/**
    * 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.ipc;
  
  import static org.junit.Assert.assertEquals;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.util.Arrays;
  
  import org.apache.commons.lang.time.StopWatch;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.commons.logging.impl.Log4JLogger;
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.CellScanner;
  import org.apache.hadoop.hbase.CellUtil;
  import org.apache.hadoop.hbase.HBaseConfiguration;
  import org.apache.hadoop.hbase.KeyValue;
  import org.apache.hadoop.hbase.codec.Codec;
  import org.apache.hadoop.hbase.codec.KeyValueCodec;
  import org.apache.hadoop.hbase.io.SizedCellScanner;
  import org.apache.hadoop.hbase.testclassification.ClientTests;
  import org.apache.hadoop.hbase.testclassification.SmallTests;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.ClassSize;
  import org.apache.hadoop.io.compress.CompressionCodec;
  import org.apache.hadoop.io.compress.DefaultCodec;
  import org.apache.hadoop.io.compress.GzipCodec;
  import org.apache.log4j.Level;
  import org.junit.Before;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  @Category({ ClientTests.class, SmallTests.class })
  public class TestCellBlockBuilder {
  
    private static final Log LOG = LogFactory.getLog(TestCellBlockBuilder.class);
  
    private CellBlockBuilder builder;
  
    @Before
    public void before() {
      this.builder = new CellBlockBuilder(HBaseConfiguration.create());
    }
  
    @Test
    public void testBuildCellBlock() throws IOException {
      doBuildCellBlockUndoCellBlock(this.builder, new KeyValueCodec(), null);
      doBuildCellBlockUndoCellBlock(this.builder, new KeyValueCodec(), new DefaultCodec());
      doBuildCellBlockUndoCellBlock(this.builder, new KeyValueCodec(), new GzipCodec());
    }
  
    static void doBuildCellBlockUndoCellBlock(final CellBlockBuilder builder, final Codec codec,
        final CompressionCodec compressor) throws IOException {
      doBuildCellBlockUndoCellBlock(builder, codec, compressor, 10, 1, false);
    }
  
    static void doBuildCellBlockUndoCellBlock(final CellBlockBuilder builder, final Codec codec,
        final CompressionCodec compressor, final int count, final int size, final boolean sized)
        throws IOException {
      Cell[] cells = getCells(count, size);
      CellScanner cellScanner = sized ? getSizedCellScanner(cells)
          : CellUtil.createCellScanner(Arrays.asList(cells).iterator());
      ByteBuffer bb = builder.buildCellBlock(codec, compressor, cellScanner);
      cellScanner = builder.createCellScanner(codec, compressor, bb);
      int i = 0;
      while (cellScanner.advance()) {
        i++;
      }
      assertEquals(count, i);
    }
  
    static CellScanner getSizedCellScanner(final Cell[] cells) {
      int size = -1;
      for (Cell cell : cells) {
        size += CellUtil.estimatedSerializedSizeOf(cell);
      }
      final int totalSize = ClassSize.align(size);
      final CellScanner cellScanner = CellUtil.createCellScanner(cells);
      return new SizedCellScanner() {
        @Override
        public long heapSize() {
          return totalSize;
       }
 
       @Override
       public Cell current() {
         return cellScanner.current();
       }
 
       @Override
       public boolean advance() throws IOException {
         return cellScanner.advance();
       }
     };
   }
 
   static Cell[] getCells(final int howMany) {
     return getCells(howMany, 1024);
   }
 
   static Cell[] getCells(final int howMany, final int valueSize) {
     Cell[] cells = new Cell[howMany];
     byte[] value = new byte[valueSize];
     for (int i = 0; i < howMany; i++) {
       byte[] index = Bytes.toBytes(i);
       KeyValue kv = new KeyValue(index, Bytes.toBytes("f"), index, value);
       cells[i] = kv;
     }
     return cells;
   }
 
   private static final String COUNT = "--count=";
   private static final String SIZE = "--size=";
 
   /**
    * Prints usage and then exits w/ passed <code>errCode</code>
    * @param errCode
    */
   private static void usage(final int errCode) {
     System.out.println("Usage: IPCUtil [options]");
     System.out.println("Micro-benchmarking how changed sizes and counts work with buffer resizing");
     System.out.println(" --count  Count of Cells");
     System.out.println(" --size   Size of Cell values");
     System.out.println("Example: IPCUtil --count=1024 --size=1024");
     System.exit(errCode);
   }
 
   private static void timerTests(final CellBlockBuilder builder, final int count, final int size,
       final Codec codec, final CompressionCodec compressor) throws IOException {
     final int cycles = 1000;
     StopWatch timer = new StopWatch();
     timer.start();
     for (int i = 0; i < cycles; i++) {
       timerTest(builder, timer, count, size, codec, compressor, false);
     }
     timer.stop();
     LOG.info("Codec=" + codec + ", compression=" + compressor + ", sized=" + false + ", count=" +
         count + ", size=" + size + ", + took=" + timer.getTime() + "ms");
     timer.reset();
     timer.start();
     for (int i = 0; i < cycles; i++) {
       timerTest(builder, timer, count, size, codec, compressor, true);
     }
     timer.stop();
     LOG.info("Codec=" + codec + ", compression=" + compressor + ", sized=" + true + ", count=" +
         count + ", size=" + size + ", + took=" + timer.getTime() + "ms");
   }
 
   private static void timerTest(final CellBlockBuilder builder, final StopWatch timer,
       final int count, final int size, final Codec codec, final CompressionCodec compressor,
       final boolean sized) throws IOException {
     doBuildCellBlockUndoCellBlock(builder, codec, compressor, count, size, sized);
   }
 
   /**
    * For running a few tests of methods herein.
    * @param args
    * @throws IOException
    */
   public static void main(String[] args) throws IOException {
     int count = 1024;
     int size = 10240;
     for (String arg : args) {
       if (arg.startsWith(COUNT)) {
         count = Integer.parseInt(arg.replace(COUNT, ""));
       } else if (arg.startsWith(SIZE)) {
         size = Integer.parseInt(arg.replace(SIZE, ""));
       } else {
         usage(1);
       }
     }
     CellBlockBuilder builder = new CellBlockBuilder(HBaseConfiguration.create());
     ((Log4JLogger) CellBlockBuilder.LOG).getLogger().setLevel(Level.ALL);
     timerTests(builder, count, size, new KeyValueCodec(), null);
     timerTests(builder, count, size, new KeyValueCodec(), new DefaultCodec());
     timerTests(builder, count, size, new KeyValueCodec(), new GzipCodec());
   }
 }