Merge pull request #12 from hmarr/performance-improvements

Faster multi-file matching

Author: Harry Marr

cmd/codeowners/main.go

@@ -1,13 +1,14 @@
 package main
 
 import (
+	"bufio"
 	"fmt"
+	"io"
 	"os"
 	"path/filepath"
 	"strings"
 
 	"github.com/hmarr/codeowners"
-	"github.com/karrick/godirwalk"
 	flag "github.com/spf13/pflag"
 )
 
@@ -50,29 +51,29 @@ func main() {
 		ownerFilters[i] = strings.TrimLeft(ownerFilters[i], "@")
 	}
 
+	out := bufio.NewWriter(os.Stdout)
+	defer out.Flush()
+
 	for _, startPath := range paths {
 		// godirwalk only accepts directories, so we need to handle files separately
 		if !isDir(startPath) {
-			if err := printFileOwners(ruleset, startPath, ownerFilters, showUnowned); err != nil {
+			if err := printFileOwners(out, ruleset, startPath, ownerFilters, showUnowned); err != nil {
 				fmt.Fprintf(os.Stderr, "error: %v", err)
 				os.Exit(1)
 			}
 			continue
 		}
 
-		err = godirwalk.Walk(startPath, &godirwalk.Options{
-			Callback: func(path string, dirent *godirwalk.Dirent) error {
-				if path == ".git" {
-					return filepath.SkipDir
-				}
-
-				// Only show code owners for files, not directories
-				if !dirent.IsDir() {
-					return printFileOwners(ruleset, path, ownerFilters, showUnowned)
-				}
-				return nil
-			},
-			Unsorted: true,
+		err = filepath.WalkDir(startPath, func(path string, d os.DirEntry, err error) error {
+			if path == ".git" {
+				return filepath.SkipDir
+			}
+
+			// Only show code owners for files, not directories
+			if !d.IsDir() {
+				return printFileOwners(out, ruleset, path, ownerFilters, showUnowned)
+			}
+			return nil
 		})
 
 		if err != nil {
@@ -82,7 +83,7 @@ func main() {
 	}
 }
 
-func printFileOwners(ruleset codeowners.Ruleset, path string, ownerFilters []string, showUnowned bool) error {
+func printFileOwners(out io.Writer, ruleset codeowners.Ruleset, path string, ownerFilters []string, showUnowned bool) error {
 	rule, err := ruleset.Match(path)
 	if err != nil {
 		return err
@@ -91,13 +92,13 @@ func printFileOwners(ruleset codeowners.Ruleset, path string, ownerFilters []str
 	if rule == nil || rule.Owners == nil {
 		// Unless explicitly requested, don't show unowned files if we're filtering by owner
 		if len(ownerFilters) == 0 || showUnowned {
-			fmt.Printf("%-70s  (unowned)\n", path)
+			fmt.Fprintf(out, "%-70s  (unowned)\n", path)
 		}
 		return nil
 	}
 
 	// Figure out which of the owners we need to show according to the --owner filters
-	owners := []string{}
+	ownersToShow := make([]string, 0, len(rule.Owners))
 	for _, o := range rule.Owners {
 		// If there are no filters, show all owners
 		filterMatch := len(ownerFilters) == 0 && !showUnowned
@@ -107,13 +108,13 @@ func printFileOwners(ruleset codeowners.Ruleset, path string, ownerFilters []str
 			}
 		}
 		if filterMatch {
-			owners = append(owners, o.String())
+			ownersToShow = append(ownersToShow, o.String())
 		}
 	}
 
 	// If the owners slice is empty, no owners matched the filters so don't show anything
-	if len(owners) > 0 {
-		fmt.Printf("%-70s  %s\n", path, strings.Join(owners, " "))
+	if len(ownersToShow) > 0 {
+		fmt.Fprintf(out, "%-70s  %s\n", path, strings.Join(ownersToShow, " "))
 	}
 	return nil
 }

codeowners.go

@@ -104,10 +104,10 @@ type Ruleset []Rule
 // last matching rule takes precedence.
 func (r Ruleset) Match(path string) (*Rule, error) {
 	for i := len(r) - 1; i >= 0; i-- {
-		rule := r[i]
+		rule := &r[i]
 		match, err := rule.Match(path)
 		if match || err != nil {
-			return &rule, err
+			return rule, err
 		}
 	}
 	return nil, nil

go.mod

@@ -3,7 +3,6 @@ module github.com/hmarr/codeowners
 go 1.14
 
 require (
-	github.com/karrick/godirwalk v1.17.0
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.8.0
 )

go.sum

@@ -1,8 +1,6 @@
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/karrick/godirwalk v1.17.0 h1:b4kY7nqDdioR/6qnbHQyDvmA17u5G1cZ6J+CZXwSWoI=
-github.com/karrick/godirwalk v1.17.0/go.mod h1:j4mkqPuvaLI8mp1DroR3P6ad7cyYd4c1qeJ3RV7ULlk=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=