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

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/*
 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.crud.mongo;

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

import com.mongodb.DBCollection;
import com.mongodb.DBObject;
import com.mongodb.DBCursor;
import com.mongodb.BasicDBObject;
import com.mongodb.WriteResult;
import com.mongodb.WriteConcern;

import com.redhat.lightblue.crud.CRUDDeleteResponse;
import com.redhat.lightblue.crud.CRUDOperationContext;
import com.redhat.lightblue.crud.DocCtx;
import com.redhat.lightblue.crud.Operation;
import com.redhat.lightblue.mongo.hystrix.FindCommand;
import com.redhat.lightblue.mongo.hystrix.RemoveCommand;

/**
 * Iterates the result set and deleted documents one by one
 */
public class IterateDeleter implements DocDeleter {

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

    private final Translator translator;

    public IterateDeleter(Translator translator) {
        this.translator = translator;
    }

    @Override
    public void delete(CRUDOperationContext ctx, DBCollection collection, DBObject mongoQuery,
            CRUDDeleteResponse response) {
        LOGGER.debug("Computing the result set for {}", mongoQuery);
        DBCursor cursor = null;
        int docIndex = 0;
        int numDeleted = 0;
        try {
            // Find docs
            cursor = new FindCommand(null, collection, mongoQuery, null).execute();
            LOGGER.debug("Found {} documents", cursor.count());
            // read-delet
            while (cursor.hasNext()) {
                DBObject document = cursor.next();
                LOGGER.debug("Retrieved doc {}", docIndex);
                Object id = document.get(MongoCRUDController.ID_STR);
                DocCtx doc = ctx.addDocument(translator.toJson(document));
                doc.setOriginalDocument(doc);
                WriteResult result = new RemoveCommand(null, collection, new BasicDBObject("_id", id),
                        WriteConcern.SAFE).execute();
                if (result.getN() == 1) {
                    numDeleted++;
                    doc.setOperationPerformed(Operation.DELETE);
                }
                docIndex++;
            }
        } finally {
            if (cursor != null) {
                cursor.close();
            }
        }
        response.setNumDeleted(numDeleted);
    }
}