util: correct comments mistake (pingcap#3121)

util/codec/bytes.go

@@ -190,7 +190,7 @@ func reverseBytes(b []byte) {
 	safeReverseBytes(b)
 }
 
-// like realloc.
+// reallocBytes is like realloc.
 func reallocBytes(b []byte, n int) []byte {
 	newSize := len(b) + n
 	if cap(b) < newSize {

util/codec/codec.go

@@ -235,7 +235,7 @@ func SetRawValues(data []byte, values []types.Datum) error {
 	return nil
 }
 
-// peeks the first encoded value from b and returns its length.
+// peek peeks the first encoded value from b and returns its length.
 func peek(b []byte) (length int, err error) {
 	if len(b) < 1 {
 		return 0, errors.New("invalid encoded key")

util/encrypt/aes.go

@@ -85,7 +85,7 @@ func newECBDecrypter(b cipher.Block) cipher.BlockMode {
 	return (*ecbDecrypter)(newECB(b))
 }
 
-// Padding using PKCS7
+// pkcs7Padding pads data using PKCS7.
 // See https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7
 func pkcs7Padding(ciphertext []byte, blockSize int) []byte {
 	// The bytes need to padding.
@@ -94,7 +94,7 @@ func pkcs7Padding(ciphertext []byte, blockSize int) []byte {
 	return append(ciphertext, padtext...)
 }
 
-// UnPadding using PKCS7
+// pkcs5UnPadding unPads data using PKCS7.
 // See https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7
 func pkcs5UnPadding(origData []byte) []byte {
 	length := len(origData)

util/filesort/filesort.go

@@ -42,7 +42,7 @@ type item struct {
 	value *comparableRow
 }
 
-// Min-heap of comparableRows
+// rowHeap maintains a min-heap property of comparableRows.
 type rowHeap struct {
 	sc     *variable.StatementContext
 	ims    []*item
@@ -92,12 +92,12 @@ func (rh *rowHeap) Less(i, j int) bool {
 	return ret
 }
 
-// Push implements heap.Interface Push interface.
+// Push pushes an element into rowHeap.
 func (rh *rowHeap) Push(x interface{}) {
 	rh.ims = append(rh.ims, x.(*item))
 }
 
-// Push implements heap.Interface Pop interface.
+// Pop pops the last element from rowHeap.
 func (rh *rowHeap) Pop() interface{} {
 	old := rh.ims
 	n := len(old)
@@ -295,7 +295,7 @@ func (fs *FileSorter) closeAllFiles() error {
 	return nil
 }
 
-// Perform full in-memory sort.
+// internalSort performs full in-memory sort.
 func (fs *FileSorter) internalSort() (*comparableRow, error) {
 	w := fs.workers[fs.cWorker]
 
@@ -314,7 +314,7 @@ func (fs *FileSorter) internalSort() (*comparableRow, error) {
 	return nil, nil
 }
 
-// Perform external file sort.
+// externalSort performs external file sort.
 func (fs *FileSorter) externalSort() (*comparableRow, error) {
 	if !fs.fetched {
 		// flush all remaining content to file (if any)
@@ -412,7 +412,7 @@ func (fs *FileSorter) openAllFiles() error {
 	return nil
 }
 
-// Fetch the next row given the source file index.
+// fetchNextRow fetches the next row given the source file index.
 func (fs *FileSorter) fetchNextRow(index int) (*comparableRow, error) {
 	n, err := fs.fds[index].Read(fs.head)
 	if err == io.EOF {
@@ -559,7 +559,7 @@ func (w *Worker) input(row *comparableRow) {
 	}
 }
 
-// Flush the buffer to file if it is full.
+// flushToFile flushes the buffer to file if it is full.
 func (w *Worker) flushToFile() {
 	defer w.ctx.wg.Done()
 	var (

util/mock/context.go

@@ -30,13 +30,11 @@ var _ context.Context = (*Context)(nil)
 
