/*
* Copyright (c) 2013, OpenCloudDB/MyCAT and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software;Designed and Developed mainly by many Chinese
* opensource volunteers. you can redistribute it and/or modify it under the
* terms of the GNU General Public License version 2 only, as published by the
* Free Software Foundation.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Any questions about this component can be directed to it's project Web address
* https://code.google.com/p/opencloudb/.
*
*/
package io.mycat.server.sqlhandler;
import io.mycat.server.ErrorCode;
import io.mycat.server.Fields;
import io.mycat.server.FrontendPrepareHandler;
import io.mycat.server.MySQLFrontConnection;
import io.mycat.server.packet.ExecutePacket;
import io.mycat.server.packet.util.BindValue;
import io.mycat.server.packet.util.ByteUtil;
import io.mycat.server.packet.util.PreparedStatement;
import io.mycat.server.response.PreparedStmtResponse;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Map;
import org.apache.log4j.Logger;
/**
* @author mycat
*/
public class ServerPrepareHandler implements FrontendPrepareHandler {
private static final Logger LOGGER = Logger.getLogger(ServerPrepareHandler.class);
private MySQLFrontConnection source;
private volatile long pstmtId;
private Map<String, PreparedStatement> pstmtForSql;
private Map<Long, PreparedStatement> pstmtForId;
public ServerPrepareHandler(MySQLFrontConnection source) {
this.source = source;
this.pstmtId = 0L;
this.pstmtForSql = new HashMap<String, PreparedStatement>();
this.pstmtForId = new HashMap<Long, PreparedStatement>();
}
@Override
public void prepare(String sql) {
LOGGER.debug("use server prepare, sql: " + sql);
PreparedStatement pstmt = null;
if ((pstmt = pstmtForSql.get(sql)) == null) {
// 解析获取字段个数和参数个数
int columnCount = getColumnCount(sql);
int paramCount = getParamCount(sql);
pstmt = new PreparedStatement(++pstmtId, sql, columnCount, paramCount);
pstmtForSql.put(pstmt.getStatement(), pstmt);
pstmtForId.put(pstmt.getId(), pstmt);
}
PreparedStmtResponse.response(pstmt, source);
}
@Override
public void execute(byte[] data) {
long pstmtId = ByteUtil.readUB4(data, 5);
PreparedStatement pstmt = null;
if ((pstmt = pstmtForId.get(pstmtId)) == null) {
source.writeErrMessage(ErrorCode.ER_ERROR_WHEN_EXECUTING_COMMAND, "Unknown pstmtId when executing.");
} else {
ExecutePacket packet = new ExecutePacket(pstmt);
try {
packet.read(data, source.getCharset());
} catch (UnsupportedEncodingException e) {
source.writeErrMessage(ErrorCode.ER_ERROR_WHEN_EXECUTING_COMMAND, e.getMessage());
return;
}
BindValue[] bindValues = packet.values;
// 还原sql中的动态参数为实际参数值
String sql = prepareStmtBindValue(pstmt, bindValues);
// 执行sql
source.getSession2().setPrepared(true);
LOGGER.debug("execute prepare sql: " + sql);
source.query(sql);
}
}
@Override
public void close(byte[] data) {
long pstmtId = ByteUtil.readUB4(data, 5); // 获取prepare stmt id
LOGGER.debug("close prepare stmt, stmtId = " + pstmtId);
PreparedStatement pstmt = pstmtForId.remove(pstmtId);
if(pstmt != null) {
pstmtForSql.remove(pstmt.getStatement());
}
}
@Override
public void clear() {
this.pstmtForId.clear();
this.pstmtForSql.clear();
}
// TODO 获取预处理语句中column的个数
private int getColumnCount(String sql) {
int columnCount = 0;
// TODO ...
return columnCount;
}
// 获取预处理sql中预处理参数个数
private int getParamCount(String sql) {
char[] cArr = sql.toCharArray();
int count = 0;
for(int i = 0; i < cArr.length; i++) {
if(cArr[i] == '?') {
count++;
}
}
return count;
}
/**
* 组装sql语句,替换动态参数为实际参数值
* @param pstmt
* @param bindValues
* @return
*/
private String prepareStmtBindValue(PreparedStatement pstmt, BindValue[] bindValues) {
String sql = pstmt.getStatement();
int paramNumber = pstmt.getParametersNumber();
int[] paramTypes = pstmt.getParametersType();
for(int i = 0; i < paramNumber; i++) {
int paramType = paramTypes[i];
BindValue bindValue = bindValues[i];
if(bindValue.isNull) {
sql = sql.replaceFirst("\\?", "NULL");
continue;
}
switch(paramType) {
case io.mycat.server.Fields.FIELD_TYPE_TINY:
sql = sql.replaceFirst("\\?", String.valueOf(bindValue.byteBinding));
break;
case Fields.FIELD_TYPE_SHORT:
sql = sql.replaceFirst("\\?", String.valueOf(bindValue.shortBinding));
break;
case Fields.FIELD_TYPE_LONG:
sql = sql.replaceFirst("\\?", String.valueOf(bindValue.intBinding));
break;
case Fields.FIELD_TYPE_LONGLONG:
sql = sql.replaceFirst("\\?", String.valueOf(bindValue.longBinding));
break;
case Fields.FIELD_TYPE_FLOAT:
sql = sql.replaceFirst("\\?", String.valueOf(bindValue.floatBinding));
break;
case Fields.FIELD_TYPE_DOUBLE:
sql = sql.replaceFirst("\\?", String.valueOf(bindValue.doubleBinding));
break;
case Fields.FIELD_TYPE_VAR_STRING:
case Fields.FIELD_TYPE_STRING:
case Fields.FIELD_TYPE_VARCHAR:
case Fields.FIELD_TYPE_BLOB:
sql = sql.replaceFirst("\\?", "'" + bindValue.value + "'");
break;
case Fields.FIELD_TYPE_TIME:
case Fields.FIELD_TYPE_DATE:
case Fields.FIELD_TYPE_DATETIME:
case Fields.FIELD_TYPE_TIMESTAMP:
sql = sql.replaceFirst("\\?", "'" + bindValue.value + "'");
break;
default:
sql = sql.replaceFirst("\\?", bindValue.value.toString());
break;
}
}
return sql;
}
}