node_exporter/vendor/github.com/godbus/dbus/variant_parser.go

818 lines
15 KiB
Go

package dbus
import (
"bytes"
"errors"
"fmt"
"io"
"reflect"
"strconv"
"strings"
"unicode/utf8"
)
type varParser struct {
tokens []varToken
i int
}
func (p *varParser) backup() {
p.i--
}
func (p *varParser) next() varToken {
if p.i < len(p.tokens) {
t := p.tokens[p.i]
p.i++
return t
}
return varToken{typ: tokEOF}
}
type varNode interface {
Infer() (Signature, error)
String() string
Sigs() sigSet
Value(Signature) (interface{}, error)
}
func varMakeNode(p *varParser) (varNode, error) {
var sig Signature
for {
t := p.next()
switch t.typ {
case tokEOF:
return nil, io.ErrUnexpectedEOF
case tokError:
return nil, errors.New(t.val)
case tokNumber:
return varMakeNumNode(t, sig)
case tokString:
return varMakeStringNode(t, sig)
case tokBool:
if sig.str != "" && sig.str != "b" {
return nil, varTypeError{t.val, sig}
}
b, err := strconv.ParseBool(t.val)
if err != nil {
return nil, err
}
return boolNode(b), nil
case tokArrayStart:
return varMakeArrayNode(p, sig)
case tokVariantStart:
return varMakeVariantNode(p, sig)
case tokDictStart:
return varMakeDictNode(p, sig)
case tokType:
if sig.str != "" {
return nil, errors.New("unexpected type annotation")
}
if t.val[0] == '@' {
sig.str = t.val[1:]
} else {
sig.str = varTypeMap[t.val]
}
case tokByteString:
if sig.str != "" && sig.str != "ay" {
return nil, varTypeError{t.val, sig}
}
b, err := varParseByteString(t.val)
if err != nil {
return nil, err
}
return byteStringNode(b), nil
default:
return nil, fmt.Errorf("unexpected %q", t.val)
}
}
}
type varTypeError struct {
val string
sig Signature
}
func (e varTypeError) Error() string {
return fmt.Sprintf("dbus: can't parse %q as type %q", e.val, e.sig.str)
}
type sigSet map[Signature]bool
func (s sigSet) Empty() bool {
return len(s) == 0
}
func (s sigSet) Intersect(s2 sigSet) sigSet {
r := make(sigSet)
for k := range s {
if s2[k] {
r[k] = true
}
}
return r
}
func (s sigSet) Single() (Signature, bool) {
if len(s) == 1 {
for k := range s {
return k, true
}
}
return Signature{}, false
}
func (s sigSet) ToArray() sigSet {
r := make(sigSet, len(s))
for k := range s {
r[Signature{"a" + k.str}] = true
}
return r
}
type numNode struct {
sig Signature
str string
val interface{}
}
var numSigSet = sigSet{
Signature{"y"}: true,
Signature{"n"}: true,
Signature{"q"}: true,
Signature{"i"}: true,
Signature{"u"}: true,
Signature{"x"}: true,
Signature{"t"}: true,
Signature{"d"}: true,
}
func (n numNode) Infer() (Signature, error) {
if strings.ContainsAny(n.str, ".e") {
return Signature{"d"}, nil
}
return Signature{"i"}, nil
}
func (n numNode) String() string {
return n.str
}
func (n numNode) Sigs() sigSet {
if n.sig.str != "" {
return sigSet{n.sig: true}
}
if strings.ContainsAny(n.str, ".e") {
return sigSet{Signature{"d"}: true}
}
return numSigSet
}
func (n numNode) Value(sig Signature) (interface{}, error) {
if n.sig.str != "" && n.sig != sig {
return nil, varTypeError{n.str, sig}
}
if n.val != nil {
return n.val, nil
}
return varNumAs(n.str, sig)
}
func varMakeNumNode(tok varToken, sig Signature) (varNode, error) {
if sig.str == "" {
return numNode{str: tok.val}, nil
}
num, err := varNumAs(tok.val, sig)
if err != nil {
return nil, err
}
return numNode{sig: sig, val: num}, nil
}
func varNumAs(s string, sig Signature) (interface{}, error) {
isUnsigned := false
size := 32
switch sig.str {
case "n":
size = 16
case "i":
case "x":
size = 64
case "y":
size = 8
isUnsigned = true
case "q":
size = 16
isUnsigned = true
case "u":
isUnsigned = true
case "t":
size = 64
isUnsigned = true
case "d":
d, err := strconv.ParseFloat(s, 64)
