More code documented

binlog/event_format_description.go

@@ -54,7 +54,7 @@ const (
 func (e *FormatDescriptionEvent) Decode(data []byte) error {
 	buf := tools.NewBuffer(data)
 	e.Version = buf.ReadUint16()
-	e.ServerVersion = trimString(buf.ReadStringVarLen(50))
+	e.ServerVersion = trimStringEOF(buf.ReadStringVarLen(50))
 	e.CreateTimestamp = buf.ReadUint32()
 	e.EventHeaderLength = buf.ReadUint8()
 	e.EventTypeHeaderLengths = buf.ReadStringEOF()
@@ -64,9 +64,6 @@ func (e *FormatDescriptionEvent) Decode(data []byte) error {
 		ChecksumAlgorithm: ChecksumAlgorithmUndefined,
 	}
 	if e.ServerDetails.Version > 50601 {
-		// Last 5 bytes are:
-		// [1] Checksum algorithm
-		// [4] Checksum
 		e.ServerDetails.ChecksumAlgorithm = ChecksumAlgorithm(data[len(data)-5])
 		e.EventTypeHeaderLengths = e.EventTypeHeaderLengths[:len(e.EventTypeHeaderLengths)-5]
 	}
@@ -127,7 +124,7 @@ func parseVersionNumber(v string) int {
 	return major*10000 + minor*100 + patch
 }
 
-func trimString(str []byte) string {
+func trimStringEOF(str []byte) string {
 	for i, c := range str {
 		if c == 0x00 {
 			return string(str[:i])

binlog/event_rotate.go

@@ -2,7 +2,8 @@ package binlog
 
 import "github.com/localhots/bocadillo/tools"
 
-// Position ...
+// Position is a pair of log file name and a binary offset in it that is used to
+// represent the beginning of the event description.
 type Position struct {
 	File   string
 	Offset uint64

binlog/event_rows.go

@@ -28,12 +28,7 @@ type RowsFlag uint16
 
 const (
 	// RowsFlagEndOfStatement is used to clear old table mappings.
-	RowsFlagEndOfStatement     RowsFlag = 0x0001
+	RowsFlagEndOfStatement RowsFlag = 0x0001
-	rowsFlagNoForeignKeyChecks RowsFlag = 0x0002
-	rowsFlagNoUniqueKeyChecks  RowsFlag = 0x0004
-	rowsFlagRowHasColumns      RowsFlag = 0x0008
-
-	freeTableMapID = 0x00FFFFFF
 )
 
 // PeekTableIDAndFlags returns table ID and flags without decoding whole event.
@@ -229,7 +224,7 @@ func (e *RowsEvent) decodeValue(buf *tools.Buffer, ct mysql.ColumnType, meta uin
 	case mysql.ColumnTypeLongblob:
 		return buf.ReadStringVarEnc(4)
 
-	// Bits
+	// Other
 	case mysql.ColumnTypeBit:
 		nbits := int(((meta >> 8) * 8) + (meta & 0xFF))
 		length = int(nbits+7) / 8
@@ -241,8 +236,6 @@ func (e *RowsEvent) decodeValue(buf *tools.Buffer, ct mysql.ColumnType, meta uin
 		v, n := mysql.DecodeBit(buf.Cur(), nbits, length)
 		buf.Skip(n)
 		return v
-
-	// Stuff
 	case mysql.ColumnTypeEnum:
 		return buf.ReadVarLen64(length)
 

mysql/column_types.go

@@ -23,12 +23,12 @@ const (
 	ColumnTypeTime       ColumnType = 0x0b
 	ColumnTypeDatetime   ColumnType = 0x0c
 	ColumnTypeYear       ColumnType = 0x0d
-	ColumnTypeNewDate    ColumnType = 0x0e // Internal
+	ColumnTypeNewDate    ColumnType = 0x0e
 	ColumnTypeVarchar    ColumnType = 0x0f
 	ColumnTypeBit        ColumnType = 0x10
-	ColumnTypeTimestamp2 ColumnType = 0x11 // Internal
+	ColumnTypeTimestamp2 ColumnType = 0x11
-	ColumnTypeDatetime2  ColumnType = 0x12 // Internal
+	ColumnTypeDatetime2  ColumnType = 0x12
-	ColumnTypeTime2      ColumnType = 0x13 // Internal
+	ColumnTypeTime2      ColumnType = 0x13
 
 	ColumnTypeJSON       ColumnType = 0xF5
 	ColumnTypeNewDecimal ColumnType = 0xF6

mysql/time.go

@@ -9,12 +9,14 @@ import (
 // Timezone is set for decoded datetime values.
 var Timezone = time.UTC
 
-// DecodeYear ...
+// DecodeYear decodes YEAR value.
+// Spec: https://dev.mysql.com/doc/refman/8.0/en/year.html
 func DecodeYear(v uint8) uint16 {
 	return uint16(v) + 1900
 }
 
