Java SnappyCodec.isNativeCodeLoaded方法代码示例

import org.apache.hadoop.io.compress.SnappyCodec; //导入方法依赖的package包/类
/**
 * Tests whether hadoop-snappy (not to be confused with other java-based snappy implementations such as jsnappy or
 * snappy-java) plus the native snappy libraries are available.
 *
 * @return true if hadoop-snappy is available on the classpath
 */
public boolean isHadoopSnappyAvailable() {
  ClassLoader cl = Thread.currentThread().getContextClassLoader();
  Thread.currentThread().setContextClassLoader( getClass().getClassLoader() );
  try {
    return SnappyCodec.isNativeCodeLoaded();
  } catch ( Throwable t ) {
    return false;
  } finally {
    Thread.currentThread().setContextClassLoader( cl );
  }
}
 

import org.apache.hadoop.io.compress.SnappyCodec; //导入方法依赖的package包/类
@Override
public void open() {
  Preconditions.checkState(state.equals(ReaderWriterState.NEW),
    "Unable to open a writer from state:%s", state);

  logger.debug(
    "Opening data file with pathTmp:{} (final path will be path:{})",
    pathTmp, path);

  try {
    CompressionCodecName codecName = CompressionCodecName.UNCOMPRESSED;
    if (enableCompression) {
       if (SnappyCodec.isNativeCodeLoaded()) {
         codecName = CompressionCodecName.SNAPPY;
       } else {
         logger.warn("Compression enabled, but Snappy native code not loaded. " +
             "Parquet file will not be compressed.");
       }
    }
    avroParquetWriter = new AvroParquetWriter<E>(fileSystem.makeQualified(pathTmp),
        schema, codecName, DEFAULT_BLOCK_SIZE,
        ParquetWriter.DEFAULT_PAGE_SIZE);
  } catch (IOException e) {
    throw new DatasetWriterException("Unable to create writer to path:" + pathTmp, e);
  }

  state = ReaderWriterState.OPEN;
}
 

import org.apache.hadoop.io.compress.SnappyCodec; //导入方法依赖的package包/类
/**
 * A tool to test native library availability, 
 */
public static void main(String[] args) {
  String usage = "NativeLibraryChecker [-a|-h]\n"
      + "  -a  use -a to check all libraries are available\n"
      + "      by default just check hadoop library is available\n"
      + "      exit with error code 1 if check failed\n"
      + "  -h  print this message\n";
  if (args.length > 1 ||
      (args.length == 1 &&
          !(args[0].equals("-a") || args[0].equals("-h")))) {
    System.err.println(usage);
    ExitUtil.terminate(1);
  }
  boolean checkAll = false;
  if (args.length == 1) {
    if (args[0].equals("-h")) {
      System.out.println(usage);
      return;
    }
    checkAll = true;
  }
  Configuration conf = new Configuration();
  boolean nativeHadoopLoaded = NativeCodeLoader.isNativeCodeLoaded();
  boolean zlibLoaded = false;
  boolean snappyLoaded = false;
  // lz4 is linked within libhadoop
  boolean lz4Loaded = nativeHadoopLoaded;
  boolean bzip2Loaded = Bzip2Factory.isNativeBzip2Loaded(conf);
  String hadoopLibraryName = "";
  String zlibLibraryName = "";
  String snappyLibraryName = "";
  String lz4LibraryName = "";
  String bzip2LibraryName = "";
  if (nativeHadoopLoaded) {
    hadoopLibraryName = NativeCodeLoader.getLibraryName();
    zlibLoaded = ZlibFactory.isNativeZlibLoaded(conf);
    if (zlibLoaded) {
      zlibLibraryName = ZlibFactory.getLibraryName();
    }
    snappyLoaded = NativeCodeLoader.buildSupportsSnappy() &&
        SnappyCodec.isNativeCodeLoaded();
    if (snappyLoaded && NativeCodeLoader.buildSupportsSnappy()) {
      snappyLibraryName = SnappyCodec.getLibraryName();
    }
    if (lz4Loaded) {
      lz4LibraryName = Lz4Codec.getLibraryName();
    }
    if (bzip2Loaded) {
      bzip2LibraryName = Bzip2Factory.getLibraryName(conf);
    }
  }
  System.out.println("Native library checking:");
  System.out.printf("hadoop: %b %s\n", nativeHadoopLoaded, hadoopLibraryName);
  System.out.printf("zlib:   %b %s\n", zlibLoaded, zlibLibraryName);
  System.out.printf("snappy: %b %s\n", snappyLoaded, snappyLibraryName);
  System.out.printf("lz4:    %b %s\n", lz4Loaded, lz4LibraryName);
  System.out.printf("bzip2:  %b %s\n", bzip2Loaded, bzip2LibraryName);
  if ((!nativeHadoopLoaded) ||
      (checkAll && !(zlibLoaded && snappyLoaded && lz4Loaded && bzip2Loaded))) {
    // return 1 to indicated check failed
    ExitUtil.terminate(1);
  }
}