 // Context represents mocked context.Context.
 type Context struct {
-	values map[fmt.Stringer]interface{}
-	// mock global variable
-	txn         kv.Transaction
-	Store       kv.Storage
+	values      map[fmt.Stringer]interface{}
+	txn         kv.Transaction // mock global variable
+	Store       kv.Storage     // mock global variable
 	sessionVars *variable.SessionVars
-	// Fix data race in ddl test.
-	mux sync.Mutex
+	mux         sync.Mutex // fix data race in ddl test.
 }
 
 // SetValue implements context.Context SetValue interface.

util/testutil/testutil.go

@@ -58,7 +58,7 @@ func CompareUnorderedStringSlice(a []string, b []string) bool {
 	return len(m) == 0
 }
 
-// DatumEquals checker.
+// datumEqualsChecker is a checker for DatumEquals.
 type datumEqualsChecker struct {
 	*check.CheckerInfo
 }

util/types/datum_eval.go

@@ -547,7 +547,7 @@ func ComputeRightShift(sc *variable.StatementContext, a, b Datum) (d Datum, err
 	return d, nil
 }
 
-// covertNonIntegerToUint64 coverts a non-integer to an uint64
+// convertNonInt2RoundUint64 converts a non-integer to an uint64
 func convertNonInt2RoundUint64(sc *variable.StatementContext, x Datum) (d uint64, err error) {
 	decimalX, err := x.ToDecimal(sc)
 	if err != nil {

util/types/etc.go

@@ -129,7 +129,7 @@ func InvOp2(x, y interface{}, o opcode.Op) (interface{}, error) {
 	return nil, errors.Errorf("Invalid operation: %v %v %v (mismatched types %T and %T)", x, o, y, x, y)
 }
 
-// Overflow returns an overflowed error.
+// overflow returns an overflowed error.
 func overflow(v interface{}, tp byte) error {
 	return ErrOverflow.Gen("constant %v overflows %s", v, TypeStr(tp))
 }

util/types/mydecimal.go

@@ -148,18 +148,15 @@ func digitsToWords(digits int) int {
 
 // MyDecimal represents a decimal value.
 type MyDecimal struct {
-	// The number of *decimal* digits before the point.
-	digitsInt int8
+	digitsInt int8 // the number of *decimal* digits before the point.
 
-	// The number of decimal digits after the point.
-	digitsFrac int8
+	digitsFrac int8 // the number of decimal digits after the point.
 
-	// result fraction digits.
-	resultFrac int8
+	resultFrac int8 // result fraction digits.
 
 	negative bool
 
-	// An array of int32 words.
+	//  wordBuf is an array of int32 words.
 	// A word is an int32 value can hold 9 digits.(0 <= word < wordBase)
 	wordBuf [maxWordBufLen]int32
 }
@@ -419,15 +416,15 @@ func (d *MyDecimal) Shift(shift int) error {
 		return nil
 	}
 	var (
-		/* index of first non zero digit (all indexes from 0) */
+		// digitBegin is index of first non zero digit (all indexes from 0).
 		digitBegin int
-		/* index of position after last decimal digit */
+		// digitEnd is index of position after last decimal digit.
 		digitEnd int
-		/* index of digit position just after point */
+		// point is index of digit position just after point.
 		point = digitsToWords(int(d.digitsInt)) * digitsPerWord
-		/* new point position */
+		// new point position.
 		newPoint = point + shift
-		/* number of digits in result */
+		// number of digits in result.
 		digitsInt, digitsFrac int
 		newFront              int
 	)

util/types/mytime.go

@@ -209,7 +209,7 @@ func calcWeekday(daynr int, sundayFirstDayOfWeek bool) int {
 type weekBehaviour uint
 
 const (
-	// If set, Sunday is first day of week, otherwise Monday is first day of week.
+	// weekBehaviourMondayFirst set Monday as first day of week; otherwise Sunday is first day of week
 	weekBehaviourMondayFirst weekBehaviour = 1 << iota
 	// If set, Week is in range 1-53, otherwise Week is in range 0-53.
 	// Note that this flag is only relevant if WEEK_JANUARY is not set.

