Package org.apache.druid.data.input.impl.systemfield

Interface SystemFieldInputSource

All Superinterfaces:

InputSource

All Known Implementing Classes:

CloudObjectInputSource, HttpInputSource, LocalInputSource

public interface SystemFieldInputSource
extends InputSource

An InputSource that can generate system fields. Implementations of InputSource.reader(InputRowSchema, InputFormat, File) tend to create a decorator factory using SystemFieldDecoratorFactory.fromInputSource(SystemFieldInputSource) on "this" and then pass it to InputEntityIteratingReader.

Field Summary

Fields

Modifier and Type	Field	Description
static String	SYSTEM_FIELDS_PROPERTY

Fields inherited from interface org.apache.druid.data.input.InputSource

TYPE_PROPERTY

Method Summary

Modifier and Type	Method	Description
Set<SystemField>	getConfiguredSystemFields()	System fields that this input source is configured to return.
Object	getSystemFieldValue(InputEntity entity, SystemField field)	Compute the value of a system field for a particular InputEntity.

Methods inherited from interface org.apache.druid.data.input.InputSource

getTypes, isSplittable, needsFormat, reader

Field Detail

SYSTEM_FIELDS_PROPERTY

static final String SYSTEM_FIELDS_PROPERTY

See Also:

Constant Field Values

Method Detail

getConfiguredSystemFields

Set<SystemField> getConfiguredSystemFields()

System fields that this input source is configured to return. This is not the same set that getSystemFieldValue(InputEntity, SystemField) returns nonnull for. For example, if a LocalInputSource is configured to return SystemField.BUCKET then it will show up in this list, even though its value is always null. For another example in a different direction, if a LocalInputSource is *not* configured to return SystemField.URI, then it will *not* show up in this list, even though its value from getSystemFieldValue(InputEntity, SystemField) would be nonnull.

getSystemFieldValue

@Nullable
Object getSystemFieldValue(InputEntity entity,
                           SystemField field)

Compute the value of a system field for a particular InputEntity.