move buildFmter into streamlog.GetFormatter

go/streamlog/streamlog.go

@@ -18,6 +18,7 @@ limitations under the License.
 package streamlog
 
 import (
+	"fmt"
 	"io"
 	"net/http"
 	"net/url"
@@ -121,3 +122,21 @@ func (logger *StreamLogger) ServeLogs(url string, messageFmt func(url.Values, in
 	})
 	log.Infof("Streaming logs from %s at %v.", logger.Name(), url)
 }
+
+// Formatter is a simple interface for objects that expose a Format function
+// as needed for streamlog.
+type Formatter interface {
+	Format(url.Values) string
+}
+
+// GetFormatter returns a formatter function for objects conforming to the
+// Formatter interface
+func GetFormatter(logger *StreamLogger) func(url.Values, interface{}) string {
+	return func(params url.Values, val interface{}) string {
+		fmter, ok := val.(Formatter)
+		if !ok {
+			return fmt.Sprintf("Error: unexpected value of type %T in %s!", val, logger.Name())
+		}
+		return fmter.Format(params)
+	}
+}

go/vt/vttablet/tabletserver/tabletenv/config.go

@@ -20,7 +20,6 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"net/url"
 	"time"
 
 	"github.com/golang/protobuf/proto"
@@ -94,11 +93,11 @@ func init() {
 // Init must be called after flag.Parse, and before doing any other operations.
 func Init() {
 	if *queryLogHandler != "" {
-		StatsLogger.ServeLogs(*queryLogHandler, buildFmter(StatsLogger))
+		StatsLogger.ServeLogs(*queryLogHandler, streamlog.GetFormatter(StatsLogger))
 	}
 
 	if *txLogHandler != "" {
-		TxLogger.ServeLogs(*txLogHandler, buildFmter(TxLogger))
+		TxLogger.ServeLogs(*txLogHandler, streamlog.GetFormatter(TxLogger))
 	}
 }
 
@@ -239,17 +238,3 @@ func VerifyConfig() error {
 	}
 	return nil
 }
-
-func buildFmter(logger *streamlog.StreamLogger) func(url.Values, interface{}) string {
-	type formatter interface {
-		Format(url.Values) string
-	}
-
-	return func(params url.Values, val interface{}) string {
-		fmter, ok := val.(formatter)
-		if !ok {
-			return fmt.Sprintf("Error: unexpected value of type %T in %s!", val, logger.Name())
-		}
-		return fmter.Format(params)
-	}
-}