-// DecodeDate ...
+// DecodeDate decodes DATE value.
+// Spec: https://dev.mysql.com/doc/refman/8.0/en/datetime.html
 func DecodeDate(v uint32) string {
 	if v == 0 {
 		return "0000-00-00"
@@ -22,7 +24,8 @@ func DecodeDate(v uint32) string {
 	return fmt.Sprintf("%04d-%02d-%02d", v/(16*32), v/32%16, v%32)
 }
 
-// DecodeTime ...
+// DecodeTime decodes TIME value.
+// Spec: https://dev.mysql.com/doc/refman/8.0/en/time.html
 func DecodeTime(v uint32) string {
 	if v == 0 {
 		return "00:00:00"
@@ -34,97 +37,12 @@ func DecodeTime(v uint32) string {
 	return fmt.Sprintf("%s%02d:%02d:%02d", sign, v/10000, (v%10000)/100, v%100)
 }
 
-// DecodeTimestamp2 ...
+// DecodeTime2 decodes TIME v2 value.
-// Implementation borrowed from https://github.com/siddontang/go-mysql/
-func DecodeTimestamp2(data []byte, dec uint16) (string, int) {
-	//get timestamp binary length
-	n := int(4 + (dec+1)/2)
-	sec := int64(binary.BigEndian.Uint32(data[0:4]))
-	usec := int64(0)
-	switch dec {
-	case 1, 2:
-		usec = int64(data[4]) * 10000
-	case 3, 4:
-		usec = int64(binary.BigEndian.Uint16(data[4:])) * 100
-	case 5, 6:
-		usec = int64(DecodeVarLen64BigEndian(data[4:7]))
-	}
-
-	if sec == 0 {
-		return formatZeroTime(int(usec), int(dec)), n
-	}
-
-	return FracTime{time.Unix(sec, usec*1000), int(dec)}.String(), n
-}
-
-// DecodeDatetime ...
-func DecodeDatetime(v uint64) string {
-	d := v / 1000000
-	t := v % 1000000
-	return FracTime{Time: time.Date(int(d/10000),
-		time.Month((d%10000)/100),
-		int(d%100),
-		int(t/10000),
-		int((t%10000)/100),
-		int(t%100),
-		0,
-		Timezone,
-	)}.String()
-}
-
-// DecodeDatetime2 ...
-// Implementation borrowed from https://github.com/siddontang/go-mysql/
-func DecodeDatetime2(data []byte, dec uint16) (string, int) {
-	const offset int64 = 0x8000000000
-	//get datetime binary length
-	n := int(5 + (dec+1)/2)
-
-	intPart := int64(DecodeVarLen64BigEndian(data[0:5])) - offset
-	var frac int64
-
-	switch dec {
-	case 1, 2:
-		frac = int64(data[5]) * 10000
-	case 3, 4:
-		frac = int64(binary.BigEndian.Uint16(data[5:7])) * 100
-	case 5, 6:
-		frac = int64(DecodeVarLen64BigEndian(data[5:8]))
-	}
-
-	if intPart == 0 {
-		return formatZeroTime(int(frac), int(dec)), n
-	}
-
-	tmp := intPart<<24 + frac
-	//handle sign???
-	if tmp < 0 {
-		tmp = -tmp
-	}
-
-	// var secPart int64 = tmp % (1 << 24)
-	ymdhms := tmp >> 24
-
-	ymd := ymdhms >> 17
-	ym := ymd >> 5
-	hms := ymdhms % (1 << 17)
-
-	day := int(ymd % (1 << 5))
-	month := int(ym % 13)
-	year := int(ym / 13)
-
-	second := int(hms % (1 << 6))
-	minute := int((hms >> 6) % (1 << 6))
-	hour := int((hms >> 12))
-
-	return FracTime{time.Date(year, time.Month(month), day, hour, minute, second, int(frac*1000), Timezone), int(dec)}.String(), n
-}
-
-// DecodeTime2 ...
 // Implementation borrowed from https://github.com/siddontang/go-mysql/
 func DecodeTime2(data []byte, dec uint16) (string, int) {
 	const offset int64 = 0x800000000000
 	const intOffset int64 = 0x800000
-	//time  binary length
+	// time  binary length
 	n := int(3 + (dec+1)/2)
 
 	tmp := int64(0)
@@ -136,8 +54,8 @@ func DecodeTime2(data []byte, dec uint16) (string, int) {
 		intPart = int64(DecodeVarLen64BigEndian(data[0:3])) - intOffset
 		frac = int64(data[3])
 		if intPart < 0 && frac > 0 {
-			intPart++     /* Shift to the next integer value */
+			intPart++     // Shift to the next integer value
-			frac -= 0x100 /* -(0x100 - frac) */
+			frac -= 0x100 // -(0x100 - frac)
 		}
 		tmp = intPart<<24 + frac*10000
 	case 3:
@@ -145,12 +63,10 @@ func DecodeTime2(data []byte, dec uint16) (string, int) {
 		intPart = int64(DecodeVarLen64BigEndian(data[0:3])) - intOffset
 		frac = int64(binary.BigEndian.Uint16(data[3:5]))
 		if intPart < 0 && frac > 0 {
-			/*
+			// Fix reverse fractional part order: "0x10000 - frac".
-			   Fix reverse fractional part order: "0x10000 - frac".
+			// See comments for FSP=1 and FSP=2 above.
-			   See comments for FSP=1 and FSP=2 above.
+			intPart++       // Shift to the next integer value
-			*/
+			frac -= 0x10000 // -(0x10000-frac)
-			intPart++       /* Shift to the next integer value */
-			frac -= 0x10000 /* -(0x10000-frac) */
 		}
 		tmp = intPart<<24 + frac*100
 
