Re: [gentoo-portage-dev] [PATCH v2] egencache: stable use.local.desc mtime for rsync (bug 557192)

[Michał Górny]

Dnia 25 sierpnia 2015 18:34:16 CEST, Zac Medico <zmedico@g.o> napisał(a):
>Preserve mtime when the md5sum is identical.

Sorry for being late to the party but wouldn't it be cleaner not to rewrite the file in the case?

>
>X-Gentoo-Bug: 557192
>X-Gentoo-Bug-url: https://bugs.gentoo.org/show_bug.cgi?id=557192
>---
>[PATCH v2] ensures exact integer mtime when there is not an existing
>file, for
>consistency with the mtime preservation code.
>
> bin/egencache | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
>diff --git a/bin/egencache b/bin/egencache
>index 5c00248..4f4c715 100755
>--- a/bin/egencache
>+++ b/bin/egencache
>@@ -7,6 +7,7 @@ from __future__ import print_function, unicode_literals
>
> import platform
> import signal
>+import stat
> import sys
> # This block ensures that ^C interrupts are handled quietly.
> try:
>@@ -487,6 +488,8 @@ class GenUseLocalDesc(object):
> 	def run(self):
> 		repo_path = self._portdb.porttrees[0]
> 		ops = {'<':0, '<=':1, '=':2, '>=':3, '>':4}
>+		prev_mtime = None
>+		prev_md5 = None
>
> 		if self._output is None or self._output != '-':
> 			if self._output is None:
>@@ -500,6 +503,12 @@ class GenUseLocalDesc(object):
> 				desc_path = self._output
>
> 			try:
>+				prev_md5 = portage.checksum.perform_md5(desc_path)
>+				prev_mtime = os.stat(desc_path)[stat.ST_MTIME]
>+			except (portage.exception.FileNotFound, OSError):
>+				pass
>+
>+			try:
> 				if self._preserve_comments:
> 					# Probe in binary mode, in order to avoid
> 					# potential character encoding issues.
>@@ -651,6 +660,17 @@ class GenUseLocalDesc(object):
> 						output.write('%s:%s - %s\n' % (cp, flag, resdesc))
>
> 		output.close()
>+		if (prev_mtime is not None and
>+			prev_md5 == portage.checksum.perform_md5(desc_path)):
>+			# Preserve mtime for rsync.
>+			mtime = prev_mtime
>+		else:
>+			# For portability, and consistency with the mtime preservation
>+			# code, set mtime to an exact integer value.
>+			mtime = int(time.time())
>+
>+		os.utime(desc_path, (mtime, mtime))
>+
>
> if sys.hexversion < 0x3000000:
> 	_filename_base = unicode

-- 
Best regards,
Michał Górny