Package org.apache.druid.segment

Class ArrayListSegment<RowType>

java.lang.Object

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

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

All Implemented Interfaces:

Closeable, AutoCloseable, Segment

public class ArrayListSegment<RowType>
extends RowBasedSegment<RowType>

A Segment that is based on a stream of objects.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
<T> T	as(Class<T> clazz)	Request an implementation of a particular interface.
void	close()

Methods inherited from class org.apache.druid.segment.RowBasedSegment

asCursorFactory, asQueryableIndex, getDataInterval, getId

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.druid.segment.Segment

asStorageAdapter, asString, isTombstone

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 RowBasedCursorFactory.makeCursorHolder(CursorBuildSpec) 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 RowBasedSegment.asCursorFactory(). Note that the ColumnSelectorFactory implementation returned by this segment's cursor factory 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 RowBasedSegment.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

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 CursorFactory, then this method behaves identically to Segment.asQueryableIndex() or Segment.asCursorFactory(). 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 CursorFactory are limited to using those classes within the extension. This means that one extension cannot rely on the `Segment.as` behavior of another extension.

Type Parameters:

T - desired interface

Parameters:

clazz - desired interface

Returns:

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

• CursorFactory, to make cursors to run queries. Never null.
• QueryableIndex, index object, if this is a memory-mapped regular segment.
• IndexedTable, table object, if this is a joinable indexed table.
• TimeBoundaryInspector, inspector for min/max timestamps, if supported by this segment.
• PhysicalSegmentInspector, inspector for physical segment details, if supported by this segment.
• MaxIngestedEventTimeInspector, inspector for DataSourceMetadataResultValue.getMaxIngestedEventTime()
• TopNOptimizationInspector, inspector containing information for topN specific optimizations
• CloseableShapeshifter, stepping stone to RowsAndColumns.
• BypassRestrictedSegment, a policy-aware segment, converted from a policy-enforced segment.

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class RowBasedSegment<RowType>