io.github.pellse.util.reactive.ReactiveUtils Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of assembler Show documentation

Small library allowing to efficiently assemble entities from querying/merging external datasources or aggregating microservices

The newest version!

/*
 * Copyright 2024 Sebastien Pelletier
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.github.pellse.util.reactive;

import reactor.core.publisher.Mono;
import reactor.core.publisher.Sinks;
import reactor.util.function.Tuple2;

import java.util.Map;
import java.util.function.Supplier;

import static io.github.pellse.util.collection.CollectionUtils.toLinkedHashMap;
import static java.lang.Math.toIntExact;
import static java.util.List.copyOf;
import static java.util.function.Function.identity;
import static reactor.core.publisher.Flux.concat;
import static reactor.core.publisher.Mono.*;

public interface ReactiveUtils {

    static  Mono> resolve(Map> monoMap) {

        final var monoLinkedMap = toLinkedHashMap(monoMap);
        final var keys = copyOf(monoLinkedMap.keySet());

        return concat(monoLinkedMap.values())
                .index()
                .collectMap(tuple -> keys.get(toIntExact(tuple.getT1())), Tuple2::getT2);
    }

    static  Map> createSinkMap(Iterable iterable) {
        return toLinkedHashMap(iterable, identity(), __ -> Sinks.one());
    }

    static  Mono nullToEmpty(T value) {
        return value != null ? just(value) : empty();
    }

    static  Mono nullToEmpty(Supplier defaultValueProvider) {
        return defaultValueProvider != null ? fromSupplier(defaultValueProvider) : empty();
    }
}