v7views.mongo.DBCollectionDataProvider.java Source code

Introduction

Here is the source code for v7views.mongo.DBCollectionDataProvider.java

Source

/**
 * Copyright (c) 2011, Thilo Planz. All rights reserved.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

package v7views.mongo;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import org.apache.click.control.Table;
import org.apache.click.dataprovider.PagingDataProvider;
import org.bson.BSONObject;

import v7views.v7db.BSONBackedObject;
import v7views.v7db.BSONBackedObjectLoader;

import com.mongodb.BasicDBObject;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;

public class DBCollectionDataProvider implements PagingDataProvider<BSONBackedObject> {

    private final V7Collection collection;

    private final Table table;

    private final DBObject orderBy;

    private final List<Object> ids;

    private final BSONBackedObject query;

    public DBCollectionDataProvider(V7Collection collection, Table table, BSONBackedObject orderBy,
            BSONBackedObject query, Collection<?> idFilter) {
        this.collection = collection;
        this.table = table;
        this.orderBy = orderBy == null ? new BasicDBObject("_id", 1) : orderBy.getDBObject();
        this.query = query;

        if (idFilter != null) {
            // first get all the ids, in the right order
            ids = new ArrayList<Object>(idFilter.size());

            for (DBObject o : collection.findIds(query).sort(this.orderBy)) {
                Object id = o.get("_id");
                if (idFilter.contains(id))
                    ids.add(id);
            }
        } else {
            ids = null;
        }

    }

    public Iterable<BSONBackedObject> getData() {

        int start = table.getFirstRow();
        int pageSize = table.getPageSize();

        if (ids != null) {

            // skip and pageSize
            if (start >= ids.size())
                return Collections.emptyList();
            int toIndex = Integer.MAX_VALUE;
            if (pageSize > 0)
                toIndex = start + pageSize;
            if (toIndex > ids.size())
                toIndex = ids.size();
            final List<Object> page = ids.subList(start, toIndex);

            return new Iterable<BSONBackedObject>() {

                public Iterator<BSONBackedObject> iterator() {

                    final Iterator<Object> p = page.iterator();

                    Iterator<BSONObject> x = new Iterator<BSONObject>() {

                        public boolean hasNext() {
                            return p.hasNext();
                        }

                        public BSONObject next() {
                            return collection.findOne(p.next());
                        }

                        public void remove() {
                            throw new UnsupportedOperationException();
                        }
                    };

                    return BSONBackedObjectLoader.wrapIterator(x, null);

                }

            };

        }

        DBCursor cursor = collection.find(query).sort(orderBy).skip(start);
        if (pageSize > 0)
            cursor = cursor.limit(pageSize);

        return BSONBackedObjectLoader.wrapIterable(cursor, null);
    }

    public int size() {
        if (ids != null)
            return ids.size();

        return (int) collection.count(query);
    }

}