2026-04-08 21:34:29 +02:00

401 lines
10 KiB
Go

package pq
import (
"bytes"
"encoding/binary"
"encoding/hex"
"errors"
"fmt"
"strconv"
"strings"
"time"
"github.com/lib/pq/internal/pqtime"
"github.com/lib/pq/oid"
)
func binaryEncode(x any) ([]byte, error) {
switch v := x.(type) {
case []byte:
return v, nil
default:
return encode(x, oid.T_unknown)
}
}
func encode(x any, pgtypOid oid.Oid) ([]byte, error) {
switch v := x.(type) {
case int64:
return strconv.AppendInt(nil, v, 10), nil
case float64:
return strconv.AppendFloat(nil, v, 'f', -1, 64), nil
case []byte:
if v == nil {
return nil, nil
}
if pgtypOid == oid.T_bytea {
return encodeBytea(v), nil
}
return v, nil
case string:
if pgtypOid == oid.T_bytea {
return encodeBytea([]byte(v)), nil
}
return []byte(v), nil
case bool:
return strconv.AppendBool(nil, v), nil
case time.Time:
return formatTS(v), nil
default:
return nil, fmt.Errorf("pq: encode: unknown type for %T", v)
}
}
func decode(ps *parameterStatus, s []byte, typ oid.Oid, f format) (any, error) {
switch f {
case formatBinary:
return binaryDecode(s, typ)
case formatText:
return textDecode(ps, s, typ)
default:
panic("unreachable")
}
}
func binaryDecode(s []byte, typ oid.Oid) (any, error) {
switch typ {
case oid.T_bytea:
return s, nil
case oid.T_int8:
return int64(binary.BigEndian.Uint64(s)), nil
case oid.T_int4:
return int64(int32(binary.BigEndian.Uint32(s))), nil
case oid.T_int2:
return int64(int16(binary.BigEndian.Uint16(s))), nil
case oid.T_uuid:
return decodeUUIDBinary(s)
default:
return nil, fmt.Errorf("pq: don't know how to decode binary parameter of type %d", uint32(typ))
}
}
// decodeUUIDBinary interprets the binary format of a uuid, returning it in text format.
func decodeUUIDBinary(src []byte) ([]byte, error) {
if len(src) != 16 {
return nil, fmt.Errorf("pq: unable to decode uuid; bad length: %d", len(src))
}
dst := make([]byte, 36)
dst[8], dst[13], dst[18], dst[23] = '-', '-', '-', '-'
hex.Encode(dst[0:], src[0:4])
hex.Encode(dst[9:], src[4:6])
hex.Encode(dst[14:], src[6:8])
hex.Encode(dst[19:], src[8:10])
hex.Encode(dst[24:], src[10:16])
return dst, nil
}
func textDecode(ps *parameterStatus, s []byte, typ oid.Oid) (any, error) {
switch typ {
case oid.T_char, oid.T_bpchar, oid.T_varchar, oid.T_text:
return string(s), nil
case oid.T_bytea:
b, err := parseBytea(s)
if err != nil {
err = errors.New("pq: " + err.Error())
}
return b, err
case oid.T_timestamptz:
return parseTS(ps.currentLocation, string(s))
case oid.T_timestamp, oid.T_date:
return parseTS(nil, string(s))
case oid.T_time:
return parseTime(typ, s)
case oid.T_timetz:
return parseTime(typ, s)
case oid.T_bool:
return s[0] == 't', nil
case oid.T_int8, oid.T_int4, oid.T_int2:
i, err := strconv.ParseInt(string(s), 10, 64)
if err != nil {
err = errors.New("pq: " + err.Error())
}
return i, err
case oid.T_float4, oid.T_float8:
// We always use 64 bit parsing, regardless of whether the input text is for
// a float4 or float8, because clients expect float64s for all float datatypes
// and returning a 32-bit parsed float64 produces lossy results.
