Merge pull request #3 from VorTECHsa/add-suffix-local-cache

feat: add file extension in functional reader

tests/test_caches.py

@@ -11,6 +11,7 @@
 from uhura.base import Readable, Writable
 from uhura.caches import (
     CachingService,
+    LocalCache,
 )
 from uhura.caching import (
     cache_local_input,
@@ -20,6 +21,7 @@
 )
 from uhura.functional import uhura_reader, uhura_writer
 from uhura.modes import fixture_builder_mode, task_test_mode
+from uhura.serde import PickleSerde
 
 
 class RandomReadable(Readable[float]):
@@ -293,3 +295,15 @@ def test_cache_key():
         assert (
             DatabaseReader("id1").read() != DatabaseReader("id2").read()
         ), "Cache key being ignored"
+
+
+def test_local_cache_path_renders_path_with_file_extension_from_serde_if_not_present():
+    cache_path = "my/cache/dir"
+    serde = PickleSerde()
+    local_cache = LocalCache(cache_path, serde)
+
+    base_path = "base/path"
+    cache_key = "filename"
+    rendered_path = local_cache.render_path(base_path, cache_key, serde)
+
+    assert rendered_path.split(".")[-1] == "pkl"

tests/test_serde.py

@@ -1,8 +1,12 @@
-from uhura.serde import PickleSerde
+import os
+from tempfile import TemporaryDirectory
+from typing import Any
+
+import pytest
+
 from uhura.base import Readable
 from uhura.modes import fixture_builder_mode, task_test_mode
-from tempfile import TemporaryDirectory
-import os
+from uhura.serde import PickleSerde, Serde
 
 
 class FakeSerde(PickleSerde):
@@ -44,3 +48,14 @@ def get_serde(self):
             assert not test_serde.has_been_read
             client.read()
             assert test_serde.has_been_read
+
+
+def test_serde_subclass_requires_file_extension():
+    with pytest.raises(AssertionError):
+
+        class Bad(Serde[Any]):
+            def read_from_file(self, file):
+                pass
+
+            def write_to_file(self, file, obj: Any):
+                pass

uhura/caches.py

@@ -7,7 +7,7 @@
 from typing import Callable, DefaultDict, Optional, Protocol, Type  # ParamSpec
 
 from uhura.composition import async_unit, compose
-from uhura.serde import Serde, DEFAULT_SERDE
+from uhura.serde import DEFAULT_SERDE, Serde
 
 logger = logging.getLogger("uhura.caches")
 
@@ -57,9 +57,18 @@ def update(self, obj):
     def get(self):
         return self._serde.read_from_file(self._path)
 
+    @classmethod
+    def render_path(cls, base_path: str, cache_key: str, serde: Serde):
+        if not cache_key.endswith(serde.file_extension):
+            cache_key = cache_key + serde.file_extension
+        return os.path.join(base_path, cache_key)
+
     @classmethod
     def cache_for_instance(cls, cacheable: Cacheable, base_path: str):
-        return cls(os.path.join(base_path, cacheable.cache_key()), cacheable.get_serde())
+        cache_key = cacheable.cache_key()
+        serde = cacheable.get_serde()
+        path = cls.render_path(base_path, cache_key, serde)
+        return cls(path, serde)
 
 
 async def _take(async_iterable, n=5):

uhura/serde.py

@@ -1,5 +1,5 @@
 import pickle
-from typing import TypeVar, Generic, ClassVar, Any
+from typing import Any, ClassVar, Generic, TypeVar
 
 import pandas as pd
 
@@ -9,6 +9,12 @@
 class Serde(Generic[SerdeType]):
     file_extension: ClassVar[str]
 
+    def __init_subclass__(cls) -> None:
+        assert hasattr(
+            cls, "file_extension"
+        ), "Serde implementations must have a valid file_extension"
+        return super().__init_subclass__()
+
     def read_from_file(self, file) -> SerdeType:
         raise NotImplementedError()