feat: add support for S3 ListObjects and ListObjectsV2 (#5350)

weed/s3api/s3api_objects_list_handlers.go

@@ -47,10 +47,6 @@ func (s3a *S3ApiServer) ListObjectsV2Handler(w http.ResponseWriter, r *http.Requ
 		s3err.WriteErrorResponse(w, r, s3err.ErrInvalidMaxKeys)
 		return
 	}
-	if delimiter != "" && delimiter != "/" {
-		s3err.WriteErrorResponse(w, r, s3err.ErrNotImplemented)
-		return
-	}
 
 	marker := continuationToken
 	if continuationToken == "" {
@@ -103,10 +99,6 @@ func (s3a *S3ApiServer) ListObjectsV1Handler(w http.ResponseWriter, r *http.Requ
 		s3err.WriteErrorResponse(w, r, s3err.ErrInvalidMaxKeys)
 		return
 	}
-	if delimiter != "" && delimiter != "/" {
-		s3err.WriteErrorResponse(w, r, s3err.ErrNotImplemented)
-		return
-	}
 
 	response, err := s3a.listFilerEntries(bucket, originalPrefix, maxKeys, marker, delimiter)
 
@@ -171,6 +163,34 @@ func (s3a *S3ApiServer) listFilerEntries(bucket string, originalPrefix string, m
 						cursor.maxKeys--
 					}
 				} else {
+					var delimiterFound bool
+					if delimiter != "" {
+						// keys that contain the same string between the prefix and the first occurrence of the delimiter are grouped together as a commonPrefix.
+						// extract the string between the prefix and the delimiter and add it to the commonPrefixes if it's unique.
+						fullPath := fmt.Sprintf("%s/%s", dir, entry.Name)[len(bucketPrefix):]
+						delimitedPath := strings.SplitN(fullPath, delimiter, 2)
+						if len(delimitedPath) == 2 {
+
+							// S3 clients expect the delimited prefix to contain the delimiter.
+							delimitedPrefix := delimitedPath[0] + delimiter
+
+							for i := range commonPrefixes {
+								if commonPrefixes[i].Prefix == delimitedPrefix {
+									delimiterFound = true
+									break
+								}
+							}
+
+							if !delimiterFound {
+								commonPrefixes = append(commonPrefixes, PrefixEntry{
+									Prefix: delimitedPrefix,
+								})
+								cursor.maxKeys--
+								delimiterFound = true
+							}
+						}
+					}
+					if !delimiterFound {
 						storageClass := "STANDARD"
 						if v, ok := entry.Extended[s3_constants.AmzStorageClass]; ok {
 							storageClass = string(v)
@@ -188,6 +208,7 @@ func (s3a *S3ApiServer) listFilerEntries(bucket string, originalPrefix string, m
 						})
 						cursor.maxKeys--
 					}
+				}
 			})
 			if doErr != nil {
 				return doErr