com.creactiviti.piper.core.context.MongoContextRepository.java Source code

Introduction

Here is the source code for com.creactiviti.piper.core.context.MongoContextRepository.java

Source

/*
 * Copyright 2016-2018 the original author or authors.
 *
 * 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 com.creactiviti.piper.core.context;

import com.creactiviti.piper.core.DSL;
import com.creactiviti.piper.core.uuid.UUIDGenerator;
import com.google.common.collect.ImmutableList;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import org.bson.BsonDocument;
import org.bson.BsonDocumentWriter;
import org.bson.Document;
import org.bson.codecs.EncoderContext;

import javax.annotation.PostConstruct;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import static com.mongodb.client.model.Aggregates.*;
import static com.mongodb.client.model.Filters.eq;
import static com.mongodb.client.model.Indexes.ascending;
import static com.mongodb.client.model.Sorts.descending;
import static java.util.stream.Stream.of;

public class MongoContextRepository implements ContextRepository<Context> {

    private final MongoCollection<Document> collection;

    public MongoContextRepository(MongoDatabase aDatabase) {
        this.collection = aDatabase.getCollection("context");
    }

    @Override
    public Context push(String aStackId, Context aContext) {
        collection.insertOne(new Document().append("_id", UUIDGenerator.generate()).append("stackId", aStackId)
                .append("context", contextToDocument(aContext)).append("createTime", new Date()));

        return aContext;
    }

    @Override
    public Context peek(String aStackId) {
        Context context = collection.withDocumentClass(Context.class)
                .aggregate(ImmutableList.of(match(eq("stackId", aStackId)), sort(descending("createTime")),
                        limit(1), replaceRoot("$context")))
                .first();

        if (context != null) {
            return context;
        }

        return null;
    }

    @Override
    public List<Context> getStack(String aStackId) {
        return collection.withDocumentClass(Context.class).aggregate(ImmutableList
                .of(match(eq("stackId", aStackId)), sort(descending("createTime")), replaceRoot("$context")))
                .into(new ArrayList<>());
    }

    private BsonDocument contextToDocument(Context aContext) {
        BsonDocument doc = new BsonDocument();

        collection.getCodecRegistry().get(Context.class).encode(new BsonDocumentWriter(doc), aContext,
                EncoderContext.builder().isEncodingCollectibleDocument(true).build());

        return doc;
    }

    @PostConstruct
    void ensureIndexes() {
        of(DSL.CREATE_TIME, "stackId").forEach(it -> collection.createIndex(ascending(it)));
    }
}