Assembler v0.7.7

What's Changed

• The Auto Caching API was renamed to Stream Table to better reflect what the API does, which is conceptually similar to what a KTable is with Apache Kafka:

Flux<BillingInfo> billingInfoFlux = ... // From e.g. Debezium/Kafka, RabbitMQ, etc.;
Flux<OrderItem> orderItemFlux = ... // From e.g. Debezium/Kafka, RabbitMQ, etc.;

var assembler = assemblerOf(Transaction.class)
  .withCorrelationIdResolver(Customer::customerId)
  .withRules(
    rule(BillingInfo::customerId,
      oneToOne(cached(call(this::getBillingInfo), streamTable(billingInfoFlux)))),
    rule(OrderItem::customerId,
      oneToMany(OrderItem::id, cachedMany(call(this::getAllOrders), streamTable(orderItemFlux)))),
    Transaction::new)
  .build();

var transactionFlux = getCustomers()
  .window(3)
  .flatMapSequential(assembler::assemble);

• Optimizations in reactive read-write lock implementation and ReactiveGuard high level api
• Updated Project Reactor to version 3.7.0 to match the release of Spring Boot 3.4.0

Assembler v0.7.6

What's Changed

• The use of embedded Assembler instances allows for the aggregation of sub-queries defined in rules. This new feature was heavily inspired by this great article from Vlad Mihalcea. It enables the modeling of a complex relationship graph (or, as mentioned in the article, a multi-level hierarchical structure) of disparate data sources (e.g., microservices, relational or non-relational databases, message queues, etc.) without triggering either N+1 queries or a Cartesian product.

  See EmbeddedAssemblerTest.java for an example of how to use this new feature:

Assembler<UserVoteView, UserVote> userVoteAssembler = assemblerOf(UserVote.class)
    .withCorrelationIdResolver(UserVoteView::id)
    .withRules(
        rule(User::id, UserVoteView::userId, oneToOne(call(this::getUsersById))),
        UserVote::new
    )
    .build();

Assembler<PostComment, PostComment> postCommentAssembler = assemblerOf(PostComment.class)
    .withCorrelationIdResolver(PostComment::id)
    .withRules(
        rule(UserVote::commentId, oneToMany(UserVote::id, call(assemble(this::getUserVoteViewsById, userVoteAssembler)))),
        PostComment::new
    )
    .build();

Assembler<PostDetails, Post> postAssembler = assemblerOf(Post.class)
    .withCorrelationIdResolver(PostDetails::id)
    .withRules(
        rule(PostComment::postId, oneToMany(PostComment::id, call(assemble(this::getPostCommentsById, postCommentAssembler)))),
        rule(PostTag::postId, oneToMany(PostTag::id, call(this::getPostTagsById))),
        Post::new
    )
    .build();

// If getPostDetails() is a finite sequence
Flux<Post> posts = postAssembler.assemble(getPostDetails());

// If getPostDetails() is a continuous stream
Flux<Post> posts = getPostDetails()
    .windowTimeout(100, Duration.ofSeconds(5))
    .flatMapSequential(postAssembler::assemble);

• Big improvement in concurrency management, better fairness introduced in reactive read-write lock implementation
• Support for configuration of Scheduler backed by virtual thread executor
  • By default, AssemblerBuilder will use Schedulers.boundedScheduler() if reactor.schedulers.defaultBoundedElasticOnVirtualThreads system property is present

Assembler v0.7.5

What's Changed

This release fixes an issue where there is no direct correlation ID between a top-level entity and a sub-level entity by introducing the concept of an ID join.

For example, before this release, there was no way to express the relationship between e.g. a PostDetails and a User because User doesn't have a postId field like Reply does, as described in #33.

record PostDetails(Long id, Long userId, String content) {
}

record User(Long Id, String username) { // No correlation Id back to PostDetails
}

record Reply(Long id, Long postId, Long userId, String content) {
}

record Post(PostDetails post, User author, List<Reply> replies) {
}

Assembler<PostDetails, Post> assembler = assemblerOf(Post.class)
    .withCorrelationIdResolver(PostDetails::id)
    .withRules(
        rule(XXXXX, oneToOne(call(PostDetails::userId, this::getUsersById))), // What should XXXXX be?
        rule(Reply::postId, oneToMany(Reply::id, call(this::getRepliesById))),
        Post::new)
    .build();

Since 0.7.5, this relationship can now be expressed:

Assembler<PostDetails, Post> assembler = assemblerOf(Post.class)
    .withCorrelationIdResolver(PostDetails::id)
    .withRules(
        rule(User::Id, PostDetails::userId, oneToOne(call(this::getUsersById))), // ID Join
        rule(Reply::postId, oneToMany(Reply::id, call(this::getRepliesById))),
        Post::new)
    .build();

This would be semantically equivalent to the following SQL query if all entities were stored in the same relational database:

