/*
 * 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.hfile;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Random;
import java.util.StringTokenizer;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.RawLocalFileSystem;
import org.apache.hadoop.hbase.HBaseTestingUtility;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.io.hfile.HFile.Reader;
import org.apache.hadoop.hbase.io.hfile.HFile.Writer;
import org.apache.hadoop.hbase.testclassification.IOTests;
import org.apache.hadoop.hbase.testclassification.SmallTests;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.RandomDistribution;
import org.apache.hadoop.io.BytesWritable;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Tag;
import org.junit.jupiter.api.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.hbase.thirdparty.org.apache.commons.cli.CommandLine;
import org.apache.hbase.thirdparty.org.apache.commons.cli.CommandLineParser;
import org.apache.hbase.thirdparty.org.apache.commons.cli.GnuParser;
import org.apache.hbase.thirdparty.org.apache.commons.cli.HelpFormatter;
import org.apache.hbase.thirdparty.org.apache.commons.cli.Option;
import org.apache.hbase.thirdparty.org.apache.commons.cli.OptionBuilder;
import org.apache.hbase.thirdparty.org.apache.commons.cli.Options;
import org.apache.hbase.thirdparty.org.apache.commons.cli.ParseException;

/**
 * test the performance for seek.
 * <p>
 * Copied from <a href="https://issues.apache.org/jira/browse/HADOOP-3315">hadoop-3315 tfile</a>.
 * Remove after tfile is committed and use the tfile version of this class instead.
 * </p>
 */
@Tag(IOTests.TAG)
@Tag(SmallTests.TAG)
public class TestHFileSeek {

  private static final byte[] CF = Bytes.toBytes("f1");
  private static final byte[] QUAL = Bytes.toBytes("q1");
  private static final boolean USE_PREAD = true;
  private MyOptions options;
  private Configuration conf;
  private Path path;
  private FileSystem fs;
  private NanoTimer timer;
  private Random rng;
  private RandomDistribution.DiscreteRNG keyLenGen;
  private KVGenerator kvGen;

  private static final Logger LOG = LoggerFactory.getLogger(TestHFileSeek.class);

  @BeforeEach
  public void setUp() throws IOException {
    if (options == null) {
      options = new MyOptions(new String[0]);
    }

    conf = new Configuration();

    if (options.useRawFs) {
      conf.setClass("fs.file.impl", RawLocalFileSystem.class, FileSystem.class);
    }

    conf.setInt("tfile.fs.input.buffer.size", options.fsInputBufferSize);
    conf.setInt("tfile.fs.output.buffer.size", options.fsOutputBufferSize);
    path = new Path(new Path(options.rootDir), options.file);
    fs = path.getFileSystem(conf);
    timer = new NanoTimer(false);
    rng = new Random(options.seed);
    keyLenGen = new RandomDistribution.Zipf(new Random(rng.nextLong()), options.minKeyLen,
      options.maxKeyLen, 1.2);
    RandomDistribution.DiscreteRNG valLenGen = new RandomDistribution.Flat(
      new Random(rng.nextLong()), options.minValLength, options.maxValLength);
    RandomDistribution.DiscreteRNG wordLenGen = new RandomDistribution.Flat(
      new Random(rng.nextLong()), options.minWordLen, options.maxWordLen);
    kvGen = new KVGenerator(rng, true, keyLenGen, valLenGen, wordLenGen, options.dictSize);
  }

  @AfterEach
  public void tearDown() {
    try {
      fs.close();
    } catch (Exception e) {
      // Nothing
    }
  }

  private static FSDataOutputStream createFSOutput(Path name, FileSystem fs) throws IOException {
    if (fs.exists(name)) {
      fs.delete(name, true);
    }
    FSDataOutputStream fout = fs.create(name);
    return fout;
  }

