Update to last common bleve (#3986)

vendor/github.com/tinylib/msgp/msgp/extension.go

@@ -0,0 +1,549 @@
+package msgp
+
+import (
+	"fmt"
+	"math"
+)
+
+const (
+	// Complex64Extension is the extension number used for complex64
+	Complex64Extension = 3
+
+	// Complex128Extension is the extension number used for complex128
+	Complex128Extension = 4
+
+	// TimeExtension is the extension number used for time.Time
+	TimeExtension = 5
+)
+
+// our extensions live here
+var extensionReg = make(map[int8]func() Extension)
+
+// RegisterExtension registers extensions so that they
+// can be initialized and returned by methods that
+// decode `interface{}` values. This should only
+// be called during initialization. f() should return
+// a newly-initialized zero value of the extension. Keep in
+// mind that extensions 3, 4, and 5 are reserved for
+// complex64, complex128, and time.Time, respectively,
+// and that MessagePack reserves extension types from -127 to -1.
+//
+// For example, if you wanted to register a user-defined struct:
+//
+//  msgp.RegisterExtension(10, func() msgp.Extension { &MyExtension{} })
+//
+// RegisterExtension will panic if you call it multiple times
+// with the same 'typ' argument, or if you use a reserved
+// type (3, 4, or 5).
+func RegisterExtension(typ int8, f func() Extension) {
+	switch typ {
+	case Complex64Extension, Complex128Extension, TimeExtension:
+		panic(fmt.Sprint("msgp: forbidden extension type:", typ))
+	}
+	if _, ok := extensionReg[typ]; ok {
+		panic(fmt.Sprint("msgp: RegisterExtension() called with typ", typ, "more than once"))
+	}
+	extensionReg[typ] = f
+}
+
+// ExtensionTypeError is an error type returned
+// when there is a mis-match between an extension type
+// and the type encoded on the wire
+type ExtensionTypeError struct {
+	Got  int8
+	Want int8
+}
+
+// Error implements the error interface
+func (e ExtensionTypeError) Error() string {
+	return fmt.Sprintf("msgp: error decoding extension: wanted type %d; got type %d", e.Want, e.Got)
+}
+
+// Resumable returns 'true' for ExtensionTypeErrors
+func (e ExtensionTypeError) Resumable() bool { return true }
+
+func errExt(got int8, wanted int8) error {
+	return ExtensionTypeError{Got: got, Want: wanted}
+}
+
+// Extension is the interface fulfilled
+// by types that want to define their
+// own binary encoding.
+type Extension interface {
+	// ExtensionType should return
+	// a int8 that identifies the concrete
+	// type of the extension. (Types <0 are
+	// officially reserved by the MessagePack
+	// specifications.)
+	ExtensionType() int8
+
+	// Len should return the length
+	// of the data to be encoded
+	Len() int
+
+	// MarshalBinaryTo should copy
+	// the data into the supplied slice,
+	// assuming that the slice has length Len()
+	MarshalBinaryTo([]byte) error
+
+	UnmarshalBinary([]byte) error
+}
+
+// RawExtension implements the Extension interface
+type RawExtension struct {
+	Data []byte
+	Type int8
+}
+
+// ExtensionType implements Extension.ExtensionType, and returns r.Type
+func (r *RawExtension) ExtensionType() int8 { return r.Type }
+
+// Len implements Extension.Len, and returns len(r.Data)
+func (r *RawExtension) Len() int { return len(r.Data) }
+
+// MarshalBinaryTo implements Extension.MarshalBinaryTo,
+// and returns a copy of r.Data
+func (r *RawExtension) MarshalBinaryTo(d []byte) error {
+	copy(d, r.Data)
+	return nil
+}
+
+// UnmarshalBinary implements Extension.UnmarshalBinary,
+// and sets r.Data to the contents of the provided slice
+func (r *RawExtension) UnmarshalBinary(b []byte) error {
