peridot/vendor/github.com/pelletier/go-toml/v2/decode.go
2024-10-16 12:56:53 +02:00

551 lines
12 KiB
Go

package toml
import (
"fmt"
"math"
"strconv"
"time"
"github.com/pelletier/go-toml/v2/unstable"
)
func parseInteger(b []byte) (int64, error) {
if len(b) > 2 && b[0] == '0' {
switch b[1] {
case 'x':
return parseIntHex(b)
case 'b':
return parseIntBin(b)
case 'o':
return parseIntOct(b)
default:
panic(fmt.Errorf("invalid base '%c', should have been checked by scanIntOrFloat", b[1]))
}
}
return parseIntDec(b)
}
func parseLocalDate(b []byte) (LocalDate, error) {
// full-date = date-fullyear "-" date-month "-" date-mday
// date-fullyear = 4DIGIT
// date-month = 2DIGIT ; 01-12
// date-mday = 2DIGIT ; 01-28, 01-29, 01-30, 01-31 based on month/year
var date LocalDate
if len(b) != 10 || b[4] != '-' || b[7] != '-' {
return date, unstable.NewParserError(b, "dates are expected to have the format YYYY-MM-DD")
}
var err error
date.Year, err = parseDecimalDigits(b[0:4])
if err != nil {
return LocalDate{}, err
}
date.Month, err = parseDecimalDigits(b[5:7])
if err != nil {
return LocalDate{}, err
}
date.Day, err = parseDecimalDigits(b[8:10])
if err != nil {
return LocalDate{}, err
}
if !isValidDate(date.Year, date.Month, date.Day) {
return LocalDate{}, unstable.NewParserError(b, "impossible date")
}
return date, nil
}
func parseDecimalDigits(b []byte) (int, error) {
v := 0
for i, c := range b {
if c < '0' || c > '9' {
return 0, unstable.NewParserError(b[i:i+1], "expected digit (0-9)")
}
v *= 10
v += int(c - '0')
}
return v, nil
}
func parseDateTime(b []byte) (time.Time, error) {
// offset-date-time = full-date time-delim full-time
// full-time = partial-time time-offset
// time-offset = "Z" / time-numoffset
// time-numoffset = ( "+" / "-" ) time-hour ":" time-minute
dt, b, err := parseLocalDateTime(b)
if err != nil {
return time.Time{}, err
}
var zone *time.Location
if len(b) == 0 {
// parser should have checked that when assigning the date time node
panic("date time should have a timezone")
}
if b[0] == 'Z' || b[0] == 'z' {
b = b[1:]
zone = time.UTC
} else {
const dateTimeByteLen = 6
if len(b) != dateTimeByteLen {
return time.Time{}, unstable.NewParserError(b, "invalid date-time timezone")
}
var direction int
switch b[0] {
case '-':
direction = -1
case '+':
direction = +1
default:
return time.Time{}, unstable.NewParserError(b[:1], "invalid timezone offset character")
}
if b[3] != ':' {
return time.Time{}, unstable.NewParserError(b[3:4], "expected a : separator")
}
hours, err := parseDecimalDigits(b[1:3])
if err != nil {
return time.Time{}, err
}
if hours > 23 {
return time.Time{}, unstable.NewParserError(b[:1], "invalid timezone offset hours")
}
minutes, err := parseDecimalDigits(b[4:6])
if err != nil {
return time.Time{}, err
}
if minutes > 59 {
return time.Time{}, unstable.NewParserError(b[:1], "invalid timezone offset minutes")
}
seconds := direction * (hours*3600 + minutes*60)
if seconds == 0 {
zone = time.UTC
} else {
zone = time.FixedZone("", seconds)
}
b = b[dateTimeByteLen:]
}
if len(b) > 0 {
return time.Time{}, unstable.NewParserError(b, "extra bytes at the end of the timezone")
}
t := time.Date(
dt.Year,
time.Month(dt.Month),
dt.Day,
dt.Hour,
dt.Minute,
dt.Second,
dt.Nanosecond,
zone)
return t, nil
}
func parseLocalDateTime(b []byte) (LocalDateTime, []byte, error) {
var dt LocalDateTime
const localDateTimeByteMinLen = 11
if len(b) < localDateTimeByteMinLen {
return dt, nil, unstable.NewParserError(b, "local datetimes are expected to have the format YYYY-MM-DDTHH:MM:SS[.NNNNNNNNN]")
}
date, err := parseLocalDate(b[:10])
if err != nil {
return dt, nil, err
}
dt.LocalDate = date
sep := b[10]
if sep != 'T' && sep != ' ' && sep != 't' {
return dt, nil, unstable.NewParserError(b[10:11], "datetime separator is expected to be T or a space")
}
t, rest, err := parseLocalTime(b[11:])
if err != nil {
return dt, nil, err
}
dt.LocalTime = t
return dt, rest, nil
}
// parseLocalTime is a bit different because it also returns the remaining
// []byte that is didn't need. This is to allow parseDateTime to parse those
// remaining bytes as a timezone.
