/**
* Counts the rows from the {@code scanner} until exhaustion. It doesn't require the scanner to be
* new, so it can be used to finish scanning a previously-started scan.
*/
protected static int countRowsInScan(AsyncKuduScanner scanner) throws Exception {
final AtomicInteger counter = new AtomicInteger();
Callback<Object, RowResultIterator> cb =
new Callback<Object, RowResultIterator>() {
@Override
public Object call(RowResultIterator arg) throws Exception {
if (arg == null) return null;
counter.addAndGet(arg.getNumRows());
return null;
}
};
while (scanner.hasMoreRows()) {
Deferred<RowResultIterator> data = scanner.nextRows();
data.addCallbacks(cb, defaultErrorCB);
data.join(DEFAULT_SLEEP);
}
Deferred<RowResultIterator> closer = scanner.close();
closer.addCallbacks(cb, defaultErrorCB);
closer.join(DEFAULT_SLEEP);
return counter.get();
}
/**
* Returns if this scanner was configured to cache data blocks or not.
*
* @return true if this scanner will cache blocks, else else.
*/
public boolean getCacheBlocks() {
return asyncScanner.getCacheBlocks();
}
/**
* Returns the maximum number of bytes returned by the scanner, on each batch.
*
* @return a long representing the maximum number of bytes that a scanner can receive at once from
* a tablet server
*/
public long getBatchSizeBytes() {
return asyncScanner.getBatchSizeBytes();
}
/**
* Returns the maximum number of rows that this scanner was configured to return.
*
* @return a long representing the maximum number of rows that can be returned
*/
public long getLimit() {
return asyncScanner.getLimit();
}
/**
* Closes this scanner (don't forget to call this when you're done with it!).
*
* <p>Closing a scanner already closed has no effect.
*
* @return a deferred object that indicates the completion of the request
*/
public RowResultIterator close() throws Exception {
Deferred<RowResultIterator> d = asyncScanner.close();
return d.join(asyncScanner.scanRequestTimeout);
}
/**
* Tells if the last rpc returned that there might be more rows to scan.
*
* @return true if there might be more data to scan, else false
*/
public boolean hasMoreRows() {
return asyncScanner.hasMoreRows();
}
/**
* Returns the projection schema of this scanner. If specific columns were not specified during
* scanner creation, the table schema is returned.
*
* @return the projection schema for this scanner
*/
public Schema getProjectionSchema() {
return asyncScanner.getProjectionSchema();
}
/**
* Returns the ReadMode for this scanner.
*
* @return the configured read mode for this scanner
*/
public ReadMode getReadMode() {
return asyncScanner.getReadMode();
}