From 469d9e26eec76341da8ebc4ef9cedb5bdb32ce73 Mon Sep 17 00:00:00 2001 From: Joe Tsai Date: Sun, 19 Feb 2023 23:19:20 -0800 Subject: 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 --- src/encoding/hex/hex.go | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'src/encoding/hex/hex.go') 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))) -- cgit v1.3