franta-hg@144: /**
franta-hg@144:  * SQL-DK
franta-hg@144:  * Copyright © 2014 František Kučera (frantovo.cz)
franta-hg@144:  *
franta-hg@144:  * This program is free software: you can redistribute it and/or modify
franta-hg@144:  * it under the terms of the GNU General Public License as published by
franta-hg@250:  * the Free Software Foundation, version 3 of the License.
franta-hg@144:  *
franta-hg@144:  * This program is distributed in the hope that it will be useful,
franta-hg@144:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
franta-hg@144:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
franta-hg@144:  * GNU General Public License for more details.
franta-hg@144:  *
franta-hg@144:  * You should have received a copy of the GNU General Public License
franta-hg@144:  * along with this program. If not, see <http://www.gnu.org/licenses/>.
franta-hg@144:  */
franta-hg@144: package info.globalcode.sql.dk.batch;
franta-hg@144: 
franta-hg@144: import info.globalcode.sql.dk.Parameter;
franta-hg@144: import info.globalcode.sql.dk.SQLCommand;
franta-hg@144: import info.globalcode.sql.dk.SQLCommandNamed;
franta-hg@144: import java.io.DataOutputStream;
franta-hg@144: import java.io.IOException;
franta-hg@144: import java.io.OutputStream;
franta-hg@144: import static info.globalcode.sql.dk.batch.BatchConstants.*;
franta-hg@144: import java.io.ByteArrayOutputStream;
franta-hg@144: import java.sql.SQLException;
franta-hg@144: import java.util.List;
franta-hg@144: 
franta-hg@144: /**
franta-hg@144:  *
franta-hg@144:  * @author Ing. František Kučera (frantovo.cz)
franta-hg@144:  */
franta-hg@144: public class BatchEncoder {
franta-hg@144: 
franta-hg@144: 	public int encode(SQLCommand sqlCommand, OutputStream out) throws BatchException {
franta-hg@144: 		try {
franta-hg@144: 			ByteArrayOutputStream bufferAOS = new ByteArrayOutputStream();
franta-hg@144: 			DataOutputStream buffer = new DataOutputStream(bufferAOS);
franta-hg@144: 
franta-hg@146: 			buffer.write(BATCH_HEADER);
franta-hg@144: 
franta-hg@145: 			if (sqlCommand instanceof SQLCommandNamed) {
franta-hg@145: 				sqlCommand = ((SQLCommandNamed) sqlCommand).getSQLCommandNumbered();
franta-hg@145: 			}
franta-hg@145: 
franta-hg@147: 			writeNextString(sqlCommand.getQuery(), buffer);
franta-hg@144: 
franta-hg@144: 			List<? extends Parameter> parameters = sqlCommand.getParameters();
franta-hg@144: 
franta-hg@144: 			buffer.writeInt(parameters.size());
franta-hg@144: 
franta-hg@144: 			for (Parameter p : parameters) {
franta-hg@144: 				buffer.writeInt(p.getType().getCode());
franta-hg@147: 				writeNextString((String) p.getValue(), buffer); // parameters are encoded before any preprocessing
franta-hg@144: 			}
franta-hg@144: 
franta-hg@144: 			buffer.flush();
franta-hg@144: 			bufferAOS.writeTo(out);
franta-hg@144: 			out.flush();
franta-hg@144: 			return bufferAOS.size();
franta-hg@144: 		} catch (IOException e) {
franta-hg@144: 			throw new BatchException("Unable to write SQL command: " + sqlCommand, e);
franta-hg@144: 		} catch (SQLException e) {
franta-hg@144: 			throw new BatchException("Unable to converd named SQL command to numbered: " + sqlCommand, e);
franta-hg@144: 		}
franta-hg@144: 	}
franta-hg@144: 
franta-hg@147: 	private void writeNextString(String s, DataOutputStream out) throws IOException {
franta-hg@147: 		byte[] bytes = toBytes(s);
franta-hg@147: 		out.writeInt(bytes.length);
franta-hg@147: 		out.write(bytes);
franta-hg@147: 	}
franta-hg@147: 
franta-hg@144: 	private static byte[] toBytes(String s) {
franta-hg@144: 		if (s == null) {
franta-hg@144: 			return new byte[]{};
franta-hg@144: 		} else {
franta-hg@144: 			return s.getBytes(CHARSET);
franta-hg@144: 		}
franta-hg@144: 	}
franta-hg@144: }