+	if cap(r.Data) >= len(b) {
+		r.Data = r.Data[0:len(b)]
+	} else {
+		r.Data = make([]byte, len(b))
+	}
+	copy(r.Data, b)
+	return nil
+}
+
+// WriteExtension writes an extension type to the writer
+func (mw *Writer) WriteExtension(e Extension) error {
+	l := e.Len()
+	var err error
+	switch l {
+	case 0:
+		o, err := mw.require(3)
+		if err != nil {
+			return err
+		}
+		mw.buf[o] = mext8
+		mw.buf[o+1] = 0
+		mw.buf[o+2] = byte(e.ExtensionType())
+	case 1:
+		o, err := mw.require(2)
+		if err != nil {
+			return err
+		}
+		mw.buf[o] = mfixext1
+		mw.buf[o+1] = byte(e.ExtensionType())
+	case 2:
+		o, err := mw.require(2)
+		if err != nil {
+			return err
+		}
+		mw.buf[o] = mfixext2
+		mw.buf[o+1] = byte(e.ExtensionType())
+	case 4:
+		o, err := mw.require(2)
+		if err != nil {
+			return err
+		}
+		mw.buf[o] = mfixext4
+		mw.buf[o+1] = byte(e.ExtensionType())
+	case 8:
+		o, err := mw.require(2)
+		if err != nil {
+			return err
+		}
+		mw.buf[o] = mfixext8
+		mw.buf[o+1] = byte(e.ExtensionType())
+	case 16:
+		o, err := mw.require(2)
+		if err != nil {
+			return err
+		}
+		mw.buf[o] = mfixext16
+		mw.buf[o+1] = byte(e.ExtensionType())
+	default:
+		switch {
+		case l < math.MaxUint8:
+			o, err := mw.require(3)
+			if err != nil {
+				return err
+			}
+			mw.buf[o] = mext8
+			mw.buf[o+1] = byte(uint8(l))
+			mw.buf[o+2] = byte(e.ExtensionType())
+		case l < math.MaxUint16:
+			o, err := mw.require(4)
+			if err != nil {
+				return err
+			}
+			mw.buf[o] = mext16
+			big.PutUint16(mw.buf[o+1:], uint16(l))
+			mw.buf[o+3] = byte(e.ExtensionType())
+		default:
+			o, err := mw.require(6)
+			if err != nil {
+				return err
+			}
+			mw.buf[o] = mext32
+			big.PutUint32(mw.buf[o+1:], uint32(l))
+			mw.buf[o+5] = byte(e.ExtensionType())
+		}
+	}
+	// we can only write directly to the
+	// buffer if we're sure that it
+	// fits the object
+	if l <= mw.bufsize() {
+		o, err := mw.require(l)
+		if err != nil {
+			return err
+		}
+		return e.MarshalBinaryTo(mw.buf[o:])
+	}
+	// here we create a new buffer
+	// just large enough for the body
+	// and save it as the write buffer
+	err = mw.flush()
+	if err != nil {
+		return err
+	}
+	buf := make([]byte, l)
+	err = e.MarshalBinaryTo(buf)
+	if err != nil {
+		return err
+	}
+	mw.buf = buf
+	mw.wloc = l
+	return nil
+}
+
+// peek at the extension type, assuming the next
+// kind to be read is Extension
+func (m *Reader) peekExtensionType() (int8, error) {
+	p, err := m.R.Peek(2)
+	if err != nil {
+		return 0, err
+	}
+	spec := sizes[p[0]]
+	if spec.typ != ExtensionType {
+		return 0, badPrefix(ExtensionType, p[0])
+	}
+	if spec.extra == constsize {
+		return int8(p[1]), nil
+	}
+	size := spec.size
+	p, err = m.R.Peek(int(size))
+	if err != nil {
+		return 0, err
+	}
+	return int8(p[size-1]), nil
+}
+
+// peekExtension peeks at the extension encoding type
+// (must guarantee at least 1 byte in 'b')
+func peekExtension(b []byte) (int8, error) {
+	spec := sizes[b[0]]
+	size := spec.size
+	if spec.typ != ExtensionType {
+		return 0, badPrefix(ExtensionType, b[0])
+	}
+	if len(b) < int(size) {
+		return 0, ErrShortBytes
+	}
+	// for fixed extensions,
+	// the type information is in
+	// the second byte
+	if spec.extra == constsize {
+		return int8(b[1]), nil
+	}
+	// otherwise, it's in the last
+	// part of the prefix
+	return int8(b[size-1]), nil
+}
+
+// ReadExtension reads the next object from the reader
+// as an extension. ReadExtension will fail if the next
+// object in the stream is not an extension, or if
+// e.Type() is not the same as the wire type.
