content: /*
   * Copyright 1999-2012 Alibaba Group.
   *  
   * 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.
   */
  package com.alibaba.cobar.server;
  
  import java.io.EOFException;
  import java.nio.channels.SocketChannel;
  import java.sql.SQLNonTransientException;
  
  import org.apache.log4j.Logger;
  
  import com.alibaba.cobar.CobarServer;
  import com.alibaba.cobar.config.ErrorCode;
  import com.alibaba.cobar.config.model.SchemaConfig;
  import com.alibaba.cobar.net.FrontendConnection;
  import com.alibaba.cobar.route.RouteResultset;
  import com.alibaba.cobar.route.ServerRouter;
  import com.alibaba.cobar.server.response.Heartbeat;
  import com.alibaba.cobar.server.response.Ping;
  import com.alibaba.cobar.server.session.BlockingSession;
  import com.alibaba.cobar.server.session.NonBlockingSession;
  import com.alibaba.cobar.util.TimeUtil;
  
  /**
   * @author xianmao.hexm 2011-4-21 上午11:22:57
   */
  public class ServerConnection extends FrontendConnection {
      private static final Logger LOGGER = Logger.getLogger(ServerConnection.class);
      private static final long AUTH_TIMEOUT = 15 * 1000L;
  
      private volatile int txIsolation;
      private volatile boolean autocommit;
      private volatile boolean txInterrupted;
      private long lastInsertId;
      private BlockingSession session;
      private NonBlockingSession session2;
  
      public ServerConnection(SocketChannel channel) {
          super(channel);
          this.txInterrupted = false;
          this.autocommit = true;
      }
  
      @Override
      public boolean isIdleTimeout() {
          if (isAuthenticated) {
              return super.isIdleTimeout();
          } else {
              return TimeUtil.currentTimeMillis() > Math.max(lastWriteTime, lastReadTime) + AUTH_TIMEOUT;
          }
      }
  
      public int getTxIsolation() {
          return txIsolation;
      }
  
      public void setTxIsolation(int txIsolation) {
          this.txIsolation = txIsolation;
      }
  
      public boolean isAutocommit() {
          return autocommit;
      }
  
      public void setAutocommit(boolean autocommit) {
          this.autocommit = autocommit;
      }
  
      public long getLastInsertId() {
          return lastInsertId;
      }
  
      public void setLastInsertId(long lastInsertId) {
          this.lastInsertId = lastInsertId;
      }
  
      /**
       * 设置是否需要中断当前事务
       */
      public void setTxInterrupt() {
          if (!autocommit && !txInterrupted) {
              txInterrupted = true;
          }
      }
  
      public BlockingSession getSession() {
          return session;
      }
  
      public void setSession(BlockingSession session) {
          this.session = session;
      }
  
      public NonBlockingSession getSession2() {
          return session2;
      }
  
      public void setSession2(NonBlockingSession session2) {
          this.session2 = session2;
      }
  
      @Override
      public void ping() {
          Ping.response(this);
      }
  
      @Override
      public void heartbeat(byte[] data) {
          Heartbeat.response(this, data);
      }
  
      public void execute(String sql, int type) {
          // 状态检查
          if (txInterrupted) {
              writeErrMessage(ErrorCode.ER_YES, "Transaction error, need to rollback.");
              return;
          }
  
          // 检查当前使用的DB
          String db = this.schema;
          if (db == null) {
              writeErrMessage(ErrorCode.ER_NO_DB_ERROR, "No database selected");
              return;
          }
          SchemaConfig schema = CobarServer.getInstance().getConfig().getSchemas().get(db);
          if (schema == null) {
              writeErrMessage(ErrorCode.ER_BAD_DB_ERROR, "Unknown database '" + db + "'");
              return;
          }
  
          // 路由计算
          RouteResultset rrs = null;
          try {
              rrs = ServerRouter.route(schema, sql, this.charset, this);
          } catch (SQLNonTransientException e) {
              StringBuilder s = new StringBuilder();
              LOGGER.warn(s.append(this).append(sql).toString(), e);
              String msg = e.getMessage();
              writeErrMessage(ErrorCode.ER_PARSE_ERROR, msg == null ? e.getClass().getSimpleName() : msg);
              return;
          }
  
          // session执行
          session.execute(rrs, type);
      }
  
      /**
       * 提交事务
       */
      public void commit() {
          if (txInterrupted) {
              writeErrMessage(ErrorCode.ER_YES, "Transaction error, need to rollback.");
          } else {
              session.commit();
          }
      }
  
      /**
       * 回滚事务
       */
      public void rollback() {
          // 状态检查
          if (txInterrupted) {
              txInterrupted = false;
          }
  
          // 执行回滚
          session.rollback();
      }
  
      /**
       * 撤销执行中的语句
       * 
       * @param sponsor 发起者为null表示是自己
       */
      public void cancel(final FrontendConnection sponsor) {
          processor.getExecutor().execute(new Runnable() {
              @Override
              public void run() {
                  session.cancel(sponsor);
              }
          });
      }
  
      @Override
      public void error(int errCode, Throwable t) {
          // 根据异常类型和信息，选择日志输出级别。
          if (t instanceof EOFException) {
              if (LOGGER.isDebugEnabled()) {
                  LOGGER.debug(toString(), t);
              }
          } else if (isConnectionReset(t)) {
              if (LOGGER.isInfoEnabled()) {
                  LOGGER.info(toString(), t);
              }
          } else {
              LOGGER.warn(toString(), t);
          }
  
          // 异常返回码处理
          switch (errCode) {
          case ErrorCode.ERR_HANDLE_DATA:
              String msg = t.getMessage();
              writeErrMessage(ErrorCode.ER_YES, msg == null ? t.getClass().getSimpleName() : msg);
              break;
          default:
              close();
          }
      }
  
      @Override
      public boolean close() {
          if (super.close()) {
              processor.getExecutor().execute(new Runnable() {
                  @Override
                  public void run() {
                      session.terminate();
                  }
              });
              return true;
          } else {
              return false;
          }
      }
  
  }
  