terraform/vendor/github.com/ziutek/mymysql/native/codecs.go

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package native
import (
"github.com/ziutek/mymysql/mysql"
"time"
)
// Integers
func DecodeU16(buf []byte) uint16 {
return uint16(buf[1])<<8 | uint16(buf[0])
}
func (pr *pktReader) readU16() uint16 {
buf := pr.buf[:2]
pr.readFull(buf)
return DecodeU16(buf)
}
func DecodeU24(buf []byte) uint32 {
return (uint32(buf[2])<<8|uint32(buf[1]))<<8 | uint32(buf[0])
}
func (pr *pktReader) readU24() uint32 {
buf := pr.buf[:3]
pr.readFull(buf)
return DecodeU24(buf)
}
func DecodeU32(buf []byte) uint32 {
return ((uint32(buf[3])<<8|uint32(buf[2]))<<8|
uint32(buf[1]))<<8 | uint32(buf[0])
}
func (pr *pktReader) readU32() uint32 {
buf := pr.buf[:4]
pr.readFull(buf)
return DecodeU32(buf)
}
func DecodeU64(buf []byte) (rv uint64) {
for ii, vv := range buf {
rv |= uint64(vv) << uint(ii*8)
}
return
}
func (pr *pktReader) readU64() (rv uint64) {
buf := pr.buf[:8]
pr.readFull(buf)
return DecodeU64(buf)
}
func EncodeU16(buf []byte, val uint16) {
buf[0] = byte(val)
buf[1] = byte(val >> 8)
}
func (pw *pktWriter) writeU16(val uint16) {
buf := pw.buf[:2]
EncodeU16(buf, val)
pw.write(buf)
}
func EncodeU24(buf []byte, val uint32) {
buf[0] = byte(val)
buf[1] = byte(val >> 8)
buf[2] = byte(val >> 16)
}
func (pw *pktWriter) writeU24(val uint32) {
buf := pw.buf[:3]
EncodeU24(buf, val)
pw.write(buf)
}
func EncodeU32(buf []byte, val uint32) {
buf[0] = byte(val)
buf[1] = byte(val >> 8)
buf[2] = byte(val >> 16)
buf[3] = byte(val >> 24)
}
func (pw *pktWriter) writeU32(val uint32) {
buf := pw.buf[:4]
EncodeU32(buf, val)
pw.write(buf)
}
func EncodeU64(buf []byte, val uint64) {
buf[0] = byte(val)
buf[1] = byte(val >> 8)
buf[2] = byte(val >> 16)
buf[3] = byte(val >> 24)
buf[4] = byte(val >> 32)
buf[5] = byte(val >> 40)
buf[6] = byte(val >> 48)
buf[7] = byte(val >> 56)
}
func (pw *pktWriter) writeU64(val uint64) {
buf := pw.buf[:8]
EncodeU64(buf, val)
pw.write(buf)
}
// Variable length values
func (pr *pktReader) readNullLCB() (lcb uint64, null bool) {
bb := pr.readByte()
switch bb {
case 251:
null = true
case 252:
lcb = uint64(pr.readU16())
case 253:
lcb = uint64(pr.readU24())
case 254:
lcb = pr.readU64()
default:
lcb = uint64(bb)
}
return
}
func (pr *pktReader) readLCB() uint64 {
lcb, null := pr.readNullLCB()
if null {
panic(mysql.ErrUnexpNullLCB)
}
return lcb
}
func (pw *pktWriter) writeLCB(val uint64) {
switch {
case val <= 250:
pw.writeByte(byte(val))
case val <= 0xffff:
pw.writeByte(252)
pw.writeU16(uint16(val))
case val <= 0xffffff:
pw.writeByte(253)
pw.writeU24(uint32(val))
default:
pw.writeByte(254)
pw.writeU64(val)
}
}
func lenLCB(val uint64) int {
switch {
case val <= 250:
return 1
case val <= 0xffff:
return 3
case val <= 0xffffff:
return 4
}
return 9
}
func (pr *pktReader) readNullBin() (buf []byte, null bool) {
var l uint64
l, null = pr.readNullLCB()
if null {
return
}
buf = make([]byte, l)
pr.readFull(buf)
return
}
func (pr *pktReader) readBin() []byte {
buf, null := pr.readNullBin()
if null {
panic(mysql.ErrUnexpNullLCS)
}
return buf
}
func (pr *pktReader) skipBin() {
n, _ := pr.readNullLCB()
pr.skipN(int(n))
}
func (pw *pktWriter) writeBin(buf []byte) {
pw.writeLCB(uint64(len(buf)))
pw.write(buf)
}
func lenBin(buf []byte) int {
return lenLCB(uint64(len(buf))) + len(buf)
}
func lenStr(str string) int {
return lenLCB(uint64(len(str))) + len(str)
}
func (pw *pktWriter) writeLC(v interface{}) {
switch val := v.(type) {
case []byte:
pw.writeBin(val)
case *[]byte:
pw.writeBin(*val)
case string:
pw.writeBin([]byte(val))
case *string:
pw.writeBin([]byte(*val))
default:
panic("Unknown data type for write as length coded string")
}
}
func lenLC(v interface{}) int {
switch val := v.(type) {
case []byte:
return lenBin(val)
case *[]byte:
return lenBin(*val)
case string:
return lenStr(val)
case *string:
return lenStr(*val)
}
panic("Unknown data type for write as length coded string")
}
func (pr *pktReader) readNTB() (buf []byte) {
for {
ch := pr.readByte()
if ch == 0 {
break
}
buf = append(buf, ch)
}
return
}
func (pw *pktWriter) writeNTB(buf []byte) {
pw.write(buf)
pw.writeByte(0)
}
func (pw *pktWriter) writeNT(v interface{}) {
switch val := v.(type) {
case []byte:
pw.writeNTB(val)
case string:
pw.writeNTB([]byte(val))
default:
panic("Unknown type for write as null terminated data")
}
}
// Date and time
func (pr *pktReader) readDuration() time.Duration {
dlen := pr.readByte()
switch dlen {
case 251:
// Null
panic(mysql.ErrUnexpNullTime)
case 0:
// 00:00:00
return 0
case 5, 8, 12:
// Properly time length
default:
panic(mysql.ErrWrongDateLen)
}
buf := pr.buf[:dlen]
pr.readFull(buf)
tt := int64(0)
switch dlen {
case 12:
// Nanosecond part
tt += int64(DecodeU32(buf[8:]))
fallthrough
case 8:
// HH:MM:SS part
tt += int64(int(buf[5])*3600+int(buf[6])*60+int(buf[7])) * 1e9
fallthrough
case 5:
// Day part
tt += int64(DecodeU32(buf[1:5])) * (24 * 3600 * 1e9)
}
if buf[0] != 0 {
tt = -tt
}
return time.Duration(tt)
}
func EncodeDuration(buf []byte, d time.Duration) int {
buf[0] = 0
if d < 0 {
buf[1] = 1
d = -d
}
if ns := uint32(d % 1e9); ns != 0 {
EncodeU32(buf[9:13], ns) // nanosecond
buf[0] += 4
}
d /= 1e9
if hms := int(d % (24 * 3600)); buf[0] != 0 || hms != 0 {
buf[8] = byte(hms % 60) // second
hms /= 60
buf[7] = byte(hms % 60) // minute
buf[6] = byte(hms / 60) // hour
buf[0] += 3
}
if day := uint32(d / (24 * 3600)); buf[0] != 0 || day != 0 {
EncodeU32(buf[2:6], day) // day
buf[0] += 4
}
buf[0]++ // For sign byte
return int(buf[0] + 1)
}
func (pw *pktWriter) writeDuration(d time.Duration) {
buf := pw.buf[:13]
n := EncodeDuration(buf, d)
pw.write(buf[:n])
}
func lenDuration(d time.Duration) int {
if d == 0 {
return 2
}
if d%1e9 != 0 {
return 13
}
d /= 1e9
if d%(24*3600) != 0 {
return 9
}
return 6
}
func (pr *pktReader) readTime() time.Time {
dlen := pr.readByte()
switch dlen {
case 251:
// Null
panic(mysql.ErrUnexpNullDate)
case 0:
// return 0000-00-00 converted to time.Time zero
return time.Time{}
case 4, 7, 11:
// Properly datetime length
default:
panic(mysql.ErrWrongDateLen)
}
buf := pr.buf[:dlen]
pr.readFull(buf)
var y, mon, d, h, m, s, u int
switch dlen {
case 11:
// 2006-01-02 15:04:05.001004005
u = int(DecodeU32(buf[7:]))
fallthrough
case 7:
// 2006-01-02 15:04:05
h = int(buf[4])
m = int(buf[5])
s = int(buf[6])
fallthrough
case 4:
// 2006-01-02
y = int(DecodeU16(buf[0:2]))
mon = int(buf[2])
d = int(buf[3])
}
n := u * int(time.Microsecond)
return time.Date(y, time.Month(mon), d, h, m, s, n, time.Local)
}
func encodeNonzeroTime(buf []byte, y int16, mon, d, h, m, s byte, u uint32) int {
buf[0] = 0
switch {
case u != 0:
EncodeU32(buf[8:12], u)
buf[0] += 4
fallthrough
case s != 0 || m != 0 || h != 0:
buf[7] = s
buf[6] = m
buf[5] = h
buf[0] += 3
}
buf[4] = d
buf[3] = mon
EncodeU16(buf[1:3], uint16(y))
buf[0] += 4
return int(buf[0] + 1)
}
func getTimeMicroseconds(t time.Time) int {
return (t.Nanosecond() + int(time.Microsecond/2)) / int(time.Microsecond)
}
func EncodeTime(buf []byte, t time.Time) int {
if t.IsZero() {
// MySQL zero
buf[0] = 0
return 1 // MySQL zero
}
y, mon, d := t.Date()
h, m, s := t.Clock()
u:= getTimeMicroseconds(t)
return encodeNonzeroTime(
buf,
int16(y), byte(mon), byte(d),
byte(h), byte(m), byte(s), uint32(u),
)
}
func (pw *pktWriter) writeTime(t time.Time) {
buf := pw.buf[:12]
n := EncodeTime(buf, t)
pw.write(buf[:n])
}
func lenTime(t time.Time) int {
switch {
case t.IsZero():
return 1
case getTimeMicroseconds(t) != 0:
return 12
case t.Second() != 0 || t.Minute() != 0 || t.Hour() != 0:
return 8
}
return 5
}
func (pr *pktReader) readDate() mysql.Date {
y, m, d := pr.readTime().Date()
return mysql.Date{int16(y), byte(m), byte(d)}
}
func EncodeDate(buf []byte, d mysql.Date) int {
if d.IsZero() {
// MySQL zero
buf[0] = 0
return 1
}
return encodeNonzeroTime(buf, d.Year, d.Month, d.Day, 0, 0, 0, 0)
}
func (pw *pktWriter) writeDate(d mysql.Date) {
buf := pw.buf[:5]
n := EncodeDate(buf, d)
pw.write(buf[:n])
}
func lenDate(d mysql.Date) int {
if d.IsZero() {
return 1
}
return 5
}