optimize cached file locations and add option for cache directory

lib/obs.py

@@ -6,6 +6,7 @@ import urllib.parse
 import xml.etree.ElementTree as ET
 from urllib.error import HTTPError
 from pathlib import Path
+from lib.proxy_sha256 import md5
 
 import osc.core
 
@@ -160,16 +161,22 @@ class OBS:
         name: str,
         revision: str,
         dirpath: str,
+        cachedir: str,
         file_md5: str,
     ) -> None:
-        cached_file = self._path_from_md5(name, dirpath, file_md5)
-        if not self.in_cache(name, dirpath, file_md5):
+        
+        cached_file = self._path_from_md5(name, cachedir, file_md5)
+        if not self.in_cache(name, cachedir, file_md5):
             with (dirpath / name).open("wb") as f:
                 f.write(self._download(project, package, name, revision).read())
             shutil.copy(dirpath / name, cached_file)
         else:
             shutil.copy(cached_file, dirpath / name)
 
+        # Validate the MD5 of the downloaded file
+        if md5(dirpath / name) != file_md5:
+            raise Exception(f"Download error in {name}")
+
     def list(self, project, package, srcmd5, linkrev):
         params = {"rev": srcmd5, "expand": "1"}
         if linkrev:
@@ -187,15 +194,11 @@ class OBS:
 
         return root
 
-    def _path_from_md5(self, name, dirpath, md5):
-        cache = dirpath.joinpath(".cache/")
-        if not Path(cache).exists():
-            cache.mkdir()
-        filepath = cache.joinpath(f"{md5[0:3]}/{md5[3:6]}/{md5[6:9]}/")
+    def _path_from_md5(self, name, cachedir, md5):
+        filepath = cachedir / md5[:3]
+        cached_file = f"{md5[3:]}-{name}"
         filepath.mkdir(parents=True, exist_ok=True)
-        return filepath.joinpath(f"{md5[9:]}-{name}")
+        return filepath / cached_file
 
-    def in_cache(self, name, dirpath, md5):
-        if self._path_from_md5(name, dirpath, md5).is_file():
-            return True
-        return False
+    def in_cache(self, name, cachedir, md5):
+        return self._path_from_md5(name, cachedir, md5).exists()