TddlGroupExecutor.java

package com.taobao.tddl.repo.mysql.executor;

import java.util.concurrent.Future;

import com.taobao.tddl.common.exception.TddlException;
import com.taobao.tddl.common.model.Group;
import com.taobao.tddl.common.model.lifecycle.AbstractLifecycle;
import com.taobao.tddl.executor.common.ExecutionContext;
import com.taobao.tddl.executor.common.ExecutorContext;
import com.taobao.tddl.executor.common.TransactionConfig;
import com.taobao.tddl.executor.cursor.ISchematicCursor;
import com.taobao.tddl.executor.cursor.ResultCursor;
import com.taobao.tddl.executor.spi.ICommandHandler;
import com.taobao.tddl.executor.spi.ICommandHandlerFactory;
import com.taobao.tddl.executor.spi.IGroupExecutor;
import com.taobao.tddl.executor.spi.IRepository;
import com.taobao.tddl.executor.spi.ITransaction;
import com.taobao.tddl.group.jdbc.TGroupDataSource;
import com.taobao.tddl.optimizer.core.plan.IDataNodeExecutor;

/**
 * 为TGroupDatasource实现的groupexecutor
 * 因为TGroupDatasource中已经做了主备切换等功能，所以TddlGroupExecutor只是简单的执行sql
 * 
 * @author mengshi.sunmengshi 2013-12-6 下午2:39:18
 * @since 5.0.0
 */
public class TddlGroupExecutor extends AbstractLifecycle implements IGroupExecutor {

    public static final String TRANSACTION_GROUP_KEY = "GROUP_KEY";
    private IRepository        repo;

    /**
     * 可能是个datasource ，也可能是个rpc客户端。放在一起的原因是
     */
    private Object             remotingExecutableObject;
    private Group              group;

    public TddlGroupExecutor(IRepository repo){
        this.repo = repo;
    }

    protected void doInit() throws TddlException {
        super.doInit();
    }

    protected void doDestory() throws TddlException {
        if (remotingExecutableObject instanceof TGroupDataSource) {
            try {
                ((TGroupDataSource) remotingExecutableObject).destroyDataSource();
            } catch (Exception e) {
                throw new TddlException(e);
            }
        }
    }

    @Override
    public ISchematicCursor execByExecPlanNode(IDataNodeExecutor qc, ExecutionContext executionContext)
                                                                                                       throws TddlException {

        executionContext.setCurrentRepository(repo);
        getTransaction(executionContext, qc);
        ISchematicCursor returnCursor = null;
        returnCursor = executeInner(qc, executionContext);
        return returnCursor;
    }

    @Override
    public Future<ISchematicCursor> execByExecPlanNodeFuture(IDataNodeExecutor qc, ExecutionContext executionContext)
                                                                                                                     throws TddlException {
        return ExecutorContext.getContext().getTopologyExecutor().execByExecPlanNodeFuture(qc, executionContext);
    }

    public ISchematicCursor executeInner(IDataNodeExecutor executor, ExecutionContext executionContext)
                                                                                                       throws TddlException {

        // 允许远程执行。在cursor里面所依赖的执行器，从本地的换为远程的。并要注意远程事务处理过程中的兼容。
        // 目前的处理方式是，走到这里的远程执行，不允许出现事务。。。出现就丢异常
        ICommandHandlerFactory commandExecutorFactory = this.repo.getCommandExecutorFactory();
        // 核心方法，用于根据当前executor,拿到对应的处理Handler
        ICommandHandler commandHandler = commandExecutorFactory.getCommandHandler(executor, executionContext);
        // command模式命令。
        return commandHandler.handle(executor, executionContext);
    }

    public void getTransaction(ExecutionContext executionContext, IDataNodeExecutor targetExecutor)
                                                                                                   throws TddlException {
        if (executionContext.getTransaction() != null) {
            return;
        }
        IRepository repo = executionContext.getCurrentRepository();

        // 如果有外部的
        TransactionConfig tc = TransactionConfig.DEFAULT;
        ITransaction trans = repo.beginTransaction(tc);
        trans.setAutoCommit(executionContext.isAutoCommit());
        executionContext.setTransaction(trans);
        // 将groupNode 放入执行的上下文
        String groupNode = targetExecutor.getDataNode();

        executionContext.setTransactionGroup(groupNode);

    }

    @Override
    public ResultCursor commit(ExecutionContext executionContext) throws TddlException {
        ResultCursor rc = new ResultCursor(null, executionContext);
        if (executionContext.getTransactionGroup() == null) {
            return rc;
        }

        executionContext.getTransaction().commit();
        return rc;
    }

    @Override
    public ResultCursor rollback(ExecutionContext executionContext) throws TddlException {
        ResultCursor rc = new ResultCursor(null, executionContext);
        if (executionContext.getTransactionGroup() == null) {
            return rc;
        }

        executionContext.getTransaction().rollback();
        return rc;
    }

    @Override
    public Future<ResultCursor> commitFuture(ExecutionContext executionContext) throws TddlException {
        return ExecutorContext.getContext().getTopologyExecutor().commitFuture(executionContext);
    }

    @Override
    public Future<ResultCursor> rollbackFuture(ExecutionContext executionContext) throws TddlException {
        return ExecutorContext.getContext().getTopologyExecutor().rollbackFuture(executionContext);
    }

    @Override
    public Group getGroupInfo() {
        return this.group;
    }

    public Object getRemotingExecutableObject() {
        return remotingExecutableObject;
    }

    public void setGroup(Group group) {
        this.group = group;
    }

    public void setRemotingExecutableObject(Object remotingExecutableObject) {
        this.remotingExecutableObject = remotingExecutableObject;
    }

    @Override
    public String toString() {
        return "GroupExecutor [groupName=" + group.getName() + ", type=" + group.getType()
               + ", remotingExecutableObject=" + remotingExecutableObject + "]";
    }
}