in some cases the value of a new parameter does not really matter,
as long as it works / there is no malfunction.
without this change, a new borg client could not commit to an old
borg server (and would fail late when trying to commit):
- when using compact=False as it does at most places
- when using cleanup_commits=True as a user might trigger by running
borg compact --cleanup-commits
we never want a borg commit "fail late", leaving the repo in a state
with uncommitted data, thus the server shall just commit, no matter
how it handles compaction or whether it can do the cleanup.
specialcase deleting / writing the manifest to be in a separate, new
segment file, so that when we supersede and compact it later, less
segment data has to be shuffled around - compaction can then just
delete this segment file and that's all.
the os level file handle is enough, the chunker will prefer it if
valid and won't use the file obj, so we can give None there.
this saves these unneeded syscalls:
fstat(5, {st_mode=S_IFREG|0664, st_size=227063, ...}) = 0
ioctl(5, TCGETS, 0x7ffd635635f0) = -1 ENOTTY (Inappropriate ioctl for device)
lseek(5, 0, SEEK_CUR) = 0
this optimization is only needed for linux, the bsd-like platforms
do not need an open file to run a ioctl against, but have bsdflags
in the stat result already.
on linux, this optimization saves 1 file open/close per input file.
when processing regular files, use a fd to query xattrs.
when the file was modified and we chunked it, we have it open anyways.
if not, we open the file once and then query xattrs, in the hope that
this is more efficient than the path based calls.
guess it is less prone to race conditions in any case.
this code used to live in borg.xattr and used ctypes
(and was the only ctypes-using code in borg).
the low level code now was converted to cython and
the platform code moved to platform package.
got rid of the code that tried to find the libc.
- reordered code a little, so files are touched in different order
let's see if this changes anything.
- create_regular_file: giving size AND contents is not supported
the code did not create a 4096 bytes long file, but just a 1 byte
long file. adding an assertion to avoid unsupported usage.
(cherry picked from commit 2d490aa8c8)
