1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
|
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
}
|