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path: root/vendor/github.com/kr/logfmt/unquote.go
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-rw-r--r--vendor/github.com/kr/logfmt/unquote.go149
1 files changed, 149 insertions, 0 deletions
diff --git a/vendor/github.com/kr/logfmt/unquote.go b/vendor/github.com/kr/logfmt/unquote.go
new file mode 100644
index 0000000..fb088a4
--- /dev/null
+++ b/vendor/github.com/kr/logfmt/unquote.go
@@ -0,0 +1,149 @@
+package logfmt
+
+import (
+ "strconv"
+ "unicode"
+ "unicode/utf16"
+ "unicode/utf8"
+)
+
+// Taken from Go's encoding/json
+
+// 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.
+
+// 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)
+}
+
+// unquote converts a quoted JSON string literal s into an actual string t.
+// The rules are different than for Go, so cannot use strconv.Unquote.
+func unquote(s []byte) (t string, ok bool) {
+ s, ok = unquoteBytes(s)
+ t = string(s)
+ return
+}
+
+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 && size == 1 {
+ 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
+}
nihil fit ex nihilo