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// Copyright 2014 The Cockroach Authors.
//
// Use of this software is governed by the CockroachDB Software License
// included in the /LICENSE file.
// Package encoding exposes some utilities for encoding data as bytes.
package encoding
import (
"bytes"
"encoding/binary"
"encoding/hex"
"fmt"
"math"
"strconv"
"strings"
"time"
"unicode"
"unicode/utf8"
"unsafe"
"github.com/cockroachdb/apd/v3"
"github.com/cockroachdb/cockroach/pkg/geo/geopb"
"github.com/cockroachdb/cockroach/pkg/util/bitarray"
"github.com/cockroachdb/cockroach/pkg/util/duration"
"github.com/cockroachdb/cockroach/pkg/util/encoding/encodingtype"
"github.com/cockroachdb/cockroach/pkg/util/ipaddr"
"github.com/cockroachdb/cockroach/pkg/util/ltree"
"github.com/cockroachdb/cockroach/pkg/util/protoutil"
"github.com/cockroachdb/cockroach/pkg/util/timeofday"
"github.com/cockroachdb/cockroach/pkg/util/timetz"
"github.com/cockroachdb/cockroach/pkg/util/timeutil"
"github.com/cockroachdb/cockroach/pkg/util/uuid"
"github.com/cockroachdb/errors"
"github.com/cockroachdb/redact"
)
const (
encodedNull = 0x00
// A marker greater than NULL but lower than any other value.
// This value is not actually ever present in a stored key, but
// it's used in keys used as span boundaries for index scans.
encodedNotNull = 0x01
floatNaN = encodedNotNull + 1
floatNeg = floatNaN + 1
floatZero = floatNeg + 1
floatPos = floatZero + 1
floatNaNDesc = floatPos + 1 // NaN encoded descendingly
// The gap between floatNaNDesc and bytesMarker was left for
// compatibility reasons.
bytesMarker byte = 0x12
bytesDescMarker = bytesMarker + 1
timeMarker = bytesDescMarker + 1
durationBigNegMarker = timeMarker + 1 // Only used for durations < MinInt64 nanos.
durationMarker = durationBigNegMarker + 1
durationBigPosMarker = durationMarker + 1 // Only used for durations > MaxInt64 nanos.
decimalNaN = durationBigPosMarker + 1 // 24
decimalNegativeInfinity = decimalNaN + 1
decimalNegLarge = decimalNegativeInfinity + 1
decimalNegMedium = decimalNegLarge + 11
decimalNegSmall = decimalNegMedium + 1
decimalZero = decimalNegSmall + 1
decimalPosSmall = decimalZero + 1
decimalPosMedium = decimalPosSmall + 1
decimalPosLarge = decimalPosMedium + 11
decimalInfinity = decimalPosLarge + 1
decimalNaNDesc = decimalInfinity + 1 // NaN encoded descendingly
decimalTerminator = 0x00
jsonInvertedIndex = decimalNaNDesc + 1
jsonEmptyArray = jsonInvertedIndex + 1
jsonEmptyObject = jsonEmptyArray + 1
bitArrayMarker = jsonEmptyObject + 1
bitArrayDescMarker = bitArrayMarker + 1
bitArrayDataTerminator = 0x00
bitArrayDataDescTerminator = 0xff
timeTZMarker = bitArrayDescMarker + 1
geoMarker = timeTZMarker + 1
geoDescMarker = geoMarker + 1
// Markers and terminators for key encoding Datum arrays in sorted order.
// For the arrayKeyMarker and other types like bytes and bit arrays, it
// might be unclear why we have a separate marker for the ascending and
// descending cases. This is necessary because the terminators for these
// encodings are different depending on the direction the data is encoded
// in. In order to safely decode a set of bytes without knowing the direction
// of the encoding, we must store this information in the marker. Otherwise,
// we would not know what terminator to look for when decoding this format.
arrayKeyMarker = geoDescMarker + 1
arrayKeyDescendingMarker = arrayKeyMarker + 1
box2DMarker = arrayKeyDescendingMarker + 1
geoInvertedIndexMarker = box2DMarker + 1
emptyArray = geoInvertedIndexMarker + 1
voidMarker = emptyArray + 1
// Defining different key markers, for the ascending designation,
// for handling different JSON values.
