remove cpu intensive compression methods for the chunks.archive

also remove the comment about how good xz compresses - while that was true for smaller index files,
it seems to be less effective with bigger ones. maybe just an issue with compression dict size.
This commit is contained in:
Thomas Waldmann 2015-08-29 23:34:58 +02:00
parent 17c4394896
commit f7210c749f
1 changed files with 4 additions and 5 deletions

View File

@ -213,9 +213,6 @@ class Cache:
so it has complete and current information about all backup archives.
Finally, it builds the master chunks index by merging all indices from
the tar.
Note: compression (esp. xz) is very effective in keeping the tar
relatively small compared to the files it contains.
"""
in_archive_path = os.path.join(self.path, 'chunks.archive')
out_archive_path = os.path.join(self.path, 'chunks.archive.tmp')
@ -234,8 +231,10 @@ class Cache:
return tf
def open_out_archive():
for compression in ('xz', 'bz2', 'gz'):
# xz needs py 3.3, bz2 and gz also work on 3.2
for compression in ('gz', ):
# 'xz' needs py 3.3 and is expensive on the cpu
# 'bz2' also works on 3.2 and is expensive on the cpu
# 'gz' also works on 3.2 and is less expensive on the cpu
try:
tf = tarfile.open(out_archive_path, 'w:'+compression, format=tarfile.PAX_FORMAT)
break