util/types/mytime_test.go

@@ -10,6 +10,7 @@
 // distributed under the License is distributed on an "AS IS" BASIS,
 // See the License for the specific language governing permissions and
 // limitations under the License.
+
 package types
 
 import (

util/types/time.go

@@ -661,6 +661,7 @@ func ParseYear(str string) (int16, error) {
 	return y, nil
 }
 
+// adjustYear adjusts year according to y.
 // See https://dev.mysql.com/doc/refman/5.7/en/two-digit-years.html
 func adjustYear(y int) int {
 	if y >= 0 && y <= 69 {
@@ -986,6 +987,7 @@ func getTime(num int64, tp byte) (Time, error) {
 	return t, errors.Trace(err)
 }
 
+// parseDateTimeFromNum parses date time from num.
 // See number_to_datetime function.
 // https://github.com/mysql/mysql-server/blob/5.7/sql-common/my_time.c
 func parseDateTimeFromNum(num int64) (Time, error) {
@@ -1354,7 +1356,7 @@ func extractSingleTimeValue(unit string, format string) (int64, int64, int64, go
 	return 0, 0, 0, 0, errors.Errorf("invalid singel timeunit - %s", unit)
 }
 
-// Format is `SS.FFFFFF`.
+// extractSecondMicrosecond extracts second and microsecond from a string and its format is `SS.FFFFFF`.
 func extractSecondMicrosecond(format string) (int64, int64, int64, gotime.Duration, error) {
 	fields := strings.Split(format, ".")
 	if len(fields) != 2 {
@@ -1374,7 +1376,7 @@ func extractSecondMicrosecond(format string) (int64, int64, int64, gotime.Durati
 	return 0, 0, 0, gotime.Duration(seconds)*gotime.Second + gotime.Duration(microseconds)*gotime.Microsecond, nil
 }
 
-// Format is `MM:SS.FFFFFF`.
+// extractMinuteMicrosecond extracts minutes and microsecond from a string and its format is `MM:SS.FFFFFF`.
 func extractMinuteMicrosecond(format string) (int64, int64, int64, gotime.Duration, error) {
 	fields := strings.Split(format, ":")
 	if len(fields) != 2 {
@@ -1394,7 +1396,7 @@ func extractMinuteMicrosecond(format string) (int64, int64, int64, gotime.Durati
 	return 0, 0, 0, gotime.Duration(minutes)*gotime.Minute + value, nil
 }
 
-// Format is `MM:SS`.
+// extractMinuteSecond extracts minutes and second from a string and its format is `MM:SS`.
 func extractMinuteSecond(format string) (int64, int64, int64, gotime.Duration, error) {
 	fields := strings.Split(format, ":")
 	if len(fields) != 2 {
@@ -1414,7 +1416,7 @@ func extractMinuteSecond(format string) (int64, int64, int64, gotime.Duration, e
 	return 0, 0, 0, gotime.Duration(minutes)*gotime.Minute + gotime.Duration(seconds)*gotime.Second, nil
 }
 
-// Format is `HH:MM:SS.FFFFFF`.
+// extractHourMicrosecond extracts hour and microsecond from a string and its format is `HH:MM:SS.FFFFFF`.
 func extractHourMicrosecond(format string) (int64, int64, int64, gotime.Duration, error) {
 	fields := strings.Split(format, ":")
 	if len(fields) != 3 {
@@ -1439,7 +1441,7 @@ func extractHourMicrosecond(format string) (int64, int64, int64, gotime.Duration
 	return 0, 0, 0, gotime.Duration(hours)*gotime.Hour + gotime.Duration(minutes)*gotime.Minute + value, nil
 }
 
