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

Interface SplittableInputSource<T>

All Superinterfaces:

InputSource

All Known Implementing Classes:

CloudObjectInputSource, CombiningInputSource, HttpInputSource, LocalInputSource

public interface SplittableInputSource<T>
extends InputSource

Splittable InputSource. ParallelIndexSupervisorTask can process InputSplits in parallel.

Field Summary

Fields

Modifier and Type	Field	Description
static SplitHintSpec	DEFAULT_SPLIT_HINT_SPEC

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

TYPE_PROPERTY

Method Summary

Modifier and Type	Method	Description
Stream<InputSplit<T>>	createSplits(InputFormat inputFormat, SplitHintSpec splitHintSpec)	Creates a Stream of InputSplits.
int	estimateNumSplits(InputFormat inputFormat, SplitHintSpec splitHintSpec)	Returns an estimated total number of splits to be created via createSplits(org.apache.druid.data.input.InputFormat, org.apache.druid.data.input.SplitHintSpec).
default SplitHintSpec	getSplitHintSpecOrDefault(SplitHintSpec splitHintSpec)
default boolean	isSplittable()	Returns true if this inputSource can be processed in parallel using ParallelIndexSupervisorTask.
InputSource	withSplit(InputSplit<T> split)	Helper method for ParallelIndexSupervisorTask.

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

getTypes, needsFormat, reader

Field Detail

DEFAULT_SPLIT_HINT_SPEC

static final SplitHintSpec DEFAULT_SPLIT_HINT_SPEC

Method Detail

isSplittable

default boolean isSplittable()

Description copied from interface: InputSource

Returns true if this inputSource can be processed in parallel using ParallelIndexSupervisorTask. It must be castable to SplittableInputSource and the various SplittableInputSource methods must work as documented.

Specified by:

isSplittable in interface InputSource

createSplits

Stream<InputSplit<T>> createSplits(InputFormat inputFormat,
                                   @Nullable
                                   SplitHintSpec splitHintSpec)
                            throws IOException

Creates a Stream of InputSplits. The returned stream is supposed to be evaluated lazily to avoid consuming too much memory. Note that this interface also has estimateNumSplits(org.apache.druid.data.input.InputFormat, org.apache.druid.data.input.SplitHintSpec) which is related to this method. The implementations should be careful to NOT cache the created splits in memory. Implementations can consider InputFormat.isSplittable() and SplitHintSpec to create splits in the same way with estimateNumSplits(org.apache.druid.data.input.InputFormat, org.apache.druid.data.input.SplitHintSpec).

Throws:

IOException

estimateNumSplits

int estimateNumSplits(InputFormat inputFormat,
                      @Nullable
                      SplitHintSpec splitHintSpec)
               throws IOException

Returns an estimated total number of splits to be created via createSplits(org.apache.druid.data.input.InputFormat, org.apache.druid.data.input.SplitHintSpec). The estimated number of splits doesn't have to be accurate and can be different from the actual number of InputSplits returned from createSplits(org.apache.druid.data.input.InputFormat, org.apache.druid.data.input.SplitHintSpec). This will be used to estimate the progress of a phase in parallel indexing. See TaskMonitor for more details of the progress estimation. This method can be expensive if an implementation iterates all directories or whatever substructure to find all input entities. Implementations can consider InputFormat.isSplittable() and SplitHintSpec to find splits in the same way with createSplits(org.apache.druid.data.input.InputFormat, org.apache.druid.data.input.SplitHintSpec).

Throws:

IOException

withSplit

InputSource withSplit(InputSplit<T> split)

Helper method for ParallelIndexSupervisorTask. Most of implementations can simply create a new instance with the given split.

getSplitHintSpecOrDefault

default SplitHintSpec getSplitHintSpecOrDefault(@Nullable
                                                SplitHintSpec splitHintSpec)