diff options
Diffstat (limited to 'vendor/github.com/go-logfmt/logfmt/jsonstring.go')
| -rw-r--r-- | vendor/github.com/go-logfmt/logfmt/jsonstring.go | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/vendor/github.com/go-logfmt/logfmt/jsonstring.go b/vendor/github.com/go-logfmt/logfmt/jsonstring.go new file mode 100644 index 0000000..030ac85 --- /dev/null +++ b/vendor/github.com/go-logfmt/logfmt/jsonstring.go @@ -0,0 +1,277 @@ +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 +} |