add cacheDir option

README.md

@@ -719,6 +719,7 @@ type Option struct {
     MemoryLimit        int     // Memory usage limit  
     MaxExecutionTime   int     // Execution timeout
     GCThreshold        int     // GC trigger threshold
+    CacheDir           string  // Compilation cache directory
 }
 ```
 

options.go

@@ -38,6 +38,7 @@ type Option struct {
 	// because every operation must check the done context, which introduces additional overhead.
 	CloseOnContextDone bool
 	DisableBuildCache  bool
+	CacheDir           string
 	MemoryLimit        int
 	MaxStackSize       int
 	MaxExecutionTime   int

runtime.go

@@ -40,6 +40,7 @@ func createGlobalCompiledModule(
 	ctx context.Context,
 	closeOnContextDone bool,
 	disableBuildCache bool,
+	cacheDir string,
 	quickjsWasmBytes ...[]byte,
 ) (err error) {
 	// Protect global compilation state with mutex
@@ -58,7 +59,13 @@ func createGlobalCompiledModule(
 
 	// Check if we need to compile or recompile
 	if compiledQJSModule == nil || cachedBytesHash != currentHash || disableBuildCache {
-		cache := wazero.NewCompilationCache()
+		var cache wazero.CompilationCache
+		if cacheDir == "" {
+			cache = wazero.NewCompilationCache()
+		} else if cache, err = wazero.NewCompilationCacheWithDir(cacheDir); err != nil {
+			return fmt.Errorf("failed to create compilation cache with dir %s: %w", cacheDir, err)
+		}
+
 		cachedRuntimeConfig = wazero.
 			NewRuntimeConfig().
 			WithCompilationCache(cache).
@@ -96,6 +103,7 @@ func New(options ...Option) (runtime *Runtime, err error) {
 		option.Context,
 		option.CloseOnContextDone,
 		option.DisableBuildCache,
+		option.CacheDir,
 		option.QuickJSWasmBytes,
 	); err != nil {
 		return nil, fmt.Errorf("failed to create global compiled module: %w", err)

runtime_test.go

@@ -3,6 +3,7 @@ package qjs_test
 import (
 	"context"
 	"fmt"
+	"os"
 	"sync"
 	"testing"
 	"time"
@@ -255,6 +256,39 @@ func TestRuntime(t *testing.T) {
 		require.NoError(t, err, "Normal runtime creation should still work after invalid attempt")
 		defer rt2.Close()
 	})
+
+	t.Run("CacheDirOption", func(t *testing.T) {
+		cacheDir := t.TempDir()
+		rt1, err := qjs.New(qjs.Option{CacheDir: cacheDir, DisableBuildCache: true})
+		require.NoError(t, err)
+
+		val, err := rt1.Eval("test.js", qjs.Code("21 + 21"))
+		require.NoError(t, err)
+		assert.Equal(t, int32(42), val.Int32())
+		val.Free()
+
+		rt1.Close()
+		entries, err := os.ReadDir(cacheDir)
+		require.NoError(t, err)
+		assert.NotEmpty(t, entries, "Cache directory should not be empty")
+	})
+
+	t.Run("CacheDirWithEmptyString", func(t *testing.T) {
+		rt, err := qjs.New(qjs.Option{CacheDir: "", DisableBuildCache: true})
+		require.NoError(t, err)
+		defer rt.Close()
+
+		val, err := rt.Eval("test.js", qjs.Code("2 * 21"))
+		require.NoError(t, err)
+		assert.Equal(t, int32(42), val.Int32())
+		val.Free()
+	})
+
+	t.Run("CacheDirWithInvalidPath", func(t *testing.T) {
+		_, err := qjs.New(qjs.Option{CacheDir: "/invalid/path/that/does/not/exist", DisableBuildCache: true})
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "failed to create compilation cache")
+	})
 }
 
 // Concurrent Runtime Usage Tests