open-nomad/vendor/gopkg.in/yaml.v2/resolve.go
Seth Hoenig 435c0d9fc8 deps: Switch to Go modules for dependency management
This PR switches the Nomad repository from using govendor to Go modules
for managing dependencies. Aspects of the Nomad workflow remain pretty
much the same. The usual Makefile targets should continue to work as
they always did. The API submodule simply defers to the parent Nomad
version on the repository, keeping the semantics of API versioning that
currently exists.
2020-06-02 14:30:36 -05:00

259 lines
6.7 KiB
Go

package yaml
import (
"encoding/base64"
"math"
"regexp"
"strconv"
"strings"
"time"
)
type resolveMapItem struct {
value interface{}
tag string
}
var resolveTable = make([]byte, 256)
var resolveMap = make(map[string]resolveMapItem)
func init() {
t := resolveTable
t[int('+')] = 'S' // Sign
t[int('-')] = 'S'
for _, c := range "0123456789" {
t[int(c)] = 'D' // Digit
}
for _, c := range "yYnNtTfFoO~" {
t[int(c)] = 'M' // In map
}
t[int('.')] = '.' // Float (potentially in map)
var resolveMapList = []struct {
v interface{}
tag string
l []string
}{
{true, yaml_BOOL_TAG, []string{"y", "Y", "yes", "Yes", "YES"}},
{true, yaml_BOOL_TAG, []string{"true", "True", "TRUE"}},
{true, yaml_BOOL_TAG, []string{"on", "On", "ON"}},
{false, yaml_BOOL_TAG, []string{"n", "N", "no", "No", "NO"}},
{false, yaml_BOOL_TAG, []string{"false", "False", "FALSE"}},
{false, yaml_BOOL_TAG, []string{"off", "Off", "OFF"}},
{nil, yaml_NULL_TAG, []string{"", "~", "null", "Null", "NULL"}},
{math.NaN(), yaml_FLOAT_TAG, []string{".nan", ".NaN", ".NAN"}},
{math.Inf(+1), yaml_FLOAT_TAG, []string{".inf", ".Inf", ".INF"}},
{math.Inf(+1), yaml_FLOAT_TAG, []string{"+.inf", "+.Inf", "+.INF"}},
{math.Inf(-1), yaml_FLOAT_TAG, []string{"-.inf", "-.Inf", "-.INF"}},
{"<<", yaml_MERGE_TAG, []string{"<<"}},
}
m := resolveMap
for _, item := range resolveMapList {
for _, s := range item.l {
m[s] = resolveMapItem{item.v, item.tag}
}
}
}
const longTagPrefix = "tag:yaml.org,2002:"
func shortTag(tag string) string {
// TODO This can easily be made faster and produce less garbage.
if strings.HasPrefix(tag, longTagPrefix) {
return "!!" + tag[len(longTagPrefix):]
}
return tag
}
func longTag(tag string) string {
if strings.HasPrefix(tag, "!!") {
return longTagPrefix + tag[2:]
}
return tag
}
func resolvableTag(tag string) bool {
switch tag {
case "", yaml_STR_TAG, yaml_BOOL_TAG, yaml_INT_TAG, yaml_FLOAT_TAG, yaml_NULL_TAG, yaml_TIMESTAMP_TAG:
return true
}
return false
}
var yamlStyleFloat = regexp.MustCompile(`^[-+]?(\.[0-9]+|[0-9]+(\.[0-9]*)?)([eE][-+]?[0-9]+)?$`)
func resolve(tag string, in string) (rtag string, out interface{}) {
if !resolvableTag(tag) {
return tag, in
}
defer func() {
switch tag {
case "", rtag, yaml_STR_TAG, yaml_BINARY_TAG:
return
case yaml_FLOAT_TAG:
if rtag == yaml_INT_TAG {
switch v := out.(type) {
case int64:
rtag = yaml_FLOAT_TAG
out = float64(v)
return
case int:
rtag = yaml_FLOAT_TAG
out = float64(v)
return
}
}
}
failf("cannot decode %s `%s` as a %s", shortTag(rtag), in, shortTag(tag))
}()
// Any data is accepted as a !!str or !!binary.
