Golang TabletInfo.DbName方法代碼示例

// runSqlCommands will send the sql commands to the remote tablet.
func runSqlCommands(wr *wrangler.Wrangler, ti *topo.TabletInfo, commands []string, abort chan struct{}, disableBinLogs bool) error {
	for _, command := range commands {
		command, err := fillStringTemplate(command, map[string]string{"DatabaseName": ti.DbName()})
		if err != nil {
			return fmt.Errorf("fillStringTemplate failed: %v", err)
		}

		ctx, cancel := context.WithTimeout(context.TODO(), 30*time.Second)
		_, err = wr.TabletManagerClient().ExecuteFetch(ctx, ti, command, 0, false, disableBinLogs)
		if err != nil {
			return err
		}
		cancel()

		// check on abort
		select {
		case <-abort:
			return nil
		default:
			break
		}
	}

	return nil
}

// applySqlShard applies a given SQL change on a given tablet alias. It allows executing arbitrary
// SQL statements, but doesn't return any results, so it's only useful for SQL statements
// that would be run for their effects (e.g., CREATE).
// It works by applying the SQL statement on the shard's master tablet with replication turned on.
// Thus it should be used only for changes that can be applies on a live instance without causing issues;
// it shouldn't be used for anything that will require a pivot.
// The SQL statement string is expected to have {{.DatabaseName}} in place of the actual db name.
func (wr *Wrangler) applySqlShard(tabletInfo *topo.TabletInfo, change string) error {
	filledChange, err := fillStringTemplate(change, map[string]string{"DatabaseName": tabletInfo.DbName()})
	if err != nil {
		return fmt.Errorf("fillStringTemplate failed: %v", err)
	}
	ctx, cancel := context.WithTimeout(wr.ctx, 30*time.Second)
	defer cancel()
	// Need to make sure that we enable binlog, since we're only applying the statement on masters.
	_, err = wr.tmc.ExecuteFetch(ctx, tabletInfo, filledChange, 0, false, false)
	return err
}

// executeFetchLoop loops over the provided insertChannel
// and sends the commands to the provided tablet.
func executeFetchLoop(wr *wrangler.Wrangler, ti *topo.TabletInfo, insertChannel chan string, abort chan struct{}, disableBinLogs bool) error {
	for {
		select {
		case cmd, ok := <-insertChannel:
			if !ok {
				// no more to read, we're done
				return nil
			}
			cmd = "INSERT INTO `" + ti.DbName() + "`." + cmd
			ctx, cancel := context.WithTimeout(context.TODO(), 30*time.Second)
			_, err := wr.TabletManagerClient().ExecuteFetch(ctx, ti, cmd, 0, false, disableBinLogs)
			if err != nil {
				return fmt.Errorf("ExecuteFetch failed: %v", err)
			}
			cancel()
		case <-abort:
			// FIXME(alainjobart): note this select case
			// could be starved here, and we might miss
			// the abort in some corner cases.
			return nil
		}
	}
}

// findChunks returns an array of chunks to use for splitting up a table
// into multiple data chunks. It only works for tables with a primary key
// (and the primary key first column is an integer type).
// The array will always look like:
// "", "value1", "value2", ""
// A non-split tablet will just return:
// "", ""
func findChunks(wr *wrangler.Wrangler, ti *topo.TabletInfo, td *myproto.TableDefinition, minTableSizeForSplit uint64, sourceReaderCount int) ([]string, error) {
	result := []string{"", ""}

	// eliminate a few cases we don't split tables for
	if len(td.PrimaryKeyColumns) == 0 {
		// no primary key, what can we do?
		return result, nil
	}
	if td.DataLength < minTableSizeForSplit {
		// table is too small to split up
		return result, nil
	}

	// get the min and max of the leading column of the primary key
	query := fmt.Sprintf("SELECT MIN(%v), MAX(%v) FROM %v.%v", td.PrimaryKeyColumns[0], td.PrimaryKeyColumns[0], ti.DbName(), td.Name)
	ctx, cancel := context.WithTimeout(context.TODO(), 30*time.Second)
	qr, err := wr.TabletManagerClient().ExecuteFetch(ctx, ti, query, 1, true, false)
	if err != nil {
		wr.Logger().Infof("Not splitting table %v into multiple chunks: %v", td.Name, err)
		return result, nil
	}
	cancel()
	if len(qr.Rows) != 1 {
		wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot get min and max", td.Name)
		return result, nil
	}
	if qr.Rows[0][0].IsNull() || qr.Rows[0][1].IsNull() {
		wr.Logger().Infof("Not splitting table %v into multiple chunks, min or max is NULL: %v %v", td.Name, qr.Rows[0][0], qr.Rows[0][1])
		return result, nil
	}
	switch qr.Fields[0].Type {
	case mproto.VT_TINY, mproto.VT_SHORT, mproto.VT_LONG, mproto.VT_LONGLONG, mproto.VT_INT24:
		minNumeric := sqltypes.MakeNumeric(qr.Rows[0][0].Raw())
		maxNumeric := sqltypes.MakeNumeric(qr.Rows[0][1].Raw())
		if qr.Rows[0][0].Raw()[0] == '-' {
			// signed values, use int64
			min, err := minNumeric.ParseInt64()
			if err != nil {
				wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert min: %v %v", td.Name, minNumeric, err)
				return result, nil
			}
			max, err := maxNumeric.ParseInt64()
			if err != nil {
				wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert max: %v %v", td.Name, maxNumeric, err)
				return result, nil
			}
			interval := (max - min) / int64(sourceReaderCount)
			if interval == 0 {
				wr.Logger().Infof("Not splitting table %v into multiple chunks, interval=0: %v %v", td.Name, max, min)
				return result, nil
			}

			result = make([]string, sourceReaderCount+1)
			result[0] = ""
			result[sourceReaderCount] = ""
			for i := int64(1); i < int64(sourceReaderCount); i++ {
				result[i] = fmt.Sprintf("%v", min+interval*i)
			}
			return result, nil
		}

		// unsigned values, use uint64
		min, err := minNumeric.ParseUint64()
		if err != nil {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert min: %v %v", td.Name, minNumeric, err)
			return result, nil
		}
		max, err := maxNumeric.ParseUint64()
		if err != nil {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert max: %v %v", td.Name, maxNumeric, err)
			return result, nil
		}
		interval := (max - min) / uint64(sourceReaderCount)
		if interval == 0 {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, interval=0: %v %v", td.Name, max, min)
			return result, nil
		}

		result = make([]string, sourceReaderCount+1)
		result[0] = ""
		result[sourceReaderCount] = ""
		for i := uint64(1); i < uint64(sourceReaderCount); i++ {
			result[i] = fmt.Sprintf("%v", min+interval*i)
		}
		return result, nil

	case mproto.VT_FLOAT, mproto.VT_DOUBLE:
		min, err := strconv.ParseFloat(qr.Rows[0][0].String(), 64)
		if err != nil {
			wr.Logger().Infof("Not splitting table %v into multiple chunks, cannot convert min: %v %v", td.Name, qr.Rows[0][0], err)
			return result, nil
		}
		max, err := strconv.ParseFloat(qr.Rows[0][1].String(), 64)
//.........這裏部分代碼省略.........