Driver

Posted 2020-08-28 超超hd

aa

 

@Override
public CommandProcessorResponse run(String command)
throws CommandNeedRetryException {
return run(command, false);
}

然后调用下面方法 

最核心

    CommandProcessorResponse cpr = runInternal(command, alreadyCompiled);

  public CommandProcessorResponse run(String command, boolean alreadyCompiled)
        throws CommandNeedRetryException {
    CommandProcessorResponse cpr = runInternal(command, alreadyCompiled);

    if(cpr.getResponseCode() == 0) {
      return cpr;
    }
    SessionState ss = SessionState.get();
    if(ss == null) {
      return cpr;
    }
    MetaDataFormatter mdf = MetaDataFormatUtils.getFormatter(ss.getConf());
    if(!(mdf instanceof JsonMetaDataFormatter)) {
      return cpr;
    }

 

调用

compileInternal这句到达核心位置

 

  private CommandProcessorResponse runInternal(String command, boolean alreadyCompiled)

    int ret;
      if (!alreadyCompiled) {
        // compile internal will automatically reset the perf logger
        ret = compileInternal(command, true);
        // then we continue to use this perf logger
        perfLogger = SessionState.getPerfLogger();
        if (ret != 0) {
          return createProcessorResponse(ret);

到达 

compile

  private int compileInternal(String command, boolean deferClose) {
    int ret;

    Metrics metrics = MetricsFactory.getInstance();
    if (metrics != null) {
      metrics.incrementCounter(MetricsConstant.WAITING_COMPILE_OPS, 1);
    }

    final ReentrantLock compileLock = tryAcquireCompileLock(isParallelEnabled,
      command);
    if (compileLock == null) {
      return ErrorMsg.COMPILE_LOCK_TIMED_OUT.getErrorCode();
    }

    try {
      if (metrics != null) {
        metrics.decrementCounter(MetricsConstant.WAITING_COMPILE_OPS, 1);
      }
      ret = compile(command, true, deferClose);
    } finally {
      compileLock.unlock();
    }

    if (ret != 0) {
      try {
        releaseLocksAndCommitOrRollback(false, null);
      } catch (LockException e) {
        LOG.warn("Exception in releasing locks. "
            + org.apache.hadoop.util.StringUtils.stringifyException(e));
      }
    }

 

dd\\

ParseDriver创建解析器 解析命令
并且ASTNode 在parse 做了词法分析 和语法分析。

   perfLogger.PerfLogBegin(CLASS_NAME, PerfLogger.PARSE);
      ParseDriver pd = new ParseDriver();
      ASTNode tree = pd.parse(command, ctx);
      tree = ParseUtils.findRootNonNullToken(tree);
      perfLogger.PerfLogEnd(CLASS_NAME, PerfLogger.PARSE);