwardSize, int backwardSize) {
      this.forwardSize = forwardSize;
      this.backwardSize = backwardSize;
      this.costs = new short[backwardSize][forwardSize];
    }
    
    public void add(int forwardId, int backwardId, int cost) {
      this.costs[backwardId][forwardId] = (short)cost;
    }
    
    public void write(String baseDir) throws IOException {
      String filename = baseDir + File.separator +
        ConnectionCosts.class.getName().replace('.', File.separatorChar) + ConnectionCosts.FILENAME_SUFFIX;
      new File(filename).getParentFile().mkdirs();
      OutputStream os = new FileOutputStream(filename);
      try {
        os = new BufferedOutputStream(os);
        final DataOutput out = new OutputStreamDataOutput(os);
        CodecUtil.writeHeader(out, ConnectionCosts.HEADER, ConnectionCosts.VERSION);
        out.writeVInt(forwardSize);
        out.writeVInt(backwardSize);
        int last = 0;
        assert costs.length == backwardSize;
        for (short[] a : costs) {
          assert a.length == forwardSize;
          for (int i = 0; i < a.length; i++) {
            int delta = (int)a[i] - last;
            out.writeZInt(delta);
            last = a[i];
          }
        }
      } finally {
        os.close();
      }
    }
    
  }