+func (m *Reader) ReadExtension(e Extension) (err error) {
+	var p []byte
+	p, err = m.R.Peek(2)
+	if err != nil {
+		return
+	}
+	lead := p[0]
+	var read int
+	var off int
+	switch lead {
+	case mfixext1:
+		if int8(p[1]) != e.ExtensionType() {
+			err = errExt(int8(p[1]), e.ExtensionType())
+			return
+		}
+		p, err = m.R.Peek(3)
+		if err != nil {
+			return
+		}
+		err = e.UnmarshalBinary(p[2:])
+		if err == nil {
+			_, err = m.R.Skip(3)
+		}
+		return
+
+	case mfixext2:
+		if int8(p[1]) != e.ExtensionType() {
+			err = errExt(int8(p[1]), e.ExtensionType())
+			return
+		}
+		p, err = m.R.Peek(4)
+		if err != nil {
+			return
+		}
+		err = e.UnmarshalBinary(p[2:])
+		if err == nil {
+			_, err = m.R.Skip(4)
+		}
+		return
+
+	case mfixext4:
+		if int8(p[1]) != e.ExtensionType() {
+			err = errExt(int8(p[1]), e.ExtensionType())
+			return
+		}
+		p, err = m.R.Peek(6)
+		if err != nil {
+			return
+		}
+		err = e.UnmarshalBinary(p[2:])
+		if err == nil {
+			_, err = m.R.Skip(6)
+		}
+		return
+
+	case mfixext8:
+		if int8(p[1]) != e.ExtensionType() {
+			err = errExt(int8(p[1]), e.ExtensionType())
+			return
+		}
+		p, err = m.R.Peek(10)
+		if err != nil {
+			return
+		}
+		err = e.UnmarshalBinary(p[2:])
+		if err == nil {
+			_, err = m.R.Skip(10)
+		}
+		return
+
+	case mfixext16:
+		if int8(p[1]) != e.ExtensionType() {
+			err = errExt(int8(p[1]), e.ExtensionType())
+			return
+		}
+		p, err = m.R.Peek(18)
+		if err != nil {
+			return
+		}
+		err = e.UnmarshalBinary(p[2:])
+		if err == nil {
+			_, err = m.R.Skip(18)
+		}
+		return
+
+	case mext8:
+		p, err = m.R.Peek(3)
+		if err != nil {
+			return
+		}
+		if int8(p[2]) != e.ExtensionType() {
+			err = errExt(int8(p[2]), e.ExtensionType())
+			return
+		}
+		read = int(uint8(p[1]))
+		off = 3
+
+	case mext16:
+		p, err = m.R.Peek(4)
+		if err != nil {
+			return
+		}
+		if int8(p[3]) != e.ExtensionType() {
+			err = errExt(int8(p[3]), e.ExtensionType())
+			return
+		}
+		read = int(big.Uint16(p[1:]))
+		off = 4
+
+	case mext32:
+		p, err = m.R.Peek(6)
+		if err != nil {
+			return
+		}
+		if int8(p[5]) != e.ExtensionType() {
+			err = errExt(int8(p[5]), e.ExtensionType())
+			return
+		}
+		read = int(big.Uint32(p[1:]))
+		off = 6
+
+	default:
+		err = badPrefix(ExtensionType, lead)
+		return
+	}
+
+	p, err = m.R.Peek(read + off)
+	if err != nil {
+		return
+	}
+	err = e.UnmarshalBinary(p[off:])
+	if err == nil {
+		_, err = m.R.Skip(read + off)
+	}
+	return
+}
+
+// AppendExtension appends a MessagePack extension to the provided slice
+func AppendExtension(b []byte, e Extension) ([]byte, error) {
+	l := e.Len()
+	var o []byte
+	var n int
+	switch l {
+	case 0:
+		o, n = ensure(b, 3)
+		o[n] = mext8
