feat(tools/spxls): introduce compile cache

spx-gui/src/components/editor/code-editor/lsp/index.ts

@@ -62,7 +62,10 @@ export class SpxLSPClient extends Disposable {
         if (['.spx', '.json'].includes(ext)) {
           // Only `.spx` & `.json` files are needed for `spxls`
           const ab = await file.arrayBuffer()
-          loadedFiles[path] = { content: new Uint8Array(ab) }
+          loadedFiles[path] = {
+            content: new Uint8Array(ab),
+            modTime: this.project.modTime ?? Date.now()
+          }
           debugFiles[path] = await toText(file)
         }
       })

spx-gui/src/models/project/index.ts

@@ -104,7 +104,7 @@ export class Project extends Disposable {
   releaseCount?: number
   remixCount?: number
 
-  /** Files' hash of game content, available when project under editing */
+  /** Files' hash of game content, available when project is under editing */
   filesHash?: string
   private lastSyncedFilesHash?: string
   /** If there is any change of game content not synced (to cloud) yet. */
@@ -114,6 +114,9 @@ export class Project extends Disposable {
     return this.lastSyncedFilesHash !== this.filesHash
   }
 
+  /** Modification time in milliseconds of project state, available when project is under editing */
+  modTime?: number
+
   stage: Stage
   sprites: Sprite[]
   sounds: Sound[]
@@ -553,7 +556,12 @@ export class Project extends Disposable {
     )
   }
 
-  /** watch for all changes, auto save to local cache, or touch all files to trigger lazy loading to ensure they are in memory */
+  /**
+   * Watch for all changes to:
+   * 1. Auto save to local cache when enabled.
+   * 2. Touch all files to trigger lazy loading when not in local cache mode.
+   * 3. Update modification time.
+   */
   private autoSaveToLocalCache: (() => void) | null = null
   private startAutoSaveToLocalCache(localCacheKey: string) {
     const saveToLocalCache = debounce(() => this.saveToLocalCache(localCacheKey), 1000)
@@ -569,6 +577,7 @@ export class Project extends Disposable {
     this.autoSaveToLocalCache = () => {
       if (this.autoSaveMode === AutoSaveMode.LocalCache) saveToLocalCache()
       else touchFiles()
+      this.modTime = Date.now()
     }
 
     this.addDisposer(
@@ -588,6 +597,7 @@ export class Project extends Disposable {
     if (this.lastSyncedFilesHash == null) {
       this.lastSyncedFilesHash = this.filesHash
     }
+    this.modTime = Date.now()
     this.startAutoSaveToCloud(localCacheKey)
     this.startAutoSaveToLocalCache(localCacheKey)
 

tools/spxls/index.d.ts

@@ -129,4 +129,5 @@ export type Files = {
  */
 export type File = {
   content: Uint8Array
+  modTime: number // unix timestamp in milliseconds
 }

tools/spxls/internal/server/command_test.go

@@ -5,29 +5,26 @@ import (
 	"testing"
 
 	"github.com/goplus/builder/tools/spxls/internal/util"
-	"github.com/goplus/builder/tools/spxls/internal/vfs"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
 func TestServerSpxGetDefinitions(t *testing.T) {
 	t.Run("Normal", func(t *testing.T) {
-		s := New(vfs.NewMapFS(func() map[string][]byte {
-			return map[string][]byte{
-				"main.spx": []byte(`
+		s := New(newMapFSWithoutModTime(map[string][]byte{
+			"main.spx": []byte(`
 var (
 	MySprite Sprite
 )
 MySprite.turn Left
 run "assets", {Title: "My Game"}
 `),
-				"MySprite.spx": []byte(`
+			"MySprite.spx": []byte(`
 onStart => {
 	MySprite.turn Right
 }
 `),
-				"assets/sprites/MySprite/index.json": []byte(`{}`),
-			}
+			"assets/sprites/MySprite/index.json": []byte(`{}`),
 		}), nil)
 
 		mainSpxFileScopeParams := []SpxGetDefinitionsParams{
@@ -143,14 +140,12 @@ onStart => {
 	})
 
 	t.Run("ParseError", func(t *testing.T) {
-		s := New(vfs.NewMapFS(func() map[string][]byte {
-			return map[string][]byte{
-				"main.spx": []byte(`
+		s := New(newMapFSWithoutModTime(map[string][]byte{
+			"main.spx": []byte(`
 // Invalid syntax
 var (
 	MySprite Sprite
 `),
-			}
 		}), nil)
 
 		mainSpxFileScopeParams := []SpxGetDefinitionsParams{
@@ -183,24 +178,22 @@ var (
 	})
 
 	t.Run("TrailingEmptyLinesOfSpriteCode", func(t *testing.T) {
-		s := New(vfs.NewMapFS(func() map[string][]byte {
-			return map[string][]byte{
-				"main.spx": []byte(`
+		s := New(newMapFSWithoutModTime(map[string][]byte{
+			"main.spx": []byte(`
 var (
 	MySprite Sprite
 )
 MySprite.turn Left
 run "assets", {Title: "My Game"}
 `),
-				"MySprite.spx": []byte(`
+			"MySprite.spx": []byte(`
 onStart => {
 	MySprite.turn Right
 }
 
