code: package zemberek.apps.lm;
  
  import com.beust.jcommander.Parameter;
  import com.google.common.base.Preconditions;
  import com.google.common.base.Splitter;
  import com.google.common.collect.Lists;
  import java.io.File;
  import java.io.IOException;
  import java.nio.file.Files;
  import java.util.List;
  import zemberek.apps.ConsoleApp;
  import zemberek.core.logging.Log;
  import zemberek.lm.compression.MultiFileUncompressedLm;
  import zemberek.lm.compression.UncompressedToSmoothLmConverter;
  
  /**
   * A command line utility class for generating compressed SmoothLm model from an Arpa language model
   * file. Run the main method to see the options.
   */
  public class CompressLm extends ConsoleApp {
  
    @Parameter(names = {"-in"},
        required = true,
        description = "Arpa input file.")
    public File arpaFile;
  
    @Parameter(names = {"-out"},
        required = true,
        description = "SmoothLm output file.")
    public File compressedLmFile;
  
    @Parameter(names = {"-tmpDir"},
        description = "Temporary folder for intermediate files. " +
            "Operating System's temporary dir with a random folder is used by default.")
    public File tmpDir;
  
    @Parameter(names = {"-spaceUsage"},
        description = "How many bits of space to be used for fingerprint, probability " +
            "and back-off values in the compressed language model. Value must be in x-y-z format. " +
            "By default it is 24-8-8 which means all values " +
            "will be 2 bytes (16 bits). Values must be an order of 8, maximum 32 is allowed.")
    public String spaceUsageStr = "24-8-8";
  
    @Parameter(names = {"-chunkBits"},
        description = "Defines the size of chunks when compressing very large models." +
            " By default it is 21 bits meaning that chunks of 2^21 n-grams are used."
            + " Value must be between 16 to 31 (inclusive).")
    public int chunkBits = 21;
  
    @Parameter(names = {"-fractionDigits"},
        description = "Probability value fractions are rounded to this digit count "
            + "before applying quantization. Default value is 4 digits.")
    public int fractionDigits = 4;
  
    private int[] spaceUsage = new int[3];
  
    public static void main(String[] args) {
      new CompressLm().execute(args);
    }
  
    @Override
    public String description() {
      return "This application generates a compressed binary language model (Smooth-Lm).";
    }
  
    @Override
    public void run() throws IOException {
      Preconditions.checkArgument(arpaFile.exists(), arpaFile + " does not exist. ");
      Log.info("Arpa file to convert:" + arpaFile);
  
      if (tmpDir == null) {
        tmpDir = com.google.common.io.Files.createTempDir();
        tmpDir.deleteOnExit();
        Log.info(("Using temporary directory: " + tmpDir));
      } else {
        Files.createDirectories(tmpDir.toPath());
      }
  
      Preconditions.checkArgument(spaceUsageStr != null && spaceUsageStr.trim().length() > 0,
          "Improper -spaceUsageStr value: " + spaceUsageStr + ". Argument seems to be empty.");
  
      List<String> tokens = Lists
          .newArrayList(Splitter.on("-").omitEmptyStrings().trimResults().split(spaceUsageStr));
  
      Preconditions.checkArgument(tokens.size() == 3,
          "Improper -spaceUsageStr value: " + spaceUsageStr
              + ". Three value is expected in x-y-z format.");
  
      for (int i = 0; i < spaceUsage.length; i++) {
        try {
          final int val = Integer.parseInt(tokens.get(i));
          if (val <= 0 || val > 32 || val % 8 != 0) {
            throw new IllegalArgumentException(
                "Improper -spaceUsageStr value: " + spaceUsageStr + ". Values can be 8,16,24 or 32");
          }
          spaceUsage[i] = val;
        } catch (NumberFormatException e) {
          throw new IllegalArgumentException(
              "Improper -spaceUsageStr value: " + spaceUsageStr + ". Values must be integers");
        }
      }
      Preconditions.checkArgument(chunkBits >= 16 && chunkBits <= 31,
          "Unexpected chunkBits value. Value must be between 16 to 31. But it is : " + chunkBits);
  
      UncompressedToSmoothLmConverter converter = new UncompressedToSmoothLmConverter(
          compressedLmFile, tmpDir);
      converter.convertLarge(
          MultiFileUncompressedLm.generate(arpaFile, tmpDir, "utf-8", fractionDigits)
              .getLmDir(),
          new UncompressedToSmoothLmConverter.NgramDataBlock(spaceUsage[0], spaceUsage[1],
              spaceUsage[2]),
          chunkBits);
    }
  }
  