forked from uptrace/bun
/
format.go
199 lines (171 loc) · 3.46 KB
/
format.go
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package pgdriver
import (
"database/sql/driver"
"encoding/hex"
"fmt"
"math"
"strconv"
"time"
"unicode/utf8"
)
func formatQueryArgs(query string, args []interface{}) (string, error) {
namedArgs := make([]driver.NamedValue, len(args))
for i, arg := range args {
namedArgs[i] = driver.NamedValue{Value: arg}
}
return formatQuery(query, namedArgs)
}
func formatQuery(query string, args []driver.NamedValue) (string, error) {
if len(args) == 0 {
return query, nil
}
dst := make([]byte, 0, 2*len(query))
p := newParser(query)
for p.Valid() {
switch c := p.Next(); c {
case '$':
if i, ok := p.Number(); ok {
if i < 1 {
return "", fmt.Errorf("pgdriver: got $%d, but the minimal arg index is 1", i)
}
if i > len(args) {
return "", fmt.Errorf("pgdriver: got %d args, wanted %d", len(args), i)
}
var err error
dst, err = appendArg(dst, args[i-1].Value)
if err != nil {
return "", err
}
} else {
dst = append(dst, '$')
}
case '\'':
if b, ok := p.QuotedString(); ok {
dst = append(dst, b...)
} else {
dst = append(dst, '\'')
}
default:
dst = append(dst, c)
}
}
return bytesToString(dst), nil
}
func appendArg(b []byte, v interface{}) ([]byte, error) {
switch v := v.(type) {
case nil:
return append(b, "NULL"...), nil
case int64:
return strconv.AppendInt(b, v, 10), nil
case float64:
switch {
case math.IsNaN(v):
return append(b, "'NaN'"...), nil
case math.IsInf(v, 1):
return append(b, "'Infinity'"...), nil
case math.IsInf(v, -1):
return append(b, "'-Infinity'"...), nil
default:
return strconv.AppendFloat(b, v, 'f', -1, 64), nil
}
case bool:
if v {
return append(b, "TRUE"...), nil
}
return append(b, "FALSE"...), nil
case []byte:
if v == nil {
return append(b, "NULL"...), nil
}
b = append(b, `'\x`...)
s := len(b)
b = append(b, make([]byte, hex.EncodedLen(len(v)))...)
hex.Encode(b[s:], v)
b = append(b, "'"...)
return b, nil
case string:
b = append(b, '\'')
for _, r := range v {
if r == '\000' {
continue
}
if r == '\'' {
b = append(b, '\'', '\'')
continue
}
if r < utf8.RuneSelf {
b = append(b, byte(r))
continue
}
l := len(b)
if cap(b)-l < utf8.UTFMax {
b = append(b, make([]byte, utf8.UTFMax)...)
}
n := utf8.EncodeRune(b[l:l+utf8.UTFMax], r)
b = b[:l+n]
}
b = append(b, '\'')
return b, nil
case time.Time:
if v.IsZero() {
return append(b, "NULL"...), nil
}
return v.UTC().AppendFormat(b, "'2006-01-02 15:04:05.999999-07:00'"), nil
default:
return nil, fmt.Errorf("pgdriver: unexpected arg: %T", v)
}
}
type parser struct {
b []byte
i int
}
func newParser(s string) *parser {
return &parser{
b: stringToBytes(s),
}
}
func (p *parser) Valid() bool {
return p.i < len(p.b)
}
func (p *parser) Next() byte {
c := p.b[p.i]
p.i++
return c
}
func (p *parser) Number() (int, bool) {
start := p.i
end := len(p.b)
for i := p.i; i < len(p.b); i++ {
c := p.b[i]
if !isNum(c) {
end = i
break
}
}
p.i = end
b := p.b[start:end]
n, err := strconv.Atoi(bytesToString(b))
if err != nil {
return 0, false
}
return n, true
}
func (p *parser) QuotedString() ([]byte, bool) {
start := p.i - 1
end := len(p.b)
var c byte
for i := p.i; i < len(p.b); i++ {
next := p.b[i]
if c == '\'' && next != '\'' {
end = i
break
}
c = next
}
p.i = end
b := p.b[start:end]
return b, true
}
func isNum(c byte) bool {
return c >= '0' && c <= '9'
}