* Reads the metadata and sends the data in one 'DATA_CHUNK'
* @param in
*/
void readMetadata(DataInputStream in) throws IOException {
Block block = new Block( in.readLong(), 0 , in.readLong());
MetaDataInputStream checksumIn = null;
DataOutputStream out = null;
try {
checksumIn = data.getMetaDataInputStream(block);
long fileSize = checksumIn.getLength();
if (fileSize >= 1L<<31 || fileSize <= 0) {
throw new IOException("Unexpected size for checksumFile of block" +
block);
}