Enhance ListObjectsV2 API to return UserDefined metadata (#8539)

cmd/bucket-handlers-listobjects.go

@@ -126,6 +126,90 @@ func (api objectAPIHandlers) ListBucketObjectVersionsHandler(w http.ResponseWrit
 	writeSuccessResponseXML(w, encodeResponse(response))
 }
 
+// ListObjectsV2MHandler - GET Bucket (List Objects) Version 2 with metadata.
+// --------------------------
+// This implementation of the GET operation returns some or all (up to 10000)
+// of the objects in a bucket. You can use the request parame<ters as selection
+// criteria to return a subset of the objects in a bucket.
+//
+// NOTE: It is recommended that this API to be used for application development.
+// MinIO continues to support ListObjectsV1 and V2 for supporting legacy tools.
+func (api objectAPIHandlers) ListObjectsV2MHandler(w http.ResponseWriter, r *http.Request) {
+	ctx := newContext(r, w, "ListObjectsV2M")
+
+	defer logger.AuditLog(w, r, "ListObjectsV2M", mustGetClaimsFromToken(r))
+
+	vars := mux.Vars(r)
+	bucket := vars["bucket"]
+
+	objectAPI := api.ObjectAPI()
+	if objectAPI == nil {
+		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrServerNotInitialized), r.URL, guessIsBrowserReq(r))
+		return
+	}
+
+	if s3Error := checkRequestAuthType(ctx, r, policy.ListBucketAction, bucket, ""); s3Error != ErrNone {
+		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(s3Error), r.URL, guessIsBrowserReq(r))
+		return
+	}
+
+	urlValues := r.URL.Query()
+
+	// Extract all the listObjectsV2 query params to their native values.
+	prefix, token, startAfter, delimiter, fetchOwner, maxKeys, encodingType, errCode := getListObjectsV2Args(urlValues)
+	if errCode != ErrNone {
+		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(errCode), r.URL, guessIsBrowserReq(r))
+		return
+	}
+
+	// Validate the query params before beginning to serve the request.
+	// fetch-owner is not validated since it is a boolean
+	if s3Error := validateListObjectsArgs(token, delimiter, encodingType, maxKeys); s3Error != ErrNone {
+		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(s3Error), r.URL, guessIsBrowserReq(r))
+		return
+	}
+
+	listObjectsV2 := objectAPI.ListObjectsV2
+
+	// Inititate a list objects operation based on the input params.
+	// On success would return back ListObjectsInfo object to be
+	// marshaled into S3 compatible XML header.
+	listObjectsV2Info, err := listObjectsV2(ctx, bucket, prefix, token, delimiter, maxKeys, fetchOwner, startAfter)
+	if err != nil {
+		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL, guessIsBrowserReq(r))
+		return
+	}
+
+	for i := range listObjectsV2Info.Objects {
+		var actualSize int64
+		if listObjectsV2Info.Objects[i].IsCompressed() {
+			// Read the decompressed size from the meta.json.
+			actualSize = listObjectsV2Info.Objects[i].GetActualSize()
+			if actualSize < 0 {
+				writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidDecompressedSize), r.URL, guessIsBrowserReq(r))
+				return
+			}
+			// Set the info.Size to the actualSize.
+			listObjectsV2Info.Objects[i].Size = actualSize
+		} else if crypto.IsEncrypted(listObjectsV2Info.Objects[i].UserDefined) {
+			listObjectsV2Info.Objects[i].ETag = getDecryptedETag(r.Header, listObjectsV2Info.Objects[i], false)
+			listObjectsV2Info.Objects[i].Size, err = listObjectsV2Info.Objects[i].DecryptedSize()
+			if err != nil {
+				writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL, guessIsBrowserReq(r))
+				return
+			}
+		}
+	}
+
+	response := generateListObjectsV2Response(bucket, prefix, token,
+		listObjectsV2Info.NextContinuationToken, startAfter,
+		delimiter, encodingType, fetchOwner, listObjectsV2Info.IsTruncated,
+		maxKeys, listObjectsV2Info.Objects, listObjectsV2Info.Prefixes, true)
+
+	// Write success response.
+	writeSuccessResponseXML(w, encodeResponse(response))
+}
+
 // ListObjectsV2Handler - GET Bucket (List Objects) Version 2.
 // --------------------------
 // This implementation of the GET operation returns some or all (up to 10000)
@@ -201,8 +285,10 @@ func (api objectAPIHandlers) ListObjectsV2Handler(w http.ResponseWriter, r *http
 		}
 	}
 
-	response := generateListObjectsV2Response(bucket, prefix, token, listObjectsV2Info.NextContinuationToken, startAfter,
-		delimiter, encodingType, fetchOwner, listObjectsV2Info.IsTruncated, maxKeys, listObjectsV2Info.Objects, listObjectsV2Info.Prefixes)
+	response := generateListObjectsV2Response(bucket, prefix, token,
+		listObjectsV2Info.NextContinuationToken, startAfter,
+		delimiter, encodingType, fetchOwner, listObjectsV2Info.IsTruncated,
+		maxKeys, listObjectsV2Info.Objects, listObjectsV2Info.Prefixes, false)
 
 	// Write success response.
 	writeSuccessResponseXML(w, encodeResponse(response))