 
 `),
-				"assets/sprites/MySprite/index.json": []byte(`{}`),
-			}
+			"assets/sprites/MySprite/index.json": []byte(`{}`),
 		}), nil)
 
 		mainSpxFileScopeParams := []SpxGetDefinitionsParams{

tools/spxls/internal/server/compile.go

@@ -5,9 +5,11 @@ import (
 	"fmt"
 	"go/types"
 	"io/fs"
+	"maps"
 	"path"
 	"slices"
 	"strings"
+	"time"
 
 	"github.com/goplus/builder/tools/spxls/internal/util"
 	"github.com/goplus/builder/tools/spxls/internal/vfs"
@@ -302,16 +304,77 @@ func (r *compileResult) addDiagnostics(documentURI DocumentURI, diags ...Diagnos
 	r.diagnostics[documentURI] = append(r.diagnostics[documentURI], dedupedDiags...)
 }
 
+// compileCache represents a cache for compilation results.
+type compileCache struct {
+	result          *compileResult
+	spxFileModTimes map[string]time.Time
+}
+
 // compile compiles spx source files and returns compile result.
-//
-// TODO: Move diagnostics from [compileResult] to error return value by using
-// [errors.Join].
 func (s *Server) compile() (*compileResult, error) {
 	spxFiles, err := s.spxFiles()
 	if err != nil {
 		return nil, fmt.Errorf("failed to get spx files: %w", err)
 	}
+	if len(spxFiles) == 0 {
+		return nil, errNoValidSpxFiles
+	}
+	slices.Sort(spxFiles)
+
+	s.compileCacheMu.Lock()
+	defer s.compileCacheMu.Unlock()
+
+	// Try to use cache first.
+	if cache := s.lastCompileCache; cache != nil {
+		// Check if spx file set has changed.
+		cachedSpxFiles := slices.Sorted(maps.Keys(cache.spxFileModTimes))
+		if slices.Equal(spxFiles, cachedSpxFiles) {
+			// Check if any spx file has been modified.
+			modified := false
+			for _, spxFile := range spxFiles {
+				fi, err := fs.Stat(s.workspaceRootFS, spxFile)
+				if err != nil {
+					return nil, fmt.Errorf("failed to stat file %q: %w", spxFile, err)
+				}
+				if cachedModTime, ok := cache.spxFileModTimes[spxFile]; !ok || !fi.ModTime().Equal(cachedModTime) {
+					modified = true
+					break
+				}
+			}
+			if !modified {
+				return cache.result, nil
+			}
+		}
+	}
 
+	// Compile uncached if cache is not used.
+	result, err := s.compileUncached(spxFiles)
+	if err != nil {
+		return nil, err
+	}
+
+	// Update cache.
+	modTimes := make(map[string]time.Time, len(spxFiles))
+	for _, spxFile := range spxFiles {
+		fi, err := fs.Stat(s.workspaceRootFS, spxFile)
+		if err != nil {
+			return nil, fmt.Errorf("failed to stat file %q: %w", spxFile, err)
+		}
+		modTimes[spxFile] = fi.ModTime()
+	}
+	s.lastCompileCache = &compileCache{
+		result:          result,
+		spxFileModTimes: modTimes,
+	}
+
+	return result, nil
+}
+
+// compileUncached compiles spx source files without using cache.
+//
+// TODO: Move diagnostics from [compileResult] to error return value by using
+// [errors.Join].
+func (s *Server) compileUncached(spxFiles []string) (*compileResult, error) {
 	result := &compileResult{
 		fset:                    goptoken.NewFileSet(),
 		mainPkg:                 types.NewPackage("main", "main"),
@@ -419,6 +482,7 @@ func (s *Server) compile() (*compileResult, error) {
 		return result, nil
 	}
 
+	var err error
 	result.spxPkg, err = s.importer.Import(spxPkgPath)
 	if err != nil {
 		return nil, fmt.Errorf("failed to import spx package: %w", err)

tools/spxls/internal/server/completion_test.go

@@ -4,30 +4,27 @@ import (
 	"testing"
 
 	"github.com/goplus/builder/tools/spxls/internal/util"
-	"github.com/goplus/builder/tools/spxls/internal/vfs"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
 func TestServerTextDocumentCompletion(t *testing.T) {
 	t.Run("Normal", func(t *testing.T) {
-		s := New(vfs.NewMapFS(func() map[string][]byte {
-			return map[string][]byte{
-				"main.spx": []byte(`
+		s := New(newMapFSWithoutModTime(map[string][]byte{
+			"main.spx": []byte(`
 var (
 	MySprite Sprite
 )
 
 MySprite.
 run "assets", {Title: "My Game"}
 `),
-				"MySprite.spx": []byte(`
+			"MySprite.spx": []byte(`
 onStart => {
 	MySprite.turn Right
 }
 `),
-				"assets/sprites/MySprite/index.json": []byte(`{}`),
-			}
+			"assets/sprites/MySprite/index.json": []byte(`{}`),
 		}), nil)
 
 		emptyLineItems, err := s.textDocumentCompletion(&CompletionParams{