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package pq
import (
"bytes"
"database/sql/driver"
"encoding/binary"
"encoding/hex"
"errors"
"fmt"
"math"
"strconv"
"strings"
"sync"
"time"
"github.com/lib/pq/oid"
)
func binaryEncode(parameterStatus *parameterStatus, x interface{}) []byte {
switch v := x.(type) {
case []byte:
return v
default:
return encode(parameterStatus, x, oid.T_unknown)
}
}
func encode(parameterStatus *parameterStatus, x interface{}, pgtypOid oid.Oid) []byte {
switch v := x.(type) {
case int64:
return strconv.AppendInt(nil, v, 10)
case float64:
return strconv.AppendFloat(nil, v, 'f', -1, 64)
case []byte:
if pgtypOid == oid.T_bytea {
return encodeBytea(parameterStatus.serverVersion, v)
}
return v
case string:
if pgtypOid == oid.T_bytea {
return encodeBytea(parameterStatus.serverVersion, []byte(v))
}
return []byte(v)
case bool:
return strconv.AppendBool(nil, v)
case time.Time:
return formatTs(v)
default:
errorf("encode: unknown type for %T", v)
}
panic("not reached")
}
func decode(parameterStatus *parameterStatus, s []byte, typ oid.Oid, f format) interface{} {
switch f {
case formatBinary:
return binaryDecode(parameterStatus, s, typ)
case formatText:
return textDecode(parameterStatus, s, typ)
default:
panic("not reached")
}
}
func binaryDecode(parameterStatus *parameterStatus, s []byte, typ oid.Oid) interface{} {
switch typ {
case oid.T_bytea:
return s
case oid.T_int8:
return int64(binary.BigEndian.Uint64(s))
case oid.T_int4:
return int64(int32(binary.BigEndian.Uint32(s)))
case oid.T_int2:
return int64(int16(binary.BigEndian.Uint16(s)))
case oid.T_uuid:
b, err := decodeUUIDBinary(s)
if err != nil {
panic(err)
}
return b
default:
errorf("don't know how to decode binary parameter of type %d", uint32(typ))
}
panic("not reached")
}
func textDecode(parameterStatus *parameterStatus, s []byte, typ oid.Oid) interface{} {
switch typ {
case oid.T_char, oid.T_varchar, oid.T_text:
return string(s)
case oid.T_bytea:
b, err := parseBytea(s)
if err != nil {
errorf("%s", err)
}
return b
case oid.T_timestamptz:
return parseTs(parameterStatus.currentLocation, string(s))
case oid.T_timestamp, oid.T_date:
return parseTs(nil, string(s))
case oid.T_time:
return mustParse("15:04:05", typ, s)
case oid.T_timetz:
return mustParse("15:04:05-07", typ, s)
case oid.T_bool:
return s[0] == 't'
case oid.T_int8, oid.T_int4, oid.T_int2:
i, err := strconv.ParseInt(string(s), 10, 64)
if err != nil {
errorf("%s", err)
}
return i
case oid.T_float4, oid.T_float8:
bits := 64
if typ == oid.T_float4 {
bits = 32
}
f, err := strconv.ParseFloat(string(s), bits)
if err != nil {
errorf("%s", err)
}
return f
}
return s
}
// appendEncodedText encodes item in text format as required by COPY
// and appends to buf
func appendEncodedText(parameterStatus *parameterStatus, buf []byte, x interface{}) []byte {
switch v := x.(type) {
case int64:
return strconv.AppendInt(buf, v, 10)
case float64:
return strconv.AppendFloat(buf, v, 'f', -1, 64)
case []byte:
encodedBytea := encodeBytea(parameterStatus.serverVersion, v)
return appendEscapedText(buf, string(encodedBytea))
case string:
return appendEscapedText(buf, v)
case bool:
return strconv.AppendBool(buf, v)
case time.Time:
return append(buf, formatTs(v)...)
case nil:
return append(buf, "\\N"...)
