Add listBucketObjectsVersions implementation (#8093)

This API implementation simply behaves like listObjects()
but returns back single version for each object, this
implementation should be considered dummy it is only
meant for some applications which rely on this.

cmd/bucket-handlers-listobjects.go

@@ -49,6 +49,83 @@ func validateListObjectsArgs(prefix, marker, delimiter, encodingType string, max
 	return ErrNone
 }
 
+// ListBucketObjectVersions - GET Bucket Object versions
+// You can use the versions subresource to list metadata about all
+// of the versions of objects in a bucket.
+func (api objectAPIHandlers) ListBucketObjectVersionsHandler(w http.ResponseWriter, r *http.Request) {
+	ctx := newContext(r, w, "ListBucketObjectVersions")
+
+	defer logger.AuditLog(w, r, "ListBucketObjectVersions", 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 listBucketVersions query params to their native values.
+	// versionIDMarker is ignored here.
+	prefix, marker, delimiter, maxkeys, encodingType, _, errCode := getListBucketObjectVersionsArgs(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.
+	if s3Error := validateListObjectsArgs(prefix, marker, delimiter, encodingType, maxkeys); s3Error != ErrNone {
+		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(s3Error), r.URL, guessIsBrowserReq(r))
+		return
+	}
+
+	listObjects := objectAPI.ListObjects
+
+	// 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.
+	listObjectsInfo, err := listObjects(ctx, bucket, prefix, marker, delimiter, maxkeys)
+	if err != nil {
+		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL, guessIsBrowserReq(r))
+		return
+	}
+
+	for i := range listObjectsInfo.Objects {
+		var actualSize int64
+		if listObjectsInfo.Objects[i].IsCompressed() {
+			// Read the decompressed size from the meta.json.
+			actualSize = listObjectsInfo.Objects[i].GetActualSize()
+			if actualSize < 0 {
+				writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidDecompressedSize),
+					r.URL, guessIsBrowserReq(r))
+				return
+			}
+			// Set the info.Size to the actualSize.
+			listObjectsInfo.Objects[i].Size = actualSize
+		} else if crypto.IsEncrypted(listObjectsInfo.Objects[i].UserDefined) {
+			listObjectsInfo.Objects[i].ETag = getDecryptedETag(r.Header, listObjectsInfo.Objects[i], false)
+			listObjectsInfo.Objects[i].Size, err = listObjectsInfo.Objects[i].DecryptedSize()
+			if err != nil {
+				writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL, guessIsBrowserReq(r))
+				return
+			}
+		}
+	}
+
+	response := generateListVersionsResponse(bucket, prefix, marker, delimiter, encodingType, maxkeys, listObjectsInfo)
+
+	// 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 1000)