Package org.apache.iceberg.data

Class BaseDeleteLoader

java.lang.Object

org.apache.iceberg.data.BaseDeleteLoader

All Implemented Interfaces:

DeleteLoader

public class BaseDeleteLoader
extends Object
implements DeleteLoader

Constructor Summary

Constructors

Constructor	Description
BaseDeleteLoader(Function<DeleteFile,InputFile> loadInputFile)
BaseDeleteLoader(Function<DeleteFile,InputFile> loadInputFile, ExecutorService workerPool)

Method Summary

Modifier and Type	Method	Description
protected boolean	canCache(long size)	Checks if the given number of bytes can be cached.
protected <V> V	getOrLoad(String key, Supplier<V> valueSupplier, long valueSize)	Gets the cached value for the key or populates the cache with a new mapping.
StructLikeSet	loadEqualityDeletes(Iterable<DeleteFile> deleteFiles, Schema projection)	Loads the content of equality delete files into a set.
PositionDeleteIndex	loadPositionDeletes(Iterable<DeleteFile> deleteFiles, CharSequence filePath)	Loads the content of a deletion vector or position delete files for a given data file path into a position index.

Methods inherited from class java.lang.Object

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

Constructor Details

BaseDeleteLoader

public BaseDeleteLoader(Function<DeleteFile,InputFile> loadInputFile)

BaseDeleteLoader

public BaseDeleteLoader(Function<DeleteFile,InputFile> loadInputFile,
 ExecutorService workerPool)

Method Details

canCache

protected boolean canCache(long size)

Checks if the given number of bytes can be cached.

Implementations should override this method if they support caching. It is also recommended to use the provided size as a guideline to decide whether the value is eligible for caching. For instance, it may be beneficial to discard values that are too large to optimize the cache performance and utilization.

getOrLoad

protected <V> V getOrLoad(String key,
 Supplier<V> valueSupplier,
 long valueSize)

Gets the cached value for the key or populates the cache with a new mapping.

If the value for the specified key is in the cache, it should be returned. If the value is not in the cache, implementations should compute the value using the provided supplier, cache it, and then return it.

This method will be called only if canCache(long) returned true.

loadEqualityDeletes

public StructLikeSet loadEqualityDeletes(Iterable<DeleteFile> deleteFiles,
 Schema projection)

Description copied from interface: DeleteLoader

Loads the content of equality delete files into a set.

Specified by:

loadEqualityDeletes in interface DeleteLoader

Parameters:

deleteFiles - equality delete files

projection - a projection of columns to load

Returns:

a set of equality deletes

loadPositionDeletes

public PositionDeleteIndex loadPositionDeletes(Iterable<DeleteFile> deleteFiles,
 CharSequence filePath)

Loads the content of a deletion vector or position delete files for a given data file path into a position index.

The deletion vector is currently loaded without caching as the existing Puffin reader requires at least 3 requests to fetch the entire file. Caching a single deletion vector may only be useful when multiple data file splits are processed on the same node, which is unlikely as task locality is not guaranteed.

For position delete files, however, there is no efficient way to read deletes for a particular data file. Therefore, caching may be more effective as such delete files potentially apply to many data files, especially in unpartitioned tables and tables with deep partitions. If a position delete file qualifies for caching, this method will attempt to cache a position index for each referenced data file.

Specified by:

loadPositionDeletes in interface DeleteLoader

Parameters:

deleteFiles - a deletion vector or position delete files

filePath - the data file path for which to load deletes

Returns:

a position delete index for the provided data file path