Removed old impl

resolver-go/internal/resolver/resolver.go

@@ -14,8 +14,10 @@ import (
 	"regexp"
 	"sort"
 	"strings"
+	"sync"
 
-	"github.com/tgckpg/botanres-go/internal/classmap"
+	"github.com/tgckpg/resolver-go/internal/classmap"
+	"github.com/tgckpg/resolver-go/internal/closure"
 )
 
 type OutputMode string
@@ -38,6 +40,9 @@ type Result struct {
 type Resolver struct {
 	Root string
 	Map  *classmap.Map
+
+	externMu    sync.RWMutex
+	externCache map[string]closure.SourceInput
 }
 
 func New(root string, m *classmap.Map) (*Resolver, error) {
@@ -45,7 +50,11 @@ func New(root string, m *classmap.Map) (*Resolver, error) {
 	if err != nil {
 		return nil, err
 	}
-	return &Resolver{Root: root, Map: m}, nil
+	return &Resolver{
+		Root:        root,
+		Map:         m,
+		externCache: make(map[string]closure.SourceInput),
+	}, nil
 }
 
 func (r *Resolver) ResolveRequest(code string, mode OutputMode, excludes []string) (Result, error) {
@@ -242,6 +251,55 @@ func (r *Resolver) MergeCSS(files []classmap.Resource) ([]byte, string, error) {
 	return b.Bytes(), hashList(files, "css"), nil
 }
 
+func (r *Resolver) GetExterns(files []string) ([]closure.SourceInput, error) {
+	sources := make([]closure.SourceInput, 0, len(files))
+
+	for _, f := range files {
+		src, ok, err := r.getExtern(f)
+		if err != nil {
+			return nil, err
+		}
+		if !ok {
+			continue
+		}
+
+		sources = append(sources, src)
+	}
+
+	return sources, nil
+}
+
+func (r *Resolver) getExtern(f string) (closure.SourceInput, bool, error) {
+	// Fast path: read cache.
+	r.externMu.RLock()
+	src, ok := r.externCache[f]
+	r.externMu.RUnlock()
+	if ok {
+		return src, true, nil
+	}
+
+	// Slow path: read file.
+	b, err := os.ReadFile(filepath.Join(r.Root, filepath.FromSlash(f)))
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return closure.SourceInput{}, false, nil
+		}
+		return closure.SourceInput{}, false, err
+	}
+
+	src = closure.SourceInput{
+		Name:   f,
+		Source: string(b),
+	}
+
+	// Store cache.
+	r.externMu.Lock()
+	r.externCache[f] = src
+	r.externMu.Unlock()
+
+	return src, true, nil
+}
+
 func DecodeRequest(code string) ([]string, error) {
 	sep := "/"
 	decoded := code