if err != nil {
return nil, err
}
return d, nil
default:
return nil, varTypeError{s, sig}
}
base := 10
if strings.HasPrefix(s, "0x") {
base = 16
s = s[2:]
}
if strings.HasPrefix(s, "0") && len(s) != 1 {
base = 8
s = s[1:]
}
if isUnsigned {
i, err := strconv.ParseUint(s, base, size)
if err != nil {
return nil, err
}
var v interface{} = i
switch sig.str {
case "y":
v = byte(i)
case "q":
v = uint16(i)
case "u":
v = uint32(i)
}
return v, nil
}
i, err := strconv.ParseInt(s, base, size)
if err != nil {
return nil, err
}
var v interface{} = i
switch sig.str {
case "n":
v = int16(i)
case "i":
v = int32(i)
}
return v, nil
}
type stringNode struct {
sig Signature
str string // parsed
val interface{} // has correct type
}
var stringSigSet = sigSet{
Signature{"s"}: true,
Signature{"g"}: true,
Signature{"o"}: true,
}
func (n stringNode) Infer() (Signature, error) {
return Signature{"s"}, nil
}
func (n stringNode) String() string {
return n.str
}
func (n stringNode) Sigs() sigSet {
if n.sig.str != "" {
return sigSet{n.sig: true}
}
return stringSigSet
}
func (n stringNode) Value(sig Signature) (interface{}, error) {
if n.sig.str != "" && n.sig != sig {
return nil, varTypeError{n.str, sig}
}
if n.val != nil {
return n.val, nil
}
switch {
case sig.str == "g":
return Signature{n.str}, nil
case sig.str == "o":
return ObjectPath(n.str), nil
case sig.str == "s":
return n.str, nil
default:
return nil, varTypeError{n.str, sig}
}
}
func varMakeStringNode(tok varToken, sig Signature) (varNode, error) {
if sig.str != "" && sig.str != "s" && sig.str != "g" && sig.str != "o" {
return nil, fmt.Errorf("invalid type %q for string", sig.str)
}
s, err := varParseString(tok.val)
if err != nil {
return nil, err
}
n := stringNode{str: s}
if sig.str == "" {
return stringNode{str: s}, nil
}
n.sig = sig
switch sig.str {
case "o":
n.val = ObjectPath(s)
case "g":
n.val = Signature{s}
case "s":
n.val = s
}
return n, nil
}
func varParseString(s string) (string, error) {
// quotes are guaranteed to be there
s = s[1 : len(s)-1]
buf := new(bytes.Buffer)
for len(s) != 0 {
r, size := utf8.DecodeRuneInString(s)
if r == utf8.RuneError && size == 1 {
return "", errors.New("invalid UTF-8")
}
s = s[size:]
if r != '\\' {
buf.WriteRune(r)
continue
}
r, size = utf8.DecodeRuneInString(s)
if r == utf8.RuneError && size == 1 {
return "", errors.New("invalid UTF-8")
}
s = s[size:]
switch r {
case 'a':
buf.WriteRune(0x7)
case 'b':
buf.WriteRune(0x8)
case 'f':
buf.WriteRune(0xc)
case 'n':
buf.WriteRune('\n')
case 'r':
buf.WriteRune('\r')
case 't':
buf.WriteRune('\t')
case '\n':
case 'u':
if len(s) < 4 {
return "", errors.New("short unicode escape")
}
r, err := strconv.ParseUint(s[:4], 16, 32)
if err != nil {
return "", err
}
buf.WriteRune(rune(r))
s = s[4:]
case 'U':
if len(s) < 8 {
return "", errors.New("short unicode escape")
}
r, err := strconv.ParseUint(s[:8], 16, 32)
if err != nil {
return "", err
}
buf.WriteRune(rune(r))
s = s[8:]
default:
buf.WriteRune(r)
}
}
return buf.String(), nil
}
var boolSigSet = sigSet{Signature{"b"}: true}
type boolNode bool
func (boolNode) Infer() (Signature, error) {
return Signature{"b"}, nil
}
func (b boolNode) String() string {
if b {
return "true"
}
return "false"
}
func (boolNode) Sigs() sigSet {
return boolSigSet
}
func (b boolNode) Value(sig Signature) (interface{}, error) {
if sig.str != "b" {
return nil, varTypeError{b.String(), sig}
}
return bool(b), nil
}
type arrayNode struct {
set sigSet
children []varNode
val interface{}
}
func (n arrayNode) Infer() (Signature, error) {
for _, v := range n.children {
csig, err := varInfer(v)
if err != nil {
continue
}
