a reasonable defafult sort function for data replicas

Author: d-w-moore

irods/data_object.py

@@ -1,8 +1,9 @@
+import ast
+import datetime
 import io
-import sys
 import logging
 import os
-import ast
+import sys
 
 from irods.models import DataObject
 from irods.meta import iRODSMetaCollection
@@ -41,6 +42,20 @@ def __repr__(self):
         return "<{}.{} {}>".format(self.__class__.__module__, self.__class__.__name__, self.resource_name)
 
 
+_REPL_STATUSES = (1, 0, 2, 3, 4)
+_REFERENCE_DATETIME = datetime.datetime(1970, 1, 1, 0, 0, 0, tzinfo=datetime.timezone.utc)
+
+def _DEFAULT_SORT_KEY_FN(row):
+    repl_status = int(row[DataObject.replica_status])
+   
+    repl_status_rank = (
+        _REPL_STATUSES.index(repl_status) if _REPL_STATUSES.count(repl_status)
+        else sys.maxsize
+    )
+
+    return (repl_status_rank, _REFERENCE_DATETIME - row[DataObject.modify_time])
+
+
 class iRODSDataObject:
     def __init__(self, manager, parent=None, results=None):
         self.manager = manager
@@ -54,7 +69,7 @@ def __init__(self, manager, parent=None, results=None):
                         # backward compatibility with older schema versions
                         pass
             self.path = self.collection.path + "/" + self.name
-            replicas = sorted(results, key=lambda r: r[DataObject.replica_number])
+            replicas = sorted(results, key=_DEFAULT_SORT_KEY_FN)
 
             # The status quo before iRODS 5