default:
errorf("encode: unknown type for %T", v)
}
panic("not reached")
}
func appendEscapedText(buf []byte, text string) []byte {
escapeNeeded := false
startPos := 0
var c byte
// 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++ {
c = text[i]
switch 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 mustParse(f string, typ oid.Oid, s []byte) time.Time {
str := string(s)
// check for a 30-minute-offset timezone
if (typ == oid.T_timestamptz || typ == oid.T_timetz) &&
str[len(str)-3] == ':' {
f += ":00"
}
t, err := time.Parse(f, str)
if err != nil {
errorf("decode: %s", err)
}
return t
}
var errInvalidTimestamp = errors.New("invalid timestamp")
type timestampParser struct {
err error
}
func (p *timestampParser) expect(str string, char byte, pos int) {
if p.err != nil {
return
}
if pos+1 > len(str) {
p.err = errInvalidTimestamp
return
}
if c := str[pos]; c != char && p.err == nil {
p.err = fmt.Errorf("expected '%v' at position %v; got '%v'", char, pos, c)
}
}
func (p *timestampParser) mustAtoi(str string, begin int, end int) int {
if p.err != nil {
return 0
}
if begin < 0 || end < 0 || begin > end || end > len(str) {
p.err = errInvalidTimestamp
return 0
}
result, err := strconv.Atoi(str[begin:end])
if err != nil {
if p.err == nil {
p.err = fmt.Errorf("expected number; got '%v'", str)
}
return 0
}
return result
}
// The location cache caches the time zones typically used by the client.
type locationCache struct {
cache map[int]*time.Location
lock sync.Mutex
}
// All connections share the same list of timezones. Benchmarking shows that
// about 5% speed could be gained by putting the cache in the connection and
// losing the mutex, at the cost of a small amount of memory and a somewhat
// significant increase in code complexity.
var globalLocationCache = newLocationCache()
func newLocationCache() *locationCache {
return &locationCache{cache: make(map[int]*time.Location)}
}
// Returns the cached timezone for the specified offset, creating and caching
// it if necessary.
func (c *locationCache) getLocation(offset int) *time.Location {
c.lock.Lock()
defer c.lock.Unlock()
location, ok := c.cache[offset]
if !ok {
location = time.FixedZone("", offset)
c.cache[offset] = location
}
return location
}
var infinityTsEnabled = false
var infinityTsNegative time.Time
var infinityTsPositive time.Time
const (
infinityTsEnabledAlready = "pq: infinity timestamp enabled already"
infinityTsNegativeMustBeSmaller = "pq: infinity timestamp: negative value must be smaller (before) than positive"
)
// 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(infinityTsEnabledAlready)
}
if !negative.Before(positive) {
panic(infinityTsNegativeMustBeSmaller)
}
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) interface{} {
switch str {
case "-infinity":
if infinityTsEnabled {
return infinityTsNegative
}
return []byte(str)
case "infinity":
if infinityTsEnabled {
return infinityTsPositive
}
return []byte(str)
}
t, err := ParseTimestamp(currentLocation, str)
if err != nil {
panic(err)
}
return t
}
// 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) {
p := timestampParser{}
monSep := strings.IndexRune(str, '-')
// this is Gregorian year, not ISO Year
// In Gregorian system, the year 1 BC is followed by AD 1
year := p.mustAtoi(str, 0, monSep)
daySep := monSep + 3
month := p.mustAtoi(str, monSep+1, daySep)
p.expect(str, '-', daySep)
timeSep := daySep + 3
day := p.mustAtoi(str, daySep+1, timeSep)
var hour, minute, second int
if len(str) > monSep+len("01-01")+1 {
p.expect(str, ' ', timeSep)
minSep := timeSep + 3
p.expect(str, ':', minSep)
hour = p.mustAtoi(str, timeSep+1, minSep)
secSep := minSep + 3
p.expect(str, ':', secSep)
minute = p.mustAtoi(str, minSep+1, secSep)
secEnd := secSep + 3
second = p.mustAtoi(str, secSep+1, secEnd)
}
remainderIdx := monSep + len("01-01 00:00:00") + 1
// Three optional (but ordered) sections follow: the
// fractional seconds, the time zone offset, and the BC
// designation. We set them up here and adjust the other
// offsets if the preceding sections exist.
