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-rw-r--r--dependencies/pkg/mod/github.com/go-sql-driver/mysql@v1.8.1/utils.go843
1 files changed, 843 insertions, 0 deletions
diff --git a/dependencies/pkg/mod/github.com/go-sql-driver/mysql@v1.8.1/utils.go b/dependencies/pkg/mod/github.com/go-sql-driver/mysql@v1.8.1/utils.go
new file mode 100644
index 0000000..cda24fe
--- /dev/null
+++ b/dependencies/pkg/mod/github.com/go-sql-driver/mysql@v1.8.1/utils.go
@@ -0,0 +1,843 @@
+// Go MySQL Driver - A MySQL-Driver for Go's database/sql package
+//
+// Copyright 2012 The Go-MySQL-Driver Authors. All rights reserved.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package mysql
+
+import (
+ "crypto/tls"
+ "database/sql"
+ "database/sql/driver"
+ "encoding/binary"
+ "errors"
+ "fmt"
+ "io"
+ "strconv"
+ "strings"
+ "sync"
+ "sync/atomic"
+ "time"
+)
+
+// Registry for custom tls.Configs
+var (
+ tlsConfigLock sync.RWMutex
+ tlsConfigRegistry map[string]*tls.Config
+)
+
+// RegisterTLSConfig registers a custom tls.Config to be used with sql.Open.
+// Use the key as a value in the DSN where tls=value.
+//
+// Note: The provided tls.Config is exclusively owned by the driver after
+// registering it.
+//
+// rootCertPool := x509.NewCertPool()
+// pem, err := os.ReadFile("/path/ca-cert.pem")
+// if err != nil {
+// log.Fatal(err)
+// }
+// if ok := rootCertPool.AppendCertsFromPEM(pem); !ok {
+// log.Fatal("Failed to append PEM.")
+// }
+// clientCert := make([]tls.Certificate, 0, 1)
+// certs, err := tls.LoadX509KeyPair("/path/client-cert.pem", "/path/client-key.pem")
+// if err != nil {
+// log.Fatal(err)
+// }
+// clientCert = append(clientCert, certs)
+// mysql.RegisterTLSConfig("custom", &tls.Config{
+// RootCAs: rootCertPool,
+// Certificates: clientCert,
+// })
+// db, err := sql.Open("mysql", "user@tcp(localhost:3306)/test?tls=custom")
+func RegisterTLSConfig(key string, config *tls.Config) error {
+ if _, isBool := readBool(key); isBool || strings.ToLower(key) == "skip-verify" || strings.ToLower(key) == "preferred" {
+ return fmt.Errorf("key '%s' is reserved", key)
+ }
+
+ tlsConfigLock.Lock()
+ if tlsConfigRegistry == nil {
+ tlsConfigRegistry = make(map[string]*tls.Config)
+ }
+
+ tlsConfigRegistry[key] = config
+ tlsConfigLock.Unlock()
+ return nil
+}
+
+// DeregisterTLSConfig removes the tls.Config associated with key.
+func DeregisterTLSConfig(key string) {
+ tlsConfigLock.Lock()
+ if tlsConfigRegistry != nil {
+ delete(tlsConfigRegistry, key)
+ }
+ tlsConfigLock.Unlock()
+}
+
+func getTLSConfigClone(key string) (config *tls.Config) {
+ tlsConfigLock.RLock()
+ if v, ok := tlsConfigRegistry[key]; ok {
+ config = v.Clone()
+ }
+ tlsConfigLock.RUnlock()
+ return
+}
+
+// Returns the bool value of the input.