  private void createTFile() throws IOException {
    long totalBytes = 0;
    FSDataOutputStream fout = createFSOutput(path, fs);
    try {
      HFileContext context = new HFileContextBuilder().withBlockSize(options.minBlockSize)
        .withCompression(HFileWriterImpl.compressionByName(options.compress)).build();
      Writer writer = HFile.getWriterFactoryNoCache(conf).withOutputStream(fout)
        .withFileContext(context).create();
      try {
        BytesWritable key = new BytesWritable();
        BytesWritable val = new BytesWritable();
        timer.start();
        for (long i = 0; true; ++i) {
          if (i % 1000 == 0) { // test the size for every 1000 rows.
            if (fs.getFileStatus(path).getLen() >= options.fileSize) {
              break;
            }
          }
          kvGen.next(key, val, false);
          byte[] k = new byte[key.getLength()];
          System.arraycopy(key.getBytes(), 0, k, 0, key.getLength());
          byte[] v = new byte[val.getLength()];
          System.arraycopy(val.getBytes(), 0, v, 0, key.getLength());
          KeyValue kv = new KeyValue(k, CF, QUAL, v);
          writer.append(kv);
          totalBytes += kv.getKeyLength();
          totalBytes += kv.getValueLength();
        }
        timer.stop();
      } finally {
        writer.close();
      }
    } finally {
      fout.close();
    }
    double duration = (double) timer.read() / 1000; // in us.
    long fsize = fs.getFileStatus(path).getLen();

    LOG.info(String.format("time: %s...uncompressed: %.2fMB...raw thrpt: %.2fMB/s\n",
      timer.toString(), (double) totalBytes / 1024 / 1024, totalBytes / duration));
    LOG.info(String.format("time: %s...file size: %.2fMB...disk thrpt: %.2fMB/s\n",
      timer.toString(), (double) fsize / 1024 / 1024, fsize / duration));
  }

  public void seekTFile() throws IOException {
    int miss = 0;
    long totalBytes = 0;
    ReaderContext context = new ReaderContextBuilder().withFileSystemAndPath(fs, path).build();
    Reader reader = TestHFile.createReaderFromStream(context, new CacheConfig(conf), conf);
    KeySampler kSampler = new KeySampler(rng, ((KeyValue) reader.getFirstKey().get()).getKey(),
      ((KeyValue) reader.getLastKey().get()).getKey(), keyLenGen);
    HFileScanner scanner = reader.getScanner(conf, false, USE_PREAD);
    BytesWritable key = new BytesWritable();
    timer.reset();
    timer.start();
    for (int i = 0; i < options.seekCount; ++i) {
      kSampler.next(key);
      byte[] k = new byte[key.getLength()];
      System.arraycopy(key.getBytes(), 0, k, 0, key.getLength());
      KeyValue kv = new KeyValue(k, CF, QUAL);
      if (scanner.seekTo(kv) >= 0) {
        ByteBuffer bbkey = ByteBuffer.wrap(((KeyValue) scanner.getKey()).getKey());
        ByteBuffer bbval = scanner.getValue();
        totalBytes += bbkey.limit();
        totalBytes += bbval.limit();
      } else {
        ++miss;
      }
    }
    timer.stop();
    LOG.info(String.format("time: %s...avg seek: %s...%d hit...%d miss...avg I/O size: %.2fKB\n",
      timer.toString(), NanoTimer.nanoTimeToString(timer.read() / options.seekCount),
      options.seekCount - miss, miss, (double) totalBytes / 1024 / (options.seekCount - miss)));

  }

  @Test
  public void testSeeks() throws IOException {
    if (options.doCreate()) {
      createTFile();
    }

    if (options.doRead()) {
      seekTFile();
    }

    if (options.doCreate()) {
      fs.delete(path, true);
    }
  }

  private static class IntegerRange {
    private final int from, to;

    public IntegerRange(int from, int to) {
      this.from = from;
      this.to = to;
    }

    public static IntegerRange parse(String s) throws ParseException {
      StringTokenizer st = new StringTokenizer(s, " \t,");
      if (st.countTokens() != 2) {
        throw new ParseException("Bad integer specification: " + s);
      }
      int from = Integer.parseInt(st.nextToken());
      int to = Integer.parseInt(st.nextToken());
      return new IntegerRange(from, to);
    }