nanoSec := 0
tzOff := 0
if remainderIdx < len(str) && str[remainderIdx] == '.' {
fracStart := remainderIdx + 1
fracOff := strings.IndexAny(str[fracStart:], "-+ ")
if fracOff < 0 {
fracOff = len(str) - fracStart
}
fracSec := p.mustAtoi(str, fracStart, fracStart+fracOff)
nanoSec = fracSec * (1000000000 / int(math.Pow(10, float64(fracOff))))
remainderIdx += fracOff + 1
}
if tzStart := remainderIdx; tzStart < len(str) && (str[tzStart] == '-' || str[tzStart] == '+') {
// time zone separator is always '-' or '+' (UTC is +00)
var tzSign int
switch c := str[tzStart]; c {
case '-':
tzSign = -1
case '+':
tzSign = +1
default:
return time.Time{}, fmt.Errorf("expected '-' or '+' at position %v; got %v", tzStart, c)
}
tzHours := p.mustAtoi(str, tzStart+1, tzStart+3)
remainderIdx += 3
var tzMin, tzSec int
if remainderIdx < len(str) && str[remainderIdx] == ':' {
tzMin = p.mustAtoi(str, remainderIdx+1, remainderIdx+3)
remainderIdx += 3
}
if remainderIdx < len(str) && str[remainderIdx] == ':' {
tzSec = p.mustAtoi(str, remainderIdx+1, remainderIdx+3)
remainderIdx += 3
}
tzOff = tzSign * ((tzHours * 60 * 60) + (tzMin * 60) + tzSec)
}
var isoYear int
if remainderIdx+3 <= len(str) && str[remainderIdx:remainderIdx+3] == " BC" {
isoYear = 1 - year
remainderIdx += 3
} else {
isoYear = year
}
if remainderIdx < len(str) {
return time.Time{}, fmt.Errorf("expected end of input, got %v", str[remainderIdx:])
}
t := time.Date(isoYear, time.Month(month), day,
hour, minute, second, nanoSec,
globalLocationCache.getLocation(tzOff))
if currentLocation != nil {
// Set the location of the returned Time based on the session's
// TimeZone value, but only if the local time zone database agrees with
// the remote database on the offset.
lt := t.In(currentLocation)
_, newOff := lt.Zone()
if newOff == tzOff {
t = lt
}
}
return t, p.err
}
// 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 {
// Need to send dates before 0001 A.D. with " BC" suffix, instead of the
// minus sign preferred by Go.
// Beware, "0000" in ISO is "1 BC", "-0001" is "2 BC" and so on
bc := false
if t.Year() <= 0 {
// flip year sign, and add 1, e.g: "0" will be "1", and "-10" will be "11"
t = t.AddDate((-t.Year())*2+1, 0, 0)
bc = true
}
b := []byte(t.Format("2006-01-02 15:04:05.999999999Z07:00"))
_, offset := t.Zone()
offset = offset % 60
if offset != 0 {
// RFC3339Nano already printed the minus sign
if offset < 0 {
offset = -offset
}
b = append(b, ':')
if offset < 10 {
b = append(b, '0')
}
b = strconv.AppendInt(b, int64(offset), 10)
}
if bc {
b = append(b, " BC"...)
}
return b
}
// 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) {
if len(s) >= 2 && bytes.Equal(s[:2], []byte("\\x")) {
// bytea_output = hex
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
}
} else {
// bytea_output = escape
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.ParseInt(string(s[1:4]), 8, 9)
if err != nil {
return nil, fmt.Errorf("could not parse bytea value: %s", err.Error())
}
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(serverVersion int, v []byte) (result []byte) {
if serverVersion >= 90000 {
// Use the hex format if we know that the server supports it
result = make([]byte, 2+hex.EncodedLen(len(v)))
result[0] = '\\'
result[1] = 'x'
hex.Encode(result[2:], v)
} else {
// .. or resort to "escape"
for _, b := range v {
if b == '\\' {
result = append(result, '\\', '\\')
} else if b < 0x20 || b > 0x7e {
result = append(result, []byte(fmt.Sprintf("\\%03o", b))...)
} else {
result = append(result, b)
}
}
}
return result
}
// NullTime represents a time.Time that may be null. NullTime implements the
// sql.Scanner interface so it can be used as a scan destination, similar to
// sql.NullString.
type NullTime struct {
Time time.Time
Valid bool // Valid is true if Time is not NULL
}
// Scan implements the Scanner interface.
func (nt *NullTime) Scan(value interface{}) error {
nt.Time, nt.Valid = value.(time.Time)
return nil
}
// Value implements the driver Valuer interface.
func (nt NullTime) Value() (driver.Value, error) {
if !nt.Valid {
return nil, nil
}
return nt.Time, nil
}