-// Format is `HH:MM:SS`.
+// extractHourSecond extracts hour and second from a string and its format is `HH:MM:SS`.
 func extractHourSecond(format string) (int64, int64, int64, gotime.Duration, error) {
 	fields := strings.Split(format, ":")
 	if len(fields) != 3 {
@@ -1464,7 +1466,7 @@ func extractHourSecond(format string) (int64, int64, int64, gotime.Duration, err
 	return 0, 0, 0, gotime.Duration(hours)*gotime.Hour + gotime.Duration(minutes)*gotime.Minute + gotime.Duration(seconds)*gotime.Second, nil
 }
 
-// Format is `HH:MM`.
+// extractHourMinute extracts hour and minute from a string and its format is `HH:MM`.
 func extractHourMinute(format string) (int64, int64, int64, gotime.Duration, error) {
 	fields := strings.Split(format, ":")
 	if len(fields) != 2 {
@@ -1484,7 +1486,7 @@ func extractHourMinute(format string) (int64, int64, int64, gotime.Duration, err
 	return 0, 0, 0, gotime.Duration(hours)*gotime.Hour + gotime.Duration(minutes)*gotime.Minute, nil
 }
 
-// Format is `DD HH:MM:SS.FFFFFF`.
+// extractDayMicrosecond extracts day and microsecond from a string and its format is `DD HH:MM:SS.FFFFFF`.
 func extractDayMicrosecond(format string) (int64, int64, int64, gotime.Duration, error) {
 	fields := strings.Split(format, " ")
 	if len(fields) != 2 {
@@ -1504,7 +1506,7 @@ func extractDayMicrosecond(format string) (int64, int64, int64, gotime.Duration,
 	return 0, 0, days, value, nil
 }
 
-// Format is `DD HH:MM:SS`.
+// extractDaySecond extracts day and hour from a string and its format is `DD HH:MM:SS`.
 func extractDaySecond(format string) (int64, int64, int64, gotime.Duration, error) {
 	fields := strings.Split(format, " ")
 	if len(fields) != 2 {
@@ -1524,7 +1526,7 @@ func extractDaySecond(format string) (int64, int64, int64, gotime.Duration, erro
 	return 0, 0, days, value, nil
 }
 
-// Format is `DD HH:MM`.
+// extractDayMinute extracts day and minute from a string and its format is `DD HH:MM`.
 func extractDayMinute(format string) (int64, int64, int64, gotime.Duration, error) {
 	fields := strings.Split(format, " ")
 	if len(fields) != 2 {
@@ -1544,7 +1546,7 @@ func extractDayMinute(format string) (int64, int64, int64, gotime.Duration, erro
 	return 0, 0, days, value, nil
 }
 
-// Format is `DD HH`.
+// extractDayHour extracts day and hour from a string and its format is `DD HH`.
 func extractDayHour(format string) (int64, int64, int64, gotime.Duration, error) {
 	fields := strings.Split(format, " ")
 	if len(fields) != 2 {
@@ -1564,7 +1566,7 @@ func extractDayHour(format string) (int64, int64, int64, gotime.Duration, error)
 	return 0, 0, days, gotime.Duration(hours) * gotime.Hour, nil
 }
 
-// Format is `YYYY-MM`.
+// extractYearMonth extracts year and month from a string and its format is `YYYY-MM`.
 func extractYearMonth(format string) (int64, int64, int64, gotime.Duration, error) {
 	fields := strings.Split(format, "-")
 	if len(fields) != 2 {
@@ -2252,7 +2254,7 @@ func monthNumeric(t *mysqlTime, input string, ctx map[string]int) (string, bool)
 	return rem, false
 }
 
-// 0th 1st 2nd 3rd ...
+//  dayOfMonthWithSuffix returns different suffix according t being which day. i.e. 0 return th. 1 return st.
 func dayOfMonthWithSuffix(t *mysqlTime, input string, ctx map[string]int) (string, bool) {
 	month, remain := parseOrdinalNumbers(input)
 	if month >= 0 {