move gotd fork into repo. (#111)

- update to latest telegram layer
- remove some references to fields in tg.Entities that don't exist in
the schema
- originally added here:
https://github.com/beeper/td/commit/820929062a2ba0104397bc01235ab58a9cff780e
  - referenced here
-
https://github.com/mautrix/telegramgo/commit/124f0967ed195b5a380c9bd02e170ada9710dde3
-
https://github.com/mautrix/telegramgo/commit/4205047aab2e0639217148b5d125bfaab668bd8e

pkg/gotd/bin/encode.go

@@ -0,0 +1,107 @@
+package bin
+
+import (
+	"encoding/binary"
+	"math"
+)
+
+// PutID serializes type definition id, like a8509bda.
+func (b *Buffer) PutID(id uint32) {
+	b.PutUint32(id)
+}
+
+// Put appends raw bytes to buffer.
+//
+// Buffer does not retain raw.
+func (b *Buffer) Put(raw []byte) {
+	b.Buf = append(b.Buf, raw...)
+}
+
+// PutString serializes bare string.
+func (b *Buffer) PutString(s string) {
+	b.Buf = encodeString(b.Buf, s)
+}
+
+// PutBytes serializes bare byte string.
+func (b *Buffer) PutBytes(v []byte) {
+	b.Buf = encodeBytes(b.Buf, v)
+}
+
+// PutVectorHeader serializes vector header with provided length.
+func (b *Buffer) PutVectorHeader(length int) {
+	b.PutID(TypeVector)
+	b.PutInt32(int32(length))
+}
+
+// PutInt serializes v as signed 32-bit integer.
+//
+// If v is bigger than 32-bit, `behavior` is undefined.
+func (b *Buffer) PutInt(v int) {
+	b.PutInt32(int32(v))
+}
+
+// PutBool serializes bare boolean.
+func (b *Buffer) PutBool(v bool) {
+	switch v {
+	case true:
+		b.PutID(TypeTrue)
+	case false:
+		b.PutID(TypeFalse)
+	}
+}
+
+// PutUint16 serializes unsigned 16-bit integer.
+func (b *Buffer) PutUint16(v uint16) {
+	t := make([]byte, 2)
+	binary.LittleEndian.PutUint16(t, v)
+	b.Buf = append(b.Buf, t...)
+}
+
+// PutInt32 serializes signed 32-bit integer.
+func (b *Buffer) PutInt32(v int32) {
+	b.PutUint32(uint32(v))
+}
+
+// PutUint32 serializes unsigned 32-bit integer.
+func (b *Buffer) PutUint32(v uint32) {
+	t := make([]byte, Word)
+	binary.LittleEndian.PutUint32(t, v)
+	b.Buf = append(b.Buf, t...)
+}
+
+// PutInt53 serializes v as signed integer.
+func (b *Buffer) PutInt53(v int64) {
+	b.PutLong(v)
+}
+
+// PutLong serializes v as signed integer.
+func (b *Buffer) PutLong(v int64) {
+	b.PutUint64(uint64(v))
+}
+
+// PutUint64 serializes v as unsigned 64-bit integer.
+func (b *Buffer) PutUint64(v uint64) {
+	t := make([]byte, Word*2)
+	binary.LittleEndian.PutUint64(t, v)
+	b.Buf = append(b.Buf, t...)
+}
+
+// PutDouble serializes v as 64-bit floating point.
+func (b *Buffer) PutDouble(v float64) {
+	b.PutUint64(math.Float64bits(v))
+}
+
+// PutInt128 serializes v as 128-bit signed integer.
+func (b *Buffer) PutInt128(v Int128) {
+	b.Buf = append(b.Buf, v[:]...)
+}
+
+// PutInt256 serializes v as 256-bit signed integer.
+func (b *Buffer) PutInt256(v Int256) {
+	b.Buf = append(b.Buf, v[:]...)
+}
+
+// Reset buffer to zero length.
+func (b *Buffer) Reset() {
+	b.Buf = b.Buf[:0]
+}