Add Init()

Author: gen2brain

jpegli.go

@@ -166,6 +166,12 @@ func Encode(w io.Writer, m image.Image, o ...*EncodingOptions) error {
 	return nil
 }
 
+// Init initializes wazero runtime and compiles the module.
+// There is no need to explicitly call this function, first Decode/Encode will initialize the runtime.
+func Init() {
+	initOnce()
+}
+
 func imageToRGBA(src image.Image) *image.RGBA {
 	if dst, ok := src.(*image.RGBA); ok {
 		return dst

jpegli_test.go

@@ -30,6 +30,10 @@ var testRgba []byte
 //go:embed testdata/cmyk.jpg
 var testCmyk []byte
 
+func init() {
+	jpegli.Init()
+}
+
 func TestDecode(t *testing.T) {
 	img, err := jpegli.Decode(bytes.NewReader(testJpg))
 	if err != nil {
@@ -235,7 +239,7 @@ func TestEncodeSync(t *testing.T) {
 		t.Error(err)
 	}
 
-	for i := 0; i < 100; i++ {
+	for i := 0; i < 10; i++ {
 		wg.Add(1)
 		go func() {
 			ch <- true

jpegli_wazero.go

@@ -10,6 +10,7 @@ import (
 	"image/color"
 	"io"
 	"os"
+	"sync"
 	"unsafe"
 
 	"github.com/tetratelabs/wazero"
@@ -28,6 +29,8 @@ const (
 )
 
 func decode(r io.Reader, configOnly, fancyUpsampling, blockSmoothing, arithCode bool, dctMethod DCTMethod, tw, th int) (image.Image, image.Config, error) {
+	initOnce()
+
 	var err error
 	var cfg image.Config
 	var data []byte
@@ -217,6 +220,8 @@ func decode(r io.Reader, configOnly, fancyUpsampling, blockSmoothing, arithCode
 func encode(w io.Writer, m image.Image, quality, chromaSubsampling, progressiveLevel int, optimizeCoding, adaptiveQuantization,
 	standardQuantTables, fancyDownsampling bool, dctMethod DCTMethod) error {
 
+	initOnce()
+
 	var data []byte
 	var colorspace int
 	var chroma int
@@ -336,9 +341,11 @@ var (
 	rt wazero.Runtime
 	cm wazero.CompiledModule
 	mc wazero.ModuleConfig
+
+	initOnce = sync.OnceFunc(initialize)
 )
 
-func init() {
+func initialize() {
 	ctx := context.Background()
 	rt = wazero.NewRuntime(ctx)