| package backtype.storm.spout; |
| |
| import backtype.storm.task.OutputCollector; |
| import backtype.storm.utils.Utils; |
| import java.util.List; |
| |
| /** |
| * This output collector exposes the API for emitting tuples from an {@link backtype.storm.topology.IRichSpout}. |
| * The main difference between this output collector and {@link OutputCollector} |
| * for {@link backtype.storm.topology.IRichBolt} is that spouts can tag messages with ids so that they can be |
| * acked or failed later on. This is the Spout portion of Storm's API to |
| * guarantee that each message is fully processed at least once. |
| */ |
| public class SpoutOutputCollector implements ISpoutOutputCollector { |
| ISpoutOutputCollector _delegate; |
| |
| public SpoutOutputCollector(ISpoutOutputCollector delegate) { |
| _delegate = delegate; |
| } |
| |
| /** |
| * Emits a new tuple to the specified output stream with the given message ID. |
| * When Storm detects that this tuple has been fully processed, or has failed |
| * to be fully processed, the spout will receive an ack or fail callback respectively |
| * with the messageId as long as the messageId was not null. If the messageId was null, |
| * Storm will not track the tuple and no callback will be received. |
| * |
| * @return the list of task ids that this tuple was sent to |
| */ |
| public List<Integer> emit(int streamId, List<Object> tuple, Object messageId) { |
| return _delegate.emit(streamId, tuple, messageId); |
| } |
| |
| /** |
| * Emits a new tuple to the default output stream with the given message ID. |
| * When Storm detects that this tuple has been fully processed, or has failed |
| * to be fully processed, the spout will receive an ack or fail callback respectively |
| * with the messageId as long as the messageId was not null. If the messageId was null, |
| * Storm will not track the tuple and no callback will be received. |
| * |
| * @return the list of task ids that this tuple was sent to |
| */ |
| public List<Integer> emit(List<Object> tuple, Object messageId) { |
| return emit(Utils.DEFAULT_STREAM_ID, tuple, messageId); |
| } |
| |
| /** |
| * Emits a tuple to the default output stream with a null message id. Storm will |
| * not track this message so ack and fail will never be called for this tuple. |
| */ |
| public List<Integer> emit(List<Object> tuple) { |
| return emit(tuple, null); |
| } |
| |
| /** |
| * Emits a tuple to the specified output stream with a null message id. Storm will |
| * not track this message so ack and fail will never be called for this tuple. |
| */ |
| public List<Integer> emit(int streamId, List<Object> tuple) { |
| return emit(streamId, tuple, null); |
| } |
| |
| /** |
| * Emits a tuple to the specified task on the specified output stream. This output |
| * stream must have been declared as a direct stream, and the specified task must |
| * use a direct grouping on this stream to receive the message. |
| */ |
| public void emitDirect(int taskId, int streamId, List<Object> tuple, Object messageId) { |
| _delegate.emitDirect(taskId, streamId, tuple, messageId); |
| } |
| |
| /** |
| * Emits a tuple to the specified task on the default output stream. This output |
| * stream must have been declared as a direct stream, and the specified task must |
| * use a direct grouping on this stream to receive the message. |
| */ |
| public void emitDirect(int taskId, List<Object> tuple, Object messageId) { |
| emitDirect(taskId, Utils.DEFAULT_STREAM_ID, tuple, messageId); |
| } |
| |
| /** |
| * Emits a tuple to the specified task on the specified output stream. This output |
| * stream must have been declared as a direct stream, and the specified task must |
| * use a direct grouping on this stream to receive the message. |
| * |
| * <p> Because no message id is specified, Storm will not track this message |
| * so ack and fail will never be called for this tuple.</p> |
| */ |
| public void emitDirect(int taskId, int streamId, List<Object> tuple) { |
| emitDirect(taskId, streamId, tuple, null); |
| } |
| |
| /** |
| * Emits a tuple to the specified task on the default output stream. This output |
| * stream must have been declared as a direct stream, and the specified task must |
| * use a direct grouping on this stream to receive the message. |
| * |
| * <p> Because no message id is specified, Storm will not track this message |
| * so ack and fail will never be called for this tuple.</p> |
| */ |
| public void emitDirect(int taskId, List<Object> tuple) { |
| emitDirect(taskId, tuple, null); |
| } |
| } |