ShowTableQuery.java

package org.wonderdb.query.parse;

/*******************************************************************************
 *    Copyright 2013 Vilas Athavale
 *
 *    Licensed 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.
 *******************************************************************************/

import java.util.Iterator;
import java.util.List;

import org.wonderdb.cluster.Shard;
import org.wonderdb.expression.AndExpression;
import org.wonderdb.metadata.StorageMetadata;
import org.wonderdb.parser.ShowIndexStmt;
import org.wonderdb.parser.jtree.SimpleNode;
import org.wonderdb.parser.jtree.SimpleNodeHelper;
import org.wonderdb.parser.jtree.UQLParserTreeConstants;
import org.wonderdb.schema.CollectionMetadata;
import org.wonderdb.schema.SchemaMetadata;
import org.wonderdb.types.ColumnNameMeta;
import org.wonderdb.types.IndexNameMeta;


public class ShowTableQuery extends BaseDBQuery {
	String collectionName;
	
	public ShowTableQuery(String q, SimpleNode query) {
		super(q, query, -1, null);
		SimpleNode node = SimpleNodeHelper.getInstance().getFirstNode(query, UQLParserTreeConstants.JJTTABLENAME);
		if (node == null) {
			throw new RuntimeException("Invalid syntax:");
		}
		collectionName = node.jjtGetFirstToken().image;
	}
	
	public ShowTableQuery(String q, String tableName) {
		super(q, null, -1, null);
		collectionName = tableName;
	}
	
	public String execute() {
		CollectionMetadata colMeta = SchemaMetadata.getInstance().getCollectionMetadata(collectionName);
		if (colMeta == null) {
			return "\n";
		}
		StringBuilder builder = new StringBuilder();
		
		byte fileId = colMeta.getRecordList(new Shard("")).getHead().getFileId();
		String storage = StorageMetadata.getInstance().getFileName(fileId);
		
		List<ColumnNameMeta> cols = colMeta.getCollectionColumns();
		Iterator<ColumnNameMeta> iter = cols.iterator();
		while (iter.hasNext()) {
			ColumnNameMeta ct = iter.next();
			builder.append(ct.getColumnName()).append("\t");
			builder.append(ct.getColumnType());
		}
		
		builder.append("\n");
		builder.append("STORAGE: ").append(storage).append("\n");
		builder.append("\n");

		List<IndexNameMeta> list = SchemaMetadata.getInstance().getIndexes(collectionName);
		for (IndexNameMeta idxMeta : list) {
			builder.append("\n");
			ShowIndexStmt stmt = new ShowIndexStmt();
			stmt.indexName = idxMeta.getIndexName();
			ShowIndexQuery q = new ShowIndexQuery(getQueryString(), stmt);
			builder.append(q.execute());
		}
		return builder.toString();
	}
	
	public static String getType(String s) {
		if (s.equals("is")) {
			return "int";
		}
		if (s.equals("ls")) {
			return "long";
		}
		if (s.equals("fs")) {
			return "float";
		}
		if (s.equals("ds")) {
			return "double";
		}
		if (s.equals("ss")) {
			return "string";
		}
		if (s.equals("bs")) {
			return "byte type";
		}
		return s;
	}

	@Override
	public AndExpression getExpression() {
		return null;
	}
}