com.redhat.lightblue.mongo.crud.UpdateIfSameProtocol.java Source code

Introduction

Here is the source code for com.redhat.lightblue.mongo.crud.UpdateIfSameProtocol.java

Source

/*
 Copyright 2013 Red Hat, Inc. and/or its affiliates.
    
 This file is part of lightblue.
    
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.
    
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
    
 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.redhat.lightblue.mongo.crud;

import java.util.Map;
import java.util.Set;
import java.util.HashSet;
import java.util.List;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Collection;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.mongodb.DBObject;
import com.mongodb.BasicDBObject;
import com.mongodb.DBCollection;
import com.mongodb.WriteConcern;
import com.mongodb.BulkWriteOperation;
import com.mongodb.BulkWriteResult;
import com.mongodb.BulkWriteException;
import com.mongodb.BulkWriteError;

import org.bson.types.ObjectId;

import com.redhat.lightblue.util.Error;

/**
 * Updates documents in a batch only if they are unmodified from the
 * version they were read.
 */
public class UpdateIfSameProtocol implements BatchUpdate {

    private static final Logger LOGGER = LoggerFactory.getLogger(MongoSafeUpdateProtocol.class);

    /**
     * The document version to be assigned to the documents modified by this updater
     */
    public final ObjectId docVer = new ObjectId();

    /**
     * Set of documents and their versions to be updated.
     */
    private final Set<DocIdVersion> versions = new HashSet<>();

    /**
     * A map with docId key, and its corresponding version the value
     */
    private final Map<Object, DocIdVersion> id2VersionMap = new HashMap<>();

    private final List<BatchDoc> batch = new ArrayList<>(128);
    private BulkWriteOperation bwo;
    private DBCollection collection;
    private WriteConcern writeConcern;

    private final static class BatchDoc {
        final DBObject doc;
        final DocIdVersion version;

        BatchDoc(DBObject doc, DocIdVersion v) {
            this.doc = doc;
            this.version = v;
        }
    }

    public UpdateIfSameProtocol(DBCollection collection, WriteConcern writeConcern) {
        this.collection = collection;
        this.writeConcern = writeConcern;
        bwo = collection.initializeUnorderedBulkOperation();
    }

    public void addVersion(DocIdVersion v) {
        versions.add(v);
        id2VersionMap.put(v.id, v);
    }

    public void addVersions(Collection<DocIdVersion> collection) {
        for (DocIdVersion v : collection) {
            addVersion(v);
        }
    }

    @Override
    public void addDoc(DBObject doc) {
        BatchDoc batchDoc = null;
        // Is this document in the versions set? If not, we cannot update it
        Object id = DocTranslator.createIdFrom(doc.get("_id"));
        if (id != null) {
            DocIdVersion v = id2VersionMap.get(id);
            if (v != null) {
                batchDoc = new BatchDoc(doc, v);
            }
        }
        if (batchDoc != null) {
            // Include this doc in batch
            DocVerUtil.cleanupOldDocVer(batchDoc.doc, docVer);
            DocVerUtil.setDocVer(batchDoc.doc, docVer);
            batch.add(batchDoc);
            DBObject query = new BasicDBObject("_id", doc.get("_id")).append(MongoSafeUpdateProtocol.DOCVER_FLD0,
                    batchDoc.version.version);
            LOGGER.debug("replaceQuery={}", query);
            bwo.find(query).replaceOne(batchDoc.doc);
        }
    }

    @Override
    public int getSize() {
        return batch.size();
    }

    @Override
    public CommitInfo commit() {
        CommitInfo ci = new CommitInfo();
        if (!batch.isEmpty()) {
            if (!BatchUpdate.batchUpdate(bwo, writeConcern, batch.size(), ci.errors, LOGGER))
                findConcurrentModifications(ci.errors);
        }
        batch.clear();
        bwo = collection.initializeUnorderedBulkOperation();
        return ci;
    }

    /**
    * This executes a query to find out documents with concurrent modification errors
    *
    * Returns true if there are concurrent modification errors
    */
    protected void findConcurrentModifications(Map<Integer, Error> results) {
        List<Object> updatedIds = new ArrayList<>(batch.size());
        // Collect all ids without errors
        int index = 0;
        for (BatchDoc doc : batch) {
            if (!results.containsKey(index))
                updatedIds.add(doc.version.id);
            index++;
        }
        LOGGER.debug("checking for concurrent modifications:{}", updatedIds);
        if (!updatedIds.isEmpty()) {
            Set<Object> failedIds = BatchUpdate.getFailedUpdates(collection, docVer, updatedIds);
            if (!failedIds.isEmpty()) {
                index = 0;
                for (BatchDoc doc : batch) {
                    if (!results.containsKey(index)) { // No other errors for this id
                        if (failedIds.contains(doc.version.id)) {
                            // concurrency errors for this id
                            results.put(index, Error.get("update", MongoCrudConstants.ERR_CONCURRENT_UPDATE,
                                    doc.version.id.toString()));
                        }
                    }
                    index++;
                }
            }
        }
    }

}