Only compile wasm once per process

Author: anuraaga

internal/ext/wasm/runner.go

@@ -1,7 +1,12 @@
 package wasm
 
+import "github.com/tetratelabs/wazero"
+
 type Runner struct {
 	URL    string
 	SHA256 string
 	Env    []string
+
+	rt   wazero.Runtime
+	code wazero.CompiledModule
 }

internal/ext/wasm/wasm.go

@@ -29,6 +29,15 @@ import (
 	"github.com/sqlc-dev/sqlc/internal/plugin"
 )
 
+func NewRunner(url string, checksum string, env []string) *Runner {
+	return &Runner{
+		URL:    url,
+		SHA256: checksum,
+		Env:    env,
+		rt:     wazero.NewRuntime(context.Background()),
+	}
+}
+
 func cacheDir() (string, error) {
 	cache := os.Getenv("SQLCCACHE")
 	if cache != "" {
@@ -61,7 +70,7 @@ func (r *Runner) getChecksum(ctx context.Context) (string, error) {
 	return sum, nil
 }
 
-func (r *Runner) loadBytes(ctx context.Context) ([]byte, error) {
+func (r *Runner) loadAndCompile(ctx context.Context) (wazero.CompiledModule, error) {
 	expected, err := r.getChecksum(ctx)
 	if err != nil {
 		return nil, err
@@ -71,14 +80,14 @@ func (r *Runner) loadBytes(ctx context.Context) ([]byte, error) {
 		return nil, err
 	}
 	value, err, _ := flight.Do(expected, func() (interface{}, error) {
-		return r.loadWASM(ctx, cacheDir, expected)
+		return r.loadAndCompileWASM(ctx, cacheDir, expected)
 	})
 	if err != nil {
 		return nil, err
 	}
-	data, ok := value.([]byte)
+	data, ok := value.(wazero.CompiledModule)
 	if !ok {
-		return nil, fmt.Errorf("returned value was not a byte slice")
+		return nil, fmt.Errorf("returned value was not a compiled module")
 	}
 	return data, nil
 }
@@ -124,7 +133,7 @@ func (r *Runner) fetch(ctx context.Context, uri string) ([]byte, string, error)
 	return wmod, actual, nil
 }
 
-func (r *Runner) loadWASM(ctx context.Context, cache string, expected string) ([]byte, error) {
+func (r *Runner) loadAndCompileWASM(ctx context.Context, cache string, expected string) (wazero.CompiledModule, error) {
 	pluginDir := filepath.Join(cache, expected)
 	pluginPath := filepath.Join(pluginDir, "plugin.wasm")
 	_, staterr := os.Stat(pluginPath)
@@ -153,7 +162,22 @@ func (r *Runner) loadWASM(ctx context.Context, cache string, expected string) ([
 		}
 	}
 
-	return wmod, nil
+	wazeroCache, err := wazero.NewCompilationCacheWithDir(filepath.Join(cache, "wazero"))
+	if err != nil {
+		return nil, fmt.Errorf("wazero.NewCompilationCacheWithDir: %w", err)
+	}
+	config := wazero.NewRuntimeConfig().WithCompilationCache(wazeroCache)
+	r.rt = wazero.NewRuntimeWithConfig(ctx, config)
+	// TODO: Handle error
+	wasi_snapshot_preview1.MustInstantiate(ctx, r.rt)
+
+	// Compile the Wasm binary once so that we can skip the entire compilation time during instantiation.
+	code, err := r.rt.CompileModule(ctx, wmod)
+	if err != nil {
+		return nil, fmt.Errorf("compile module: %w", err)
+	}
+
+	return code, nil
 }
 
 // removePGCatalog removes the pg_catalog schema from the request. There is a
@@ -195,47 +219,25 @@ func (r *Runner) Invoke(ctx context.Context, method string, args any, reply any,
 		return fmt.Errorf("failed to encode codegen request: %w", err)
 	}
 
-	cacheDir, err := cache.PluginsDir()
-	if err != nil {
-		return err
-	}
-
-	cache, err := wazero.NewCompilationCacheWithDir(filepath.Join(cacheDir, "wazero"))
-	if err != nil {
-		return err
-	}
-
-	wasmBytes, err := r.loadBytes(ctx)
-	if err != nil {
-		return fmt.Errorf("loadModule: %w", err)
-	}
-
-	config := wazero.NewRuntimeConfig().WithCompilationCache(cache)
-	rt := wazero.NewRuntimeWithConfig(ctx, config)
-	defer rt.Close(ctx)
-
-	// TODO: Handle error
-	wasi_snapshot_preview1.MustInstantiate(ctx, rt)
-
-	// Compile the Wasm binary once so that we can skip the entire compilation time during instantiation.
-	mod, err := rt.CompileModule(ctx, wasmBytes)
+	wasmCompiled, err := r.loadAndCompile(ctx)
 	if err != nil {
-		return err
+		return fmt.Errorf("loadBytes: %w", err)
 	}
 
 	var stderr, stdout bytes.Buffer
 
-	conf := wazero.NewModuleConfig()
-	conf = conf.WithArgs("plugin.wasm", method)
-	conf = conf.WithEnv("SQLC_VERSION", info.Version)
+	conf := wazero.NewModuleConfig().
+		WithName("").
+		WithArgs("plugin.wasm", method).
+		WithStdin(bytes.NewReader(stdinBlob)).
+		WithStdout(&stdout).
+		WithStderr(&stderr).
+		WithEnv("SQLC_VERSION", info.Version)
 	for _, key := range r.Env {
 		conf = conf.WithEnv(key, os.Getenv(key))
 	}
-	conf = conf.WithStdin(bytes.NewReader(stdinBlob))
-	conf = conf.WithStdout(&stdout)
-	conf = conf.WithStderr(&stderr)
 
-	result, err := rt.InstantiateModule(ctx, mod, conf)
+	result, err := r.rt.InstantiateModule(ctx, wasmCompiled, conf)
 	if result != nil {
 		defer result.Close(ctx)
 	}