// Postgres currently has a special case (maybe a bug) where the empty JSON
// Array sorts before all other JSON values. See the bug report:
// https://www.postgresql.org/message-id/17873-826fdc8bbcace4f1%40postgresql.org
jsonEmptyArrayKeyMarker = voidMarker + 1
jsonNullKeyMarker = jsonEmptyArrayKeyMarker + 1
jsonStringKeyMarker = jsonNullKeyMarker + 1
jsonNumberKeyMarker = jsonStringKeyMarker + 1
jsonFalseKeyMarker = jsonNumberKeyMarker + 1
jsonTrueKeyMarker = jsonFalseKeyMarker + 1
jsonArrayKeyMarker = jsonTrueKeyMarker + 1
jsonObjectKeyMarker = jsonArrayKeyMarker + 1
arrayKeyTerminator byte = 0x00
arrayKeyDescendingTerminator byte = 0xFF
// We use different null encodings for nulls within key arrays. Doing this
// allows for the terminator to be less/greater than the null value within
// arrays. These byte values overlap with encodedNotNull and
// encodedNotNullDesc, but they can only exist within an encoded array key.
// Because of the context, they cannot be ambiguous with these other bytes.
ascendingNullWithinArrayKey byte = 0x01
descendingNullWithinArrayKey byte = 0xFE
// Defining different key markers, for the descending designation,
// for handling different JSON values.
jsonEmptyArrayKeyDescendingMarker = jsonObjectKeyMarker + 8
jsonNullKeyDescendingMarker = jsonEmptyArrayKeyDescendingMarker - 1
jsonStringKeyDescendingMarker = jsonNullKeyDescendingMarker - 1
jsonNumberKeyDescendingMarker = jsonStringKeyDescendingMarker - 1
jsonFalseKeyDescendingMarker = jsonNumberKeyDescendingMarker - 1
jsonTrueKeyDescendingMarker = jsonFalseKeyDescendingMarker - 1
jsonArrayKeyDescendingMarker = jsonTrueKeyDescendingMarker - 1
jsonObjectKeyDescendingMarker = jsonArrayKeyDescendingMarker - 1
// LTREE key encoding markers
ltreeKeyMarker = jsonEmptyArrayKeyDescendingMarker + 1
ltreeKeyDescendingMarker = ltreeKeyMarker + 1
// Terminators for JSON Key encoding.
jsonKeyTerminator byte = 0x00
jsonKeyDescendingTerminator byte = 0xFF
// Terminators for LTREE Key encoding.
ltreeKeyTerminator byte = 0x00
ltreeKeyDescendingTerminator byte = 0xFF
ltreeLabelKeyTerminator byte = 0x01
ltreeLabelKeyDescendingTerminator byte = 0xFE
// IntMin is chosen such that the range of int tags does not overlap the
// ascii character set that is frequently used in testing.
IntMin = 0x80 // 128
intMaxWidth = 8
intZero = IntMin + intMaxWidth // 136
intSmall = IntMax - intZero - intMaxWidth // 109
// IntMax is the maximum int tag value.
IntMax = 0xfd // 253
// Nulls come last when encoded descendingly.
// This value is not actually ever present in a stored key, but
// it's used in keys used as span boundaries for index scans.
encodedNotNullDesc = 0xfe
encodedNullDesc = 0xff
// offsetSecsToMicros is a constant that allows conversion from seconds
// to microseconds for offsetSecs type calculations (e.g. for TimeTZ).
offsetSecsToMicros = 1000000
)
const (
// EncodedDurationMaxLen is the largest number of bytes used when encoding a
// Duration.
EncodedDurationMaxLen = 1 + 3*binary.MaxVarintLen64 // 3 varints are encoded.
// EncodedTimeTZMaxLen is the largest number of bytes used when encoding a
// TimeTZ.
EncodedTimeTZMaxLen = 1 + binary.MaxVarintLen64 + binary.MaxVarintLen32
)
// Direction for ordering results.
type Direction int
// Direction values.
const (
_ Direction = iota
Ascending
Descending
)
const escapeLength = 2
// EncodeUint16Ascending encodes the uint16 value using a big-endian 2 byte
// representation. The bytes are appended to the supplied buffer and
// the final buffer is returned.
func EncodeUint16Ascending(b []byte, v uint16) []byte {
return append(b, byte(v>>8), byte(v))
}
// PutUint16Ascending encodes the uint16 value using a big-endian 2 byte
// representation at the specified index, lengthening the input slice if
// necessary.
func PutUint16Ascending(b []byte, v uint16, idx int) []byte {
for len(b) < idx+2 {
b = append(b, 0)
}
b[idx] = byte(v >> 8)
b[idx+1] = byte(v)
return b
}
// EncodeUint32Ascending encodes the uint32 value using a big-endian 4 byte
// representation. The bytes are appended to the supplied buffer and
// the final buffer is returned.
func EncodeUint32Ascending(b []byte, v uint32) []byte {
return append(b, byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
}
// PutUint32Ascending encodes the uint32 value using a big-endian 4 byte
// representation at the specified index, lengthening the input slice if
// necessary.
