perf: make fmt parallel (#2102)

Author: okhowang

format/format.go

@@ -4,11 +4,14 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"io/fs"
 	"os"
 	"path/filepath"
+	"runtime"
 	"strings"
 
 	"github.com/swaggo/swag"
+	"golang.org/x/sync/errgroup"
 )
 
 // Format implements `fmt` command for formatting swag comments in Go source
@@ -58,24 +61,27 @@ func (f *Format) Build(config *Config) error {
 			f.exclude[filepath.Clean(fi)] = true
 		}
 	}
+	var eg errgroup.Group
+	eg.SetLimit(runtime.GOMAXPROCS(0))
 	for _, searchDir := range searchDirs {
-		err := filepath.Walk(searchDir, f.visit)
+		err := filepath.Walk(searchDir, func(path string, fileInfo fs.FileInfo, err error) error {
+			if fileInfo.IsDir() && f.excludeDir(path) {
+				return filepath.SkipDir
+			}
+			if f.excludeFile(path) {
+				return nil
+			}
+			eg.Go(func() error {
+				return f.format(path)
+			})
+			return nil
+		})
 		if err != nil {
 			return err
 		}
 	}
-	return nil
-}
-
-func (f *Format) visit(path string, fileInfo os.FileInfo, err error) error {
-	if fileInfo.IsDir() && f.excludeDir(path) {
-		return filepath.SkipDir
-	}
-	if f.excludeFile(path) {
-		return nil
-	}
-	if err := f.format(path); err != nil {
-		return fmt.Errorf("fmt: %w", err)
+	if err := eg.Wait(); err != nil {
+		return err
 	}
 	return nil
 }

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/go-openapi/spec v0.20.4
 	github.com/stretchr/testify v1.7.0
 	github.com/urfave/cli/v2 v2.3.0
+	golang.org/x/sync v0.12.0
 	golang.org/x/text v0.23.0
 	golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d
 	sigs.k8s.io/yaml v1.3.0