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Diffstat (limited to 'vendor/github.com/getlantern/hex/hex.go')
-rw-r--r--vendor/github.com/getlantern/hex/hex.go107
1 files changed, 107 insertions, 0 deletions
diff --git a/vendor/github.com/getlantern/hex/hex.go b/vendor/github.com/getlantern/hex/hex.go
new file mode 100644
index 0000000..d1270e9
--- /dev/null
+++ b/vendor/github.com/getlantern/hex/hex.go
@@ -0,0 +1,107 @@
+// Copyright 2009 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 hex implements hexadecimal encoding and decoding. It's taken almost
+// verbatim from golang/encoding/hex, however it allows using a different set
+// of encoding characters than the standard 0-F.
+package hex
+
+import (
+ "errors"
+ "fmt"
+)
+
+// DefaultEncoding behaves just like golang/encoding/hex.
+var DefaultEncoding = NewEncoding("0123456789abcdef")
+
+// An Encoding that uses a specific table of encoding characters.
+type Encoding struct {
+ hextable string
+}
+
+// NewEncoding constructs an Encoding using the given hextable.
+func NewEncoding(hextable string) *Encoding {
+ return &Encoding{hextable}
+}
+
+// EncodedLen returns the length of an encoding of n source bytes.
+func EncodedLen(n int) int { return n * 2 }
+
+// Encode encodes src into EncodedLen(len(src))
+// bytes of dst. As a convenience, it returns the number
+// of bytes written to dst, but this value is always EncodedLen(len(src)).
+// Encode implements hexadecimal encoding.
+func (e *Encoding) Encode(dst, src []byte) int {
+ for i, v := range src {
+ dst[i*2] = e.hextable[v>>4]
+ dst[i*2+1] = e.hextable[v&0x0f]
+ }
+
+ return len(src) * 2
+}
+
+// ErrLength results from decoding an odd length slice.
+var ErrLength = errors.New("encoding/hex: odd length hex string")
+
+// InvalidByteError values describe errors resulting from an invalid byte in a hex string.
+type InvalidByteError byte
+
+func (e InvalidByteError) Error() string {
+ return fmt.Sprintf("encoding/hex: invalid byte: %#U", rune(e))
+}
+
+func DecodedLen(x int) int { return x / 2 }
+
+// Decode decodes src into DecodedLen(len(src)) bytes, returning the actual
+// number of bytes written to dst.
+//
+// If Decode encounters invalid input, it returns an error describing the failure.
+func (e *Encoding) Decode(dst, src []byte) (int, error) {
+ if len(src)%2 == 1 {
+ return 0, ErrLength
+ }
+
+ for i := 0; i < len(src)/2; i++ {
+ a, ok := e.fromHexChar(src[i*2])
+ if !ok {
+ return 0, InvalidByteError(src[i*2])
+ }
+ b, ok := e.fromHexChar(src[i*2+1])
+ if !ok {
+ return 0, InvalidByteError(src[i*2+1])
+ }
+ dst[i] = (a << 4) | b
+ }
+
+ return len(src) / 2, nil
+}
+
+// fromHexChar converts a hex character into its value and a success flag.
+func (e *Encoding) fromHexChar(c byte) (byte, bool) {
+ for i, ch := range []byte(e.hextable) {
+ if ch == c {
+ return byte(i), true
+ }
+ }
+
+ return 0, false
+}
+
+// EncodeToString returns the hexadecimal encoding of src.
+func (e *Encoding) EncodeToString(src []byte) string {
+ dst := make([]byte, EncodedLen(len(src)))
+ e.Encode(dst, src)
+ return string(dst)
+}
+
+// DecodeString returns the bytes represented by the hexadecimal string s.
+func (e *Encoding) DecodeString(s string) ([]byte, error) {
+ src := []byte(s)
+ dst := make([]byte, DecodedLen(len(src)))
+ _, err := e.Decode(dst, src)
+ if err != nil {
+ return nil, err
+ }
+ return dst, nil
+}