func PutUint32Ascending(b []byte, v uint32, idx int) []byte {
for len(b) < idx+4 {
b = append(b, 0)
}
b[idx] = byte(v >> 24)
b[idx+1] = byte(v >> 16)
b[idx+2] = byte(v >> 8)
b[idx+3] = byte(v)
return b
}
// EncodeUint32Descending encodes the uint32 value so that it sorts in
// reverse order, from largest to smallest.
func EncodeUint32Descending(b []byte, v uint32) []byte {
return EncodeUint32Ascending(b, ^v)
}
// DecodeUint16Ascending decodes a uint16 from the input buffer, treating
// the input as a big-endian 2 byte uint16 representation. The remainder
// of the input buffer and the decoded uint16 are returned.
func DecodeUint16Ascending(b []byte) ([]byte, uint16, error) {
if len(b) < 2 {
return nil, 0, errors.Errorf("insufficient bytes to decode uint16 int value")
}
v := binary.BigEndian.Uint16(b)
return b[2:], v, nil
}
// DecodeUint32Ascending decodes a uint32 from the input buffer, treating
// the input as a big-endian 4 byte uint32 representation. The remainder
// of the input buffer and the decoded uint32 are returned.
func DecodeUint32Ascending(b []byte) ([]byte, uint32, error) {
if len(b) < 4 {
return nil, 0, errors.Errorf("insufficient bytes to decode uint32 int value")
}
v := binary.BigEndian.Uint32(b)
return b[4:], v, nil
}
// DecodeUint32Descending decodes a uint32 value which was encoded
// using EncodeUint32Descending.
func DecodeUint32Descending(b []byte) ([]byte, uint32, error) {
leftover, v, err := DecodeUint32Ascending(b)
return leftover, ^v, err
}
const uint64AscendingEncodedLength = 8
// EncodeUint64Ascending encodes the uint64 value using a big-endian 8 byte
// representation. The bytes are appended to the supplied buffer and
// the final buffer is returned.
func EncodeUint64Ascending(b []byte, v uint64) []byte {
return append(b,
byte(v>>56), byte(v>>48), byte(v>>40), byte(v>>32),
byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
}
// EncodeUint64Descending encodes the uint64 value so that it sorts in
// reverse order, from largest to smallest.
func EncodeUint64Descending(b []byte, v uint64) []byte {
return EncodeUint64Ascending(b, ^v)
}
// DecodeUint64Ascending decodes a uint64 from the input buffer, treating
// the input as a big-endian 8 byte uint64 representation. The remainder
// of the input buffer and the decoded uint64 are returned.
func DecodeUint64Ascending(b []byte) ([]byte, uint64, error) {
if len(b) < 8 {
return nil, 0, errors.Errorf("insufficient bytes to decode uint64 int value")
}
v := binary.BigEndian.Uint64(b)
return b[8:], v, nil
}
// DecodeUint64Descending decodes a uint64 value which was encoded
// using EncodeUint64Descending.
func DecodeUint64Descending(b []byte) ([]byte, uint64, error) {
leftover, v, err := DecodeUint64Ascending(b)
return leftover, ^v, err
}
// MaxVarintLen is the maximum length of a value encoded using any of:
// - EncodeVarintAscending
// - EncodeVarintDescending
// - EncodeUvarintAscending
// - EncodeUvarintDescending
const MaxVarintLen = 9
// EncodeVarintAscending encodes the int64 value using a variable length
// (length-prefixed) representation. The length is encoded as a single
// byte. If the value to be encoded is negative the length is encoded
// as 8-numBytes. If the value is positive it is encoded as
// 8+numBytes. The encoded bytes are appended to the supplied buffer
// and the final buffer is returned.
func EncodeVarintAscending(b []byte, v int64) []byte {
if v < 0 {
switch {
case v >= -0xff:
return append(b, IntMin+7, byte(v))
case v >= -0xffff:
return append(b, IntMin+6, byte(v>>8), byte(v))
case v >= -0xffffff:
return append(b, IntMin+5, byte(v>>16), byte(v>>8), byte(v))
case v >= -0xffffffff:
return append(b, IntMin+4, byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
case v >= -0xffffffffff:
return append(b, IntMin+3, byte(v>>32), byte(v>>24), byte(v>>16), byte(v>>8),
byte(v))
case v >= -0xffffffffffff:
return append(b, IntMin+2, byte(v>>40), byte(v>>32), byte(v>>24), byte(v>>16),
byte(v>>8), byte(v))
case v >= -0xffffffffffffff:
return append(b, IntMin+1, byte(v>>48), byte(v>>40), byte(v>>32), byte(v>>24),
byte(v>>16), byte(v>>8), byte(v))
default:
return append(b, IntMin, byte(v>>56), byte(v>>48), byte(v>>40), byte(v>>32),
byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
}
}
return EncodeUvarintAscending(b, uint64(v))
}
// EncodeVarintDescending encodes the int64 value so that it sorts in reverse
// order, from largest to smallest.
