org.apache.beam.io.requestresponse

Class Cache

java.lang.Object

org.apache.beam.io.requestresponse.Cache

public final class Cache
extends java.lang.Object

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

Nested Class Summary

Nested Classes

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

Constructor Summary

Constructors

Constructor and Description
Cache()

Method Summary

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

Methods inherited from class java.lang.Object

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

Constructor Detail

Cache

public Cache()

Method Detail

usingRedis

public static <RequestT,ResponseT> Cache.Pair<RequestT,ResponseT> usingRedis(java.net.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 RequestT and ResponseT pairs. The purpose of the cache is to offload RequestTs from the API and instead return the ResponseT if the association is known. Since the RequestTs and ResponseTs 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 RequestT Coder to encode and decode RequestTs during cache read and writes.
• Duration expiry - the duration to hold RequestT and ResponseT pairs in the cache.

Throws:

Coder.NonDeterministicException