+++ /dev/null
-package logfmt
-
-import (
- "bytes"
- "io"
- "strconv"
- "sync"
- "unicode"
- "unicode/utf16"
- "unicode/utf8"
-)
-
-// Taken from Go's encoding/json and modified for use here.
-
-// Copyright 2010 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.
-
-var hex = "0123456789abcdef"
-
-var bufferPool = sync.Pool{
- New: func() interface{} {
- return &bytes.Buffer{}
- },
-}
-
-func getBuffer() *bytes.Buffer {
- return bufferPool.Get().(*bytes.Buffer)
-}
-
-func poolBuffer(buf *bytes.Buffer) {
- buf.Reset()
- bufferPool.Put(buf)
-}
-
-// NOTE: keep in sync with writeQuotedBytes below.
-func writeQuotedString(w io.Writer, s string) (int, error) {
- buf := getBuffer()
- buf.WriteByte('"')
- start := 0
- for i := 0; i < len(s); {
- if b := s[i]; b < utf8.RuneSelf {
- if 0x20 <= b && b != '\\' && b != '"' {
- i++
- continue
- }
- if start < i {
- buf.WriteString(s[start:i])
- }
- switch b {
- case '\\', '"':
- buf.WriteByte('\\')
- buf.WriteByte(b)
- case '\n':
- buf.WriteByte('\\')
- buf.WriteByte('n')
- case '\r':
- buf.WriteByte('\\')
- buf.WriteByte('r')
- case '\t':
- buf.WriteByte('\\')
- buf.WriteByte('t')
- default:
- // This encodes bytes < 0x20 except for \n, \r, and \t.
- buf.WriteString(`\u00`)
- buf.WriteByte(hex[b>>4])
- buf.WriteByte(hex[b&0xF])
- }
- i++
- start = i
- continue
- }
- c, size := utf8.DecodeRuneInString(s[i:])
- if c == utf8.RuneError {
- if start < i {
- buf.WriteString(s[start:i])
- }
- buf.WriteString(`\ufffd`)
- i += size
- start = i
- continue
- }
- i += size
- }
- if start < len(s) {
- buf.WriteString(s[start:])
- }
- buf.WriteByte('"')
- n, err := w.Write(buf.Bytes())
- poolBuffer(buf)
- return n, err
-}
-
-// NOTE: keep in sync with writeQuoteString above.
-func writeQuotedBytes(w io.Writer, s []byte) (int, error) {
- buf := getBuffer()
- buf.WriteByte('"')
- start := 0
- for i := 0; i < len(s); {
- if b := s[i]; b < utf8.RuneSelf {
- if 0x20 <= b && b != '\\' && b != '"' {
- i++
- continue
- }
- if start < i {
- buf.Write(s[start:i])
- }
- switch b {
- case '\\', '"':
- buf.WriteByte('\\')
- buf.WriteByte(b)
- case '\n':
- buf.WriteByte('\\')
- buf.WriteByte('n')
- case '\r':
- buf.WriteByte('\\')
- buf.WriteByte('r')
- case '\t':
- buf.WriteByte('\\')
- buf.WriteByte('t')
- default:
- // This encodes bytes < 0x20 except for \n, \r, and \t.
- buf.WriteString(`\u00`)
- buf.WriteByte(hex[b>>4])
- buf.WriteByte(hex[b&0xF])
- }
- i++
- start = i
- continue
- }
- c, size := utf8.DecodeRune(s[i:])
- if c == utf8.RuneError {
- if start < i {
- buf.Write(s[start:i])
- }
- buf.WriteString(`\ufffd`)
- i += size
- start = i
- continue
- }
- i += size
- }
- if start < len(s) {
- buf.Write(s[start:])
- }
- buf.WriteByte('"')
- n, err := w.Write(buf.Bytes())
- poolBuffer(buf)
- return n, err
-}
-
-// getu4 decodes \uXXXX from the beginning of s, returning the hex value,
-// or it returns -1.
-func getu4(s []byte) rune {
- if len(s) < 6 || s[0] != '\\' || s[1] != 'u' {
- return -1
- }
- r, err := strconv.ParseUint(string(s[2:6]), 16, 64)
- if err != nil {
- return -1
- }
- return rune(r)
-}
-
-func unquoteBytes(s []byte) (t []byte, ok bool) {
- if len(s) < 2 || s[0] != '"' || s[len(s)-1] != '"' {
- return
- }
- s = s[1 : len(s)-1]
-
- // Check for unusual characters. If there are none,
- // then no unquoting is needed, so return a slice of the
- // original bytes.
- r := 0
- for r < len(s) {
- c := s[r]
- if c == '\\' || c == '"' || c < ' ' {
- break
- }
- if c < utf8.RuneSelf {
- r++
- continue
- }
- rr, size := utf8.DecodeRune(s[r:])
- if rr == utf8.RuneError {
- break
- }
- r += size
- }
- if r == len(s) {
- return s, true
- }
-
- b := make([]byte, len(s)+2*utf8.UTFMax)
- w := copy(b, s[0:r])
- for r < len(s) {
- // Out of room? Can only happen if s is full of
- // malformed UTF-8 and we're replacing each
- // byte with RuneError.
- if w >= len(b)-2*utf8.UTFMax {
- nb := make([]byte, (len(b)+utf8.UTFMax)*2)
- copy(nb, b[0:w])
- b = nb
- }
- switch c := s[r]; {
- case c == '\\':
- r++
- if r >= len(s) {
- return
- }
- switch s[r] {
- default:
- return
- case '"', '\\', '/', '\'':
- b[w] = s[r]
- r++
- w++
- case 'b':
- b[w] = '\b'
- r++
- w++
- case 'f':
- b[w] = '\f'
- r++
- w++
- case 'n':
- b[w] = '\n'
- r++
- w++
- case 'r':
- b[w] = '\r'
- r++
- w++
- case 't':
- b[w] = '\t'
- r++
- w++
- case 'u':
- r--
- rr := getu4(s[r:])
- if rr < 0 {
- return
- }
- r += 6
- if utf16.IsSurrogate(rr) {
- rr1 := getu4(s[r:])
- if dec := utf16.DecodeRune(rr, rr1); dec != unicode.ReplacementChar {
- // A valid pair; consume.
- r += 6
- w += utf8.EncodeRune(b[w:], dec)
- break
- }
- // Invalid surrogate; fall back to replacement rune.
- rr = unicode.ReplacementChar
- }
- w += utf8.EncodeRune(b[w:], rr)
- }
-
- // Quote, control characters are invalid.
- case c == '"', c < ' ':
- return
-
- // ASCII
- case c < utf8.RuneSelf:
- b[w] = c
- r++
- w++
-
- // Coerce to well-formed UTF-8.
- default:
- rr, size := utf8.DecodeRune(s[r:])
- r += size
- w += utf8.EncodeRune(b[w:], rr)
- }
- }
- return b[0:w], true
-}
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