func EncodeVarintDescending(b []byte, v int64) []byte {
return EncodeVarintAscending(b, ^v)
}
// getVarintLen returns the encoded length of an encoded varint. Assumes the
// slice has at least one byte.
func getVarintLen(b []byte) (int, error) {
length := int(b[0]) - intZero
if length >= 0 {
if length <= intSmall {
// just the tag
return 1, nil
}
// tag and length-intSmall bytes
length = 1 + length - intSmall
} else {
// tag and -length bytes
length = 1 - length
}
if length > len(b) {
return 0, errors.Errorf("varint length %d exceeds slice length %d", length, len(b))
}
return length, nil
}
// DecodeVarintAscending decodes a value encoded by EncodeVarintAscending.
func DecodeVarintAscending(b []byte) ([]byte, int64, error) {
if len(b) == 0 {
return nil, 0, errors.Errorf("insufficient bytes to decode varint value")
}
length := int(b[0]) - intZero
if length < 0 {
length = -length
remB := b[1:]
if len(remB) < length {
return nil, 0, errors.Errorf("insufficient bytes to decode varint value: %q", remB)
}
var v int64
// Use the ones-complement of each encoded byte in order to build
// up a positive number, then take the ones-complement again to
// arrive at our negative value.
for _, t := range remB[:length] {
v = (v << 8) | int64(^t)
}
return remB[length:], ^v, nil
}
remB, v, err := DecodeUvarintAscending(b)
if err != nil {
return remB, 0, err
}
if v > math.MaxInt64 {
return nil, 0, errors.Errorf("varint %d overflows int64", v)
}
return remB, int64(v), nil
}
// DecodeVarintDescending decodes a int64 value which was encoded
// using EncodeVarintDescending.
func DecodeVarintDescending(b []byte) ([]byte, int64, error) {
leftover, v, err := DecodeVarintAscending(b)
return leftover, ^v, err
}
// EncodeUvarintAscending encodes the uint64 value using a variable length
// (length-prefixed) representation. The length is encoded as a single
// byte indicating the number of encoded bytes (-8) to follow. See
// EncodeVarintAscending for rationale. The encoded bytes are appended to the
// supplied buffer and the final buffer is returned.
func EncodeUvarintAscending(b []byte, v uint64) []byte {
switch {
case v <= intSmall:
return append(b, intZero+byte(v))
case v <= 0xff:
return append(b, IntMax-7, byte(v))
case v <= 0xffff:
return append(b, IntMax-6, byte(v>>8), byte(v))
case v <= 0xffffff:
return append(b, IntMax-5, byte(v>>16), byte(v>>8), byte(v))
case v <= 0xffffffff:
return append(b, IntMax-4, byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
case v <= 0xffffffffff:
return append(b, IntMax-3, byte(v>>32), byte(v>>24), byte(v>>16), byte(v>>8),
byte(v))
case v <= 0xffffffffffff:
return append(b, IntMax-2, byte(v>>40), byte(v>>32), byte(v>>24), byte(v>>16),
byte(v>>8), byte(v))
case v <= 0xffffffffffffff:
return append(b, IntMax-1, byte(v>>48), byte(v>>40), byte(v>>32), byte(v>>24),
byte(v>>16), byte(v>>8), byte(v))
default:
return append(b, IntMax, byte(v>>56), byte(v>>48), byte(v>>40), byte(v>>32),
byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
}
}
// EncodedLengthUvarintAscending returns the length of the variable length
// representation, i.e. the number of bytes appended by EncodeUvarintAscending.
func EncodedLengthUvarintAscending(v uint64) int {
switch {
case v <= intSmall:
return 1
case v <= 0xff:
return 2
case v <= 0xffff:
return 3
case v <= 0xffffff:
return 4
case v <= 0xffffffff:
return 5
case v <= 0xffffffffff:
return 6
case v <= 0xffffffffffff:
return 7
case v <= 0xffffffffffffff:
return 8
default:
return 9
}
}
// EncodeUvarintDescending encodes the uint64 value so that it sorts in
// reverse order, from largest to smallest.
func EncodeUvarintDescending(b []byte, v uint64) []byte {
switch {
case v == 0:
return append(b, IntMin+8)
case v <= 0xff:
v = ^v
return append(b, IntMin+7, byte(v))
case v <= 0xffff:
v = ^v
return append(b, IntMin+6, byte(v>>8), byte(v))
case v <= 0xffffff:
v = ^v
return append(b, IntMin+5, byte(v>>16), byte(v>>8), byte(v))
case v <= 0xffffffff:
v = ^v
return append(b, IntMin+4, byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
case v <= 0xffffffffff:
v = ^v
return append(b, IntMin+3, byte(v>>32), byte(v>>24), byte(v>>16), byte(v>>8),
byte(v))
case v <= 0xffffffffffff:
v = ^v
return append(b, IntMin+2, byte(v>>40), byte(v>>32), byte(v>>24), byte(v>>16),
byte(v>>8), byte(v))
case v <= 0xffffffffffffff:
v = ^v
return append(b, IntMin+1, byte(v>>48), byte(v>>40), byte(v>>32), byte(v>>24),
byte(v>>16), byte(v>>8), byte(v))
default:
v = ^v
return append(b, IntMin, byte(v>>56), byte(v>>48), byte(v>>40), byte(v>>32),
byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
}
}
// highestByteIndex returns the index (0 to 7) of the highest nonzero byte in v.
