http://bugs.gentoo.org/show_bug.cgi?id=83379
Author: Zac Medico
This patch uses prelink --undo-output=prelink_tmpfile in order to avoid extra
copying. Files rejected by prelink are checksummed in place. With this patch
applied, I have measured a 7.75% decrease in the time taken to checksum non-elf
files when prelink is enabled.
Comments?
Zac
Index: portage-2.0.51.22/pym/portage_checksum.py
===================================================================
--- portage-2.0.51.22.orig/pym/portage_checksum.py
+++ portage-2.0.51.22/pym/portage_checksum.py
@@ -111,24 +111,18 @@ def perform_checksum(filename, hash_func
if calc_prelink and prelink_capable:
mylock = portage_locks.lockfile(prelink_tmpfile, wantnewlockfile=1)
- # Create non-prelinked temporary file to md5sum.
- # Raw data is returned on stdout, errors on stderr.
- # Non-prelinks are just returned.
- try:
- shutil.copy2(filename,prelink_tmpfile)
- except SystemExit, e:
- raise
- except Exception,e:
- portage_util.writemsg("!!! Unable to copy file '"+str(filename)+"'.\n")
- portage_util.writemsg("!!! "+str(e)+"\n")
- sys.exit(1)
- portage_exec.spawn(PRELINK_BINARY+" --undo "+prelink_tmpfile,fd_pipes={})
- myfilename=prelink_tmpfile
+ # Create non-prelinked temporary file to checksum.
+ # Files rejected by prelink are summed in place.
+ retval=portage_exec.spawn([PRELINK_BINARY,"--undo","-o",prelink_tmpfile,filename],fd_pipes={})
+ if retval==0:
+ #portage_util.writemsg(">>> prelink checksum '"+str(filename)+"'.\n")
+ myfilename=prelink_tmpfile
myhash, mysize = hash_function(myfilename)
if calc_prelink and prelink_capable:
- os.unlink(prelink_tmpfile)
+ if os.path.exists(prelink_tmpfile):
+ os.unlink(prelink_tmpfile)
portage_locks.unlockfile(mylock)
return (myhash,mysize)
