static int longToInt(final long l) {
    // Expecting the size() of a block not exceeding 4GB. Assuming the
    // size() will wrap to negative integer if it exceeds 2GB (From tfile).
    return (int) (l & 0x00000000ffffffffL);
  }
Get names of supported compression algorithms. The names are acceptable by HFile.Writer.
@return Array of strings, each represents a supported compression algorithm. Currently, the
        following compression algorithms are supported.
        <ul>
        <li>"none" - No compression.
        <li>"gz" - GZIP compression.
        </ul>
hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFile.java