org.obiba.magma.datasource.mongodb.MongoDBVariableEntityProvider.java Source code

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Here is the source code for org.obiba.magma.datasource.mongodb.MongoDBVariableEntityProvider.java

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/*
 * Copyright (c) 2013 OBiBa. All rights reserved.
 *
 * This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0.
 *
 * 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 org.obiba.magma.datasource.mongodb;

import java.util.Set;

import javax.validation.constraints.NotNull;

import org.obiba.magma.Value;
import org.obiba.magma.VariableEntity;
import org.obiba.magma.support.VariableEntityBean;
import org.obiba.magma.support.VariableEntityProvider;

import com.google.common.collect.ImmutableSet;
import com.mongodb.BasicDBObject;
import com.mongodb.BasicDBObjectBuilder;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;

class MongoDBVariableEntityProvider implements VariableEntityProvider {

    private String entityType;

    private final MongoDBValueTable table;

    private Set<VariableEntity> cachedEntities;

    private Value lastUpdated;

    MongoDBVariableEntityProvider(MongoDBValueTable table, String entityType) {
        this.table = table;
        this.entityType = entityType;
    }

    @NotNull
    @Override
    public String getEntityType() {
        if (entityType == null) {
            entityType = (String) table.asDBObject().get("entityType");
        }
        return entityType;
    }

    @Override
    public boolean isForEntityType(@SuppressWarnings("ParameterHidesMemberVariable") String entityType) {
        return getEntityType().equals(entityType);
    }

    @NotNull
    @Override
    public Set<VariableEntity> getVariableEntities() {
        Value tableLastUpdate = table.getTimestamps().getLastUpdate();
        if (cachedEntities == null || lastUpdated == null || !lastUpdated.equals(tableLastUpdate)) {
            lastUpdated = tableLastUpdate;
            cachedEntities = loadEntities();
        }
        return cachedEntities;
    }

    private Set<VariableEntity> loadEntities() {
        ImmutableSet.Builder<VariableEntity> builder = ImmutableSet.builder();
        try (DBCursor cursor = table.getValueSetCollection().find(new BasicDBObject(),
                BasicDBObjectBuilder.start("_id", 1).get())) {
            while (cursor.hasNext()) {
                DBObject next = cursor.next();
                builder.add(new VariableEntityBean(getEntityType(), next.get("_id").toString()));
            }
        }
        return builder.build();
    }
}