SELECT 
    p.id AS post_id,
    p.userId AS post_userId,
    p.content AS post_content,
    u.id AS author_id,
    u.username AS author_username,
    r.id AS reply_id,
    r.postId AS reply_postId,
    r.userId AS reply_userId,
    r.content AS reply_content
FROM 
    PostDetails p
JOIN 
    User u ON p.userId = u.id -- rule(User::Id, PostDetails::userId, ...)
LEFT JOIN 
    Reply r ON p.id = r.postId -- rule(Reply::postId, ...)
WHERE 
    p.id IN (1, 2, 3); -- withCorrelationIdResolver(PostDetails::id)

Assembler v0.7.4

This release brings 2 new features:

• Support for Spring Caching, allowing the use of any caching implementation supported by the Spring Framework (example taken from demo project https://github.com/pellse/assembler-spring-graphql-example):

import org.springframework.cache.CacheManager;
import static io.github.pellse.assembler.caching.spring.SpringCacheFactory.springCache;
...

@Controller
public class SpO2MonitoringGraphQLController {

  record SpO2Reading(SpO2 spO2, Patient patient, BodyMeasurement bodyMeasurement) {
  }

  private final Assembler<SpO2, SpO2Reading> spO2ReadingAssembler;

  SpO2MonitoringGraphQLController(
      PatientService ps,
      BodyMeasurementService bms,
      CacheManager cacheManager) {

    final var patientCache = cacheManager.getCache("patientCache");
    final var bodyMeasurementCache = cacheManager.getCache("bodyMeasurementCache");

    spO2ReadingAssembler = assemblerOf(SpO2Reading.class)
      .withCorrelationIdResolver(SpO2::patientId)
      .withRules(
        rule(Patient::id, oneToOne(cached(call(SpO2::healthCardNumber, ps::findPatientsByHealthCardNumber), springCache(patientCache)))),
        rule(BodyMeasurement::patientId, oneToOne(cached(call(bms::getBodyMeasurements), springCache(bodyMeasurementCache)))),
        SpO2Reading::new)
      .build();
  }
}

• Ability to configure read and write non-blocking bounded queues in ConcurrentCache

Assembler v0.7.3

This release primarily aims to enhance performance. It features the following updates:

• A redesigned Caching API that generically supports both single values and collections of values as cache entries, providing dual Map/MultiMap semantics.
• A comprehensive overhaul of the caching concurrency logic, leading to a substantial performance improvement over the previous version.

Assembler v0.7.2

This release introduce asynchronous caching for default cache implementation, and reverts the name of the library back to Assembler (previously CohereFlux)

What's Changed

• Async cache by @pellse in #29

Full Changelog: v0.7.1...v0.7.2

CohereFlux v0.7.1

This is a big release, with a re-architecture of the framework allowing query functions to have access to the whole entity from the upstream instead of having to rely solely on IDs

What's Changed

• The framework is now called CohereFlux, the whole API was modified to reflect that change
• Now passing entities T down the entire processing chain instead of ID
• Adding RuleMapperSource.call() to invoke a queryFunction with list of IDs instead of Collection of top level entities
• New BatchRule API
• Adding factory methods in CaffeineCacheFactory for max size and cache access expiry duration
• Replaced RC with Flux<R> in CohereFlux interface, type parameters are now CohereFlux<T, R>
• FetchFunction in CacheFactory now returns an empty Map when no RuleMapperSource is defined

Assembler v0.6.6

What's Changed (from Git Commit messages)

• Adding BatchRuleBuilder and BatchRule for easier integration with Spring GraphQL

import io.github.pellse.reactive.assembler.Rule.BatchRule;

import static io.github.pellse.reactive.assembler.Rule.batchRule;
import static io.github.pellse.reactive.assembler.RuleMapper.oneToMany;
import static io.github.pellse.reactive.assembler.RuleMapper.oneToOne;
import static io.github.pellse.reactive.assembler.caching.AutoCacheFactory.autoCache;
import static io.github.pellse.reactive.assembler.caching.CacheFactory.cached;

@Controller
public class PatientObservationGraphQLController {

    private final PatientService patientService;

    private final BatchRule<Patient, BodyMeasurement> bodyMeasurementBatchRule;
    private final BatchRule<Patient, List<SpO2>> spO2BatchRule;

    PatientObservationGraphQLController(PatientService ps, BodyMeasurementService bms, SpO2StreamingService spO2ss) {

        this.patientService = ps;

        this.bodyMeasurementBatchRule = batchRule(BodyMeasurement::patientId, oneToOne(cached(bms::retrieveBodyMeasurements)))
                .withIdExtractor(Patient::id);

        this.spO2BatchRule = batchRule(SpO2::patientId, oneToMany(SpO2::id, cached(autoCache(spO2ss::spO2Flux))))
                .withIdExtractor(Patient::id);
    }

    @QueryMapping
    Flux<Patient> patients() {
        return patientService.findAllPatients();
    }

    @BatchMapping
    Mono<Map<Patient, BodyMeasurement>> bodyMeasurement(List<Patient> patients) {
        return bodyMeasurementBatchRule.executeToMono(patients);
    }

    @BatchMapping
    Flux<List<SpO2>> spO2(List<Patient> patients) {
        return spO2BatchRule.executeToFlux(patients);
    }
}

Full Changelog: v0.6.5...v0.6.6

Assembler v0.6.5

This release focuses on performance and consistency optimization of caching, including the auto caching feature.

