/*
// Licensed to Julian Hyde under one or more contributor license
// agreements. See the NOTICE file distributed with this work for
// additional information regarding copyright ownership.
//
// Julian Hyde licenses this file to you 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 net.hydromatic.optiq.impl.mongodb;
import net.hydromatic.linq4j.*;
import net.hydromatic.linq4j.function.Function1;
import net.hydromatic.optiq.*;
import net.hydromatic.optiq.impl.AbstractTableQueryable;
import net.hydromatic.optiq.impl.java.AbstractQueryableTable;
import org.eigenbase.rel.RelNode;
import org.eigenbase.relopt.RelOptCluster;
import org.eigenbase.relopt.RelOptTable;
import org.eigenbase.reltype.RelDataType;
import org.eigenbase.reltype.RelDataTypeFactory;
import org.eigenbase.sql.type.SqlTypeName;
import org.eigenbase.util.Util;
import com.mongodb.*;
import com.mongodb.util.JSON;
import java.util.*;
/**
* Table based on a MongoDB collection.
*/
public class MongoTable extends AbstractQueryableTable
implements TranslatableTable {
protected final String collectionName;
/** Creates a MongoTable. */
MongoTable(String collectionName) {
super(Object[].class);
this.collectionName = collectionName;
}
public String toString() {
return "MongoTable {" + collectionName + "}";
}
public RelDataType getRowType(RelDataTypeFactory typeFactory) {
final RelDataType mapType =
typeFactory.createMapType(
typeFactory.createSqlType(SqlTypeName.VARCHAR),
typeFactory.createSqlType(SqlTypeName.ANY));
return typeFactory.builder().add("_MAP", mapType).build();
}
public <T> Queryable<T> asQueryable(QueryProvider queryProvider,
SchemaPlus schema, String tableName) {
return new MongoQueryable<T>(queryProvider, schema, this, tableName);
}
public RelNode toRel(
RelOptTable.ToRelContext context,
RelOptTable relOptTable) {
final RelOptCluster cluster = context.getCluster();
return new MongoTableScan(cluster, cluster.traitSetOf(MongoRel.CONVENTION),
relOptTable, this, null);
}
/** Executes a "find" operation on the underlying collection.
*
* <p>For example,
* <code>zipsTable.find("{state: 'OR'}", "{city: 1, zipcode: 1}")</code></p>
*
* @param mongoDb MongoDB connection
* @param filterJson Filter JSON string, or null
* @param projectJson Project JSON string, or null
* @param fields List of fields to project; or null to return map
* @return Enumerator of results
*/
public Enumerable<Object> find(DB mongoDb, String filterJson,
String projectJson, List<Map.Entry<String, Class>> fields) {
final DBCollection collection =
mongoDb.getCollection(collectionName);
final DBObject filter =
filterJson == null ? null : (DBObject) JSON.parse(filterJson);
final DBObject project =
projectJson == null ? null : (DBObject) JSON.parse(projectJson);
final Function1<DBObject, Object> getter = MongoEnumerator.getter(fields);
return new AbstractEnumerable<Object>() {
public Enumerator<Object> enumerator() {
final DBCursor cursor = collection.find(filter, project);
return new MongoEnumerator(cursor, getter);
}
};
}
/** Executes an "aggregate" operation on the underlying collection.
*
* <p>For example:
* <code>zipsTable.aggregate(
* "{$filter: {state: 'OR'}",
* "{$group: {_id: '$city', c: {$sum: 1}, p: {$sum: '$pop'}}}")
* </code></p>
*
* @param mongoDb MongoDB connection
* @param fields List of fields to project; or null to return map
* @param operations One or more JSON strings
* @return Enumerator of results
*/
public Enumerable<Object> aggregate(final DB mongoDb,
final List<Map.Entry<String, Class>> fields,
final List<String> operations) {
List<DBObject> list = new ArrayList<DBObject>();
for (String operation : operations) {
list.add((DBObject) JSON.parse(operation));
}
final DBObject first = list.get(0);
final List<DBObject> rest = Util.skip(list);
final Function1<DBObject, Object> getter =
MongoEnumerator.getter(fields);
return new AbstractEnumerable<Object>() {
public Enumerator<Object> enumerator() {
final AggregationOutput result;
try {
result = mongoDb.getCollection(collectionName)
.aggregate(first, rest.toArray(new DBObject[rest.size()]));
} catch (Exception e) {
throw new RuntimeException("While running MongoDB query "
+ Util.toString(operations, "[", ",\n", "]"), e);
}
return new MongoEnumerator(result.results().iterator(), getter);
}
};
}
/** Implementation of {@link net.hydromatic.linq4j.Queryable} based on
* a {@link net.hydromatic.optiq.impl.mongodb.MongoTable}. */
public static class MongoQueryable<T> extends AbstractTableQueryable<T> {
public MongoQueryable(QueryProvider queryProvider, SchemaPlus schema,
MongoTable table, String tableName) {
super(queryProvider, schema, table, tableName);
}
public Enumerator<T> enumerator() {
//noinspection unchecked
final Enumerable<T> enumerable =
(Enumerable<T>) getTable().find(getMongoDb(), null, null, null);
return enumerable.enumerator();
}
private DB getMongoDb() {
return schema.unwrap(MongoSchema.class).mongoDb;
}
private MongoTable getTable() {
return (MongoTable) table;
}
/** Called via code-generation.
*
* @see net.hydromatic.optiq.impl.mongodb.MongoMethod#MONGO_QUERYABLE_AGGREGATE
*/
@SuppressWarnings("UnusedDeclaration")
public Enumerable<Object> aggregate(List<Map.Entry<String, Class>> fields,
List<String> operations) {
return getTable().aggregate(getMongoDb(), fields, operations);
}
/** Called via code-generation.
*
* @see net.hydromatic.optiq.impl.mongodb.MongoMethod#MONGO_QUERYABLE_FIND
*/
@SuppressWarnings("UnusedDeclaration")
public Enumerable<Object> find(String filterJson,
String projectJson, List<Map.Entry<String, Class>> fields) {
return getTable().find(getMongoDb(), filterJson, projectJson, fields);
}
}
}
// End MongoTable.java