org.apache.druid.query.cache

Class CacheKeyBuilder

java.lang.Object

org.apache.druid.query.cache.CacheKeyBuilder

public class CacheKeyBuilder
extends Object

CacheKeyBuilder is a tool for easily generating cache keys of Cacheable objects. The layout of the serialized cache key is like below. +--------------------------------------------------------+ | ID (1 byte) | | type key (1 byte) | serialized value (variable length) | | type key (1 byte) | serialized value (variable length) | | ... | +--------------------------------------------------------+

Constructor Summary

Constructors

Constructor and Description
CacheKeyBuilder(byte id)

Method Summary

Modifier and Type	Method and Description
CacheKeyBuilder	appendBoolean(boolean input)
CacheKeyBuilder	appendByte(byte input)
CacheKeyBuilder	appendByteArray(byte[] input)
CacheKeyBuilder	appendCacheable(Cacheable input)
CacheKeyBuilder	appendCacheables(Collection<? extends Cacheable> input) Add a collection of Cacheables to the cache key.
CacheKeyBuilder	appendCacheablesIgnoringOrder(Collection<? extends Cacheable> input) Add a collection of Cacheables to the cache key.
CacheKeyBuilder	appendDouble(double input)
CacheKeyBuilder	appendDoubleArray(double[] input)
CacheKeyBuilder	appendFloat(float input)
CacheKeyBuilder	appendFloatArray(float[] input)
CacheKeyBuilder	appendInt(int input)
CacheKeyBuilder	appendLong(long input)
CacheKeyBuilder	appendString(String input)
CacheKeyBuilder	appendStrings(Collection<String> input) Add a collection of strings to the cache key.
CacheKeyBuilder	appendStringsIgnoringOrder(Collection<String> input) Add a collection of strings to the cache key.
byte[]	build()

Methods inherited from class java.lang.Object

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

Constructor Detail

CacheKeyBuilder

public CacheKeyBuilder(byte id)

Method Detail

appendByte

public CacheKeyBuilder appendByte(byte input)

appendByteArray

public CacheKeyBuilder appendByteArray(byte[] input)

appendString

public CacheKeyBuilder appendString(@Nullable
                                    String input)

appendStrings

public CacheKeyBuilder appendStrings(Collection<String> input)

Add a collection of strings to the cache key. Strings in the collection are concatenated with a separator of '0xFF', and they appear in the cache key in their input order.

Parameters:

input - a collection of strings to be included in the cache key

Returns:

this instance

appendStringsIgnoringOrder

public CacheKeyBuilder appendStringsIgnoringOrder(Collection<String> input)

Add a collection of strings to the cache key. Strings in the collection are sorted by their byte representation and concatenated with a separator of '0xFF'.

Parameters:

input - a collection of strings to be included in the cache key

Returns:

this instance

appendBoolean

public CacheKeyBuilder appendBoolean(boolean input)

appendInt

public CacheKeyBuilder appendInt(int input)

appendLong

public CacheKeyBuilder appendLong(long input)

appendFloat

public CacheKeyBuilder appendFloat(float input)

appendDouble

public CacheKeyBuilder appendDouble(double input)

appendDoubleArray

public CacheKeyBuilder appendDoubleArray(double[] input)

appendFloatArray

public CacheKeyBuilder appendFloatArray(float[] input)

appendCacheable

public CacheKeyBuilder appendCacheable(@Nullable
                                       Cacheable input)

appendCacheables

public CacheKeyBuilder appendCacheables(Collection<? extends Cacheable> input)

Add a collection of Cacheables to the cache key. Cacheables in the collection are concatenated without any separator, and they appear in the cache key in their input order.

Parameters:

input - a collection of Cacheables to be included in the cache key

Returns:

this instance

appendCacheablesIgnoringOrder

public CacheKeyBuilder appendCacheablesIgnoringOrder(Collection<? extends Cacheable> input)

Add a collection of Cacheables to the cache key. Cacheables in the collection are sorted by their byte representation and concatenated without any separator.

Parameters:

input - a collection of Cacheables to be included in the cache key

Returns:

this instance

build

public byte[] build()