feat: add static Go 1.27 simd/archsimd backend (fixes #17)

base64x_error_native_amd64_test.go

@@ -12,8 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//go:build amd64 && !noasm && !appengine
-// +build amd64,!noasm,!appengine
+//go:build !goexperiment.simd && amd64 && !noasm && !appengine
+// +build !goexperiment.simd,amd64,!noasm,!appengine
 
 package base64x
 

base64x_fallback_test.go

@@ -1,5 +1,5 @@
-//go:build !amd64 || noasm || appengine
-// +build !amd64 noasm appengine
+//go:build goexperiment.simd || !amd64 || noasm || appengine
+// +build goexperiment.simd !amd64 noasm appengine
 
 /*
  * Copyright 2024 CloudWeGo Authors

base64x_native.go

@@ -1,5 +1,5 @@
-//go:build amd64 && !noasm && !appengine
-// +build amd64,!noasm,!appengine
+//go:build !goexperiment.simd && amd64 && !noasm && !appengine
+// +build !goexperiment.simd,amd64,!noasm,!appengine
 
 /*
  * Copyright 2024 CloudWeGo Authors

base64x_simd_amd64.go

@@ -0,0 +1,158 @@
+//go:build goexperiment.simd && amd64 && !noasm && !appengine
+
+/*
+ * Copyright 2024 CloudWeGo Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package base64x
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"simd/archsimd"
+
+	"github.com/cloudwego/base64x/internal/simd"
+)
+
+func encode(out *[]byte, src []byte, mode int) {
+	if !archsimd.X86.AVX2() {
+		encodeStdlib(out, src, mode)
+		return
+	}
+	url := 0
+	if mode&_MODE_URL != 0 {
+		url = 1
+	}
+	pad := 1
+	if mode&_MODE_RAW != 0 {
+		pad = 0
+	}
+	enc := encodingForModeSimd(mode)
+	dst := *out
+	start := len(dst)
+	need := enc.EncodedLen(len(src))
+	dst = dst[:start+need]
+	simd.B64_encode(src, uint64(len(src)), dst[start:start+need], uint64(need), url, pad)
+	*out = dst[:start+need]
+}
+
+func decode(out *[]byte, src []byte, mode int) (int, error) {
+	input := src
+	if mode&_MODE_JSON != 0 {
+		unquoted, err := unquoteJSONBase64(src)
+		if err != nil {
+			return 0, err
+		}
+		input = unquoted
+	}
+	if !archsimd.X86.AVX2() {
+		return decodeStdlib(out, input, mode)
+	}
+
+	url := 0
+	if mode&_MODE_URL != 0 {
+		url = 1
+	}
+	pad := 1
+	if mode&_MODE_RAW != 0 {
+		pad = 0
+	}
+	enc := encodingForModeSimd(mode)
+	dst := *out
+	start := len(dst)
+	need := enc.DecodedLen(len(input))
+
+	// The vector decode loop writes in 32-byte chunks.
+	// If the destination slice capacity cannot safely hold 32 bytes from start,
+	// decode into a stack scratch buffer and copy back to avoid out-of-bounds writes.
+	if cap(dst)-start < 32 || cap(dst)-start < need+8 {
+		var tmp [256]byte
+		var buf []byte
+		allocCap := need + 32
+		if allocCap <= len(tmp) {
+			buf = tmp[:allocCap]
+		} else {
+			buf = make([]byte, allocCap)
+		}
+		var posErr uint64
+		w := simd.B64_decode(input, uint64(len(input)), buf, uint64(len(buf)), url, pad, &posErr)
+		if posErr != ^uint64(0) {
+			return 0, base64.CorruptInputError(posErr)
+		}
+		dst = dst[:start+int(w)]
+		copy(dst[start:], buf[:w])
+		*out = dst
+		return int(w), nil
+	}
+
+	dst = dst[:start+need]
+	var posErr uint64
+	availCap := uint64(cap(dst) - start)
+	w := simd.B64_decode(input, uint64(len(input)), dst[start:cap(dst)], availCap, url, pad, &posErr)
+	if posErr != ^uint64(0) {
+		return 0, base64.CorruptInputError(posErr)
+	}
+	*out = dst[:start+int(w)]
+	return int(w), nil
+}
+
+func encodingForModeSimd(mode int) *base64.Encoding {
+	switch mode & (_MODE_URL | _MODE_RAW) {
+	case _MODE_URL:
+		return base64.URLEncoding
+	case _MODE_RAW:
+		return base64.RawStdEncoding
+	case _MODE_URL | _MODE_RAW:
+		return base64.RawURLEncoding
+	default:
+		return base64.StdEncoding
+	}
+}
+
+func encodeStdlib(out *[]byte, src []byte, mode int) {
+	enc := encodingForModeSimd(mode)
+	dst := *out
+	start := len(dst)
+	need := enc.EncodedLen(len(src))
+	dst = dst[:start+need]
+	enc.Encode(dst[start:], src)
+	*out = dst
+}
+
+func decodeStdlib(out *[]byte, input []byte, mode int) (int, error) {
+	enc := encodingForModeSimd(mode)
+	dst := *out
+	start := len(dst)
+	buf := dst[start:cap(dst)]
+	n, err := enc.Decode(buf, input)
+	if err != nil {
+		return 0, err
+	}
+	*out = dst[:start+n]
+	return n, nil
+}
+
+func unquoteJSONBase64(src []byte) ([]byte, error) {
+	quoted := make([]byte, 0, len(src)+2)
+	quoted = append(quoted, '"')
+	quoted = append(quoted, src...)
+	quoted = append(quoted, '"')
+
+	var decoded string
+	if err := json.Unmarshal(quoted, &decoded); err != nil {
+		return nil, err
+	}
+	return []byte(decoded), nil
+}

base64x_subr_native_amd64.go

@@ -12,8 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//go:build amd64 && !noasm && !appengine
-// +build amd64,!noasm,!appengine
+//go:build !goexperiment.simd && amd64 && !noasm && !appengine
+// +build !goexperiment.simd,amd64,!noasm,!appengine
 
 package base64x