func highestByteIndex(v uint64) int {
l := 0
if v > 0xffffffff {
v >>= 32
l += 4
}
if v > 0xffff {
v >>= 16
l += 2
}
if v > 0xff {
l++
}
return l
}
// EncLenUvarintAscending returns the encoding length for EncodeUvarintAscending
// without actually encoding.
func EncLenUvarintAscending(v uint64) int {
if v <= intSmall {
return 1
}
return 2 + highestByteIndex(v)
}
// EncLenUvarintDescending returns the encoding length for
// EncodeUvarintDescending without actually encoding.
func EncLenUvarintDescending(v uint64) int {
if v == 0 {
return 1
}
return 2 + highestByteIndex(v)
}
// GetUvarintLen is similar to DecodeUvarintAscending except that it returns the
// length of the prefix that encodes a uint64 value in bytes without actually
// decoding the value. An error is returned if b does not contain a valid
// encoding of an unsigned int datum.
func GetUvarintLen(b []byte) (int, error) {
if len(b) == 0 {
return 0, errors.Errorf("insufficient bytes to decode uvarint value")
}
length := int(b[0]) - intZero
if length <= intSmall {
return 1, nil
}
length -= intSmall
if length < 0 || length > 8 {
return 0, errors.Errorf("invalid uvarint length of %d", length)
} else if len(b) <= length {
// Note: we use <= for comparison here as opposed to the < in
// DecodeUvarintAscending because in the latter the first byte for the
// uvarint is removed as part of decoding. We need to account for the first
// byte when assessing the size.
return 0, errors.Errorf("insufficient bytes to decode uvarint value: %q", b)
}
return 1 + length, nil
}
// DecodeUvarintAscending decodes a uint64 encoded uint64 from the input
// buffer. The remainder of the input buffer and the decoded uint64
// are returned.
func DecodeUvarintAscending(b []byte) ([]byte, uint64, error) {
if len(b) == 0 {
return nil, 0, errors.Errorf("insufficient bytes to decode uvarint value")
}
length := int(b[0]) - intZero
b = b[1:] // skip length byte
if length <= intSmall {
return b, uint64(length), nil
}
length -= intSmall
if length < 0 || length > 8 {
return nil, 0, errors.Errorf("invalid uvarint length of %d", length)
} else if len(b) < length {
return nil, 0, errors.Errorf("insufficient bytes to decode uvarint value: %q", b)
}
var v uint64
// It is faster to range over the elements in a slice than to index
// into the slice on each loop iteration.
for _, t := range b[:length] {
v = (v << 8) | uint64(t)
}
return b[length:], v, nil
}
// DecodeUvarintDescending decodes a uint64 value which was encoded
// using EncodeUvarintDescending.
func DecodeUvarintDescending(b []byte) ([]byte, uint64, error) {
if len(b) == 0 {
return nil, 0, errors.Errorf("insufficient bytes to decode uvarint value")
}
length := intZero - int(b[0])
b = b[1:] // skip length byte
if length < 0 || length > 8 {
return nil, 0, errors.Errorf("invalid uvarint length of %d", length)
} else if len(b) < length {
return nil, 0, errors.Errorf("insufficient bytes to decode uvarint value: %q", b)
}
var x uint64
for _, t := range b[:length] {
x = (x << 8) | uint64(^t)
}
return b[length:], x, nil
}
const (
// <term> -> \x00\x01
// \x00 -> \x00\xff
escape byte = 0x00
escapedTerm byte = 0x01
escapedJSONObjectKeyTerm byte = 0x02
escapedJSONArray byte = 0x03
escaped00 byte = 0xff
escapedFF byte = 0x00
)
type escapes struct {
escape byte
escapedTerm byte
escaped00 byte
escapedFF byte
marker byte
}
var (
ascendingBytesEscapes = escapes{escape, escapedTerm, escaped00, escapedFF, bytesMarker}
descendingBytesEscapes = escapes{^escape, ^escapedTerm, ^escaped00, ^escapedFF, bytesDescMarker}
ascendingGeoEscapes = escapes{escape, escapedTerm, escaped00, escapedFF, geoMarker}
descendingGeoEscapes = escapes{^escape, ^escapedTerm, ^escaped00, ^escapedFF, geoDescMarker}
)
// EncodeBytesAscending encodes the []byte value using an escape-based
// encoding. The encoded value is terminated with the sequence
// "\x00\x01" which is guaranteed to not occur elsewhere in the
// encoded value. The encoded bytes are append to the supplied buffer
// and the resulting buffer is returned.
