Allow cads-adaptors to directly write on the cache filesystem

cads_adaptors/adaptors/__init__.py

@@ -1,5 +1,6 @@
 import abc
 import contextlib
+import pathlib
 from typing import Any, BinaryIO
 
 import cads_adaptors.tools.logger
@@ -85,6 +86,7 @@ def __init__(
         self,
         form: list[dict[str, Any]] | dict[str, Any] | None,
         context: Context | None = None,
+        cache_tmp_path: pathlib.Path | None = None,
         **config: Any,
     ) -> None:
         self.form = form
@@ -93,6 +95,9 @@ def __init__(
             self.context = Context()
         else:
             self.context = context
+        self.cache_tmp_path = (
+            pathlib.Path() if cache_tmp_path is None else cache_tmp_path
+        )
 
     @abc.abstractmethod
     def normalise_request(self, request: Request) -> Request:
@@ -184,11 +189,19 @@ def retrieve(self, request: Request) -> BinaryIO:
                 microseconds=time_elapsed.microsecond,
             ).total_seconds()
 
+        self.context.add_stdout(f"Sleeping {time_sleep} s")
         time.sleep(time_sleep)
-        with open("dummy.grib", "wb") as fp:
+
+        dummy_file = self.cache_tmp_path / "dummy.grib"
+        self.context.add_stdout(f"Writing {size} B to {dummy_file!s}")
+        tic = time.perf_counter()
+        with dummy_file.open("wb") as fp:
             with open("/dev/urandom", "rb") as random:
                 while size > 0:
                     length = min(size, 10240)
                     fp.write(random.read(length))
                     size -= length
-        return open("dummy.grib", "rb")
+        toc = time.perf_counter()
+        self.context.add_stdout(f"Elapsed time to write the file: {toc - tic} s")
+
+        return dummy_file.open("rb")

tests/test_10_cache_tmp_path.py

@@ -0,0 +1,11 @@
+import os
+import pathlib
+
+import cads_adaptors
+
+
+def test_cache_tmp_path_dummy_adaptor(tmp_path: pathlib.Path) -> None:
+    dummy_adaptor = cads_adaptors.DummyAdaptor(None, cache_tmp_path=tmp_path)
+    result = dummy_adaptor.retrieve({"size": 1})
+    assert result.name == str(tmp_path / "dummy.grib")
+    assert os.path.getsize(result.name) == 1