+// The 2nd return value indicates if the input was a valid bool value
+func readBool(input string) (value bool, valid bool) {
+ switch input {
+ case "1", "true", "TRUE", "True":
+ return true, true
+ case "0", "false", "FALSE", "False":
+ return false, true
+ }
+
+ // Not a valid bool value
+ return
+}
+
+/******************************************************************************
+* Time related utils *
+******************************************************************************/
+
+func parseDateTime(b []byte, loc *time.Location) (time.Time, error) {
+ const base = "0000-00-00 00:00:00.000000"
+ switch len(b) {
+ case 10, 19, 21, 22, 23, 24, 25, 26: // up to "YYYY-MM-DD HH:MM:SS.MMMMMM"
+ if string(b) == base[:len(b)] {
+ return time.Time{}, nil
+ }
+
+ year, err := parseByteYear(b)
+ if err != nil {
+ return time.Time{}, err
+ }
+ if b[4] != '-' {
+ return time.Time{}, fmt.Errorf("bad value for field: `%c`", b[4])
+ }
+
+ m, err := parseByte2Digits(b[5], b[6])
+ if err != nil {
+ return time.Time{}, err
+ }
+ month := time.Month(m)
+
+ if b[7] != '-' {
+ return time.Time{}, fmt.Errorf("bad value for field: `%c`", b[7])
+ }
+
+ day, err := parseByte2Digits(b[8], b[9])
+ if err != nil {
+ return time.Time{}, err
+ }
+ if len(b) == 10 {
+ return time.Date(year, month, day, 0, 0, 0, 0, loc), nil
+ }
+
+ if b[10] != ' ' {
+ return time.Time{}, fmt.Errorf("bad value for field: `%c`", b[10])
+ }
+
+ hour, err := parseByte2Digits(b[11], b[12])
+ if err != nil {
+ return time.Time{}, err
+ }
+ if b[13] != ':' {
+ return time.Time{}, fmt.Errorf("bad value for field: `%c`", b[13])
+ }
+
+ min, err := parseByte2Digits(b[14], b[15])
+ if err != nil {
+ return time.Time{}, err
+ }
+ if b[16] != ':' {
+ return time.Time{}, fmt.Errorf("bad value for field: `%c`", b[16])
+ }
+
+ sec, err := parseByte2Digits(b[17], b[18])
+ if err != nil {
+ return time.Time{}, err
+ }
+ if len(b) == 19 {
+ return time.Date(year, month, day, hour, min, sec, 0, loc), nil
+ }
+
+ if b[19] != '.' {
+ return time.Time{}, fmt.Errorf("bad value for field: `%c`", b[19])
+ }
+ nsec, err := parseByteNanoSec(b[20:])
+ if err != nil {
+ return time.Time{}, err
+ }
+ return time.Date(year, month, day, hour, min, sec, nsec, loc), nil
+ default:
+ return time.Time{}, fmt.Errorf("invalid time bytes: %s", b)
+ }
+}
+
+func parseByteYear(b []byte) (int, error) {
+ year, n := 0, 1000
+ for i := 0; i < 4; i++ {
+ v, err := bToi(b[i])
+ if err != nil {
+ return 0, err
+ }
+ year += v * n
+ n /= 10
+ }
+ return year, nil
+}
+
+func parseByte2Digits(b1, b2 byte) (int, error) {
+ d1, err := bToi(b1)
+ if err != nil {
+ return 0, err
+ }
+ d2, err := bToi(b2)
+ if err != nil {
+ return 0, err
+ }
+ return d1*10 + d2, nil
+}
+
+func parseByteNanoSec(b []byte) (int, error) {
+ ns, digit := 0, 100000 // max is 6-digits
+ for i := 0; i < len(b); i++ {
+ v, err := bToi(b[i])
+ if err != nil {
+ return 0, err
+ }
+ ns += v * digit
+ digit /= 10
+ }
+ // nanoseconds has 10-digits. (needs to scale digits)
+ // 10 - 6 = 4, so we have to multiple 1000.
