com.amazon.redshift.core

Class ResultHandlerBase

java.lang.Object

com.amazon.redshift.core.ResultHandlerBase

All Implemented Interfaces:

ResultHandler

Direct Known Subclasses:

BatchResultHandler, RedshiftResultSet.CursorResultHandler, RedshiftStatementImpl.StatementResultHandler

public class ResultHandlerBase
extends Object
implements ResultHandler

Empty implementation of ResultHandler interface. SQLException.setNextException(SQLException) has O(N) complexity, so this class tracks the last exception object to speedup setNextException.

Constructor Summary

Constructors

Constructor and Description
ResultHandlerBase()

Method Summary

Modifier and Type	Method and Description
SQLException	getException() Returns the first encountered exception.
SQLWarning	getWarning() Returns the first encountered warning.
void	handleCommandStatus(String status, long updateCount, long insertOID) Called when a query that did not return a resultset completes.
void	handleCompletion() Called before a QueryExecutor method returns.
void	handleError(SQLException error) Called when an error occurs.
void	handleResultRows(Query fromQuery, Field[] fields, List<Tuple> tuples, ResultCursor cursor, RedshiftRowsBlockingQueue<Tuple> queueTuples, int[] rowCount, Thread ringBufferThread) Called when result rows are received from a query.
void	handleWarning(SQLWarning warning) Called when a warning is emitted.
void	secureProgress() Callback for batch statements.
void	setStatementStateIdleFromInQuery() Set statement state on completion of the Ring buffer thread.
void	setStatementStateInQueryFromIdle() Set statement state on start from IDLE to IN_QUERY, in case Ring Buffer thread reset the new query state as IDLE.
boolean	wantsScrollableResultSet() Check the statement type

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ResultHandlerBase

public ResultHandlerBase()

Method Detail

handleResultRows

public void handleResultRows(Query fromQuery,
                             Field[] fields,
                             List<Tuple> tuples,
                             ResultCursor cursor,
                             RedshiftRowsBlockingQueue<Tuple> queueTuples,
                             int[] rowCount,
                             Thread ringBufferThread)

Description copied from interface: ResultHandler

Called when result rows are received from a query.

Specified by:

handleResultRows in interface ResultHandler

Parameters:

fromQuery - the underlying query that generated these results; this may not be very specific (e.g. it may be a query that includes multiple statements).

fields - column metadata for the resultset; might be null if Query.QUERY_NO_METADATA was specified.

tuples - the actual data. If this is set then queueTuples will be null.

cursor - a cursor to use to fetch additional data; null if no further results are present.

queueTuples - the actual data in a blocking queue. If this is set then tuples will be null.

rowCount - number of rows fetched from the socket.

ringBufferThread - a thread to fetch rows in the limited rows buffer.

handleCommandStatus

public void handleCommandStatus(String status,
                                long updateCount,
                                long insertOID)

Description copied from interface: ResultHandler

Called when a query that did not return a resultset completes.

Specified by:

handleCommandStatus in interface ResultHandler

Parameters:

status - the command status string (e.g. "SELECT") returned by the backend

updateCount - the number of rows affected by an INSERT, UPDATE, DELETE, FETCH, or MOVE command; -1 if not available.

insertOID - for a single-row INSERT query, the OID of the newly inserted row; 0 if not available.

secureProgress

public void secureProgress()

Description copied from interface: ResultHandler

Callback for batch statements. In case batch statement is executed in autocommit==true mode, the executor might commit "as it this it is best", so the result handler should track which statements are executed successfully and which are not.

Specified by:

secureProgress in interface ResultHandler

handleWarning

public void handleWarning(SQLWarning warning)

Description copied from interface: ResultHandler

Called when a warning is emitted.

Specified by:

handleWarning in interface ResultHandler

Parameters:

warning - the warning that occurred.

handleError

public void handleError(SQLException error)

Description copied from interface: ResultHandler

Called when an error occurs. Subsequent queries are abandoned; in general the only calls between a handleError call and a subsequent handleCompletion call are handleError or handleWarning.

Specified by:

handleError in interface ResultHandler

Parameters:

error - the error that occurred

handleCompletion

public void handleCompletion()
                      throws SQLException

Description copied from interface: ResultHandler

Called before a QueryExecutor method returns. This method may throw a SQLException if desired; if it does, the QueryExecutor method will propagate that exception to the original caller.

Specified by:

handleCompletion in interface ResultHandler

Throws:

SQLException - if the handler wishes the original method to throw an exception.

getException

public SQLException getException()

Description copied from interface: ResultHandler

Returns the first encountered exception. The rest are chained via SQLException.setNextException(SQLException)

Specified by:

getException in interface ResultHandler

Returns:

the first encountered exception

getWarning

public SQLWarning getWarning()

Description copied from interface: ResultHandler

Returns the first encountered warning. The rest are chained via SQLException.setNextException(SQLException)

Specified by:

getWarning in interface ResultHandler

Returns:

the first encountered warning

setStatementStateIdleFromInQuery

public void setStatementStateIdleFromInQuery()

Description copied from interface: ResultHandler

Set statement state on completion of the Ring buffer thread.

Specified by:

setStatementStateIdleFromInQuery in interface ResultHandler

setStatementStateInQueryFromIdle

public void setStatementStateInQueryFromIdle()

Description copied from interface: ResultHandler

Set statement state on start from IDLE to IN_QUERY, in case Ring Buffer thread reset the new query state as IDLE.

Specified by:

setStatementStateInQueryFromIdle in interface ResultHandler

wantsScrollableResultSet

public boolean wantsScrollableResultSet()

Description copied from interface: ResultHandler

Check the statement type

Specified by:

wantsScrollableResultSet in interface ResultHandler

Returns:

true if scrollable, false for forward only.