    public int from() {
      return from;
    }

    public int to() {
      return to;
    }
  }

  private static class MyOptions {
    // hard coded constants
    int dictSize = 1000;
    int minWordLen = 5;
    int maxWordLen = 20;

    private HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
    String rootDir = TEST_UTIL.getDataTestDir("TestTFileSeek").toString();
    String file = "TestTFileSeek";
    // String compress = "lzo"; DISABLED
    String compress = "none";
    int minKeyLen = 10;
    int maxKeyLen = 50;
    int minValLength = 1024;
    int maxValLength = 2 * 1024;
    int minBlockSize = 1 * 1024 * 1024;
    int fsOutputBufferSize = 1;
    int fsInputBufferSize = 0;
    // Default writing 10MB.
    long fileSize = 10 * 1024 * 1024;
    long seekCount = 1000;
    long trialCount = 1;
    long seed;
    boolean useRawFs = false;

    static final int OP_CREATE = 1;
    static final int OP_READ = 2;
    int op = OP_CREATE | OP_READ;

    boolean proceed = false;

    public MyOptions(String[] args) {
      seed = System.nanoTime();

      try {
        Options opts = buildOptions();
        CommandLineParser parser = new GnuParser();
        CommandLine line = parser.parse(opts, args, true);
        processOptions(line, opts);
        validateOptions();
      } catch (ParseException e) {
        System.out.println(e.getMessage());
        System.out.println("Try \"--help\" option for details.");
        setStopProceed();
      }
    }

    public boolean proceed() {
      return proceed;
    }

    private Options buildOptions() {
      Option compress = OptionBuilder.withLongOpt("compress").withArgName("[none|lzo|gz|snappy]")
        .hasArg().withDescription("compression scheme").create('c');

      Option fileSize = OptionBuilder.withLongOpt("file-size").withArgName("size-in-MB").hasArg()
        .withDescription("target size of the file (in MB).").create('s');

      Option fsInputBufferSz = OptionBuilder.withLongOpt("fs-input-buffer").withArgName("size")
        .hasArg().withDescription("size of the file system input buffer (in bytes).").create('i');

      Option fsOutputBufferSize = OptionBuilder.withLongOpt("fs-output-buffer").withArgName("size")
        .hasArg().withDescription("size of the file system output buffer (in bytes).").create('o');

      Option keyLen = OptionBuilder.withLongOpt("key-length").withArgName("min,max").hasArg()
        .withDescription("the length range of the key (in bytes)").create('k');

      Option valueLen = OptionBuilder.withLongOpt("value-length").withArgName("min,max").hasArg()
        .withDescription("the length range of the value (in bytes)").create('v');

      Option blockSz = OptionBuilder.withLongOpt("block").withArgName("size-in-KB").hasArg()
        .withDescription("minimum block size (in KB)").create('b');

      Option operation = OptionBuilder.withLongOpt("operation").withArgName("r|w|rw").hasArg()
        .withDescription("action: seek-only, create-only, seek-after-create").create('x');

      Option rootDir = OptionBuilder.withLongOpt("root-dir").withArgName("path").hasArg()
        .withDescription("specify root directory where files will be created.").create('r');

      Option file = OptionBuilder.withLongOpt("file").withArgName("name").hasArg()
        .withDescription("specify the file name to be created or read.").create('f');

      Option seekCount = OptionBuilder.withLongOpt("seek").withArgName("count").hasArg()
        .withDescription("specify how many seek operations we perform (requires -x r or -x rw.")
        .create('n');

      Option trialCount = OptionBuilder.withLongOpt("trials").withArgName("n").hasArg()
        .withDescription("specify how many times to run the whole benchmark").create('t');

      Option useRawFs = OptionBuilder.withLongOpt("rawfs")
        .withDescription("use raw instead of checksummed file system").create();

      Option help = OptionBuilder.withLongOpt("help").hasArg(false)
        .withDescription("show this screen").create("h");

      return new Options().addOption(compress).addOption(fileSize).addOption(fsInputBufferSz)
        .addOption(fsOutputBufferSize).addOption(keyLen).addOption(blockSz).addOption(rootDir)
        .addOption(valueLen).addOption(operation).addOption(seekCount).addOption(file)
        .addOption(trialCount).addOption(useRawFs).addOption(help);