func parseLocalTime(b []byte) (LocalTime, []byte, error) {
var (
nspow = [10]int{0, 1e8, 1e7, 1e6, 1e5, 1e4, 1e3, 1e2, 1e1, 1e0}
t LocalTime
)
// check if b matches to have expected format HH:MM:SS[.NNNNNN]
const localTimeByteLen = 8
if len(b) < localTimeByteLen {
return t, nil, unstable.NewParserError(b, "times are expected to have the format HH:MM:SS[.NNNNNN]")
}
var err error
t.Hour, err = parseDecimalDigits(b[0:2])
if err != nil {
return t, nil, err
}
if t.Hour > 23 {
return t, nil, unstable.NewParserError(b[0:2], "hour cannot be greater 23")
}
if b[2] != ':' {
return t, nil, unstable.NewParserError(b[2:3], "expecting colon between hours and minutes")
}
t.Minute, err = parseDecimalDigits(b[3:5])
if err != nil {
return t, nil, err
}
if t.Minute > 59 {
return t, nil, unstable.NewParserError(b[3:5], "minutes cannot be greater 59")
}
if b[5] != ':' {
return t, nil, unstable.NewParserError(b[5:6], "expecting colon between minutes and seconds")
}
t.Second, err = parseDecimalDigits(b[6:8])
if err != nil {
return t, nil, err
}
if t.Second > 60 {
return t, nil, unstable.NewParserError(b[6:8], "seconds cannot be greater 60")
}
b = b[8:]
if len(b) >= 1 && b[0] == '.' {
frac := 0
precision := 0
digits := 0
for i, c := range b[1:] {
if !isDigit(c) {
if i == 0 {
return t, nil, unstable.NewParserError(b[0:1], "need at least one digit after fraction point")
}
break
}
digits++
const maxFracPrecision = 9
if i >= maxFracPrecision {
// go-toml allows decoding fractional seconds
// beyond the supported precision of 9
// digits. It truncates the fractional component
// to the supported precision and ignores the
// remaining digits.
//
// https://github.com/pelletier/go-toml/discussions/707
continue
}
frac *= 10
frac += int(c - '0')
precision++
}
if precision == 0 {
return t, nil, unstable.NewParserError(b[:1], "nanoseconds need at least one digit")
}
t.Nanosecond = frac * nspow[precision]
t.Precision = precision
return t, b[1+digits:], nil
}
return t, b, nil
}
//nolint:cyclop
func parseFloat(b []byte) (float64, error) {
if len(b) == 4 && (b[0] == '+' || b[0] == '-') && b[1] == 'n' && b[2] == 'a' && b[3] == 'n' {
return math.NaN(), nil
}
cleaned, err := checkAndRemoveUnderscoresFloats(b)
if err != nil {
return 0, err
}
if cleaned[0] == '.' {
return 0, unstable.NewParserError(b, "float cannot start with a dot")
}
if cleaned[len(cleaned)-1] == '.' {
return 0, unstable.NewParserError(b, "float cannot end with a dot")
}
dotAlreadySeen := false
for i, c := range cleaned {
if c == '.' {
if dotAlreadySeen {
return 0, unstable.NewParserError(b[i:i+1], "float can have at most one decimal point")
}
if !isDigit(cleaned[i-1]) {
return 0, unstable.NewParserError(b[i-1:i+1], "float decimal point must be preceded by a digit")
}
if !isDigit(cleaned[i+1]) {
return 0, unstable.NewParserError(b[i:i+2], "float decimal point must be followed by a digit")
}
dotAlreadySeen = true
}
}
start := 0
if cleaned[0] == '+' || cleaned[0] == '-' {
start = 1
}
if cleaned[start] == '0' && len(cleaned) > start+1 && isDigit(cleaned[start+1]) {
return 0, unstable.NewParserError(b, "float integer part cannot have leading zeroes")
}
f, err := strconv.ParseFloat(string(cleaned), 64)
if err != nil {
return 0, unstable.NewParserError(b, "unable to parse float: %w", err)
}
return f, nil
}
func parseIntHex(b []byte) (int64, error) {
cleaned, err := checkAndRemoveUnderscoresIntegers(b[2:])
if err != nil {
return 0, err
}
i, err := strconv.ParseInt(string(cleaned), 16, 64)
if err != nil {
return 0, unstable.NewParserError(b, "couldn't parse hexadecimal number: %w", err)
}
return i, nil
}
func parseIntOct(b []byte) (int64, error) {
cleaned, err := checkAndRemoveUnderscoresIntegers(b[2:])
if err != nil {
return 0, err
}
i, err := strconv.ParseInt(string(cleaned), 8, 64)
if err != nil {
return 0, unstable.NewParserError(b, "couldn't parse octal number: %w", err)
}
return i, nil
}
func parseIntBin(b []byte) (int64, error) {
cleaned, err := checkAndRemoveUnderscoresIntegers(b[2:])
if err != nil {
return 0, err
}
