From ac3cedb108c93ffc1b536ef282443559d29b11c8 Mon Sep 17 00:00:00 2001
From: johncming <johncming@yahoo.com>
Date: Sat, 24 Aug 2019 09:39:15 +0800
Subject: [PATCH] promql: Modify the order of return values. (#5940)

Signed-off-by: johncming <johncming@yahoo.com>
---
 promql/query_logger.go      | 12 ++++++------
 promql/query_logger_test.go |  2 +-
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/promql/query_logger.go b/promql/query_logger.go
index 3d30062d6..256c3d775 100644
--- a/promql/query_logger.go
+++ b/promql/query_logger.go
@@ -76,27 +76,27 @@ func logUnfinishedQueries(filename string, filesize int, logger log.Logger) {
 	}
 }
 
-func getMMapedFile(filename string, filesize int, logger log.Logger) (error, []byte) {
+func getMMapedFile(filename string, filesize int, logger log.Logger) ([]byte, error) {
 
 	file, err := os.OpenFile(filename, os.O_CREATE|os.O_RDWR|os.O_TRUNC, 0644)
 	if err != nil {
 		level.Error(logger).Log("msg", "Error opening query log file", "file", filename, "err", err)
-		return err, []byte{}
+		return nil, err
 	}
 
 	err = file.Truncate(int64(filesize))
 	if err != nil {
 		level.Error(logger).Log("msg", "Error setting filesize.", "filesize", filesize, "err", err)
-		return err, []byte{}
+		return nil, err
 	}
 
 	fileAsBytes, err := mmap.Map(file, mmap.RDWR, 0)
 	if err != nil {
 		level.Error(logger).Log("msg", "Failed to mmap", "file", filename, "Attempted size", filesize, "err", err)
-		return err, []byte{}
+		return nil, err
 	}
 
-	return err, fileAsBytes
+	return fileAsBytes, err
 }
 
 func NewActiveQueryTracker(localStoragePath string, maxQueries int, logger log.Logger) *ActiveQueryTracker {
@@ -108,7 +108,7 @@ func NewActiveQueryTracker(localStoragePath string, maxQueries int, logger log.L
 	filename, filesize := filepath.Join(localStoragePath, "queries.active"), 1+maxQueries*entrySize
 	logUnfinishedQueries(filename, filesize, logger)
 
-	err, fileAsBytes := getMMapedFile(filename, filesize, logger)
+	fileAsBytes, err := getMMapedFile(filename, filesize, logger)
 	if err != nil {
 		panic("Unable to create mmap-ed active query log")
 	}
diff --git a/promql/query_logger_test.go b/promql/query_logger_test.go
index cc3743244..27e5b6644 100644
--- a/promql/query_logger_test.go
+++ b/promql/query_logger_test.go
@@ -113,7 +113,7 @@ func TestMMapFile(t *testing.T) {
 	filename := file.Name()
 	defer os.Remove(filename)
 
-	err, fileAsBytes := getMMapedFile(filename, 2, nil)
+	fileAsBytes, err := getMMapedFile(filename, 2, nil)
 
 	if err != nil {
 		t.Fatalf("Couldn't create test mmaped file")