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path: root/vendor/github.com/godbus/dbus/decoder.go
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Diffstat (limited to 'vendor/github.com/godbus/dbus/decoder.go')
-rw-r--r--vendor/github.com/godbus/dbus/decoder.go228
1 files changed, 228 insertions, 0 deletions
diff --git a/vendor/github.com/godbus/dbus/decoder.go b/vendor/github.com/godbus/dbus/decoder.go
new file mode 100644
index 000000000..ef50dcab9
--- /dev/null
+++ b/vendor/github.com/godbus/dbus/decoder.go
@@ -0,0 +1,228 @@
+package dbus
+
+import (
+ "encoding/binary"
+ "io"
+ "reflect"
+)
+
+type decoder struct {
+ in io.Reader
+ order binary.ByteOrder
+ pos int
+}
+
+// newDecoder returns a new decoder that reads values from in. The input is
+// expected to be in the given byte order.
+func newDecoder(in io.Reader, order binary.ByteOrder) *decoder {
+ dec := new(decoder)
+ dec.in = in
+ dec.order = order
+ return dec
+}
+
+// align aligns the input to the given boundary and panics on error.
+func (dec *decoder) align(n int) {
+ if dec.pos%n != 0 {
+ newpos := (dec.pos + n - 1) & ^(n - 1)
+ empty := make([]byte, newpos-dec.pos)
+ if _, err := io.ReadFull(dec.in, empty); err != nil {
+ panic(err)
+ }
+ dec.pos = newpos
+ }
+}
+
+// Calls binary.Read(dec.in, dec.order, v) and panics on read errors.
+func (dec *decoder) binread(v interface{}) {
+ if err := binary.Read(dec.in, dec.order, v); err != nil {
+ panic(err)
+ }
+}
+
+func (dec *decoder) Decode(sig Signature) (vs []interface{}, err error) {
+ defer func() {
+ var ok bool
+ v := recover()
+ if err, ok = v.(error); ok {
+ if err == io.EOF || err == io.ErrUnexpectedEOF {
+ err = FormatError("unexpected EOF")
+ }
+ }
+ }()
+ vs = make([]interface{}, 0)
+ s := sig.str
+ for s != "" {
+ err, rem := validSingle(s, 0)
+ if err != nil {
+ return nil, err
+ }
+ v := dec.decode(s[:len(s)-len(rem)], 0)
+ vs = append(vs, v)
+ s = rem
+ }
+ return vs, nil
+}
+
+func (dec *decoder) decode(s string, depth int) interface{} {
+ dec.align(alignment(typeFor(s)))
+ switch s[0] {
+ case 'y':
+ var b [1]byte
+ if _, err := dec.in.Read(b[:]); err != nil {
+ panic(err)
+ }
+ dec.pos++
+ return b[0]
+ case 'b':
+ i := dec.decode("u", depth).(uint32)
+ switch {
+ case i == 0:
+ return false
+ case i == 1:
+ return true
+ default:
+ panic(FormatError("invalid value for boolean"))
+ }
+ case 'n':
+ var i int16
+ dec.binread(&i)
+ dec.pos += 2
+ return i
+ case 'i':
+ var i int32
+ dec.binread(&i)
+ dec.pos += 4
+ return i
+ case 'x':
+ var i int64
+ dec.binread(&i)
+ dec.pos += 8
+ return i
+ case 'q':
+ var i uint16
+ dec.binread(&i)
+ dec.pos += 2
+ return i
+ case 'u':
+ var i uint32
+ dec.binread(&i)
+ dec.pos += 4
+ return i
+ case 't':
+ var i uint64
+ dec.binread(&i)
+ dec.pos += 8
+ return i
+ case 'd':
+ var f float64
+ dec.binread(&f)
+ dec.pos += 8
+ return f
+ case 's':
+ length := dec.decode("u", depth).(uint32)
+ b := make([]byte, int(length)+1)
+ if _, err := io.ReadFull(dec.in, b); err != nil {
+ panic(err)
+ }
+ dec.pos += int(length) + 1
+ return string(b[:len(b)-1])
+ case 'o':
+ return ObjectPath(dec.decode("s", depth).(string))
+ case 'g':
+ length := dec.decode("y", depth).(byte)
+ b := make([]byte, int(length)+1)
+ if _, err := io.ReadFull(dec.in, b); err != nil {
+ panic(err)
+ }
+ dec.pos += int(length) + 1
+ sig, err := ParseSignature(string(b[:len(b)-1]))
+ if err != nil {
+ panic(err)
+ }
+ return sig
+ case 'v':
+ if depth >= 64 {
+ panic(FormatError("input exceeds container depth limit"))
+ }
+ var variant Variant
+ sig := dec.decode("g", depth).(Signature)
+ if len(sig.str) == 0 {
+ panic(FormatError("variant signature is empty"))
+ }
+ err, rem := validSingle(sig.str, 0)
+ if err != nil {
+ panic(err)
+ }
+ if rem != "" {
+ panic(FormatError("variant signature has multiple types"))
+ }
+ variant.sig = sig
+ variant.value = dec.decode(sig.str, depth+1)
+ return variant
+ case 'h':
+ return UnixFDIndex(dec.decode("u", depth).(uint32))
+ case 'a':
+ if len(s) > 1 && s[1] == '{' {
+ ksig := s[2:3]
+ vsig := s[3 : len(s)-1]
+ v := reflect.MakeMap(reflect.MapOf(typeFor(ksig), typeFor(vsig)))
+ if depth >= 63 {
+ panic(FormatError("input exceeds container depth limit"))
+ }
+ length := dec.decode("u", depth).(uint32)
+ // Even for empty maps, the correct padding must be included
+ dec.align(8)
+ spos := dec.pos
+ for dec.pos < spos+int(length) {
+ dec.align(8)
+ if !isKeyType(v.Type().Key()) {
+ panic(InvalidTypeError{v.Type()})
+ }
+ kv := dec.decode(ksig, depth+2)
+ vv := dec.decode(vsig, depth+2)
+ v.SetMapIndex(reflect.ValueOf(kv), reflect.ValueOf(vv))
+ }
+ return v.Interface()
+ }
+ if depth >= 64 {
+ panic(FormatError("input exceeds container depth limit"))
+ }
+ length := dec.decode("u", depth).(uint32)
+ v := reflect.MakeSlice(reflect.SliceOf(typeFor(s[1:])), 0, int(length))
+ // Even for empty arrays, the correct padding must be included
+ dec.align(alignment(typeFor(s[1:])))
+ spos := dec.pos
+ for dec.pos < spos+int(length) {
+ ev := dec.decode(s[1:], depth+1)
+ v = reflect.Append(v, reflect.ValueOf(ev))
+ }
+ return v.Interface()
+ case '(':
+ if depth >= 64 {
+ panic(FormatError("input exceeds container depth limit"))
+ }
+ dec.align(8)
+ v := make([]interface{}, 0)
+ s = s[1 : len(s)-1]
+ for s != "" {
+ err, rem := validSingle(s, 0)
+ if err != nil {
+ panic(err)
+ }
+ ev := dec.decode(s[:len(s)-len(rem)], depth+1)
+ v = append(v, ev)
+ s = rem
+ }
+ return v
+ default:
+ panic(SignatureError{Sig: s})
+ }
+}
+
+// A FormatError is an error in the wire format.
+type FormatError string
+
+func (e FormatError) Error() string {
+ return "dbus: wire format error: " + string(e)
+}