public long size() throws FileLockException, IOException {
        long size = 0L;
        for (int bucketId = 0; bucketId < hashFunction.getNumberOfBuckets(); bucketId++) {
            HeaderIndexFile<Data> headerIndexFile = new HeaderIndexFile<Data>(gp.DATABASE_DIRECTORY + "/"
                    + hashFunction.getFilename(bucketId), gp.HEADER_FILE_LOCK_RETRY, gp);
            size += headerIndexFile.getFilledUpFromContentStart() / gp.getElementSize();
            headerIndexFile.close();
        }
        return size;
    }
public long size ( ) throws FileLockException , IOException { long size = 0L ; for ( int bucketId = 0 ; bucketId < hashFunction . getNumberOfBuckets ( ) ; bucketId ++ ) { HeaderIndexFile < Data > headerIndexFile = new HeaderIndexFile < Data > ( gp . DATABASE_DIRECTORY + "/" + hashFunction . getFilename ( bucketId ) , gp . HEADER_FILE_LOCK_RETRY , gp ) ; size += headerIndexFile . getFilledUpFromContentStart ( ) / gp . getElementSize ( ) ; headerIndexFile . close ( ) ; } return size ; }
Determines the number of elements in each buckets by opening all files.

@return the number of elements in the database.
@throws IOException
@throws FileLockException