Package org.apache.hadoop.hbase.io.compress

Class DictionaryCache

java.lang.Object

org.apache.hadoop.hbase.io.compress.DictionaryCache

@Private
public final class DictionaryCache
extends Object

A utility class for managing compressor/decompressor dictionary loading and caching of load results. Useful for any codec that can support changing dictionaries at runtime, such as ZStandard.

Field Summary

Fields

Modifier and Type	Field	Description
private static org.apache.hbase.thirdparty.com.google.common.cache.LoadingCache<String,byte[]>	CACHE
static final int	DEFAULT_DICTIONARY_MAX_SIZE
static final String	DICTIONARY_MAX_SIZE_KEY
private static final org.slf4j.Logger	LOG
static final String	RESOURCE_SCHEME

Constructor Summary

Constructors

Modifier	Constructor	Description
private	DictionaryCache()

Method Summary

Modifier and Type	Method	Description
static boolean	contains(String dictionaryPath)
static byte[]	getDictionary(org.apache.hadoop.conf.Configuration conf, String path)	Load a dictionary or return a previously cached load.
private static byte[]	loadFromHadoopFs(org.apache.hadoop.conf.Configuration conf, String s, int maxSize)
static byte[]	loadFromResource(org.apache.hadoop.conf.Configuration conf, String s, int maxSize)

Methods inherited from class java.lang.Object

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

Field Details

DICTIONARY_MAX_SIZE_KEY

public static final String DICTIONARY_MAX_SIZE_KEY

See Also:

• Constant Field Values

DEFAULT_DICTIONARY_MAX_SIZE

public static final int DEFAULT_DICTIONARY_MAX_SIZE

See Also:

• Constant Field Values

RESOURCE_SCHEME

public static final String RESOURCE_SCHEME

See Also:

• Constant Field Values

LOG

private static final org.slf4j.Logger LOG

CACHE

private static volatile org.apache.hbase.thirdparty.com.google.common.cache.LoadingCache<String,byte[]> CACHE

Constructor Details

DictionaryCache

private DictionaryCache()

Method Details

getDictionary

public static byte[] getDictionary(org.apache.hadoop.conf.Configuration conf,
 String path)
                            throws IOException

Load a dictionary or return a previously cached load.

Parameters:

conf - configuration

path - the hadoop Path where the dictionary is located, as a String

Returns:

the dictionary bytes if successful, null otherwise

Throws:

IOException

loadFromResource

public static byte[] loadFromResource(org.apache.hadoop.conf.Configuration conf,
 String s,
 int maxSize)
                               throws IOException

Throws:

IOException

loadFromHadoopFs

private static byte[] loadFromHadoopFs(org.apache.hadoop.conf.Configuration conf,
 String s,
 int maxSize)
                                throws IOException

Throws:

IOException

contains

public static boolean contains(String dictionaryPath)