func EncodeBytesAscending(b []byte, data []byte) []byte {
return encodeBytesAscendingWithTerminatorAndPrefix(b, data, ascendingBytesEscapes.escapedTerm, bytesMarker)
}
// EncodeNextBytesAscending encodes the []byte value with an extra 0x00 byte
// appended before encoding. It's equivalent to
//
// EncodeBytesAscending(b, append(data, 0x00))
//
// but may avoid an allocation when the data slice does not have additional
// capacity.
func EncodeNextBytesAscending(b []byte, data []byte) []byte {
b = append(b, bytesMarker)
return encodeNextBytesAscendingWithTerminator(b, data, ascendingBytesEscapes.escapedTerm)
}
func encodeNextBytesAscendingWithTerminator(b []byte, data []byte, terminator byte) []byte {
bs := encodeBytesAscendingWithoutTerminatorOrPrefix(b, data)
return append(bs, escape, escaped00, escape, terminator)
}
// encodeBytesAscendingWithTerminatorAndPrefix encodes the []byte value using an escape-based
// encoding. The encoded value is terminated with the sequence
// "\x00\terminator". The encoded bytes are append to the supplied buffer
// and the resulting buffer is returned. The terminator allows us to pass
// different terminators for things such as JSON key encoding.
func encodeBytesAscendingWithTerminatorAndPrefix(
b []byte, data []byte, terminator byte, prefix byte,
) []byte {
b = append(b, prefix)
return encodeBytesAscendingWithTerminator(b, data, terminator)
}
// encodeBytesAscendingWithTerminator encodes the []byte value using an escape-based
// encoding. The encoded value is terminated with the sequence
// "\x00\terminator". The encoded bytes are append to the supplied buffer
// and the resulting buffer is returned. The terminator allows us to pass
// different terminators for things such as JSON key encoding.
func encodeBytesAscendingWithTerminator(b []byte, data []byte, terminator byte) []byte {
bs := encodeBytesAscendingWithoutTerminatorOrPrefix(b, data)
return append(bs, escape, terminator)
}
// encodeBytesAscendingWithoutTerminatorOrPrefix encodes the []byte value using an escape-based
// encoding.
func encodeBytesAscendingWithoutTerminatorOrPrefix(b []byte, data []byte) []byte {
for {
// IndexByte is implemented by the go runtime in assembly and is
// much faster than looping over the bytes in the slice.
i := bytes.IndexByte(data, escape)
if i == -1 {
break
}
b = append(b, data[:i]...)
b = append(b, escape, escaped00)
data = data[i+1:]
}
return append(b, data...)
}
// EncodeBytesDescending encodes the []byte value using an
// escape-based encoding and then inverts (ones complement) the result
// so that it sorts in reverse order, from larger to smaller
// lexicographically.
func EncodeBytesDescending(b []byte, data []byte) []byte {
n := len(b)
b = EncodeBytesAscending(b, data)
b[n] = bytesDescMarker
onesComplement(b[n+1:])
return b
}
// EncodeBytesSize returns the size of the []byte value when encoded using
// EncodeBytes{Ascending,Descending}. The function accounts for the encoding
// marker, escaping, and the terminator.
func EncodeBytesSize(data []byte) int {
// Encoding overhead:
// +1 for [bytesMarker] prefix
// +2 for [escape, escapedTerm] suffix
// +1 for each byte that needs to be escaped
//
// NOTE: bytes.Count is implemented by the go runtime in assembly and is
// much faster than looping over the bytes in the slice, especially when
// given a single-byte separator.
return len(data) + 3 + bytes.Count(data, []byte{escape})
}
// EncodeNextBytesSize returns the size of the []byte value when suffixed with a
// zero byte and then encoded using EncodeNextBytes{Ascending,Descending}. The
// function accounts for the encoding marker, escaping, and the terminator.
func EncodeNextBytesSize(data []byte) int {
// Encoding overhead:
// +1 for [bytesMarker] prefix
// +2 for [escape, escapedTerm] suffix
// +1 for each byte that needs to be escaped
// +2 for the appended 0x00 byte, plus its escaping byte
//
// NOTE: bytes.Count is implemented by the go runtime in assembly and is
// much faster than looping over the bytes in the slice, especially when
// given a single-byte separator.
return len(data) + 5 + bytes.Count(data, []byte{escape})
}
// DecodeBytesAscending decodes a []byte value from the input buffer
// which was encoded using EncodeBytesAscending. The decoded bytes
// are appended to r. The remainder of the input buffer and the
// decoded []byte are returned.
