How to use

parseChecksummedMap

method

in

org.h2.mvstore.DataUtils

/**
 * Try to read a chunk footer.
 *
 * @param end the end of the chunk
 * @return the chunk, or null if not successful
 */
private Chunk readChunkFooter(long end) {
  // the following can fail for various reasons
  try {
    // read the chunk footer of the last block of the file
    ByteBuffer lastBlock = fileStore.readFully(
        end - Chunk.FOOTER_LENGTH, Chunk.FOOTER_LENGTH);
    byte[] buff = new byte[Chunk.FOOTER_LENGTH];
    lastBlock.get(buff);
    HashMap<String, String> m = DataUtils.parseChecksummedMap(buff);
    if (m != null) {
      int chunk = DataUtils.readHexInt(m, "chunk", 0);
      Chunk c = new Chunk(chunk);
      c.version = DataUtils.readHexLong(m, "version", 0);
      c.block = DataUtils.readHexLong(m, "block", 0);
      return c;
    }
  } catch (Exception e) {
    // ignore
  }
  return null;
}

HashMap<String, String> m = DataUtils.parseChecksummedMap(buff);
if (m == null) {
  continue;

/**
 * Try to read a chunk footer.
 *
 * @param end the end of the chunk
 * @return the chunk, or null if not successful
 */
private Chunk readChunkFooter(long end) {
  // the following can fail for various reasons
  try {
    // read the chunk footer of the last block of the file
    ByteBuffer lastBlock = fileStore.readFully(
        end - Chunk.FOOTER_LENGTH, Chunk.FOOTER_LENGTH);
    byte[] buff = new byte[Chunk.FOOTER_LENGTH];
    lastBlock.get(buff);
    HashMap<String, String> m = DataUtils.parseChecksummedMap(buff);
    if (m != null) {
      int chunk = DataUtils.readHexInt(m, "chunk", 0);
      Chunk c = new Chunk(chunk);
      c.version = DataUtils.readHexLong(m, "version", 0);
      c.block = DataUtils.readHexLong(m, "block", 0);
      return c;
    }
  } catch (Exception e) {
    // ignore
  }
  return null;
}

HashMap<String, String> m = DataUtils.parseChecksummedMap(buff);
if (m == null) {
  continue;