Merge pull request #218 from kkpattern/preallocate_precord_map

Preallocate pmap according to PRecord fields count
tobgu · Jun 5, 2021 · 97c6309 · 97c6309
2 parents be23bac + 79ba001
commit 97c6309
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Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/pyrsistent/_pmap.py b/pyrsistent/_pmap.py
@@ -445,7 +445,7 @@ def pmap(initial={}, pre_size=0):
     >>> pmap({'a': 13, 'b': 14})
     pmap({'b': 14, 'a': 13})
     """
-    if not initial:
+    if not initial and pre_size == 0:
         return _EMPTY_PMAP
 
     return _turbo_mapping(initial, pre_size)

diff --git a/pyrsistent/_precord.py b/pyrsistent/_precord.py
@@ -46,7 +46,7 @@ def __new__(cls, **kwargs):
                                   for k, v in cls._precord_initial_values.items())
             initial_values.update(kwargs)
 
-        e = _PRecordEvolver(cls, pmap(), _factory_fields=factory_fields, _ignore_extra=ignore_extra)
+        e = _PRecordEvolver(cls, pmap(pre_size=len(cls._precord_fields)), _factory_fields=factory_fields, _ignore_extra=ignore_extra)
         for k, v in initial_values.items():
             e[k] = v