io.crate.operation.projectors

Class WriterProjector

java.lang.Object

io.crate.operation.projectors.AbstractProjector

io.crate.operation.projectors.WriterProjector

All Implemented Interfaces:

Projector, RowReceiver, RowUpstream

public class WriterProjector
extends AbstractProjector

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.concurrent.atomic.AtomicLong	counter

Fields inherited from class io.crate.operation.projectors.AbstractProjector

downstream

Constructor Summary

Constructors

Constructor and Description
WriterProjector(java.util.concurrent.ExecutorService executorService, java.lang.String uri, WriterProjection.CompressionType compressionType, java.util.List<Input<?>> inputs, java.util.Set<CollectExpression<Row,?>> collectExpressions, java.util.Map<ColumnIdent,java.lang.Object> overwrites, java.util.List<java.lang.String> outputNames, WriterProjection.OutputFormat outputFormat)

Method Summary

Modifier and Type	Method and Description
void	fail(java.lang.Throwable throwable) Is called from the upstream in case of a failure.
void	finish() Called from the upstream to indicate that all rows are sent.
void	prepare() prepares / starts the RowReceiver, after this call it must be ready to receive rows
boolean	setNextRow(Row row) Feed the downstream with the next input row.
protected static java.util.Map<java.lang.String,java.lang.Object>	toNestedStringObjectMap(java.util.Map<ColumnIdent,java.lang.Object> columnIdentObjectMap)

Methods inherited from class io.crate.operation.projectors.AbstractProjector

downstream, kill, pause, repeat, requirements, resume, setUpstream

Methods inherited from class java.lang.Object

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

Field Detail

counter

protected final java.util.concurrent.atomic.AtomicLong counter

Constructor Detail

WriterProjector

public WriterProjector(java.util.concurrent.ExecutorService executorService,
                       java.lang.String uri,
                       @Nullable
                       WriterProjection.CompressionType compressionType,
                       @Nullable
                       java.util.List<Input<?>> inputs,
                       java.util.Set<CollectExpression<Row,?>> collectExpressions,
                       java.util.Map<ColumnIdent,java.lang.Object> overwrites,
                       @Nullable
                       java.util.List<java.lang.String> outputNames,
                       WriterProjection.OutputFormat outputFormat)

Parameters:

inputs - a list of Input. If null the row that is received in setNextRow(Row) is expected to contain the raw source in its first column. That raw source is then written to the output

If inputs is not null the inputs are consumed to write a JSON array to the output.

Method Detail

toNestedStringObjectMap

protected static java.util.Map<java.lang.String,java.lang.Object> toNestedStringObjectMap(java.util.Map<ColumnIdent,java.lang.Object> columnIdentObjectMap)

prepare

public void prepare()

Description copied from interface: RowReceiver

prepares / starts the RowReceiver, after this call it must be ready to receive rows

Specified by:

prepare in interface RowReceiver

Overrides:

prepare in class AbstractProjector

setNextRow

public boolean setNextRow(Row row)

Description copied from interface: RowReceiver

Feed the downstream with the next input row. If the downstream does not need any more rows, it returns false, true otherwise. Any upstream who calls this methods must call RowReceiver.setUpstream(RowUpstream) exactly once so that the receiver is able to call pause/resume on its upstream. RowReceiver.finish() and RowReceiver.fail(Throwable) may be called without calling setUpstream if there are no rows.

Parameters:

row - the next row - the row is usually a shared object and the instances content change after the setNextRow call.

Returns:

false if the downstream does not need any more rows, true otherwise.

finish

public void finish()

Description copied from interface: RowReceiver

Called from the upstream to indicate that all rows are sent. NOTE: This method must not throw any exceptions!

fail

public void fail(java.lang.Throwable throwable)

Description copied from interface: RowReceiver

Is called from the upstream in case of a failure. This is the equivalent to finish and indicates that the upstream is finished

Parameters:

throwable - the cause of the fail NOTE: This method must not throw any exceptions!