    }

    private void processOptions(CommandLine line, Options opts) throws ParseException {
      // --help -h and --version -V must be processed first.
      if (line.hasOption('h')) {
        HelpFormatter formatter = new HelpFormatter();
        System.out.println("TFile and SeqFile benchmark.");
        System.out.println();
        formatter.printHelp(100, "java ... TestTFileSeqFileComparison [options]",
          "\nSupported options:", opts, "");
        return;
      }

      if (line.hasOption('c')) {
        compress = line.getOptionValue('c');
      }

      if (line.hasOption('d')) {
        dictSize = Integer.parseInt(line.getOptionValue('d'));
      }

      if (line.hasOption('s')) {
        fileSize = Long.parseLong(line.getOptionValue('s')) * 1024 * 1024;
      }

      if (line.hasOption('i')) {
        fsInputBufferSize = Integer.parseInt(line.getOptionValue('i'));
      }

      if (line.hasOption('o')) {
        fsOutputBufferSize = Integer.parseInt(line.getOptionValue('o'));
      }

      if (line.hasOption('n')) {
        seekCount = Integer.parseInt(line.getOptionValue('n'));
      }

      if (line.hasOption('t')) {
        trialCount = Integer.parseInt(line.getOptionValue('t'));
      }

      if (line.hasOption('k')) {
        IntegerRange ir = IntegerRange.parse(line.getOptionValue('k'));
        minKeyLen = ir.from();
        maxKeyLen = ir.to();
      }

      if (line.hasOption('v')) {
        IntegerRange ir = IntegerRange.parse(line.getOptionValue('v'));
        minValLength = ir.from();
        maxValLength = ir.to();
      }

      if (line.hasOption('b')) {
        minBlockSize = Integer.parseInt(line.getOptionValue('b')) * 1024;
      }

      if (line.hasOption('r')) {
        rootDir = line.getOptionValue('r');
      }

      if (line.hasOption('f')) {
        file = line.getOptionValue('f');
      }

      if (line.hasOption('S')) {
        seed = Long.parseLong(line.getOptionValue('S'));
      }

      if (line.hasOption('x')) {
        String strOp = line.getOptionValue('x');
        if (strOp.equals("r")) {
          op = OP_READ;
        } else if (strOp.equals("w")) {
          op = OP_CREATE;
        } else if (strOp.equals("rw")) {
          op = OP_CREATE | OP_READ;
        } else {
          throw new ParseException("Unknown action specifier: " + strOp);
        }
      }

      useRawFs = line.hasOption("rawfs");

      proceed = true;
    }

    private void validateOptions() throws ParseException {
      if (
        !compress.equals("none") && !compress.equals("lzo") && !compress.equals("gz")
          && !compress.equals("snappy")
      ) {
        throw new ParseException("Unknown compression scheme: " + compress);
      }

      if (minKeyLen >= maxKeyLen) {
        throw new ParseException("Max key length must be greater than min key length.");
      }

      if (minValLength >= maxValLength) {
        throw new ParseException("Max value length must be greater than min value length.");
      }

      if (minWordLen >= maxWordLen) {
        throw new ParseException("Max word length must be greater than min word length.");
      }
      return;
    }

    private void setStopProceed() {
      proceed = false;
    }

    public boolean doCreate() {
      return (op & OP_CREATE) != 0;
    }

    public boolean doRead() {
      return (op & OP_READ) != 0;
    }
  }

  public static void main(String[] argv) throws IOException {
    TestHFileSeek testCase = new TestHFileSeek();
    MyOptions options = new MyOptions(argv);

    if (options.proceed == false) {
      return;
    }

    testCase.options = options;
    for (int i = 0; i < options.trialCount; i++) {
      LOG.info("Beginning trial " + (i + 1));
      testCase.setUp();
      testCase.testSeeks();
      testCase.tearDown();
    }
  }

}
