// Name returns a view of the name. Caller must not keep references to
// it past the lifetime of the view.
//
// If the message is truncated, returns an empty string.
func (v *PersonV2View) Name() string {
l, n := varuint.Uint64(v.data[slotsLenPersonV2View:])
if n < 0 {
return ""
}
if l == 0 {
panic("TODO padding not handled yet")
}
l--
const maxInt = int(^uint(0) >> 1)
if l > uint64(maxInt) {
// technically, it has to be truncated because it wouldn't fit
// in memory ;)
return ""
}
end := slotsLenPersonV2View + n + int(l)
if end > len(v.data) {
return ""
}
var s string
p := (*reflect.StringHeader)(unsafe.Pointer(&s))
p.Data = uintptr(unsafe.Pointer(&v.data[slotsLenPersonV2View+n]))
p.Len = int(l)
return s
}
// Next returns the contents of the next frame.
//
// Returns io.EOF if there are no more frames. Returns
// io.ErrUnexpectedEOF on truncated data.
func (v *FramedView) Next() ([]byte, error) {
loop:
if len(v.data) == 0 {
return nil, io.EOF
}
l, n := varuint.Uint64(v.data)
if n < 0 {
return nil, io.ErrUnexpectedEOF
}
if l == 0 {
goto loop
}
l--
const maxInt = int(^uint(0) >> 1)
if l > uint64(maxInt) {
// technically, it has to be truncated because it wouldn't fit
// in memory ;)
return nil, io.ErrUnexpectedEOF
}
end := n + int(l)
if end > len(v.data) {
return nil, io.ErrUnexpectedEOF
}
b := v.data[n:end]
v.data = v.data[end:]
return b, nil
}
func chitinParseLengthPrefixed(data []byte) (msg []byte, next []byte, err error) {
loop:
l, n := varuint.Uint64(data)
if n < 0 {
return nil, nil, io.ErrUnexpectedEOF
}
if l == 0 {
// padding
data = data[n:]
goto loop
}
l--
const maxInt = int(^uint(0) >> 1)
if l > uint64(maxInt) {
// technically, it has to be truncated because it wouldn't fit
// in memory ;)
return nil, nil, io.ErrUnexpectedEOF
}
li := int(l)
// TODO prevent overflow here
end := n + li
if end > len(data) {
return nil, nil, io.ErrUnexpectedEOF
}
low := n
high := low + li
return data[low:high], data[high:], nil
}
func BenchmarkDchestUint64MaxLen(b *testing.B) {
var res uint64
b.SetBytes(8)
for i := 0; i < b.N; i++ {
res, _ = varuint.Uint64(tests[17].encoded)
}
_ = res
}
func BenchmarkDchestUint64All(b *testing.B) {
var res uint64
b.SetBytes(8)
for i := 0; i < b.N; i++ {
for _, test := range tests {
res, _ = varuint.Uint64(test.encoded)
}
}
_ = res
}
func NewMyProtocolView(data []byte) (MyProtocolMessage, error) {
if len(data) == 0 {
return nil, chitin.ErrWrongSize
}
kind, n := varuint.Uint64(data)
if n < 0 {
return nil, chitin.ErrWrongSize
}
data = data[n:]
switch kind {
default:
return nil, chitin.ErrUnknownMessageKind
case 0:
return nil, chitin.ErrIsPadding
case 1:
return NewPersonV2View(data)
}
}
func TestVaruint(t *testing.T) {
for i, test := range tests {
b := make([]byte, len(test.encoded))
n := varuint.PutUint64(b, test.decoded)
if n != test.n {
t.Errorf("encode %d: got %d want %d", i, n, test.n)
}
if !bytes.Equal(b, test.encoded) {
t.Errorf("encode %d: got %v want %v", i, b[0:n], test.encoded)
}
v, n := varuint.Uint64(test.encoded)
if n != test.n {
t.Errorf("decode %d: got %d want %d", i, n, test.n)
}
if v != test.decoded {
t.Errorf("decode %d: got %d want %d", i, v, test.decoded)
}
}
}