+		o[n+1] = 0
+		o[n+2] = byte(e.ExtensionType())
+		return o[:n+3], nil
+	case 1:
+		o, n = ensure(b, 3)
+		o[n] = mfixext1
+		o[n+1] = byte(e.ExtensionType())
+		n += 2
+	case 2:
+		o, n = ensure(b, 4)
+		o[n] = mfixext2
+		o[n+1] = byte(e.ExtensionType())
+		n += 2
+	case 4:
+		o, n = ensure(b, 6)
+		o[n] = mfixext4
+		o[n+1] = byte(e.ExtensionType())
+		n += 2
+	case 8:
+		o, n = ensure(b, 10)
+		o[n] = mfixext8
+		o[n+1] = byte(e.ExtensionType())
+		n += 2
+	case 16:
+		o, n = ensure(b, 18)
+		o[n] = mfixext16
+		o[n+1] = byte(e.ExtensionType())
+		n += 2
+	default:
+		switch {
+		case l < math.MaxUint8:
+			o, n = ensure(b, l+3)
+			o[n] = mext8
+			o[n+1] = byte(uint8(l))
+			o[n+2] = byte(e.ExtensionType())
+			n += 3
+		case l < math.MaxUint16:
+			o, n = ensure(b, l+4)
+			o[n] = mext16
+			big.PutUint16(o[n+1:], uint16(l))
+			o[n+3] = byte(e.ExtensionType())
+			n += 4
+		default:
+			o, n = ensure(b, l+6)
+			o[n] = mext32
+			big.PutUint32(o[n+1:], uint32(l))
+			o[n+5] = byte(e.ExtensionType())
+			n += 6
+		}
+	}
+	return o, e.MarshalBinaryTo(o[n:])
+}
+
+// ReadExtensionBytes reads an extension from 'b' into 'e'
+// and returns any remaining bytes.
+// Possible errors:
+// - ErrShortBytes ('b' not long enough)
+// - ExtensionTypeErorr{} (wire type not the same as e.Type())
+// - TypeErorr{} (next object not an extension)
+// - InvalidPrefixError
+// - An umarshal error returned from e.UnmarshalBinary
+func ReadExtensionBytes(b []byte, e Extension) ([]byte, error) {
+	l := len(b)
+	if l < 3 {
+		return b, ErrShortBytes
+	}
+	lead := b[0]
+	var (
+		sz  int // size of 'data'
+		off int // offset of 'data'
+		typ int8
+	)
+	switch lead {
+	case mfixext1:
+		typ = int8(b[1])
+		sz = 1
+		off = 2
+	case mfixext2:
+		typ = int8(b[1])
+		sz = 2
+		off = 2
+	case mfixext4:
+		typ = int8(b[1])
+		sz = 4
+		off = 2
+	case mfixext8:
+		typ = int8(b[1])
+		sz = 8
+		off = 2
+	case mfixext16:
+		typ = int8(b[1])
+		sz = 16
+		off = 2
+	case mext8:
+		sz = int(uint8(b[1]))
+		typ = int8(b[2])
+		off = 3
+		if sz == 0 {
+			return b[3:], e.UnmarshalBinary(b[3:3])
+		}
+	case mext16:
+		if l < 4 {
+			return b, ErrShortBytes
+		}
+		sz = int(big.Uint16(b[1:]))
+		typ = int8(b[3])
+		off = 4
+	case mext32:
+		if l < 6 {
+			return b, ErrShortBytes
+		}
+		sz = int(big.Uint32(b[1:]))
+		typ = int8(b[5])
+		off = 6
+	default:
+		return b, badPrefix(ExtensionType, lead)
+	}
+
+	if typ != e.ExtensionType() {
+		return b, errExt(typ, e.ExtensionType())
+	}
+
+	// the data of the extension starts
+	// at 'off' and is 'sz' bytes long
+	if len(b[off:]) < sz {
+		return b, ErrShortBytes
+	}
+	tot := off + sz
+	return b[tot:], e.UnmarshalBinary(b[off:tot])
+}