Using sqlflow.Run

[tonyyang-svail]

Probably need to refactor runExtendedSQL in sqlflow.

package sqlflowserver

func runExtendedSQL(slct string, stream SQLFlow_RunServer) error {
    logChan := make(chan Log)
    go sqlflow.runExtendedSQL(slct, db, logChan)

    for {
        log, more := <- logChan
        if !more {
            break
        }
        if log.Err != nil {
            return log.Err
        }
        err := stream.Send(log)
        if err {
            close(logChan)
            return err
        }
    }

    return nil
}

package sqlflow

struct Log {
    Log string
    Err error
}

func runExtendedSQL(slct string, db *sql.DB, logChan chan Log) {
    // chan may be closed, need to recover
    defer func() {
        if x := recover(); x != nil {
            log.Printf("run time panic: %v", x)
        }
    }()

    logChan <- Log{"parsing...", nil}
    ...

    logChan <- Log{"verifying...", nil}
    ...

    logChan <- Log{"executing...", nil}
    ...

    close(logChan)
}