return Signature{"a" + csig.str}, nil
}
return Signature{}, fmt.Errorf("can't infer type for %q", n.String())
}
func (n arrayNode) String() string {
s := "["
for i, v := range n.children {
s += v.String()
if i != len(n.children)-1 {
s += ", "
}
}
return s + "]"
}
func (n arrayNode) Sigs() sigSet {
return n.set
}
func (n arrayNode) Value(sig Signature) (interface{}, error) {
if n.set.Empty() {
// no type information whatsoever, so this must be an empty slice
return reflect.MakeSlice(typeFor(sig.str), 0, 0).Interface(), nil
}
if !n.set[sig] {
return nil, varTypeError{n.String(), sig}
}
s := reflect.MakeSlice(typeFor(sig.str), len(n.children), len(n.children))
for i, v := range n.children {
rv, err := v.Value(Signature{sig.str[1:]})
if err != nil {
return nil, err
}
s.Index(i).Set(reflect.ValueOf(rv))
}
return s.Interface(), nil
}
func varMakeArrayNode(p *varParser, sig Signature) (varNode, error) {
var n arrayNode
if sig.str != "" {
n.set = sigSet{sig: true}
}
if t := p.next(); t.typ == tokArrayEnd {
return n, nil
} else {
p.backup()
}
Loop:
for {
t := p.next()
switch t.typ {
case tokEOF:
return nil, io.ErrUnexpectedEOF
case tokError:
return nil, errors.New(t.val)
}
p.backup()
cn, err := varMakeNode(p)
if err != nil {
return nil, err
}
if cset := cn.Sigs(); !cset.Empty() {
if n.set.Empty() {
n.set = cset.ToArray()
} else {
nset := cset.ToArray().Intersect(n.set)
if nset.Empty() {
return nil, fmt.Errorf("can't parse %q with given type information", cn.String())
}
n.set = nset
}
}
n.children = append(n.children, cn)
switch t := p.next(); t.typ {
case tokEOF:
return nil, io.ErrUnexpectedEOF
case tokError:
return nil, errors.New(t.val)
case tokArrayEnd:
break Loop
case tokComma:
continue
default:
return nil, fmt.Errorf("unexpected %q", t.val)
}
}
return n, nil
}
type variantNode struct {
n varNode
}
var variantSet = sigSet{
Signature{"v"}: true,
}
func (variantNode) Infer() (Signature, error) {
return Signature{"v"}, nil
}
func (n variantNode) String() string {
return "<" + n.n.String() + ">"
}
func (variantNode) Sigs() sigSet {
return variantSet
}
func (n variantNode) Value(sig Signature) (interface{}, error) {
if sig.str != "v" {
return nil, varTypeError{n.String(), sig}
}
sig, err := varInfer(n.n)
if err != nil {
return nil, err
}
v, err := n.n.Value(sig)
if err != nil {
return nil, err
}
return MakeVariant(v), nil
}
func varMakeVariantNode(p *varParser, sig Signature) (varNode, error) {
n, err := varMakeNode(p)
if err != nil {
return nil, err
}
if t := p.next(); t.typ != tokVariantEnd {
return nil, fmt.Errorf("unexpected %q", t.val)
}
vn := variantNode{n}
if sig.str != "" && sig.str != "v" {
return nil, varTypeError{vn.String(), sig}
}
return variantNode{n}, nil
}
type dictEntry struct {
key, val varNode
}
type dictNode struct {
kset, vset sigSet
children []dictEntry
val interface{}
}
func (n dictNode) Infer() (Signature, error) {
for _, v := range n.children {
ksig, err := varInfer(v.key)
if err != nil {
continue
}
vsig, err := varInfer(v.val)
if err != nil {
continue
}
return Signature{"a{" + ksig.str + vsig.str + "}"}, nil
}
return Signature{}, fmt.Errorf("can't infer type for %q", n.String())
}
func (n dictNode) String() string {
s := "{"
for i, v := range n.children {
s += v.key.String() + ": " + v.val.String()
if i != len(n.children)-1 {
s += ", "
}
}
return s + "}"
}
func (n dictNode) Sigs() sigSet {
r := sigSet{}
for k := range n.kset {
for v := range n.vset {
sig := "a{" + k.str + v.str + "}"
r[Signature{sig}] = true
}
}
return r
}
func (n dictNode) Value(sig Signature) (interface{}, error) {
set := n.Sigs()
if set.Empty() {
// no type information -> empty dict
