# HG changeset patch
# User Franz Glasner <f.glasner@feldmann-mg.com>
# Date 1650549679 -7200
# Node ID 8352da172a3e0e7dcb6ed7a8caae5735bc480d25
# Parent  06b2a504b8f6ddd512f1d07dbb03daf349f3de7b
Use "fadvise()" with POSIX_FADV_SEQUENTIAL -- if available

diff -r 06b2a504b8f6 -r 8352da172a3e cutils/shasum.py
--- a/cutils/shasum.py	Thu Apr 21 09:18:23 2022 +0200
+++ b/cutils/shasum.py	Thu Apr 21 16:01:19 2022 +0200
@@ -597,6 +597,9 @@
             use_mmap = True
         if mmap is None or not use_mmap:
             # No mmap available or wanted -> use traditional low-level file IO
+            fadvise = getattr(os, "posix_fadvise", None)
+            if fadvise:
+                fadvise(fd, 0, 0, os.POSIX_FADV_SEQUENTIAL)
             while True:
                 try:
                     buf = os.read(fd, READ_CHUNK_SIZE)