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authorupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
committerupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
commit554fd8c5195424bdbcabf5de30fdc183aba391bd (patch)
tree976dc5ab7fddf506dadce60ae936f43f58787092 /libgo/go/encoding/hex
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Diffstat (limited to 'libgo/go/encoding/hex')
-rw-r--r--libgo/go/encoding/hex/hex.go101
-rw-r--r--libgo/go/encoding/hex/hex_test.go149
2 files changed, 250 insertions, 0 deletions
diff --git a/libgo/go/encoding/hex/hex.go b/libgo/go/encoding/hex/hex.go
new file mode 100644
index 000000000..292d917eb
--- /dev/null
+++ b/libgo/go/encoding/hex/hex.go
@@ -0,0 +1,101 @@
+// 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.
+
+// This package implements hexadecimal encoding and decoding.
+package hex
+
+import (
+ "os"
+ "strconv"
+)
+
+const hextable = "0123456789abcdef"
+
+// 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 Encode(dst, src []byte) int {
+ for i, v := range src {
+ dst[i*2] = hextable[v>>4]
+ dst[i*2+1] = hextable[v&0x0f]
+ }
+
+ return len(src) * 2
+}
+
+// OddLengthInputError results from decoding an odd length slice.
+type OddLengthInputError struct{}
+
+func (OddLengthInputError) String() string { return "odd length hex string" }
+
+// InvalidHexCharError results from finding an invalid character in a hex string.
+type InvalidHexCharError byte
+
+func (e InvalidHexCharError) String() string {
+ return "invalid hex char: " + strconv.Itoa(int(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 OddLengthInputError or an
+// InvalidHexCharError.
+func Decode(dst, src []byte) (int, os.Error) {
+ if len(src)%2 == 1 {
+ return 0, OddLengthInputError{}
+ }
+
+ for i := 0; i < len(src)/2; i++ {
+ a, ok := fromHexChar(src[i*2])
+ if !ok {
+ return 0, InvalidHexCharError(src[i*2])
+ }
+ b, ok := fromHexChar(src[i*2+1])
+ if !ok {
+ return 0, InvalidHexCharError(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 fromHexChar(c byte) (byte, bool) {
+ switch {
+ case '0' <= c && c <= '9':
+ return c - '0', true
+ case 'a' <= c && c <= 'f':
+ return c - 'a' + 10, true
+ case 'A' <= c && c <= 'F':
+ return c - 'A' + 10, true
+ }
+
+ return 0, false
+}
+
+// EncodeToString returns the hexadecimal encoding of src.
+func EncodeToString(src []byte) string {
+ dst := make([]byte, EncodedLen(len(src)))
+ Encode(dst, src)
+ return string(dst)
+}
+
+// DecodeString returns the bytes represented by the hexadecimal string s.
+func DecodeString(s string) ([]byte, os.Error) {
+ src := []byte(s)
+ dst := make([]byte, DecodedLen(len(src)))
+ _, err := Decode(dst, src)
+ if err != nil {
+ return nil, err
+ }
+ return dst, nil
+}
diff --git a/libgo/go/encoding/hex/hex_test.go b/libgo/go/encoding/hex/hex_test.go
new file mode 100644
index 000000000..a14c9d4f4
--- /dev/null
+++ b/libgo/go/encoding/hex/hex_test.go
@@ -0,0 +1,149 @@
+// 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
+
+import (
+ "bytes"
+ "testing"
+)
+
+type encodeTest struct {
+ in, out []byte
+}
+
+var encodeTests = []encodeTest{
+ {[]byte{}, []byte{}},
+ {[]byte{0x01}, []byte{'0', '1'}},
+ {[]byte{0xff}, []byte{'f', 'f'}},
+ {[]byte{0xff, 00}, []byte{'f', 'f', '0', '0'}},
+ {[]byte{0}, []byte{'0', '0'}},
+ {[]byte{1}, []byte{'0', '1'}},
+ {[]byte{2}, []byte{'0', '2'}},
+ {[]byte{3}, []byte{'0', '3'}},