return reflect.MakeMap(typeFor(sig.str)).Interface(), nil
}
if !set[sig] {
return nil, varTypeError{n.String(), sig}
}
m := reflect.MakeMap(typeFor(sig.str))
ksig := Signature{sig.str[2:3]}
vsig := Signature{sig.str[3 : len(sig.str)-1]}
for _, v := range n.children {
kv, err := v.key.Value(ksig)
if err != nil {
return nil, err
}
vv, err := v.val.Value(vsig)
if err != nil {
return nil, err
}
m.SetMapIndex(reflect.ValueOf(kv), reflect.ValueOf(vv))
}
return m.Interface(), nil
}
func varMakeDictNode(p *varParser, sig Signature) (varNode, error) {
var n dictNode
if sig.str != "" {
if len(sig.str) < 5 {
return nil, fmt.Errorf("invalid signature %q for dict type", sig)
}
ksig := Signature{string(sig.str[2])}
vsig := Signature{sig.str[3 : len(sig.str)-1]}
n.kset = sigSet{ksig: true}
n.vset = sigSet{vsig: true}
}
if t := p.next(); t.typ == tokDictEnd {
return n, nil
} else {
p.backup()
}
Loop:
for {
t := p.next()
switch t.typ {
case tokEOF:
return nil, io.ErrUnexpectedEOF
case tokError:
return nil, errors.New(t.val)
}
p.backup()
kn, err := varMakeNode(p)
if err != nil {
return nil, err
}
if kset := kn.Sigs(); !kset.Empty() {
if n.kset.Empty() {
n.kset = kset
} else {
n.kset = kset.Intersect(n.kset)
if n.kset.Empty() {
return nil, fmt.Errorf("can't parse %q with given type information", kn.String())
}
}
}
t = p.next()
switch t.typ {
case tokEOF:
return nil, io.ErrUnexpectedEOF
case tokError:
return nil, errors.New(t.val)
case tokColon:
default:
return nil, fmt.Errorf("unexpected %q", t.val)
}
t = p.next()
switch t.typ {
case tokEOF:
return nil, io.ErrUnexpectedEOF
case tokError:
return nil, errors.New(t.val)
}
p.backup()
vn, err := varMakeNode(p)
if err != nil {
return nil, err
}
if vset := vn.Sigs(); !vset.Empty() {
if n.vset.Empty() {
n.vset = vset
} else {
n.vset = n.vset.Intersect(vset)
if n.vset.Empty() {
return nil, fmt.Errorf("can't parse %q with given type information", vn.String())
}
}
}
n.children = append(n.children, dictEntry{kn, vn})
t = p.next()
switch t.typ {
case tokEOF:
return nil, io.ErrUnexpectedEOF
case tokError:
return nil, errors.New(t.val)
case tokDictEnd:
break Loop
case tokComma:
continue
default:
return nil, fmt.Errorf("unexpected %q", t.val)
}
}
return n, nil
}
type byteStringNode []byte
var byteStringSet = sigSet{
Signature{"ay"}: true,
}
func (byteStringNode) Infer() (Signature, error) {
return Signature{"ay"}, nil
}
func (b byteStringNode) String() string {
return string(b)
}
func (b byteStringNode) Sigs() sigSet {
return byteStringSet
}
func (b byteStringNode) Value(sig Signature) (interface{}, error) {
if sig.str != "ay" {
return nil, varTypeError{b.String(), sig}
}
return []byte(b), nil
}
func varParseByteString(s string) ([]byte, error) {
// quotes and b at start are guaranteed to be there
b := make([]byte, 0, 1)
s = s[2 : len(s)-1]
for len(s) != 0 {
c := s[0]
s = s[1:]
if c != '\\' {
b = append(b, c)
continue
}
c = s[0]
s = s[1:]
switch c {
case 'a':
b = append(b, 0x7)
case 'b':
b = append(b, 0x8)
case 'f':
b = append(b, 0xc)
case 'n':
b = append(b, '\n')
case 'r':
b = append(b, '\r')
case 't':
b = append(b, '\t')
case 'x':
if len(s) < 2 {
return nil, errors.New("short escape")
}
n, err := strconv.ParseUint(s[:2], 16, 8)
if err != nil {
return nil, err
}
b = append(b, byte(n))
s = s[2:]
case '0':
if len(s) < 3 {
return nil, errors.New("short escape")
}
n, err := strconv.ParseUint(s[:3], 8, 8)
if err != nil {
return nil, err
}
b = append(b, byte(n))
s = s[3:]
default:
b = append(b, c)
}
}
return append(b, 0), nil
}
func varInfer(n varNode) (Signature, error) {
if sig, ok := n.Sigs().Single(); ok {
return sig, nil
}
return n.Infer()
}