i, err := strconv.ParseInt(string(cleaned), 2, 64)
if err != nil {
return 0, unstable.NewParserError(b, "couldn't parse binary number: %w", err)
}
return i, nil
}
func isSign(b byte) bool {
return b == '+' || b == '-'
}
func parseIntDec(b []byte) (int64, error) {
cleaned, err := checkAndRemoveUnderscoresIntegers(b)
if err != nil {
return 0, err
}
startIdx := 0
if isSign(cleaned[0]) {
startIdx++
}
if len(cleaned) > startIdx+1 && cleaned[startIdx] == '0' {
return 0, unstable.NewParserError(b, "leading zero not allowed on decimal number")
}
i, err := strconv.ParseInt(string(cleaned), 10, 64)
if err != nil {
return 0, unstable.NewParserError(b, "couldn't parse decimal number: %w", err)
}
return i, nil
}
func checkAndRemoveUnderscoresIntegers(b []byte) ([]byte, error) {
start := 0
if b[start] == '+' || b[start] == '-' {
start++
}
if len(b) == start {
return b, nil
}
if b[start] == '_' {
return nil, unstable.NewParserError(b[start:start+1], "number cannot start with underscore")
}
if b[len(b)-1] == '_' {
return nil, unstable.NewParserError(b[len(b)-1:], "number cannot end with underscore")
}
// fast path
i := 0
for ; i < len(b); i++ {
if b[i] == '_' {
break
}
}
if i == len(b) {
return b, nil
}
before := false
cleaned := make([]byte, i, len(b))
copy(cleaned, b)
for i++; i < len(b); i++ {
c := b[i]
if c == '_' {
if !before {
return nil, unstable.NewParserError(b[i-1:i+1], "number must have at least one digit between underscores")
}
before = false
} else {
before = true
cleaned = append(cleaned, c)
}
}
return cleaned, nil
}
func checkAndRemoveUnderscoresFloats(b []byte) ([]byte, error) {
if b[0] == '_' {
return nil, unstable.NewParserError(b[0:1], "number cannot start with underscore")
}
if b[len(b)-1] == '_' {
return nil, unstable.NewParserError(b[len(b)-1:], "number cannot end with underscore")
}
// fast path
i := 0
for ; i < len(b); i++ {
if b[i] == '_' {
break
}
}
if i == len(b) {
return b, nil
}
before := false
cleaned := make([]byte, 0, len(b))
for i := 0; i < len(b); i++ {
c := b[i]
switch c {
case '_':
if !before {
return nil, unstable.NewParserError(b[i-1:i+1], "number must have at least one digit between underscores")
}
if i < len(b)-1 && (b[i+1] == 'e' || b[i+1] == 'E') {
return nil, unstable.NewParserError(b[i+1:i+2], "cannot have underscore before exponent")
}
before = false
case '+', '-':
// signed exponents
cleaned = append(cleaned, c)
before = false
case 'e', 'E':
if i < len(b)-1 && b[i+1] == '_' {
return nil, unstable.NewParserError(b[i+1:i+2], "cannot have underscore after exponent")
}
cleaned = append(cleaned, c)
case '.':
if i < len(b)-1 && b[i+1] == '_' {
return nil, unstable.NewParserError(b[i+1:i+2], "cannot have underscore after decimal point")
}
if i > 0 && b[i-1] == '_' {
return nil, unstable.NewParserError(b[i-1:i], "cannot have underscore before decimal point")
}
cleaned = append(cleaned, c)
default:
before = true
cleaned = append(cleaned, c)
}
}
return cleaned, nil
}
// isValidDate checks if a provided date is a date that exists.
func isValidDate(year int, month int, day int) bool {
return month > 0 && month < 13 && day > 0 && day <= daysIn(month, year)
}
// daysBefore[m] counts the number of days in a non-leap year
// before month m begins. There is an entry for m=12, counting
// the number of days before January of next year (365).
var daysBefore = [...]int32{
0,
31,
31 + 28,
31 + 28 + 31,
31 + 28 + 31 + 30,
31 + 28 + 31 + 30 + 31,
31 + 28 + 31 + 30 + 31 + 30,
31 + 28 + 31 + 30 + 31 + 30 + 31,
31 + 28 + 31 + 30 + 31 + 30 + 31 + 31,
31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30,
31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31,
31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30,
31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30 + 31,
}
func daysIn(m int, year int) int {
if m == 2 && isLeap(year) {
return 29
}
return int(daysBefore[m] - daysBefore[m-1])
}
func isLeap(year int) bool {
return year%4 == 0 && (year%100 != 0 || year%400 == 0)
}
func isDigit(r byte) bool {
return r >= '0' && r <= '9'
}