+ {[]byte{4}, []byte{'0', '4'}},
+ {[]byte{5}, []byte{'0', '5'}},
+ {[]byte{6}, []byte{'0', '6'}},
+ {[]byte{7}, []byte{'0', '7'}},
+ {[]byte{8}, []byte{'0', '8'}},
+ {[]byte{9}, []byte{'0', '9'}},
+ {[]byte{10}, []byte{'0', 'a'}},
+ {[]byte{11}, []byte{'0', 'b'}},
+ {[]byte{12}, []byte{'0', 'c'}},
+ {[]byte{13}, []byte{'0', 'd'}},
+ {[]byte{14}, []byte{'0', 'e'}},
+ {[]byte{15}, []byte{'0', 'f'}},
+}
+
+func TestEncode(t *testing.T) {
+ for i, test := range encodeTests {
+ dst := make([]byte, EncodedLen(len(test.in)))
+ n := Encode(dst, test.in)
+ if n != len(dst) {
+ t.Errorf("#%d: bad return value: got: %d want: %d", i, n, len(dst))
+ }
+ if bytes.Compare(dst, test.out) != 0 {
+ t.Errorf("#%d: got: %#v want: %#v", i, dst, test.out)
+ }
+ }
+}
+
+type decodeTest struct {
+ in, out []byte
+ ok bool
+}
+
+var decodeTests = []decodeTest{
+ {[]byte{}, []byte{}, true},
+ {[]byte{'0'}, []byte{}, false},
+ {[]byte{'0', 'g'}, []byte{}, false},
+ {[]byte{'0', '\x01'}, []byte{}, false},
+ {[]byte{'0', '0'}, []byte{0}, true},
+ {[]byte{'0', '1'}, []byte{1}, true},
+ {[]byte{'0', '2'}, []byte{2}, true},
+ {[]byte{'0', '3'}, []byte{3}, true},
+ {[]byte{'0', '4'}, []byte{4}, true},
+ {[]byte{'0', '5'}, []byte{5}, true},
+ {[]byte{'0', '6'}, []byte{6}, true},
+ {[]byte{'0', '7'}, []byte{7}, true},
+ {[]byte{'0', '8'}, []byte{8}, true},
+ {[]byte{'0', '9'}, []byte{9}, true},
+ {[]byte{'0', 'a'}, []byte{10}, true},
+ {[]byte{'0', 'b'}, []byte{11}, true},
+ {[]byte{'0', 'c'}, []byte{12}, true},
+ {[]byte{'0', 'd'}, []byte{13}, true},
+ {[]byte{'0', 'e'}, []byte{14}, true},
+ {[]byte{'0', 'f'}, []byte{15}, true},
+ {[]byte{'0', 'A'}, []byte{10}, true},
+ {[]byte{'0', 'B'}, []byte{11}, true},
+ {[]byte{'0', 'C'}, []byte{12}, true},
+ {[]byte{'0', 'D'}, []byte{13}, true},
+ {[]byte{'0', 'E'}, []byte{14}, true},
+ {[]byte{'0', 'F'}, []byte{15}, true},
+}
+
+func TestDecode(t *testing.T) {
+ for i, test := range decodeTests {
+ dst := make([]byte, DecodedLen(len(test.in)))
+ n, err := Decode(dst, test.in)
+ if err == nil && n != len(dst) {
+ t.Errorf("#%d: bad return value: got:%d want:%d", i, n, len(dst))
+ }
+ if test.ok != (err == nil) {
+ t.Errorf("#%d: unexpected err value: %s", i, err)
+ }
+ if err == nil && bytes.Compare(dst, test.out) != 0 {
+ t.Errorf("#%d: got: %#v want: %#v", i, dst, test.out)
+ }
+ }
+}
+
+type encodeStringTest struct {
+ in []byte
+ out string
+}
+
+var encodeStringTests = []encodeStringTest{
+ {[]byte{}, ""},
+ {[]byte{0}, "00"},
+ {[]byte{0, 1}, "0001"},
+ {[]byte{0, 1, 255}, "0001ff"},
+}
+
+func TestEncodeToString(t *testing.T) {
+ for i, test := range encodeStringTests {
+ s := EncodeToString(test.in)
+ if s != test.out {
+ t.Errorf("#%d got:%s want:%s", i, s, test.out)
+ }
+ }
+}
+
+type decodeStringTest struct {
+ in string
+ out []byte
+ ok bool
+}
+
+var decodeStringTests = []decodeStringTest{
+ {"", []byte{}, true},
+ {"0", []byte{}, false},
+ {"00", []byte{0}, true},
+ {"0\x01", []byte{}, false},
+ {"0g", []byte{}, false},
+ {"00ff00", []byte{0, 255, 0}, true},
+ {"0000ff", []byte{0, 0, 255}, true},
+}
+
+func TestDecodeString(t *testing.T) {
+ for i, test := range decodeStringTests {
+ dst, err := DecodeString(test.in)
+ if test.ok != (err == nil) {
+ t.Errorf("#%d: unexpected err value: %s", i, err)
+ }
+ if err == nil && bytes.Compare(dst, test.out) != 0 {
+ t.Errorf("#%d: got: %#v want: #%v", i, dst, test.out)
+ }
+ }
+}