From: Daan De Meyer <daan.j.demeyer@gmail.com>
Date: Mon, 8 Jul 2024 21:26:10 +0000 (+0200)
Subject: Optimize hash_file()
X-Git-Tag: v24~46^2~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2e736afb75726d9afee55ac3ba7e03bd43aa832b;p=thirdparty%2Fmkosi.git

Optimize hash_file()

Let's reduce unnecessary copies.
---

diff --git a/mkosi/util.py b/mkosi/util.py
index 8b1d1f199..637b918b5 100644
--- a/mkosi/util.py
+++ b/mkosi/util.py
@@ -309,12 +309,13 @@ def resource_path(mod: ModuleType) -> Iterator[Path]:
 
 def hash_file(path: Path) -> str:
     # TODO Replace with hashlib.file_digest after dropping support for Python 3.10.
-    bs = 16 * 1024**2
     h = hashlib.sha256()
+    b  = bytearray(16 * 1024**2)
+    mv = memoryview(b)
 
-    with path.open("rb") as sf:
-        while (buf := sf.read(bs)):
-            h.update(buf)
+    with path.open("rb", buffering=0) as f:
+        while n := f.readinto(mv):
+            h.update(mv[:n])
 
     return h.hexdigest()