+ return ns * 1000, nil
+}
+
+func bToi(b byte) (int, error) {
+ if b < '0' || b > '9' {
+ return 0, errors.New("not [0-9]")
+ }
+ return int(b - '0'), nil
+}
+
+func parseBinaryDateTime(num uint64, data []byte, loc *time.Location) (driver.Value, error) {
+ switch num {
+ case 0:
+ return time.Time{}, nil
+ case 4:
+ return time.Date(
+ int(binary.LittleEndian.Uint16(data[:2])), // year
+ time.Month(data[2]), // month
+ int(data[3]), // day
+ 0, 0, 0, 0,
+ loc,
+ ), nil
+ case 7:
+ return time.Date(
+ int(binary.LittleEndian.Uint16(data[:2])), // year
+ time.Month(data[2]), // month
+ int(data[3]), // day
+ int(data[4]), // hour
+ int(data[5]), // minutes
+ int(data[6]), // seconds
+ 0,
+ loc,
+ ), nil
+ case 11:
+ return time.Date(
+ int(binary.LittleEndian.Uint16(data[:2])), // year
+ time.Month(data[2]), // month
+ int(data[3]), // day
+ int(data[4]), // hour
+ int(data[5]), // minutes
+ int(data[6]), // seconds
+ int(binary.LittleEndian.Uint32(data[7:11]))*1000, // nanoseconds
+ loc,
+ ), nil
+ }
+ return nil, fmt.Errorf("invalid DATETIME packet length %d", num)
+}
+
+func appendDateTime(buf []byte, t time.Time, timeTruncate time.Duration) ([]byte, error) {
+ if timeTruncate > 0 {
+ t = t.Truncate(timeTruncate)
+ }
+
+ year, month, day := t.Date()
+ hour, min, sec := t.Clock()
+ nsec := t.Nanosecond()
+
+ if year < 1 || year > 9999 {
+ return buf, errors.New("year is not in the range [1, 9999]: " + strconv.Itoa(year)) // use errors.New instead of fmt.Errorf to avoid year escape to heap
+ }
+ year100 := year / 100
+ year1 := year % 100
+
+ var localBuf [len("2006-01-02T15:04:05.999999999")]byte // does not escape
+ localBuf[0], localBuf[1], localBuf[2], localBuf[3] = digits10[year100], digits01[year100], digits10[year1], digits01[year1]
+ localBuf[4] = '-'
+ localBuf[5], localBuf[6] = digits10[month], digits01[month]
+ localBuf[7] = '-'
+ localBuf[8], localBuf[9] = digits10[day], digits01[day]
+
+ if hour == 0 && min == 0 && sec == 0 && nsec == 0 {
+ return append(buf, localBuf[:10]...), nil
+ }
+
+ localBuf[10] = ' '
+ localBuf[11], localBuf[12] = digits10[hour], digits01[hour]
+ localBuf[13] = ':'
+ localBuf[14], localBuf[15] = digits10[min], digits01[min]
+ localBuf[16] = ':'
+ localBuf[17], localBuf[18] = digits10[sec], digits01[sec]
+
+ if nsec == 0 {
+ return append(buf, localBuf[:19]...), nil
+ }
+ nsec100000000 := nsec / 100000000
+ nsec1000000 := (nsec / 1000000) % 100
+ nsec10000 := (nsec / 10000) % 100
+ nsec100 := (nsec / 100) % 100
+ nsec1 := nsec % 100
+ localBuf[19] = '.'
+
+ // milli second
+ localBuf[20], localBuf[21], localBuf[22] =
+ digits01[nsec100000000], digits10[nsec1000000], digits01[nsec1000000]
+ // micro second
+ localBuf[23], localBuf[24], localBuf[25] =
+ digits10[nsec10000], digits01[nsec10000], digits10[nsec100]
+ // nano second
+ localBuf[26], localBuf[27], localBuf[28] =
+ digits01[nsec100], digits10[nsec1], digits01[nsec1]
+
+ // trim trailing zeros
+ n := len(localBuf)
+ for n > 0 && localBuf[n-1] == '0' {
+ n--
+ }
+
+ return append(buf, localBuf[:n]...), nil
+}
+
+// zeroDateTime is used in formatBinaryDateTime to avoid an allocation
+// if the DATE or DATETIME has the zero value.
+// It must never be changed.
+// The current behavior depends on database/sql copying the result.
+var zeroDateTime = []byte("0000-00-00 00:00:00.000000")
+
+const digits01 = "0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789"
+const digits10 = "0000000000111111111122222222223333333333444444444455555555556666666666777777777788888888889999999999"
+
+func appendMicrosecs(dst, src []byte, decimals int) []byte {
+ if decimals <= 0 {
+ return dst
+ }
+ if len(src) == 0 {
+ return append(dst, ".000000"[:decimals+1]...)
+ }
+
+ microsecs := binary.LittleEndian.Uint32(src[:4])
+ p1 := byte(microsecs / 10000)
+ microsecs -= 10000 * uint32(p1)
+ p2 := byte(microsecs / 100)
+ microsecs -= 100 * uint32(p2)
+ p3 := byte(microsecs)
+
+ switch decimals {
+ default:
+ return append(dst, '.',
+ digits10[p1], digits01[p1],
+ digits10[p2], digits01[p2],
+ digits10[p3], digits01[p3],
+ )
+ case 1:
+ return append(dst, '.',
+ digits10[p1],
+ )
+ case 2:
+ return append(dst, '.',
+ digits10[p1], digits01[p1],
+ )
+ case 3:
+ return append(dst, '.',
+ digits10[p1], digits01[p1],
+ digits10[p2],
+ )
+ case 4:
+ return append(dst, '.',
+ digits10[p1], digits01[p1],
+ digits10[p2], digits01[p2],
+ )
+ case 5:
+ return append(dst, '.',
+ digits10[p1], digits01[p1],
+ digits10[p2], digits01[p2],
+ digits10[p3],
+ )
+ }
+}
+
+func formatBinaryDateTime(src []byte, length uint8) (driver.Value, error) {
+ // length expects the deterministic length of the zero value,
+ // negative time and 100+ hours are automatically added if needed
+ if len(src) == 0 {
+ return zeroDateTime[:length], nil
+ }
+ var dst []byte // return value
+ var p1, p2, p3 byte // current digit pair
+
+ switch length {
+ case 10, 19, 21, 22, 23, 24, 25, 26:
+ default:
+ t := "DATE"
+ if length > 10 {
+ t += "TIME"
+ }
+ return nil, fmt.Errorf("illegal %s length %d", t, length)
+ }
+ switch len(src) {
+ case 4, 7, 11:
+ default:
+ t := "DATE"
+ if length > 10 {
+ t += "TIME"
+ }
+ return nil, fmt.Errorf("illegal %s packet length %d", t, len(src))
+ }
+ dst = make([]byte, 0, length)
+ // start with the date
+ year := binary.LittleEndian.Uint16(src[:2])
+ pt := year / 100
+ p1 = byte(year - 100*uint16(pt))
+ p2, p3 = src[2], src[3]
+ dst = append(dst,
+ digits10[pt], digits01[pt],
+ digits10[p1], digits01[p1], '-',
+ digits10[p2], digits01[p2], '-',
+ digits10[p3], digits01[p3],
+ )
+ if length == 10 {
+ return dst, nil
+ }
+ if len(src) == 4 {
+ return append(dst, zeroDateTime[10:length]...), nil
+ }
+ dst = append(dst, ' ')
+ p1 = src[4] // hour
+ src = src[5:]
+
+ // p1 is 2-digit hour, src is after hour
+ p2, p3 = src[0], src[1]
+ dst = append(dst,
+ digits10[p1], digits01[p1], ':',
+ digits10[p2], digits01[p2], ':',
+ digits10[p3], digits01[p3],
+ )
+ return appendMicrosecs(dst, src[2:], int(length)-20), nil
+}
+
+func formatBinaryTime(src []byte, length uint8) (driver.Value, error) {
+ // length expects the deterministic length of the zero value,
+ // negative time and 100+ hours are automatically added if needed
+ if len(src) == 0 {
+ return zeroDateTime[11 : 11+length], nil
+ }
+ var dst []byte // return value
+
+ switch length {
+ case
+ 8, // time (can be up to 10 when negative and 100+ hours)
+ 10, 11, 12, 13, 14, 15: // time with fractional seconds
+ default:
+ return nil, fmt.Errorf("illegal TIME length %d", length)
+ }
+ switch len(src) {
+ case 8, 12:
+ default:
+ return nil, fmt.Errorf("invalid TIME packet length %d", len(src))
+ }
+ // +2 to enable negative time and 100+ hours
+ dst = make([]byte, 0, length+2)
+ if src[0] == 1 {
+ dst = append(dst, '-')
+ }
+ days := binary.LittleEndian.Uint32(src[1:5])
+ hours := int64(days)*24 + int64(src[5])
+
+ if hours >= 100 {
+ dst = strconv.AppendInt(dst, hours, 10)
+ } else {
+ dst = append(dst, digits10[hours], digits01[hours])
+ }
+
+ min, sec := src[6], src[7]
+ dst = append(dst, ':',
+ digits10[min], digits01[min], ':',
+ digits10[sec], digits01[sec],
+ )
+ return appendMicrosecs(dst, src[8:], int(length)-9), nil
+}
+
+/******************************************************************************
+* Convert from and to bytes *
+******************************************************************************/
+
+func uint64ToBytes(n uint64) []byte {
+ return []byte{
+ byte(n),
+ byte(n >> 8),
+ byte(n >> 16),
+ byte(n >> 24),
+ byte(n >> 32),
+ byte(n >> 40),
+ byte(n >> 48),
+ byte(n >> 56),
+ }
+}
+
+func uint64ToString(n uint64) []byte {
+ var a [20]byte
+ i := 20
+
+ // U+0030 = 0
+ // ...
+ // U+0039 = 9
+
+ var q uint64
+ for n >= 10 {
+ i--
+ q = n / 10
+ a[i] = uint8(n-q*10) + 0x30
+ n = q
+ }
+
+ i--
+ a[i] = uint8(n) + 0x30
+
+ return a[i:]
+}
+
+// treats string value as unsigned integer representation
+func stringToInt(b []byte) int {
+ val := 0
+ for i := range b {
+ val *= 10
+ val += int(b[i] - 0x30)
+ }
+ return val
+}
+
+// returns the string read as a bytes slice, whether the value is NULL,
+// the number of bytes read and an error, in case the string is longer than
+// the input slice
+func readLengthEncodedString(b []byte) ([]byte, bool, int, error) {
+ // Get length
+ num, isNull, n := readLengthEncodedInteger(b)
+ if num < 1 {
+ return b[n:n], isNull, n, nil
+ }
+
+ n += int(num)
+
+ // Check data length
+ if len(b) >= n {
+ return b[n-int(num) : n : n], false, n, nil
+ }
+ return nil, false, n, io.EOF
+}
+
+// returns the number of bytes skipped and an error, in case the string is
+// longer than the input slice
+func skipLengthEncodedString(b []byte) (int, error) {
+ // Get length
+ num, _, n := readLengthEncodedInteger(b)
+ if num < 1 {
+ return n, nil
+ }
+
+ n += int(num)
+
+ // Check data length
+ if len(b) >= n {
+ return n, nil
+ }
+ return n, io.EOF
+}
+
+// returns the number read, whether the value is NULL and the number of bytes read
+func readLengthEncodedInteger(b []byte) (uint64, bool, int) {
+ // See issue #349
+ if len(b) == 0 {
+ return 0, true, 1
+ }
+
+ switch b[0] {
+ // 251: NULL
+ case 0xfb:
+ return 0, true, 1
+
+ // 252: value of following 2
+ case 0xfc:
+ return uint64(b[1]) | uint64(b[2])<<8, false, 3
+
+ // 253: value of following 3
+ case 0xfd:
+ return uint64(b[1]) | uint64(b[2])<<8 | uint64(b[3])<<16, false, 4
+
+ // 254: value of following 8
+ case 0xfe:
+ return uint64(b[1]) | uint64(b[2])<<8 | uint64(b[3])<<16 |
+ uint64(b[4])<<24 | uint64(b[5])<<32 | uint64(b[6])<<40 |
+ uint64(b[7])<<48 | uint64(b[8])<<56,
+ false, 9
+ }
+
+ // 0-250: value of first byte
+ return uint64(b[0]), false, 1
+}
+
+// encodes a uint64 value and appends it to the given bytes slice
+func appendLengthEncodedInteger(b []byte, n uint64) []byte {
+ switch {
+ case n <= 250:
+ return append(b, byte(n))
+
+ case n <= 0xffff:
+ return append(b, 0xfc, byte(n), byte(n>>8))
+
+ case n <= 0xffffff:
+ return append(b, 0xfd, byte(n), byte(n>>8), byte(n>>16))
+ }
+ return append(b, 0xfe, byte(n), byte(n>>8), byte(n>>16), byte(n>>24),
+ byte(n>>32), byte(n>>40), byte(n>>48), byte(n>>56))
+}
+
+func appendLengthEncodedString(b []byte, s string) []byte {
+ b = appendLengthEncodedInteger(b, uint64(len(s)))
+ return append(b, s...)
+}
+
+// reserveBuffer checks cap(buf) and expand buffer to len(buf) + appendSize.
+// If cap(buf) is not enough, reallocate new buffer.
+func reserveBuffer(buf []byte, appendSize int) []byte {
+ newSize := len(buf) + appendSize
+ if cap(buf) < newSize {
+ // Grow buffer exponentially
+ newBuf := make([]byte, len(buf)*2+appendSize)
+ copy(newBuf, buf)
+ buf = newBuf
+ }
+ return buf[:newSize]
+}
+
+// escapeBytesBackslash escapes []byte with backslashes (\)
+// This escapes the contents of a string (provided as []byte) by adding backslashes before special
+// characters, and turning others into specific escape sequences, such as
+// turning newlines into \n and null bytes into \0.
+// https://github.com/mysql/mysql-server/blob/mysql-5.7.5/mysys/charset.c#L823-L932
+func escapeBytesBackslash(buf, v []byte) []byte {
+ pos := len(buf)
+ buf = reserveBuffer(buf, len(v)*2)
+
+ for _, c := range v {
+ switch c {
+ case '\x00':
+ buf[pos+1] = '0'
+ buf[pos] = '\\'
+ pos += 2
+ case '\n':
+ buf[pos+1] = 'n'
+ buf[pos] = '\\'
+ pos += 2
+ case '\r':
+ buf[pos+1] = 'r'
+ buf[pos] = '\\'
+ pos += 2
+ case '\x1a':
+ buf[pos+1] = 'Z'
+ buf[pos] = '\\'
+ pos += 2
+ case '\'':
+ buf[pos+1] = '\''
+ buf[pos] = '\\'
+ pos += 2
+ case '"':
+ buf[pos+1] = '"'
+ buf[pos] = '\\'
+ pos += 2
+ case '\\':
+ buf[pos+1] = '\\'
+ buf[pos] = '\\'
+ pos += 2
+ default:
+ buf[pos] = c
+ pos++
+ }
+ }
+
+ return buf[:pos]
+}
+
+// escapeStringBackslash is similar to escapeBytesBackslash but for string.
+func escapeStringBackslash(buf []byte, v string) []byte {
+ pos := len(buf)
+ buf = reserveBuffer(buf, len(v)*2)
+
+ for i := 0; i < len(v); i++ {
+ c := v[i]
+ switch c {
+ case '\x00':
+ buf[pos+1] = '0'
+ buf[pos] = '\\'
+ pos += 2
+ case '\n':
+ buf[pos+1] = 'n'
+ buf[pos] = '\\'
+ pos += 2
+ case '\r':
+ buf[pos+1] = 'r'
+ buf[pos] = '\\'
+ pos += 2
+ case '\x1a':
+ buf[pos+1] = 'Z'
+ buf[pos] = '\\'
+ pos += 2
+ case '\'':
+ buf[pos+1] = '\''
+ buf[pos] = '\\'
+ pos += 2
+ case '"':
+ buf[pos+1] = '"'
+ buf[pos] = '\\'
+ pos += 2
+ case '\\':
+ buf[pos+1] = '\\'
+ buf[pos] = '\\'
+ pos += 2
+ default:
+ buf[pos] = c
+ pos++
+ }
+ }
+
+ return buf[:pos]
+}
+
+// escapeBytesQuotes escapes apostrophes in []byte by doubling them up.
