org.apache.hudi.io.hfile

Class CachingHFileReaderImpl

java.lang.Object

org.apache.hudi.io.hfile.HFileReaderImpl

org.apache.hudi.io.hfile.CachingHFileReaderImpl

All Implemented Interfaces:

Closeable, AutoCloseable, HFileReader

public class CachingHFileReaderImpl
extends HFileReaderImpl

HFile reader implementation with integrated caching functionality. This extends BaseHFileReaderImpl and overrides the block instantiation method to add caching capabilities.

Uses a shared static cache across all instances to maximize cache hits when multiple readers access the same file.

Field Summary

Fields inherited from class org.apache.hudi.io.hfile.HFileReaderImpl

context, currentDataBlock, currentDataBlockEntry, cursor, dataBlockIndexEntryMap, fileInfo, fileSize, isMetadataInitialized, metaBlockIndexEntryMap, stream, trailer

Fields inherited from interface org.apache.hudi.io.hfile.HFileReader

SEEK_TO_BEFORE_BLOCK_FIRST_KEY, SEEK_TO_BEFORE_FILE_FIRST_KEY, SEEK_TO_EOF, SEEK_TO_FOUND, SEEK_TO_IN_RANGE

Constructor Summary

Constructors

Constructor and Description
CachingHFileReaderImpl(SeekableDataInputStream stream, long fileSize, String filePath, int cacheSize, int cacheTtlMinutes)

Method Summary

Modifier and Type	Method and Description
void	clearCache() Clears the global block cache.
void	close()
long	getCacheSize() Gets current cache size from the global cache.
String	getCacheStats() Gets cache statistics for monitoring optimization effectiveness.
HFileDataBlock	instantiateHFileDataBlock(BlockIndexEntry blockToRead) Creates an HFile data block.
static void	resetGlobalCache() Clears the global cache.

Methods inherited from class org.apache.hudi.io.hfile.HFileReaderImpl

getKeyValue, getMetaBlock, getMetaInfo, getNumKeyValueEntries, initializeMetadata, isSeeked, next, seekTo, seekTo

Methods inherited from class java.lang.Object

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

Constructor Detail

CachingHFileReaderImpl

public CachingHFileReaderImpl(SeekableDataInputStream stream,
                              long fileSize,
                              String filePath,
                              int cacheSize,
                              int cacheTtlMinutes)

Method Detail

instantiateHFileDataBlock

public HFileDataBlock instantiateHFileDataBlock(BlockIndexEntry blockToRead)
                                         throws IOException

Description copied from class: HFileReaderImpl

Creates an HFile data block.

Overrides:

instantiateHFileDataBlock in class HFileReaderImpl

Parameters:

blockToRead - the block index entry to read

Returns:

the instantiated HFile data block

Throws:

IOException - if there's an error reading the block

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class HFileReaderImpl

Throws:

IOException

getCacheSize

public long getCacheSize()

Gets current cache size from the global cache.

Returns:

number of cached blocks

clearCache

public void clearCache()

Clears the global block cache.

getCacheStats

public String getCacheStats()

Gets cache statistics for monitoring optimization effectiveness.

Returns:

string representation of cache statistics

resetGlobalCache

public static void resetGlobalCache()

Clears the global cache. Should only be used for testing.