Completed the implementation for File system cache

jax/experimental/compilation_cache/file_system_cache.py

@@ -0,0 +1,42 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from typing import Optional
+import os
+
+class FileSystemCache:
+
+  def __init__(self, path: str):
+    """Sets up a cache at 'path'. Cached values may already be present."""
+    os.makedirs(path, exist_ok=True)
+    self._path  = path
+
+  def get(self, key: str) -> Optional[bytes]:
+    """Returns None if 'key' isn't present."""
+    if not key:
+      raise ValueError("key cannot be empty")
+    path_to_key = os.path.join(self._path, key)
+    if os.path.exists(path_to_key):
+      with open(path_to_key, "rb") as file:
+        return file.read()
+    else:
+      return None
+
+  def put(self, key: str, value: bytes):
+    """Adds new cache entry, possibly evicting older entries."""
+    if not key:
+      raise ValueError("key cannot be empty")
+      #TODO(colemanliyah):implement eviction
+    with open(os.path.join(self._path, key), "wb") as file:
+      file.write(value)

tests/file_system_cache_test.py

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+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from absl.testing import absltest
+from jax.experimental.compilation_cache.file_system_cache import FileSystemCache
+import jax.test_util as jtu
+import tempfile
+
+class FileSystemCacheTest(jtu.JaxTestCase):
+
+  def test_get_nonexistent_key(self):
+   with tempfile.TemporaryDirectory() as tmpdir:
+     cache = FileSystemCache(tmpdir)
+     self.assertEqual(cache.get("nonExistentKey"), None)
+
+  def test_put_and_get_key(self):
+   with tempfile.TemporaryDirectory() as tmpdir:
+     cache = FileSystemCache(tmpdir)
+     cache.put("foo", b"bar")
+     self.assertEqual(cache.get("foo"), b"bar")
+
+  def test_existing_cache_path(self):
+    with tempfile.TemporaryDirectory() as tmpdir:
+      cache1 = FileSystemCache(tmpdir)
+      cache1.put("foo", b"bar")
+      del cache1
+      cache2 = FileSystemCache(tmpdir)
+      self.assertEqual(cache2.get("foo"), b"bar")
+
+  def test_empty_value_put(self):
+    with tempfile.TemporaryDirectory() as tmpdir:
+     cache = FileSystemCache(tmpdir)
+     cache.put("foo", b"")
+     self.assertEqual(cache.get("foo"), b"")
+
+  def test_empty_key_put(self):
+    with tempfile.TemporaryDirectory() as tmpdir:
+     cache = FileSystemCache(tmpdir)
+     with self.assertRaisesRegex(ValueError , r"key cannot be empty"):
+       cache.put("", b"bar")
+
+  def test_empty_key_get(self):
+    with tempfile.TemporaryDirectory() as tmpdir:
+     cache = FileSystemCache(tmpdir)
+     with self.assertRaisesRegex(ValueError , r"key cannot be empty"):
+       cache.get("")
+
+if __name__ == "__main__":
+  absltest.main(testLoader=jtu.JaxTestLoader())