From 469d9e26eec76341da8ebc4ef9cedb5bdb32ce73 Mon Sep 17 00:00:00 2001 From: Joe Tsai Date: Sun, 19 Feb 2023 23:19:20 -0800 Subject: [PATCH] encoding: add AppendEncode and AppendDecode Implement append-like equivalent of Encode and Decode functions. Fixes #53693 Change-Id: I79d8d834e3c8f77fad32be2fd391e33d4d1527ea Reviewed-on: https://go-review.googlesource.com/c/go/+/504884 Reviewed-by: Dmitri Shuralyov TryBot-Result: Gopher Robot Reviewed-by: Ian Lance Taylor Run-TryBot: Joseph Tsai Auto-Submit: Joseph Tsai --- api/next/53693.txt | 6 ++++++ src/encoding/base32/base32.go | 20 ++++++++++++++++++++ src/encoding/base32/base32_test.go | 10 +++++++--- src/encoding/base64/base64.go | 20 ++++++++++++++++++++ src/encoding/base64/base64_test.go | 9 +++++++-- src/encoding/hex/hex.go | 20 ++++++++++++++++++++ src/encoding/hex/hex_test.go | 12 ++++++++++++ src/go/build/deps_test.go | 2 +- 8 files changed, 93 insertions(+), 6 deletions(-) create mode 100644 api/next/53693.txt diff --git a/api/next/53693.txt b/api/next/53693.txt new file mode 100644 index 0000000000..5a6f09e6c8 --- /dev/null +++ b/api/next/53693.txt @@ -0,0 +1,6 @@ +pkg encoding/base32, method (*Encoding) AppendDecode([]uint8, []uint8) ([]uint8, error) #53693 +pkg encoding/base32, method (*Encoding) AppendEncode([]uint8, []uint8) []uint8 #53693 +pkg encoding/base64, method (*Encoding) AppendDecode([]uint8, []uint8) ([]uint8, error) #53693 +pkg encoding/base64, method (*Encoding) AppendEncode([]uint8, []uint8) []uint8 #53693 +pkg encoding/hex, func AppendDecode([]uint8, []uint8) ([]uint8, error) #53693 +pkg encoding/hex, func AppendEncode([]uint8, []uint8) []uint8 #53693 diff --git a/src/encoding/base32/base32.go b/src/encoding/base32/base32.go index 69ced9ca3c..7cccbd17be 100644 --- a/src/encoding/base32/base32.go +++ b/src/encoding/base32/base32.go @@ -7,6 +7,7 @@ package base32 import ( "io" + "slices" "strconv" ) @@ -176,6 +177,15 @@ func (enc *Encoding) Encode(dst, src []byte) { } } +// AppendEncode appends the base32 encoded src to dst +// and returns the extended buffer. +func (enc *Encoding) AppendEncode(dst, src []byte) []byte { + n := enc.EncodedLen(len(src)) + dst = slices.Grow(dst, n) + enc.Encode(dst[len(dst):][:n], src) + return dst[:len(dst)+n] +} + // EncodeToString returns the base32 encoding of src. func (enc *Encoding) EncodeToString(src []byte) string { buf := make([]byte, enc.EncodedLen(len(src))) @@ -378,6 +388,16 @@ func (enc *Encoding) Decode(dst, src []byte) (n int, err error) { return } +// AppendDecode appends the base32 decoded src to dst +// and returns the extended buffer. +// If the input is malformed, it returns the partially decoded src and an error. +func (enc *Encoding) AppendDecode(dst, src []byte) ([]byte, error) { + n := enc.DecodedLen(len(src)) + dst = slices.Grow(dst, n) + n, err := enc.Decode(dst[len(dst):][:n], src) + return dst[:len(dst)+n], err +} + // DecodeString returns the bytes represented by the base32 string s. func (enc *Encoding) DecodeString(s string) ([]byte, error) { buf := []byte(s) diff --git a/src/encoding/base32/base32_test.go b/src/encoding/base32/base32_test.go index bdb9f0e61f..0132744507 100644 --- a/src/encoding/base32/base32_test.go +++ b/src/encoding/base32/base32_test.go @@ -57,6 +57,8 @@ func TestEncode(t *testing.T) { for _, p := range pairs { got := StdEncoding.EncodeToString([]byte(p.decoded)) testEqual(t, "Encode(%q) = %q, want %q", p.decoded, got, p.encoded) + dst := StdEncoding.AppendEncode([]byte("lead"), []byte(p.decoded)) + testEqual(t, `AppendEncode("lead", %q) = %q, want %q`, p.decoded, string(dst), "lead"+p.encoded) } } @@ -99,13 +101,15 @@ func TestDecode(t *testing.T) { if len(p.encoded) > 0 { testEqual(t, "Decode(%q) = end %v, want %v", p.encoded, end, (p.encoded[len(p.encoded)-1] == '=')) } - testEqual(t, "Decode(%q) = %q, want %q", p.encoded, - string(dbuf[0:count]), - p.decoded) + testEqual(t, "Decode(%q) = %q, want %q", p.encoded, string(dbuf[0:count]), p.decoded) dbuf, err = StdEncoding.DecodeString(p.encoded) testEqual(t, "DecodeString(%q) = error %v, want %v", p.encoded, err, error(nil)) testEqual(t, "DecodeString(%q) = %q, want %q", p.encoded, string(dbuf), p.decoded) + + dst, err := StdEncoding.AppendDecode([]byte("lead"), []byte(p.encoded)) + testEqual(t, "AppendDecode(%q) = error %v, want %v", p.encoded, err, error(nil)) + testEqual(t, `AppendDecode("lead", %q) = %q, want %q`, p.encoded, string(dst), "lead"+p.decoded) } } diff --git a/src/encoding/base64/base64.go b/src/encoding/base64/base64.go index 87f6897062..5db72b91e2 100644 --- a/src/encoding/base64/base64.go +++ b/src/encoding/base64/base64.go @@ -8,6 +8,7 @@ package base64 import ( "encoding/binary" "io" + "slices" "strconv" ) @@ -191,6 +192,15 @@ func (enc *Encoding) Encode(dst, src []byte) { } } +// AppendEncode appends the base64 encoded src to dst +// and returns the extended buffer. +func (enc *Encoding) AppendEncode(dst, src []byte) []byte { + n := enc.EncodedLen(len(src)) + dst = slices.Grow(dst, n) + enc.Encode(dst[len(dst):][:n], src) + return dst[:len(dst)+n] +} + // EncodeToString returns the base64 encoding of src. func (enc *Encoding) EncodeToString(src []byte) string { buf := make([]byte, enc.EncodedLen(len(src))) @@ -395,6 +405,16 @@ func (enc *Encoding) decodeQuantum(dst, src []byte, si int) (nsi, n int, err err return si, dlen - 1, err } +// AppendDecode appends the base64 decoded src to dst +// and returns the extended buffer. +// If the input is malformed, it returns the partially decoded src and an error. +func (enc *Encoding) AppendDecode(dst, src []byte) ([]byte, error) { + n := enc.DecodedLen(len(src)) + dst = slices.Grow(dst, n) + n, err := enc.Decode(dst[len(dst):][:n], src) + return dst[:len(dst)+n], err +} + // DecodeString returns the bytes represented by the base64 string s. func (enc *Encoding) DecodeString(s string) ([]byte, error) { dbuf := make([]byte, enc.DecodedLen(len(s))) diff --git a/src/encoding/base64/base64_test.go b/src/encoding/base64/base64_test.go index 97aea845ae..4d7437b919 100644 --- a/src/encoding/base64/base64_test.go +++ b/src/encoding/base64/base64_test.go @@ -113,8 +113,9 @@ func TestEncode(t *testing.T) { for _, p := range pairs { for _, tt := range encodingTests { got := tt.enc.EncodeToString([]byte(p.decoded)) - testEqual(t, "Encode(%q) = %q, want %q", p.decoded, - got, tt.conv(p.encoded)) + testEqual(t, "Encode(%q) = %q, want %q", p.decoded, got, tt.conv(p.encoded)) + dst := tt.enc.AppendEncode([]byte("lead"), []byte(p.decoded)) + testEqual(t, `AppendEncode("lead", %q) = %q, want %q`, p.decoded, string(dst), "lead"+tt.conv(p.encoded)) } } } @@ -162,6 +163,10 @@ func TestDecode(t *testing.T) { dbuf, err = tt.enc.DecodeString(encoded) testEqual(t, "DecodeString(%q) = error %v, want %v", encoded, err, error(nil)) testEqual(t, "DecodeString(%q) = %q, want %q", encoded, string(dbuf), p.decoded) + + dst, err := tt.enc.AppendDecode([]byte("lead"), []byte(encoded)) + testEqual(t, "AppendDecode(%q) = error %v, want %v", p.encoded, err, error(nil)) + testEqual(t, `AppendDecode("lead", %q) = %q, want %q`, p.encoded, string(dst), "lead"+p.decoded) } } } diff --git a/src/encoding/hex/hex.go b/src/encoding/hex/hex.go index 375f583170..ccc395e2f7 100644 --- a/src/encoding/hex/hex.go +++ b/src/encoding/hex/hex.go @@ -9,6 +9,7 @@ import ( "errors" "fmt" "io" + "slices" "strings" ) @@ -51,6 +52,15 @@ func Encode(dst, src []byte) int { return len(src) * 2 } +// AppendEncode appends the hexadecimally encoded src to dst +// and returns the extended buffer. +func AppendEncode(dst, src []byte) []byte { + n := EncodedLen(len(src)) + dst = slices.Grow(dst, n) + Encode(dst[len(dst):][:n], src) + return dst[:len(dst)+n] +} + // ErrLength reports an attempt to decode an odd-length input // using Decode or DecodeString. // The stream-based Decoder returns io.ErrUnexpectedEOF instead of ErrLength. @@ -102,6 +112,16 @@ func Decode(dst, src []byte) (int, error) { return i, nil } +// AppendDecode appends the hexadecimally decoded src to dst +// and returns the extended buffer. +// If the input is malformed, it returns the partially decoded src and an error. +func AppendDecode(dst, src []byte) ([]byte, error) { + n := DecodedLen(len(src)) + dst = slices.Grow(dst, n) + n, err := Decode(dst[len(dst):][:n], src) + return dst[:len(dst)+n], err +} + // EncodeToString returns the hexadecimal encoding of src. func EncodeToString(src []byte) string { dst := make([]byte, EncodedLen(len(src))) diff --git a/src/encoding/hex/hex_test.go b/src/encoding/hex/hex_test.go index a820fe7a15..03331eaae5 100644 --- a/src/encoding/hex/hex_test.go +++ b/src/encoding/hex/hex_test.go @@ -37,6 +37,11 @@ func TestEncode(t *testing.T) { if string(dst) != test.enc { t.Errorf("#%d: got: %#v want: %#v", i, dst, test.enc) } + dst = []byte("lead") + dst = AppendEncode(dst, test.dec) + if string(dst) != "lead"+test.enc { + t.Errorf("#%d: got: %#v want: %#v", i, dst, "lead"+test.enc) + } } } @@ -52,6 +57,13 @@ func TestDecode(t *testing.T) { } else if !bytes.Equal(dst, test.dec) { t.Errorf("#%d: got: %#v want: %#v", i, dst, test.dec) } + dst = []byte("lead") + dst, err = AppendDecode(dst, []byte(test.enc)) + if err != nil { + t.Errorf("#%d: AppendDecode error: %v", i, err) + } else if string(dst) != "lead"+string(test.dec) { + t.Errorf("#%d: got: %#v want: %#v", i, dst, "lead"+string(test.dec)) + } } } diff --git a/src/go/build/deps_test.go b/src/go/build/deps_test.go index bdb09737b0..39f22af5f9 100644 --- a/src/go/build/deps_test.go +++ b/src/go/build/deps_test.go @@ -210,7 +210,7 @@ var depsRules = ` # encodings # core ones do not use fmt. - io, strconv + io, strconv, slices < encoding; encoding, reflect -- 2.44.0