org.apache.hudi.io.hfile

Class HFileBlockCache

java.lang.Object

org.apache.hudi.io.hfile.HFileBlockCache

public class HFileBlockCache
extends Object

Least Frequently Used (LFU) cache for HFile blocks to improve read performance by avoiding repeated block reads. Uses Caffeine cache with configurable size and TTL. Thread-safe for concurrent access.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	HFileBlockCache.BlockCacheKey Cache key for identifying blocks uniquely.

Constructor Summary

Constructors

Constructor and Description
HFileBlockCache(int maxCacheSize, long expireAfterWrite, TimeUnit timeUnit)

Method Summary

Modifier and Type	Method and Description
void	cleanUp() Forces cache maintenance operations like eviction.
void	clear() Clears all cached blocks.
HFileBlock	getBlock(HFileBlockCache.BlockCacheKey key) Gets a block from cache.
HFileBlock	getOrCompute(HFileBlockCache.BlockCacheKey key, Callable<HFileBlock> loader) Gets a block from cache, or computes and caches it if not present.
void	putBlock(HFileBlockCache.BlockCacheKey key, HFileBlock block) Puts a block into cache.
long	size() Gets current cache size.

Methods inherited from class java.lang.Object

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

Constructor Detail

HFileBlockCache

public HFileBlockCache(int maxCacheSize,
                       long expireAfterWrite,
                       TimeUnit timeUnit)

Method Detail

getBlock

public HFileBlock getBlock(HFileBlockCache.BlockCacheKey key)

Gets a block from cache.

Parameters:

key - the cache key

Returns:

cached block or null if not found

putBlock

public void putBlock(HFileBlockCache.BlockCacheKey key,
                     HFileBlock block)

Puts a block into cache.

Parameters:

key - the cache key

block - the block to cache

getOrCompute

public HFileBlock getOrCompute(HFileBlockCache.BlockCacheKey key,
                               Callable<HFileBlock> loader)
                        throws Exception

Gets a block from cache, or computes and caches it if not present.

Parameters:

key - the cache key

loader - callable to load the block if not in cache

Returns:

cached or newly computed block

Throws:

Exception - if the loader throws an exception

clear

public void clear()

Clears all cached blocks.

size

public long size()

Gets current cache size.

Returns:

number of cached blocks

cleanUp

public void cleanUp()

Forces cache maintenance operations like eviction. This is useful for testing to ensure consistent behavior.