func DecodeBytesAscending(b []byte, r []byte) ([]byte, []byte, error) {
return decodeBytesInternal(b, r, ascendingBytesEscapes, true /* expectMarker */, false /* deepCopy */)
}
// ValidateDecodeBytesAscending is like DecodeBytesAscending, but discards the
// decoded bytes. The remainder of the input buffer is returned on success.
func ValidateDecodeBytesAscending(b []byte) ([]byte, error) {
return validateDecodeBytesInternal(b, ascendingBytesEscapes, true /* expectMarker */)
}
// DecodeBytesAscendingDeepCopy is the same as DecodeBytesAscending, but the
// decoded []byte will never alias memory of b.
func DecodeBytesAscendingDeepCopy(b []byte, r []byte) ([]byte, []byte, error) {
return decodeBytesInternal(b, r, ascendingBytesEscapes, true /* expectMarker */, true /* deepCopy */)
}
// DecodeBytesDescending decodes a []byte value from the input buffer
// which was encoded using EncodeBytesDescending. The decoded bytes
// are appended to r. The remainder of the input buffer and the
// decoded []byte are returned.
//
// Note that this method internally will always perform a deep copy, so there is
// no need to introduce DecodeBytesDescendingDeepCopy to mirror
// DecodeBytesAscendingDeepCopy.
func DecodeBytesDescending(b []byte, r []byte) ([]byte, []byte, error) {
// Ask for the deep copy to make sure we never get back a sub-slice of `b`,
// since we're going to modify the contents of the slice.
b, r, err := decodeBytesInternal(b, r, descendingBytesEscapes, true /* expectMarker */, true /* deepCopy */)
onesComplement(r)
return b, r, err
}
// decodeBytesInternal decodes an encoded []byte value from b and appends it to
// r. The remainder of b and the decoded []byte are returned. If deepCopy is
// true, then the decoded []byte will be deep copied from b and there will no
// aliasing of the same memory.
func decodeBytesInternal(
b []byte, r []byte, e escapes, expectMarker bool, deepCopy bool,
) ([]byte, []byte, error) {
if expectMarker {
if len(b) == 0 || b[0] != e.marker {
return nil, nil, errors.Errorf("did not find marker %#x in buffer %#x", e.marker, b)
}
b = b[1:]
}
for {
i := bytes.IndexByte(b, e.escape)
if i == -1 {
return nil, nil, errors.Errorf("did not find terminator %#x in buffer %#x", e.escape, b)
}
if i+1 >= len(b) {
return nil, nil, errors.Errorf("malformed escape in buffer %#x", b)
}
v := b[i+1]
if v == e.escapedTerm {
if r == nil && !deepCopy {
r = b[:i]
} else {
r = append(r, b[:i]...)
}
return b[i+2:], r, nil
}
if v != e.escaped00 {
return nil, nil, errors.Errorf("unknown escape sequence: %#x %#x", e.escape, v)
}
r = append(r, b[:i]...)
r = append(r, e.escapedFF)
b = b[i+2:]
}
}
// validateDecodeBytesInternal decodes an encoded []byte value from b,
// discarding the decoded value. The remainder of b is returned on success, or a
// non-nil error otherwise.
func validateDecodeBytesInternal(b []byte, e escapes, expectMarker bool) ([]byte, error) {
if expectMarker {
if len(b) == 0 || b[0] != e.marker {
return nil, errors.Errorf("did not find marker %#x in buffer %#x", e.marker, b)
}
b = b[1:]
}
for {
i := bytes.IndexByte(b, e.escape)
if i == -1 {
return nil, errors.Errorf("did not find terminator %#x in buffer %#x", e.escape, b)
}
if i+1 >= len(b) {
return nil, errors.Errorf("malformed escape in buffer %#x", b)
}
v := b[i+1]
if v == e.escapedTerm {
return b[i+2:], nil
}
if v != e.escaped00 {
return nil, errors.Errorf("unknown escape sequence: %#x %#x", e.escape, v)
}
b = b[i+2:]
}
}
// getBytesLength finds the length of a bytes encoding.
func getBytesLength(b []byte, e escapes) (int, error) {
// Skip the tag.
skipped := 1
for {
i := bytes.IndexByte(b[skipped:], e.escape)
if i == -1 {
return 0, errors.Errorf("did not find terminator %#x in buffer %#x", e.escape, b)
}
if i+1 >= len(b) {
return 0, errors.Errorf("malformed escape in buffer %#x", b)
}
skipped += i + escapeLength
if b[skipped-1] == e.escapedTerm {
return skipped, nil
}
}
}
// getLTreeLength finds the length of a ltree encoding.