// Otherwise, the prefix is enough of a hint about what it might be.
hint := byte('N')
if in != "" {
hint = resolveTable[in[0]]
}
if hint != 0 && tag != yaml_STR_TAG && tag != yaml_BINARY_TAG {
// Handle things we can lookup in a map.
if item, ok := resolveMap[in]; ok {
return item.tag, item.value
}
// Base 60 floats are a bad idea, were dropped in YAML 1.2, and
// are purposefully unsupported here. They're still quoted on
// the way out for compatibility with other parser, though.
switch hint {
case 'M':
// We've already checked the map above.
case '.':
// Not in the map, so maybe a normal float.
floatv, err := strconv.ParseFloat(in, 64)
if err == nil {
return yaml_FLOAT_TAG, floatv
}
case 'D', 'S':
// Int, float, or timestamp.
// Only try values as a timestamp if the value is unquoted or there's an explicit
// !!timestamp tag.
if tag == "" || tag == yaml_TIMESTAMP_TAG {
t, ok := parseTimestamp(in)
if ok {
return yaml_TIMESTAMP_TAG, t
}
}
plain := strings.Replace(in, "_", "", -1)
intv, err := strconv.ParseInt(plain, 0, 64)
if err == nil {
if intv == int64(int(intv)) {
return yaml_INT_TAG, int(intv)
} else {
return yaml_INT_TAG, intv
}
}
uintv, err := strconv.ParseUint(plain, 0, 64)
if err == nil {
return yaml_INT_TAG, uintv
}
if yamlStyleFloat.MatchString(plain) {
floatv, err := strconv.ParseFloat(plain, 64)
if err == nil {
return yaml_FLOAT_TAG, floatv
}
}
if strings.HasPrefix(plain, "0b") {
intv, err := strconv.ParseInt(plain[2:], 2, 64)
if err == nil {
if intv == int64(int(intv)) {
return yaml_INT_TAG, int(intv)
} else {
return yaml_INT_TAG, intv
}
}
uintv, err := strconv.ParseUint(plain[2:], 2, 64)
if err == nil {
return yaml_INT_TAG, uintv
}
} else if strings.HasPrefix(plain, "-0b") {
intv, err := strconv.ParseInt("-" + plain[3:], 2, 64)
if err == nil {
if true || intv == int64(int(intv)) {
return yaml_INT_TAG, int(intv)
} else {
return yaml_INT_TAG, intv
}
}
}
default:
panic("resolveTable item not yet handled: " + string(rune(hint)) + " (with " + in + ")")
}
}
return yaml_STR_TAG, in
}
// encodeBase64 encodes s as base64 that is broken up into multiple lines
// as appropriate for the resulting length.
func encodeBase64(s string) string {
const lineLen = 70
encLen := base64.StdEncoding.EncodedLen(len(s))
lines := encLen/lineLen + 1
buf := make([]byte, encLen*2+lines)
in := buf[0:encLen]
out := buf[encLen:]
base64.StdEncoding.Encode(in, []byte(s))
k := 0
for i := 0; i < len(in); i += lineLen {
j := i + lineLen
if j > len(in) {
j = len(in)
}
k += copy(out[k:], in[i:j])
if lines > 1 {
out[k] = '\n'
k++
}
}
return string(out[:k])
}
// This is a subset of the formats allowed by the regular expression
// defined at http://yaml.org/type/timestamp.html.
var allowedTimestampFormats = []string{
"2006-1-2T15:4:5.999999999Z07:00", // RCF3339Nano with short date fields.
"2006-1-2t15:4:5.999999999Z07:00", // RFC3339Nano with short date fields and lower-case "t".
"2006-1-2 15:4:5.999999999", // space separated with no time zone
"2006-1-2", // date only
// Notable exception: time.Parse cannot handle: "2001-12-14 21:59:43.10 -5"
// from the set of examples.
}
// parseTimestamp parses s as a timestamp string and
// returns the timestamp and reports whether it succeeded.
// Timestamp formats are defined at http://yaml.org/type/timestamp.html
func parseTimestamp(s string) (time.Time, bool) {
// TODO write code to check all the formats supported by
// http://yaml.org/type/timestamp.html instead of using time.Parse.
// Quick check: all date formats start with YYYY-.
i := 0
for ; i < len(s); i++ {
if c := s[i]; c < '0' || c > '9' {
break
}
}
if i != 4 || i == len(s) || s[i] != '-' {
return time.Time{}, false
}
for _, format := range allowedTimestampFormats {
if t, err := time.Parse(format, s); err == nil {
return t, true
}
}
return time.Time{}, false
}