f, err := strconv.ParseFloat(string(s), 64)
if err != nil {
err = errors.New("pq: " + err.Error())
}
return f, err
}
return s, nil
}
// appendEncodedText encodes item in text format as required by COPY
// and appends to buf
func appendEncodedText(buf []byte, x any) ([]byte, error) {
switch v := x.(type) {
case int64:
return strconv.AppendInt(buf, v, 10), nil
case float64:
return strconv.AppendFloat(buf, v, 'f', -1, 64), nil
case []byte:
encodedBytea := encodeBytea(v)
return appendEscapedText(buf, string(encodedBytea)), nil
case string:
return appendEscapedText(buf, v), nil
case bool:
return strconv.AppendBool(buf, v), nil
case time.Time:
return append(buf, formatTS(v)...), nil
case nil:
return append(buf, `\N`...), nil
default:
return nil, fmt.Errorf("pq: encode: unknown type for %T", v)
}
}
func appendEscapedText(buf []byte, text string) []byte {
escapeNeeded := false
startPos := 0
// check if we need to escape
for i := 0; i < len(text); i++ {
c := text[i]
if c == '\\' || c == '\n' || c == '\r' || c == '\t' {
escapeNeeded = true
startPos = i
break
}
}
if !escapeNeeded {
return append(buf, text...)
}
// copy till first char to escape, iterate the rest
result := append(buf, text[:startPos]...)
for i := startPos; i < len(text); i++ {
switch c := text[i]; c {
case '\\':
result = append(result, '\\', '\\')
case '\n':
result = append(result, '\\', 'n')
case '\r':
result = append(result, '\\', 'r')
case '\t':
result = append(result, '\\', 't')
default:
result = append(result, c)
}
}
return result
}
func parseTime(typ oid.Oid, s []byte) (time.Time, error) {
str := string(s)
f := "15:04:05"
if typ == oid.T_timetz {
f = "15:04:05-07"
// PostgreSQL just sends the hour if the minute and second is 0:
// 22:04:59+00
// 22:04:59+08
// 22:04:59+08:30
// 22:04:59+08:30:40
// 23:00:00.112321+02:12:13
// So add those to the format string.
c := strings.Count(str, ":")
if c > 3 {
f = "15:04:05-07:00:00"
} else if c > 2 {
f = "15:04:05-07:00"
}
}
// Go doesn't parse 24:00, so manually set that to midnight on Jan 2. 24:00
// is never with subseconds but may have a timezone:
// 24:00:00
// 24:00:00+08
// 24:00:00-08:01:01
var is2400Time bool
if strings.HasPrefix(str, "24:00:00") {
is2400Time = true
if len(str) > 8 {
str = "00:00:00" + str[8:]
} else {
str = "00:00:00"
}
}
t, err := time.Parse(f, str)
if err != nil {
return time.Time{}, errors.New("pq: " + err.Error())
}
if is2400Time {
t = t.Add(24 * time.Hour)
}
// TODO(v2): it uses UTC, which it shouldn't. But I'm afraid changing it now
// will break people's code.
//if typ == oid.T_time {
// // Don't use UTC but time.FixedZone("", 0)
// t = t.In(globalLocationCache.getLocation(0))
//}
return t, nil
}
var (
infinityTSEnabled = false
infinityTSNegative time.Time
infinityTSPositive time.Time
)
// EnableInfinityTs controls the handling of Postgres' "-infinity" and
// "infinity" "timestamp"s.
//
// If EnableInfinityTs is not called, "-infinity" and "infinity" will return
// []byte("-infinity") and []byte("infinity") respectively, and potentially
// cause error "sql: Scan error on column index 0: unsupported driver -> Scan
// pair: []uint8 -> *time.Time", when scanning into a time.Time value.
//
// Once EnableInfinityTs has been called, all connections created using this
// driver will decode Postgres' "-infinity" and "infinity" for "timestamp",
// "timestamp with time zone" and "date" types to the predefined minimum and
// maximum times, respectively. When encoding time.Time values, any time which
// equals or precedes the predefined minimum time will be encoded to
// "-infinity". Any values at or past the maximum time will similarly be
// encoded to "infinity".