func getLTreeLength(b []byte, dir Direction) (int, error) {
var i int
if dir == Ascending {
i = bytes.IndexByte(b, ltreeKeyTerminator)
} else {
i = bytes.IndexByte(b, ltreeKeyDescendingTerminator)
}
if i == -1 {
return 0, errors.Errorf("did not find terminator")
}
return i + 1, nil
}
// prettyPrintInvertedIndexKey returns a string representation of the path part of a JSON inverted
// index.
func prettyPrintInvertedIndexKey(b []byte) (string, []byte, error) {
outBytes := ""
// We're skipping the first byte because it's the JSON tag.
tempB := b[1:]
for {
i := bytes.IndexByte(tempB, escape)
if i == -1 {
return "", nil, errors.Errorf("did not find terminator %#x in buffer %#x", escape, b)
}
if i+1 >= len(tempB) {
return "", nil, errors.Errorf("malformed escape in buffer %#x", b)
}
switch tempB[i+1] {
case escapedTerm:
if len(tempB[:i]) > 0 {
outBytes = outBytes + strconv.Quote(UnsafeConvertBytesToString(tempB[:i]))
} else {
lenOut := len(outBytes)
if lenOut > 1 && outBytes[lenOut-1] == '/' {
outBytes = outBytes[:lenOut-1]
}
}
return outBytes, tempB[i+escapeLength:], nil
case escapedJSONObjectKeyTerm:
outBytes = outBytes + strconv.Quote(UnsafeConvertBytesToString(tempB[:i])) + "/"
case escapedJSONArray:
outBytes = outBytes + "Arr/"
if i+2 >= len(tempB) {
// The key ends in an escaped JSON array byte, which is used in
// spans to scan over non-empty arrays.
return outBytes, nil, nil
}
case escaped00:
if i+2 >= len(tempB) {
// The key ends in an escaped NULL byte.
return outBytes, nil, nil
}
default:
return "", nil, errors.Errorf("malformed escape in buffer %#x", b)
}
tempB = tempB[i+escapeLength:]
}
}
// UnsafeConvertStringToBytes converts a string to a byte array to be used with
// string encoding functions. Note that the output byte array should not be
// modified if the input string is expected to be used again - doing so could
// violate Go semantics.
func UnsafeConvertStringToBytes(s string) []byte {
// unsafe.StringData output is unspecified for empty string input so always
// return nil.
if len(s) == 0 {
return nil
}
return unsafe.Slice(unsafe.StringData(s), len(s))
}
// EncodeStringAscending encodes the string value using an escape-based encoding. See
// EncodeBytes for details. The encoded bytes are append to the supplied buffer
// and the resulting buffer is returned.
func EncodeStringAscending(b []byte, s string) []byte {
return encodeStringAscendingWithTerminatorAndPrefix(b, s, ascendingBytesEscapes.escapedTerm, bytesMarker)
}
// encodeStringAscendingWithTerminatorAndPrefix encodes the string value using an escape-based encoding. See
// EncodeBytes for details. The encoded bytes are append to the supplied buffer
// and the resulting buffer is returned. We can also pass a terminator byte to be used with
// JSON key encoding.
func encodeStringAscendingWithTerminatorAndPrefix(
b []byte, s string, terminator byte, prefix byte,
) []byte {
unsafeString := UnsafeConvertStringToBytes(s)
return encodeBytesAscendingWithTerminatorAndPrefix(b, unsafeString, terminator, prefix)
}
// EncodeJSONKeyStringAscending encodes the JSON key string value with a JSON specific escaped
// terminator. This allows us to encode keys in the same number of bytes as a string,
// while at the same time giving us a sentinel to identify JSON keys. The end parameter is used
// to determine if this is the last key in a a JSON path. If it is we don't add a separator after it.
func EncodeJSONKeyStringAscending(b []byte, s string, end bool) []byte {
str := UnsafeConvertStringToBytes(s)
if end {
return encodeBytesAscendingWithoutTerminatorOrPrefix(b, str)
}
return encodeBytesAscendingWithTerminator(b, str, escapedJSONObjectKeyTerm)
}
// EncodeJSONEmptyArray returns a byte array b with a byte to signify an empty JSON array.
func EncodeJSONEmptyArray(b []byte) []byte {
return append(b, escape, escapedTerm, jsonEmptyArray)
}
// AddJSONPathTerminator adds a json path terminator to a byte array.
func AddJSONPathTerminator(b []byte) []byte {
return append(b, escape, escapedTerm)
}
// AddJSONPathSeparator adds a json path separator to a byte array.
func AddJSONPathSeparator(b []byte) []byte {
return append(b, escape, escapedJSONObjectKeyTerm)
}
// EncodeJSONEmptyObject returns a byte array b with a byte to signify an empty JSON object.
func EncodeJSONEmptyObject(b []byte) []byte {