@@ -175,9 +91,9 @@ func DecodeTime2(data []byte, dec uint16) (string, int) {
 
 	hms = tmp >> 24
 
-	hour := (hms >> 12) % (1 << 10) /* 10 bits starting at 12th */
+	hour := (hms >> 12) % (1 << 10) // 10 bits starting at 12th
-	minute := (hms >> 6) % (1 << 6) /* 6 bits starting at 6th   */
+	minute := (hms >> 6) % (1 << 6) // 6 bits starting at 6th
-	second := hms % (1 << 6)        /* 6 bits starting at 0th   */
+	second := hms % (1 << 6)        // 6 bits starting at 0th
 	secPart := tmp % (1 << 24)
 
 	if secPart != 0 {
@@ -187,6 +103,94 @@ func DecodeTime2(data []byte, dec uint16) (string, int) {
 	return fmt.Sprintf("%s%02d:%02d:%02d", sign, hour, minute, second), n
 }
 
+// DecodeTimestamp2 decodes TIMESTAMP v2 value.
+// Spec: https://dev.mysql.com/doc/refman/8.0/en/datetime.html
+// Implementation borrowed from https://github.com/siddontang/go-mysql/
+func DecodeTimestamp2(data []byte, dec uint16) (string, int) {
+	// get timestamp binary length
+	n := int(4 + (dec+1)/2)
+	sec := int64(binary.BigEndian.Uint32(data[0:4]))
+	usec := int64(0)
+	switch dec {
+	case 1, 2:
+		usec = int64(data[4]) * 10000
+	case 3, 4:
+		usec = int64(binary.BigEndian.Uint16(data[4:])) * 100
+	case 5, 6:
+		usec = int64(DecodeVarLen64BigEndian(data[4:7]))
+	}
+
+	if sec == 0 {
+		return formatZeroTime(int(usec), int(dec)), n
+	}
+
+	return FracTime{time.Unix(sec, usec*1000), int(dec)}.String(), n
+}
+
+// DecodeDatetime decodes DATETIME value.
+// Spec: https://dev.mysql.com/doc/refman/8.0/en/datetime.html
+func DecodeDatetime(v uint64) string {
+	d := v / 1000000
+	t := v % 1000000
+	return FracTime{Time: time.Date(int(d/10000),
+		time.Month((d%10000)/100),
+		int(d%100),
+		int(t/10000),
+		int((t%10000)/100),
+		int(t%100),
+		0,
+		Timezone,
+	)}.String()
+}
+
+// DecodeDatetime2 decodes DATETIME v2 value.
+// Spec: https://dev.mysql.com/doc/refman/8.0/en/datetime.html
+// Implementation borrowed from https://github.com/siddontang/go-mysql/
+func DecodeDatetime2(data []byte, dec uint16) (string, int) {
+	const offset int64 = 0x8000000000
+	// get datetime binary length
+	n := int(5 + (dec+1)/2)
+
+	intPart := int64(DecodeVarLen64BigEndian(data[0:5])) - offset
+	var frac int64
+
+	switch dec {
+	case 1, 2:
+		frac = int64(data[5]) * 10000
+	case 3, 4:
+		frac = int64(binary.BigEndian.Uint16(data[5:7])) * 100
+	case 5, 6:
+		frac = int64(DecodeVarLen64BigEndian(data[5:8]))
+	}
+
+	if intPart == 0 {
+		return formatZeroTime(int(frac), int(dec)), n
+	}
+
+	tmp := intPart<<24 + frac
+	// handle sign???
+	if tmp < 0 {
+		tmp = -tmp
+	}
+
+	// var secPart int64 = tmp % (1 << 24)
+	ymdhms := tmp >> 24
+
+	ymd := ymdhms >> 17
+	ym := ymd >> 5
+	hms := ymdhms % (1 << 17)
+
+	day := int(ymd % (1 << 5))
+	month := int(ym % 13)
+	year := int(ym / 13)
+
+	second := int(hms % (1 << 6))
+	minute := int((hms >> 6) % (1 << 6))
+	hour := int((hms >> 12))
+
+	return FracTime{time.Date(year, time.Month(month), day, hour, minute, second, int(frac*1000), Timezone), int(dec)}.String(), n
+}
+
 var (
 	fracTimeFormat = [...]string{
 		"2006-01-02T15:04:05Z",