Package org.apache.beam.io.requestresponse

Class Cache

java.lang.Object

org.apache.beam.io.requestresponse.Cache

public final class Cache
extends Object

Transforms for reading and writing request/response associations to a cache.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Cache.Pair<RequestT,ResponseT>	A simple POJO that holds both cache read and write PTransforms.

Constructor Summary

Constructors

Constructor	Description
Cache()

Method Summary

Modifier and Type	Method	Description
static <RequestT, ResponseT> Cache.Pair<RequestT,ResponseT>	usingRedis(URI uri, Coder<RequestT> requestTCoder, Coder<ResponseT> responseTCoder, Duration expiry)	Builds a Cache.Pair using a Redis cache to read and write Cache and Cache pairs.

Methods inherited from class java.lang.Object

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

Constructor Details

Cache

public Cache()

Method Details

usingRedis

public static <RequestT,
ResponseT>
Cache.Pair<RequestT,ResponseT> usingRedis(URI uri,
 Coder<RequestT> requestTCoder,
 Coder<ResponseT> responseTCoder,
 Duration expiry)
                                   throws Coder.NonDeterministicException

Builds a Cache.Pair using a Redis cache to read and write Cache and Cache pairs. The purpose of the cache is to offload Caches from the API and instead return the Cache if the association is known. Since the Caches and Caches need encoding and decoding, checks are made whether the requestTCoder and responseTCoders are Coder.verifyDeterministic(). This feature is only appropriate for API reads such as HTTP list, get, etc.

Below describes the parameters in more detail and their usage.

• URI uri - the URI of the Redis instance.
• Coder<RequestT> requestTCoder - the Cache Coder to encode and decode Caches during cache read and writes.
• Duration expiry - the duration to hold Cache and Cache pairs in the cache.

Throws:

Coder.NonDeterministicException