GoToSocial/vendor/github.com/golang/geo/s2/encode.go
Tobi Smethurst 98263a7de6
Grand test fixup (#138)
* start fixing up tests

* fix up tests + automate with drone

* fiddle with linting

* messing about with drone.yml

* some more fiddling

* hmmm

* add cache

* add vendor directory

* verbose

* ci updates

* update some little things

* update sig
2021-08-12 21:03:24 +02:00

225 lines
4.3 KiB
Go

// Copyright 2017 Google Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package s2
import (
"encoding/binary"
"io"
"math"
)
const (
// encodingVersion is the current version of the encoding
// format that is compatible with C++ and other S2 libraries.
encodingVersion = int8(1)
// encodingCompressedVersion is the current version of the
// compressed format.
encodingCompressedVersion = int8(4)
)
// encoder handles the specifics of encoding for S2 types.
type encoder struct {
w io.Writer // the real writer passed to Encode
err error
}
func (e *encoder) writeUvarint(x uint64) {
if e.err != nil {
return
}
var buf [binary.MaxVarintLen64]byte
n := binary.PutUvarint(buf[:], x)
_, e.err = e.w.Write(buf[:n])
}
func (e *encoder) writeBool(x bool) {
if e.err != nil {
return
}
var val int8
if x {
val = 1
}
e.err = binary.Write(e.w, binary.LittleEndian, val)
}
func (e *encoder) writeInt8(x int8) {
if e.err != nil {
return
}
e.err = binary.Write(e.w, binary.LittleEndian, x)
}
func (e *encoder) writeInt16(x int16) {
if e.err != nil {
return
}
e.err = binary.Write(e.w, binary.LittleEndian, x)
}
func (e *encoder) writeInt32(x int32) {
if e.err != nil {
return
}
e.err = binary.Write(e.w, binary.LittleEndian, x)
}
func (e *encoder) writeInt64(x int64) {
if e.err != nil {
return
}
e.err = binary.Write(e.w, binary.LittleEndian, x)
}
func (e *encoder) writeUint8(x uint8) {
if e.err != nil {
return
}
_, e.err = e.w.Write([]byte{x})
}
func (e *encoder) writeUint32(x uint32) {
if e.err != nil {
return
}
e.err = binary.Write(e.w, binary.LittleEndian, x)
}
func (e *encoder) writeUint64(x uint64) {
if e.err != nil {
return
}
e.err = binary.Write(e.w, binary.LittleEndian, x)
}
func (e *encoder) writeFloat32(x float32) {
if e.err != nil {
return
}
e.err = binary.Write(e.w, binary.LittleEndian, x)
}
func (e *encoder) writeFloat64(x float64) {
if e.err != nil {
return
}
e.err = binary.Write(e.w, binary.LittleEndian, x)
}
type byteReader interface {
io.Reader
io.ByteReader
}
// byteReaderAdapter embellishes an io.Reader with a ReadByte method,
// so that it implements the io.ByteReader interface.
type byteReaderAdapter struct {
io.Reader
}
func (b byteReaderAdapter) ReadByte() (byte, error) {
buf := []byte{0}
_, err := io.ReadFull(b, buf)
return buf[0], err
}
func asByteReader(r io.Reader) byteReader {
if br, ok := r.(byteReader); ok {
return br
}
return byteReaderAdapter{r}
}
type decoder struct {
r byteReader // the real reader passed to Decode
err error
buf []byte
}
// Get a buffer of size 8, to avoid allocating over and over.
func (d *decoder) buffer() []byte {
if d.buf == nil {
d.buf = make([]byte, 8)
}
return d.buf
}
func (d *decoder) readBool() (x bool) {
if d.err != nil {
return
}
var val int8
d.err = binary.Read(d.r, binary.LittleEndian, &val)
return val == 1
}
func (d *decoder) readInt8() (x int8) {
if d.err != nil {
return
}
d.err = binary.Read(d.r, binary.LittleEndian, &x)
return
}
func (d *decoder) readInt64() (x int64) {
if d.err != nil {
return
}
d.err = binary.Read(d.r, binary.LittleEndian, &x)
return
}
func (d *decoder) readUint8() (x uint8) {
if d.err != nil {
return
}
x, d.err = d.r.ReadByte()
return
}
func (d *decoder) readUint32() (x uint32) {
if d.err != nil {
return
}
d.err = binary.Read(d.r, binary.LittleEndian, &x)
return
}
func (d *decoder) readUint64() (x uint64) {
if d.err != nil {
return
}
d.err = binary.Read(d.r, binary.LittleEndian, &x)
return
}
func (d *decoder) readFloat64() float64 {
if d.err != nil {
return 0
}
buf := d.buffer()
_, d.err = io.ReadFull(d.r, buf)
return math.Float64frombits(binary.LittleEndian.Uint64(buf))
}
func (d *decoder) readUvarint() (x uint64) {
if d.err != nil {
return
}
x, d.err = binary.ReadUvarint(d.r)
return
}