What's Changed (from Git Commit messages)

• Cache concurrency optimization by switching to MULTIPLE_READERS strategy when caching fetchFunction is guaranteed to be empty
• Ability to configure Retry strategies with specific Scheduler in concurrent cache, same Scheduler used for auto cache and retry strategies
• Ref count instead of boolean flag to manage start/stop in concurrentLifeCycleEventListener()

Breaking API changes:

• concurrency() factory methods renamed to xxxRetryStrategy() in AutoCacheFactoryBuilder

var assembler = assemblerOf(Transaction.class)
  .withCorrelationIdExtractor(Customer::customerId)
  .withAssemblerRules(
    rule(BillingInfo::customerId, oneToOne(cached(this::getBillingInfo,
      autoCacheBuilder(billingInfoFlux)
        .maxWindowSizeAndTime(100, ofSeconds(5))
        .errorHandler(error -> logger.log(WARNING, "Error in autoCache", error))
        .scheduler(newParallel("billing-info"))
        .maxRetryStrategy(50) // used to be named `concurrency()`
        .build()))),
    rule(OrderItem::customerId, oneToMany(OrderItem::id, cached(this::getAllOrders,
      autoCacheBuilder(orderItemFlux)
        .maxWindowSize(50)
        .errorHandler(onErrorMap(MyException::new))
        .scheduler(newParallel("order-item"))
        .backoffRetryStrategy(100, ofMillis(10)) // used to be named `concurrency()`
        .build()))),
    Transaction::new)
  .build();

Dependencies upgrades

• Project Reactor 3.5.6
• Kotlin 1.8.21

Assembler v0.6.4

What's Changed

• New errorHandler() methods on AutoCacheFactoryBuilder to simplify error handler config when we only want to log the error and continue processing
• New concurrency() method, ability to configure concurrency settings on AutoCacheFactoryBuilder for the underlying ConcurrentCache

import reactor.core.publisher.Flux;
import io.github.pellse.reactive.assembler.Assembler;
import static io.github.pellse.reactive.assembler.AssemblerBuilder.assemblerOf;
import static io.github.pellse.reactive.assembler.RuleMapper.oneToMany;
import static io.github.pellse.reactive.assembler.RuleMapper.oneToOne;
import static io.github.pellse.reactive.assembler.Rule.rule;
import static io.github.pellse.reactive.assembler.caching.CacheFactory.cached;
import static io.github.pellse.reactive.assembler.caching.AutoCacheFactoryBuilder.autoCacheBuilder;
import static io.github.pellse.reactive.assembler.caching.AutoCacheFactory.OnErrorContinue.onErrorContinue;
import static java.time.Duration.*;
import static java.lang.System.Logger.Level.WARNING;
import static java.lang.System.getLogger;

var logger = getLogger("logger");
Consumer<Throwable> logWarning = error -> logger.log(WARNING, "Error in autoCache", error);

Flux<BillingInfo> billingInfoFlux = ... // BillingInfo data coming from e.g. Kafka;
Flux<OrderItem> orderItemFlux = ... // OrderItem data coming from e.g. Kafka;

var assembler = assemblerOf(Transaction.class)
    .withCorrelationIdExtractor(Customer::customerId)
    .withAssemblerRules(
        rule(BillingInfo::customerId, oneToOne(cached(this::getBillingInfo,
            autoCacheBuilder(billingInfoFlux)
                .maxWindowSizeAndTime(100, ofSeconds(5))
                .errorHandler(error -> logger.log(WARNING, error)) // New `errorHandler()` method
                .concurrency(20) // New `concurrency()` method -> maxAttempts = 20
                .build()))),
        rule(OrderItem::customerId, oneToMany(OrderItem::id, cached(this::getAllOrders,
            autoCacheBuilder(orderItemFlux)
                .maxWindowSize(50)
                .errorHandler(logWarning) // New `errorHandler()` method
                .concurrency(20, ofMillis(10)) // New `concurrency()` method -> maxAttempts = 20, delay = 10 ms
                .build()))),
        Transaction::new)
    .build();
    
var transactionFlux = getCustomers()
    .window(3)
    .flatMapSequential(assembler::assemble);

Dependencies upgrades

• Caffeine 3.1.6