From 36385010f5f09dc504e4589d6321898e382e3a76 Mon Sep 17 00:00:00 2001
From: Harshavardhana <harsha@minio.io>
Date: Sat, 16 Sep 2023 19:08:59 -0700
Subject: [PATCH] use optimized pathJoin instead of path.Join (#18042)

this avoids allocations in scanner routine, they are tiny but
they allocate a lot over many cycles of the scanner.
---
 cmd/batch-handlers.go |  5 ++---
 cmd/data-scanner.go   | 12 ++++++------
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/cmd/batch-handlers.go b/cmd/batch-handlers.go
index 55ef8f3f6..d02a6f32b 100644
--- a/cmd/batch-handlers.go
+++ b/cmd/batch-handlers.go
@@ -28,7 +28,6 @@ import (
 	"math/rand"
 	"net/http"
 	"net/url"
-	"path"
 	"runtime"
 	"strconv"
 	"strings"
@@ -114,7 +113,7 @@ func (r *BatchJobReplicateV1) ReplicateFromSource(ctx context.Context, api Objec
 	srcObject := srcObjInfo.Name
 	tgtObject := srcObjInfo.Name
 	if r.Target.Prefix != "" {
-		tgtObject = path.Join(r.Target.Prefix, srcObjInfo.Name)
+		tgtObject = pathJoin(r.Target.Prefix, srcObjInfo.Name)
 	}
 
 	versionID := srcObjInfo.VersionID
@@ -182,7 +181,7 @@ func (r *BatchJobReplicateV1) copyWithMultipartfromSource(ctx context.Context, a
 	srcObject := srcObjInfo.Name
 	tgtObject := srcObjInfo.Name
 	if r.Target.Prefix != "" {
-		tgtObject = path.Join(r.Target.Prefix, srcObjInfo.Name)
+		tgtObject = pathJoin(r.Target.Prefix, srcObjInfo.Name)
 	}
 	if r.Target.Type == BatchJobReplicateResourceS3 || r.Source.Type == BatchJobReplicateResourceS3 {
 		opts.VersionID = ""
diff --git a/cmd/data-scanner.go b/cmd/data-scanner.go
index 04b0f66b8..2210e157b 100644
--- a/cmd/data-scanner.go
+++ b/cmd/data-scanner.go
@@ -409,9 +409,9 @@ func (f *folderScanner) scanFolder(ctx context.Context, folder cachedFolder, int
 
 		var existingFolders, newFolders []cachedFolder
 		var foundObjects bool
-		err := readDirFn(path.Join(f.root, folder.name), func(entName string, typ os.FileMode) error {
+		err := readDirFn(pathJoin(f.root, folder.name), func(entName string, typ os.FileMode) error {
 			// Parse
-			entName = pathClean(path.Join(folder.name, entName))
+			entName = pathClean(pathJoin(folder.name, entName))
 			if entName == "" || entName == folder.name {
 				if f.dataUsageScannerDebug {
 					console.Debugf(scannerLogPrefix+" no entity (%s,%s)\n", f.root, entName)
@@ -461,7 +461,7 @@ func (f *folderScanner) scanFolder(ctx context.Context, folder cachedFolder, int
 
 			// Get file size, ignore errors.
 			item := scannerItem{
-				Path:        path.Join(f.root, entName),
+				Path:        pathJoin(f.root, entName),
 				Typ:         typ,
 				bucket:      bucket,
 				prefix:      path.Dir(prefix),
@@ -496,7 +496,7 @@ func (f *folderScanner) scanFolder(ctx context.Context, folder cachedFolder, int
 			// Object already accounted for, remove from heal map,
 			// simply because getSize() function already heals the
 			// object.
-			delete(abandonedChildren, path.Join(item.bucket, item.objectPath()))
+			delete(abandonedChildren, pathJoin(item.bucket, item.objectPath()))
 
 			into.addSizes(sz)
 			into.Objects++
@@ -873,7 +873,7 @@ type getSizeFn func(item scannerItem) (sizeSummary, error)
 func (i *scannerItem) transformMetaDir() {
 	split := strings.Split(i.prefix, SlashSeparator)
 	if len(split) > 1 {
-		i.prefix = path.Join(split[:len(split)-1]...)
+		i.prefix = pathJoin(split[:len(split)-1]...)
 	} else {
 		i.prefix = ""
 	}
@@ -1247,7 +1247,7 @@ func applyLifecycleAction(event lifecycle.Event, src lcEventSrc, obj ObjectInfo)
 
 // objectPath returns the prefix and object name.
 func (i *scannerItem) objectPath() string {
-	return path.Join(i.prefix, i.objectName)
+	return pathJoin(i.prefix, i.objectName)
 }
 
 // healReplication will heal a scanned item that has failed replication.