//
// If EnableInfinityTs is called with negative >= positive, it will panic.
// Calling EnableInfinityTs after a connection has been established results in
// undefined behavior. If EnableInfinityTs is called more than once, it will
// panic.
func EnableInfinityTs(negative time.Time, positive time.Time) {
if infinityTSEnabled {
panic("pq: infinity timestamp already enabled")
}
if !negative.Before(positive) {
panic("pq: infinity timestamp: negative value must be smaller (before) than positive")
}
infinityTSEnabled = true
infinityTSNegative = negative
infinityTSPositive = positive
}
// Testing might want to toggle infinityTSEnabled
func disableInfinityTS() {
infinityTSEnabled = false
}
// This is a time function specific to the Postgres default DateStyle setting
// ("ISO, MDY"), the only one we currently support. This accounts for the
// discrepancies between the parsing available with time.Parse and the Postgres
// date formatting quirks.
func parseTS(currentLocation *time.Location, str string) (any, error) {
switch str {
case "-infinity":
if infinityTSEnabled {
return infinityTSNegative, nil
}
return []byte(str), nil
case "infinity":
if infinityTSEnabled {
return infinityTSPositive, nil
}
return []byte(str), nil
}
t, err := ParseTimestamp(currentLocation, str)
if err != nil {
err = errors.New("pq: " + err.Error())
}
return t, err
}
// ParseTimestamp parses Postgres' text format. It returns a time.Time in
// currentLocation iff that time's offset agrees with the offset sent from the
// Postgres server. Otherwise, ParseTimestamp returns a time.Time with the fixed
// offset offset provided by the Postgres server.
func ParseTimestamp(currentLocation *time.Location, str string) (time.Time, error) {
return pqtime.Parse(currentLocation, str)
}
// formatTS formats t into a format postgres understands.
func formatTS(t time.Time) []byte {
if infinityTSEnabled {
// t <= -infinity : ! (t > -infinity)
if !t.After(infinityTSNegative) {
return []byte("-infinity")
}
// t >= infinity : ! (!t < infinity)
if !t.Before(infinityTSPositive) {
return []byte("infinity")
}
}
return FormatTimestamp(t)
}
// FormatTimestamp formats t into Postgres' text format for timestamps.
func FormatTimestamp(t time.Time) []byte {
return pqtime.Format(t)
}
// Parse a bytea value received from the server. Both "hex" and the legacy
// "escape" format are supported.
func parseBytea(s []byte) (result []byte, err error) {
// Hex format.
if len(s) >= 2 && bytes.Equal(s[:2], []byte("\\x")) {
s = s[2:] // trim off leading "\\x"
result = make([]byte, hex.DecodedLen(len(s)))
_, err := hex.Decode(result, s)
if err != nil {
return nil, err
}
return result, nil
}
// Escape format.
for len(s) > 0 {
if s[0] == '\\' {
// escaped '\\'
if len(s) >= 2 && s[1] == '\\' {
result = append(result, '\\')
s = s[2:]
continue
}
// '\\' followed by an octal number
if len(s) < 4 {
return nil, fmt.Errorf("invalid bytea sequence %v", s)
}
r, err := strconv.ParseUint(string(s[1:4]), 8, 8)
if err != nil {
return nil, fmt.Errorf("could not parse bytea value: %w", err)
}
result = append(result, byte(r))
s = s[4:]
} else {
// We hit an unescaped, raw byte. Try to read in as many as
// possible in one go.
i := bytes.IndexByte(s, '\\')
if i == -1 {
result = append(result, s...)
break
}
result = append(result, s[:i]...)
s = s[i:]
}
}
return result, nil
}
func encodeBytea(v []byte) (result []byte) {
result = make([]byte, 2+hex.EncodedLen(len(v)))
result[0] = '\\'
result[1] = 'x'
hex.Encode(result[2:], v)
return result
}