mirror of
https://github.com/cwinfo/matterbridge.git
synced 2024-11-25 21:21:35 +00:00
271 lines
7.0 KiB
Go
271 lines
7.0 KiB
Go
// Copyright 2018 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package text
|
|
|
|
import (
|
|
"math"
|
|
"math/bits"
|
|
"strconv"
|
|
"strings"
|
|
"unicode/utf8"
|
|
|
|
"google.golang.org/protobuf/internal/detrand"
|
|
"google.golang.org/protobuf/internal/errors"
|
|
)
|
|
|
|
// encType represents an encoding type.
|
|
type encType uint8
|
|
|
|
const (
|
|
_ encType = (1 << iota) / 2
|
|
name
|
|
scalar
|
|
messageOpen
|
|
messageClose
|
|
)
|
|
|
|
// Encoder provides methods to write out textproto constructs and values. The user is
|
|
// responsible for producing valid sequences of constructs and values.
|
|
type Encoder struct {
|
|
encoderState
|
|
|
|
indent string
|
|
delims [2]byte
|
|
outputASCII bool
|
|
}
|
|
|
|
type encoderState struct {
|
|
lastType encType
|
|
indents []byte
|
|
out []byte
|
|
}
|
|
|
|
// NewEncoder returns an Encoder.
|
|
//
|
|
// If indent is a non-empty string, it causes every entry in a List or Message
|
|
// to be preceded by the indent and trailed by a newline.
|
|
//
|
|
// If delims is not the zero value, it controls the delimiter characters used
|
|
// for messages (e.g., "{}" vs "<>").
|
|
//
|
|
// If outputASCII is true, strings will be serialized in such a way that
|
|
// multi-byte UTF-8 sequences are escaped. This property ensures that the
|
|
// overall output is ASCII (as opposed to UTF-8).
|
|
func NewEncoder(indent string, delims [2]byte, outputASCII bool) (*Encoder, error) {
|
|
e := &Encoder{}
|
|
if len(indent) > 0 {
|
|
if strings.Trim(indent, " \t") != "" {
|
|
return nil, errors.New("indent may only be composed of space and tab characters")
|
|
}
|
|
e.indent = indent
|
|
}
|
|
switch delims {
|
|
case [2]byte{0, 0}:
|
|
e.delims = [2]byte{'{', '}'}
|
|
case [2]byte{'{', '}'}, [2]byte{'<', '>'}:
|
|
e.delims = delims
|
|
default:
|
|
return nil, errors.New("delimiters may only be \"{}\" or \"<>\"")
|
|
}
|
|
e.outputASCII = outputASCII
|
|
|
|
return e, nil
|
|
}
|
|
|
|
// Bytes returns the content of the written bytes.
|
|
func (e *Encoder) Bytes() []byte {
|
|
return e.out
|
|
}
|
|
|
|
// StartMessage writes out the '{' or '<' symbol.
|
|
func (e *Encoder) StartMessage() {
|
|
e.prepareNext(messageOpen)
|
|
e.out = append(e.out, e.delims[0])
|
|
}
|
|
|
|
// EndMessage writes out the '}' or '>' symbol.
|
|
func (e *Encoder) EndMessage() {
|
|
e.prepareNext(messageClose)
|
|
e.out = append(e.out, e.delims[1])
|
|
}
|
|
|
|
// WriteName writes out the field name and the separator ':'.
|
|
func (e *Encoder) WriteName(s string) {
|
|
e.prepareNext(name)
|
|
e.out = append(e.out, s...)
|
|
e.out = append(e.out, ':')
|
|
}
|
|
|
|
// WriteBool writes out the given boolean value.
|
|
func (e *Encoder) WriteBool(b bool) {
|
|
if b {
|
|
e.WriteLiteral("true")
|
|
} else {
|
|
e.WriteLiteral("false")
|
|
}
|
|
}
|
|
|
|
// WriteString writes out the given string value.
|
|
func (e *Encoder) WriteString(s string) {
|
|
e.prepareNext(scalar)
|
|
e.out = appendString(e.out, s, e.outputASCII)
|
|
}
|
|
|
|
func appendString(out []byte, in string, outputASCII bool) []byte {
|
|
out = append(out, '"')
|
|
i := indexNeedEscapeInString(in)
|
|
in, out = in[i:], append(out, in[:i]...)
|
|
for len(in) > 0 {
|
|
switch r, n := utf8.DecodeRuneInString(in); {
|
|
case r == utf8.RuneError && n == 1:
|
|
// We do not report invalid UTF-8 because strings in the text format
|
|
// are used to represent both the proto string and bytes type.
|
|
r = rune(in[0])
|
|
fallthrough
|
|
case r < ' ' || r == '"' || r == '\\' || r == 0x7f:
|
|
out = append(out, '\\')
|
|
switch r {
|
|
case '"', '\\':
|
|
out = append(out, byte(r))
|
|
case '\n':
|
|
out = append(out, 'n')
|
|
case '\r':
|
|
out = append(out, 'r')
|
|
case '\t':
|
|
out = append(out, 't')
|
|
default:
|
|
out = append(out, 'x')
|
|
out = append(out, "00"[1+(bits.Len32(uint32(r))-1)/4:]...)
