org.apache.druid.segment

Class ArrayListSegment<RowType>

java.lang.Object

org.apache.druid.segment.ArrayListSegment<RowType>

All Implemented Interfaces:

Closeable, AutoCloseable, Segment

public class ArrayListSegment<RowType>
extends Object
implements Segment

A Segment that is based on a stream of objects.

Constructor Summary

Constructors

Constructor and Description
ArrayListSegment(SegmentId segmentId, ArrayList<RowType> rows, RowAdapter<RowType> rowAdapter, RowSignature rowSignature) Create a list-based segment.

Method Summary

Modifier and Type	Method and Description
<T> T	as(Class<T> clazz) Request an implementation of a particular interface.
QueryableIndex	asQueryableIndex()
StorageAdapter	asStorageAdapter()
void	close()
org.joda.time.Interval	getDataInterval()
SegmentId	getId()

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayListSegment

public ArrayListSegment(SegmentId segmentId,
                        ArrayList<RowType> rows,
                        RowAdapter<RowType> rowAdapter,
                        RowSignature rowSignature)

Create a list-based segment.

The provided List must be in time-order according to the provided RowAdapter.timestampFunction(). The cursor returned by RowBasedStorageAdapter.makeCursors(org.apache.druid.query.filter.Filter, org.joda.time.Interval, org.apache.druid.segment.VirtualColumns, org.apache.druid.java.util.common.granularity.Granularity, boolean, org.apache.druid.query.QueryMetrics<?>) makes no attempt to verify this, and callers will expect it.

The provided "rowSignature" will be used for reporting available columns and their capabilities to users of asStorageAdapter(). Note that the ColumnSelectorFactory implementation returned by this segment's storage adapter will allow creation of selectors on any field, using the RowAdapter.columnFunction(java.lang.String) for that field, even if it doesn't appear in "rowSignature".

Parameters:

segmentId - segment identifier; will be returned by getId()

rows - objects that comprise this segment. Must be re-iterable if support for Cursor.reset() is required. Otherwise, does not need to be re-iterable.

rowAdapter - adapter used for reading these objects

rowSignature - signature of the columns in these objects

Method Detail

getId

@Nonnull
public SegmentId getId()

Specified by:

getId in interface Segment

getDataInterval

@Nonnull
public org.joda.time.Interval getDataInterval()

Specified by:

getDataInterval in interface Segment

asQueryableIndex

@Nullable
public QueryableIndex asQueryableIndex()

Specified by:

asQueryableIndex in interface Segment

asStorageAdapter

@Nonnull
public StorageAdapter asStorageAdapter()

Specified by:

asStorageAdapter in interface Segment

as

@Nullable
public <T> T as(Class<T> clazz)

Description copied from interface: Segment

Request an implementation of a particular interface. If the passed-in interface is QueryableIndex or StorageAdapter, then this method behaves identically to Segment.asQueryableIndex() or Segment.asStorageAdapter(). Other interfaces are only expected to be requested by callers that have specific knowledge of extra features provided by specific segment types. For example, an extension might provide a custom Segment type that can offer both StorageAdapter and some new interface. That extension can also offer a Query that uses that new interface. Implementations which accept classes other than QueryableIndex or StorageAdapter are limited to using those classes within the extension. This means that one extension cannot rely on the `Segment.as` behavior of another extension.

Specified by:

as in interface Segment

Type Parameters:

T - desired interface

Parameters:

clazz - desired interface

Returns:

instance of clazz, or null if the interface is not supported by this segment

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable