do not initialize fields in ObjectMD that are not used in S3C

We set fields that are not used in S3C to undefined to avoid serializing
and unecessarilty store them in the metadata. This could affect sizing and
the load on the platform.

Issue: ARSN-411

lib/models/ObjectMD.ts

@@ -32,15 +32,15 @@ export type ReplicationInfo = {
     role: string;
     storageType: string;
     dataStoreVersionId: string;
-    isNFS: boolean | null;
+    isNFS?: boolean;
 };
 
 export type ObjectMDData = {
     'owner-display-name': string;
     'owner-id': string;
     'cache-control': string;
     'content-disposition': string;
-    'content-language': string;
+    'content-language'?: string;
     'content-encoding': string;
     'creation-time'?: string;
     'last-modified'?: string;
@@ -84,12 +84,12 @@ export type ObjectMDData = {
     // Used for keeping object metadata in the oplog event
     // In case of a deletion the flag is first updated before
     // deleting the object
-    deleted: boolean;
+    deleted?: boolean;
     // PHD flag indicates whether the object is a temporary placeholder.
     // This is the case when the latest version of an object gets deleted
     // the master is set as a placeholder and gets updated with the new latest
     // version data after a certain amount of time.
-    isPHD: boolean;
+    isPHD?: boolean;
 };
 
 /**
@@ -183,7 +183,7 @@ export default class ObjectMD {
             'content-length': 0,
             'content-type': '',
             'content-md5': '',
-            'content-language': '',
+            'content-language': undefined,
             'creation-time': undefined,
             // simple/no version. will expand once object versioning is
             // introduced
@@ -197,7 +197,7 @@ export default class ObjectMD {
             'x-amz-server-side-encryption-aws-kms-key-id': '',
             'x-amz-server-side-encryption-customer-algorithm': '',
             'x-amz-website-redirect-location': '',
-            'x-amz-scal-transition-in-progress': false,
+            'x-amz-scal-transition-in-progress': undefined,
             acl: {
                 Canned: 'private',
                 FULL_CONTROL: [],
@@ -227,12 +227,12 @@ export default class ObjectMD {
                 role: '',
                 storageType: '',
                 dataStoreVersionId: '',
-                isNFS: null,
+                isNFS: undefined,
             },
             dataStoreName: '',
             originOp: '',
-            deleted: false,
-            isPHD: false,
+            deleted: undefined,
+            isPHD: undefined,
         };
     }
 
@@ -479,7 +479,7 @@ export default class ObjectMD {
      * @return content-language
      */
     getContentLanguage() {
-        return this._data['content-language'];
+        return this._data['content-language'] || '';
     }
 
     /**
@@ -677,7 +677,7 @@ export default class ObjectMD {
      * @return True if transition is in progress, false otherwise
      */
     getTransitionInProgress() {
-        return this._data['x-amz-scal-transition-in-progress'];
+        return !!this._data['x-amz-scal-transition-in-progress'];
     }
 
     /**
@@ -1065,7 +1065,7 @@ export default class ObjectMD {
             role,
             storageType: storageType || '',
             dataStoreVersionId: dataStoreVersionId || '',
-            isNFS: isNFS || null,
+            isNFS,
         };
         return this;
     }
@@ -1461,7 +1461,7 @@ export default class ObjectMD {
     * @return {Boolean}
     */
     getDeleted() {
-        return this._data.deleted;
+        return !!this._data.deleted;
     }
 
     /**
@@ -1479,6 +1479,6 @@ export default class ObjectMD {
     * @return {Boolean}
     */
     getIsPHD() {
-        return this._data.isPHD;
+        return !!this._data.isPHD;
     }
 }