Change digest API to update the single hash object

tests/ci/digest_helper.py

@@ -3,7 +3,7 @@
 from hashlib import md5
 from logging import getLogger
 from pathlib import Path
-from typing import TYPE_CHECKING, Iterable
+from typing import TYPE_CHECKING, Iterable, Optional
 from sys import modules
 
 if TYPE_CHECKING:
@@ -16,43 +16,42 @@ else:
 logger = getLogger(__name__)
 
 
-def _digest_file(file: Path) -> HASH:
+def _digest_file(file: Path, hash_object: HASH) -> None:
     assert file.is_file()
-    md5_hash = md5()
     with open(file, "rb") as fd:
         for chunk in iter(lambda: fd.read(4096), b""):
-            md5_hash.update(chunk)
-    return md5_hash
+            hash_object.update(chunk)
 
 
-def _digest_directory(directory: Path) -> HASH:
+def _digest_directory(directory: Path, hash_object: HASH) -> None:
     assert directory.is_dir()
-    md5_hash = md5()
     for p in sorted(directory.rglob("*")):
         if p.is_symlink() and p.is_dir():
             # The symlink directory is not listed recursively, so we process it manually
-            md5_hash.update(_digest_directory(p).digest())
+            (_digest_directory(p, hash_object))
         if p.is_file():
-            md5_hash.update(_digest_file(p).digest())
-    return md5_hash
+            (_digest_file(p, hash_object))
 
 
-def digest_path(path: Path) -> HASH:
-    """Calculates md5 hash of the path, either it's directory or file"""
+def digest_path(path: Path, hash_object: Optional[HASH] = None) -> HASH:
+    """Calculates md5 (or updates existing hash_object) hash of the path, either it's
+    directory or file"""
+    hash_object = hash_object or md5()
     if path.is_dir():
-        return _digest_directory(path)
-    if path.is_file():
-        return _digest_file(path)
-    return md5()
+        _digest_directory(path, hash_object)
+    elif path.is_file():
+        _digest_file(path, hash_object)
+    return hash_object
 
 
-def digest_paths(paths: Iterable[Path]) -> HASH:
-    """Calculates aggregated md5 hash of passed paths. The order matters"""
-    md5_hash = md5()
+def digest_paths(paths: Iterable[Path], hash_object: Optional[HASH] = None) -> HASH:
+    """Calculates aggregated md5 (or updates existing hash_object) hash of passed paths.
+    The order matters"""
+    hash_object = hash_object or md5()
     for path in paths:
         if path.exists():
-            md5_hash.update(digest_path(path).digest())
-    return md5_hash
+            digest_path(path, hash_object)
+    return hash_object
 
 
 def digest_script(path_str: str) -> HASH:
@@ -65,7 +64,7 @@ def digest_script(path_str: str) -> HASH:
             script_path = getattr(script, "__file__", "")
             if parent.absolute().as_posix() in script_path:
                 logger.debug("Updating the hash with %s", script_path)
-                md5_hash.update(_digest_file(Path(script_path)).digest())
+                _digest_file(Path(script_path), md5_hash)
     except RuntimeError:
         logger.warning("The modules size has changed, retry calculating digest")
         return digest_script(path_str)