+// This escapes the contents of a string by doubling up any apostrophes that
+// it contains. This is used when the NO_BACKSLASH_ESCAPES SQL_MODE is in
+// effect on the server.
+// https://github.com/mysql/mysql-server/blob/mysql-5.7.5/mysys/charset.c#L963-L1038
+func escapeBytesQuotes(buf, v []byte) []byte {
+ pos := len(buf)
+ buf = reserveBuffer(buf, len(v)*2)
+
+ for _, c := range v {
+ if c == '\'' {
+ buf[pos+1] = '\''
+ buf[pos] = '\''
+ pos += 2
+ } else {
+ buf[pos] = c
+ pos++
+ }
+ }
+
+ return buf[:pos]
+}
+
+// escapeStringQuotes is similar to escapeBytesQuotes but for string.
+func escapeStringQuotes(buf []byte, v string) []byte {
+ pos := len(buf)
+ buf = reserveBuffer(buf, len(v)*2)
+
+ for i := 0; i < len(v); i++ {
+ c := v[i]
+ if c == '\'' {
+ buf[pos+1] = '\''
+ buf[pos] = '\''
+ pos += 2
+ } else {
+ buf[pos] = c
+ pos++
+ }
+ }
+
+ return buf[:pos]
+}
+
+/******************************************************************************
+* Sync utils *
+******************************************************************************/
+
+// noCopy may be embedded into structs which must not be copied
+// after the first use.
+//
+// See https://github.com/golang/go/issues/8005#issuecomment-190753527
+// for details.
+type noCopy struct{}
+
+// Lock is a no-op used by -copylocks checker from `go vet`.
+func (*noCopy) Lock() {}
+
+// Unlock is a no-op used by -copylocks checker from `go vet`.
+// noCopy should implement sync.Locker from Go 1.11
+// https://github.com/golang/go/commit/c2eba53e7f80df21d51285879d51ab81bcfbf6bc
+// https://github.com/golang/go/issues/26165
+func (*noCopy) Unlock() {}
+
+// atomicError is a wrapper for atomically accessed error values
+type atomicError struct {
+ _ noCopy
+ value atomic.Value
+}
+
+// Set sets the error value regardless of the previous value.
+// The value must not be nil
+func (ae *atomicError) Set(value error) {
+ ae.value.Store(value)
+}
+
+// Value returns the current error value
+func (ae *atomicError) Value() error {
+ if v := ae.value.Load(); v != nil {
+ // this will panic if the value doesn't implement the error interface
+ return v.(error)
+ }
+ return nil
+}
+
+func namedValueToValue(named []driver.NamedValue) ([]driver.Value, error) {
+ dargs := make([]driver.Value, len(named))
+ for n, param := range named {
+ if len(param.Name) > 0 {
+ // TODO: support the use of Named Parameters #561
+ return nil, errors.New("mysql: driver does not support the use of Named Parameters")
+ }
+ dargs[n] = param.Value
+ }
+ return dargs, nil
+}
+
+func mapIsolationLevel(level driver.IsolationLevel) (string, error) {
+ switch sql.IsolationLevel(level) {
+ case sql.LevelRepeatableRead:
+ return "REPEATABLE READ", nil
+ case sql.LevelReadCommitted:
+ return "READ COMMITTED", nil
+ case sql.LevelReadUncommitted:
+ return "READ UNCOMMITTED", nil
+ case sql.LevelSerializable:
+ return "SERIALIZABLE", nil
+ default:
+ return "", fmt.Errorf("mysql: unsupported isolation level: %v", level)
+ }
+}