- add some caching to prevent repeated ray.put and pickling

parfor/__init__.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import logging
 import os
+from collections import OrderedDict
 from contextlib import ExitStack, redirect_stderr, redirect_stdout
 from functools import wraps
 from importlib.metadata import version
@@ -231,6 +232,28 @@ def get_worker(n_processes) -> RemoteFunction:
         return ray.remote(worker)  # type: ignore
 
 
+class DequeDict(OrderedDict):
+    def __init__(self, maxlen: int = None, *args: Any, **kwargs: Any) -> None:
+        self.maxlen = maxlen
+        super().__init__(*args, **kwargs)
+
+    def __setitem__(self, *args: Any, **kwargs: Any) -> None:
+        super().__setitem__(*args, **kwargs)
+        self.truncate()
+
+    def truncate(self) -> None:
+        if self.maxlen is not None:
+            while len(self) > self.maxlen:
+                self.popitem(False)
+
+    def update(self, *args: Any, **kwargs: Any) -> None:
+        super().update(*args, **kwargs)  # type: ignore
+        self.truncate()
+
+
+cache = DequeDict(128)
+
+
 class Task:
     def __init__(
         self,
@@ -263,9 +286,20 @@ class Task:
     @staticmethod
     def put(item: Any) -> tuple[bool, Any]:
         try:
-            return False, ray.put(item)
+            h = hash(item)
-        except Exception:  # noqa
+            if not h in cache:
-            return True, ray.put(dumps(item, recurse=True))
+                try:
+                    cache[h] = False, ray.put(item)
+                except Exception:  # noqa
+                    cache[h] = True, ray.put(dumps(item, recurse=True))
+            else:
+                cache.move_to_end(h)
+            return cache[h]
+        except TypeError:
+            try:
+                return False, ray.put(item)
+            except Exception:  # noqa
+                return True, ray.put(dumps(item, recurse=True))
 
     @property
     def fun(self) -> Callable[[Any, ...], Any]:
@@ -344,7 +378,7 @@ class ParPool:
         return self
 
     def __exit__(self, *args: Any, **kwargs: Any) -> None:
-        pass
+        self.close()
 
     def __call__(self, n: Any, handle: Hashable = None, barlength: int = 1) -> None:
         self.add_task(
@@ -354,7 +388,7 @@ class ParPool:
         )
 
     def close(self) -> None:
-        pass
+        cache.clear()
 
     def add_task(
         self,

pyproject.toml

@@ -1,11 +1,11 @@
 [project]
 name = "parfor"
-version = "2026.2.1"
+version = "2026.2.2"
 description = "A package to mimic the use of parfor as done in Matlab."
 authors = [
     { name = "Wim Pomp-Pervova", email = "wimpomp@gmail.com" }
 ]
-license = { text = "MIT"}
+license = { text = "MIT" }
 readme = "README.md"
 keywords = ["parfor", "concurrency", "multiprocessing", "parallel"]
 requires-python = ">=3.10"