|
|
out = strconv.AppendUint(out, uint64(r), 16)
|
|
}
|
|
in = in[n:]
|
|
case r >= utf8.RuneSelf && (outputASCII || r <= 0x009f):
|
|
out = append(out, '\\')
|
|
if r <= math.MaxUint16 {
|
|
out = append(out, 'u')
|
|
out = append(out, "0000"[1+(bits.Len32(uint32(r))-1)/4:]...)
|
|
out = strconv.AppendUint(out, uint64(r), 16)
|
|
} else {
|
|
out = append(out, 'U')
|
|
out = append(out, "00000000"[1+(bits.Len32(uint32(r))-1)/4:]...)
|
|
out = strconv.AppendUint(out, uint64(r), 16)
|
|
}
|
|
in = in[n:]
|
|
default:
|
|
i := indexNeedEscapeInString(in[n:])
|
|
in, out = in[n+i:], append(out, in[:n+i]...)
|
|
}
|
|
}
|
|
out = append(out, '"')
|
|
return out
|
|
}
|
|
|
|
// indexNeedEscapeInString returns the index of the character that needs
|
|
// escaping. If no characters need escaping, this returns the input length.
|
|
func indexNeedEscapeInString(s string) int {
|
|
for i := 0; i < len(s); i++ {
|
|
if c := s[i]; c < ' ' || c == '"' || c == '\'' || c == '\\' || c >= 0x7f {
|
|
return i
|
|
}
|
|
}
|
|
return len(s)
|
|
}
|
|
|
|
// WriteFloat writes out the given float value for given bitSize.
|
|
func (e *Encoder) WriteFloat(n float64, bitSize int) {
|
|
e.prepareNext(scalar)
|
|
e.out = appendFloat(e.out, n, bitSize)
|
|
}
|
|
|
|
func appendFloat(out []byte, n float64, bitSize int) []byte {
|
|
switch {
|
|
case math.IsNaN(n):
|
|
return append(out, "nan"...)
|
|
case math.IsInf(n, +1):
|
|
return append(out, "inf"...)
|
|
case math.IsInf(n, -1):
|
|
return append(out, "-inf"...)
|
|
default:
|
|
return strconv.AppendFloat(out, n, 'g', -1, bitSize)
|
|
}
|
|
}
|
|
|
|
// WriteInt writes out the given signed integer value.
|
|
func (e *Encoder) WriteInt(n int64) {
|
|
e.prepareNext(scalar)
|
|
e.out = append(e.out, strconv.FormatInt(n, 10)...)
|
|
}
|
|
|
|
// WriteUint writes out the given unsigned integer value.
|
|
func (e *Encoder) WriteUint(n uint64) {
|
|
e.prepareNext(scalar)
|
|
e.out = append(e.out, strconv.FormatUint(n, 10)...)
|
|
}
|
|
|
|
// WriteLiteral writes out the given string as a literal value without quotes.
|
|
// This is used for writing enum literal strings.
|
|
func (e *Encoder) WriteLiteral(s string) {
|
|
e.prepareNext(scalar)
|
|
e.out = append(e.out, s...)
|
|
}
|
|
|
|
// prepareNext adds possible space and indentation for the next value based
|
|
// on last encType and indent option. It also updates e.lastType to next.
|
|
func (e *Encoder) prepareNext(next encType) {
|
|
defer func() {
|
|
e.lastType = next
|
|
}()
|
|
|
|
// Single line.
|
|
if len(e.indent) == 0 {
|
|
// Add space after each field before the next one.
|
|
if e.lastType&(scalar|messageClose) != 0 && next == name {
|
|
e.out = append(e.out, ' ')
|
|
// Add a random extra space to make output unstable.
|
|
if detrand.Bool() {
|
|
e.out = append(e.out, ' ')
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
// Multi-line.
|
|
switch {
|
|
case e.lastType == name:
|
|
e.out = append(e.out, ' ')
|
|
// Add a random extra space after name: to make output unstable.
|
|
if detrand.Bool() {
|
|
e.out = append(e.out, ' ')
|
|
}
|
|
|
|
case e.lastType == messageOpen && next != messageClose:
|
|
e.indents = append(e.indents, e.indent...)
|
|
e.out = append(e.out, '\n')
|
|
e.out = append(e.out, e.indents...)
|
|
|
|
case e.lastType&(scalar|messageClose) != 0:
|
|
if next == messageClose {
|
|
e.indents = e.indents[:len(e.indents)-len(e.indent)]
|
|
}
|
|
e.out = append(e.out, '\n')
|
|
e.out = append(e.out, e.indents...)
|
|
}
|
|
}
|
|
|
|
// Snapshot returns the current snapshot for use in Reset.
|
|
func (e *Encoder) Snapshot() encoderState {
|
|
return e.encoderState
|
|
}
|
|
|
|
// Reset resets the Encoder to the given encoderState from a Snapshot.
|
|
func (e *Encoder) Reset(es encoderState) {
|
|
e.encoderState = es
|
|
}
|
|
|
|
// AppendString appends the escaped form of the input string to b.
|
|
func AppendString(b []byte, s string) []byte {
|
|
return appendString(b, s, false)
|
|
}
|