cleanup: refactor common code between FS and XL listDirFactory. (#3639)

cmd/fs-v1.go

@@ -731,37 +731,11 @@ func (fs fsObjects) listDirFactory(isLeaf isLeafFunc) listDirFunc {
 	// listDir - lists all the entries at a given prefix and given entry in the prefix.
 	listDir := func(bucket, prefixDir, prefixEntry string) (entries []string, delayIsLeaf bool, err error) {
 		entries, err = readDir(pathJoin(fs.fsPath, bucket, prefixDir))
-		if err == nil {
-			// Listing needs to be sorted.
-			sort.Strings(entries)
-
-			// Filter entries that have the prefix prefixEntry.
-			entries = filterMatchingPrefix(entries, prefixEntry)
-
-			// Can isLeaf() check be delayed till when it has to be sent down the
-			// treeWalkResult channel?
-			delayIsLeaf = delayIsLeafCheck(entries)
-			if delayIsLeaf {
-				return entries, delayIsLeaf, nil
-			}
-
-			// isLeaf() check has to happen here so that trailing "/" for objects can be removed.
-			for i, entry := range entries {
-				if isLeaf(bucket, pathJoin(prefixDir, entry)) {
-					entries[i] = strings.TrimSuffix(entry, slashSeparator)
-				}
-			}
-
-			// Sort again after removing trailing "/" for objects as the previous sort
-			// does not hold good anymore.
-			sort.Strings(entries)
-
-			// Succes.
-			return entries, delayIsLeaf, nil
-		} // Return error at the end.
-
-		// Error.
-		return nil, false, err
+		if err != nil {
+			return nil, false, err
+		}
+		entries, delayIsLeaf = filterListEntries(bucket, prefixDir, entries, prefixEntry, isLeaf)
+		return entries, delayIsLeaf, nil
 	}
 
 	// Return list factory instance.

cmd/tree-walk.go

@@ -95,53 +95,30 @@ type listDirFunc func(bucket, prefixDir, prefixEntry string) (entries []string,
 // 4. XL backend multipart listing - isLeaf is true if the entry is a directory and contains uploads.json
 type isLeafFunc func(string, string) bool
 
-// Returns function "listDir" of the type listDirFunc.
-// isLeaf - is used by listDir function to check if an entry is a leaf or non-leaf entry.
-// disks - used for doing disk.ListDir(). FS passes single disk argument, XL passes a list of disks.
-func listDirFactory(isLeaf isLeafFunc, treeWalkIgnoredErrs []error, disks ...StorageAPI) listDirFunc {
-	// listDir - lists all the entries at a given prefix and given entry in the prefix.
-	listDir := func(bucket, prefixDir, prefixEntry string) (entries []string, delayIsLeaf bool, err error) {
-		for _, disk := range disks {
-			if disk == nil {
-				continue
-			}
-			entries, err = disk.ListDir(bucket, prefixDir)
-			if err == nil {
-				// Listing needs to be sorted.
-				sort.Strings(entries)
+func filterListEntries(bucket, prefixDir string, entries []string, prefixEntry string, isLeaf isLeafFunc) ([]string, bool) {
+	// Listing needs to be sorted.
+	sort.Strings(entries)
 
-				// Filter entries that have the prefix prefixEntry.
-				entries = filterMatchingPrefix(entries, prefixEntry)
+	// Filter entries that have the prefix prefixEntry.
+	entries = filterMatchingPrefix(entries, prefixEntry)
 
-				// Can isLeaf() check be delayed till when it has to be sent down the
-				// treeWalkResult channel?
-				delayIsLeaf = delayIsLeafCheck(entries)
-				if delayIsLeaf {
-					return entries, delayIsLeaf, nil
-				}
-
-				// isLeaf() check has to happen here so that trailing "/" for objects can be removed.
-				for i, entry := range entries {
-					if isLeaf(bucket, pathJoin(prefixDir, entry)) {
-						entries[i] = strings.TrimSuffix(entry, slashSeparator)
-					}
-				}
-				// Sort again after removing trailing "/" for objects as the previous sort
-				// does not hold good anymore.
-				sort.Strings(entries)
-				return entries, delayIsLeaf, nil
-			}
-			// For any reason disk was deleted or goes offline, continue
-			// and list from other disks if possible.
-			if isErrIgnored(err, treeWalkIgnoredErrs...) {
-				continue
-			}
-			break
-		}
-		// Return error at the end.
-		return nil, false, traceError(err)
+	// Can isLeaf() check be delayed till when it has to be sent down the
+	// treeWalkResult channel?
+	delayIsLeaf := delayIsLeafCheck(entries)
+	if delayIsLeaf {
+		return entries, true
 	}
-	return listDir
+
+	// isLeaf() check has to happen here so that trailing "/" for objects can be removed.
+	for i, entry := range entries {
+		if isLeaf(bucket, pathJoin(prefixDir, entry)) {
+			entries[i] = strings.TrimSuffix(entry, slashSeparator)
+		}
+	}
+	// Sort again after removing trailing "/" for objects as the previous sort
+	// does not hold good anymore.
+	sort.Strings(entries)
+	return entries, false
 }
 
 // treeWalk walks directory tree recursively pushing treeWalkResult into the channel as and when it encounters files.

cmd/xl-v1-list-objects.go

@@ -18,6 +18,34 @@ package cmd
 
 import "strings"
 
+// Returns function "listDir" of the type listDirFunc.
+// isLeaf - is used by listDir function to check if an entry is a leaf or non-leaf entry.
+// disks - used for doing disk.ListDir(). FS passes single disk argument, XL passes a list of disks.
+func listDirFactory(isLeaf isLeafFunc, treeWalkIgnoredErrs []error, disks ...StorageAPI) listDirFunc {
+	// listDir - lists all the entries at a given prefix and given entry in the prefix.
+	listDir := func(bucket, prefixDir, prefixEntry string) (entries []string, delayIsLeaf bool, err error) {
+		for _, disk := range disks {
+			if disk == nil {
+				continue
+			}
+			entries, err = disk.ListDir(bucket, prefixDir)
+			if err == nil {
+				entries, delayIsLeaf = filterListEntries(bucket, prefixDir, entries, prefixEntry, isLeaf)
+				return entries, delayIsLeaf, nil
+			}
+			// For any reason disk was deleted or goes offline, continue
+			// and list from other disks if possible.
+			if isErrIgnored(err, treeWalkIgnoredErrs...) {
+				continue
+			}
+			break
+		}
+		// Return error at the end.
+		return nil, false, traceError(err)
+	}
+	return listDir
+}
+
 // listObjects - wrapper function implemented over file tree walk.
 func (xl xlObjects) listObjects(bucket, prefix, marker, delimiter string, maxKeys int) (ListObjectsInfo, error) {
 	// Default is recursive, if delimiter is set then list non recursive.