from __future__ import absolute_import, division
from collections import namedtuple
-from contextlib import contextmanager
+from contextlib import ExitStack
from ctypes import sizeof, c_void_p
from math import floor
from os import environ
from subprocess import PIPE, Popen
-import sys, os, pwd, subprocess, errno, socket, select, mmap, stat, re, struct
-import hashlib, heapq, math, operator, time, grp, tempfile
+from tempfile import mkdtemp
+from shutil import rmtree
+import sys, os, subprocess, errno, select, mmap, stat, re, struct
+import hashlib, heapq, math, operator, time
from bup import _helpers
-from bup import compat
-from bup.compat import argv_bytes, byte_int, pending_raise
+from bup import io
+from bup.compat import argv_bytes, byte_int, nullcontext, pending_raise
from bup.io import byte_stream, path_msg
# This function should really be in helpers, not in bup.options. But we
# want options.py to be standalone so people can include it in other projects.
pass
+def nullcontext_if_not(manager):
+ return manager if manager is not None else nullcontext()
+
+
+class finalized:
+ def __init__(self, enter_result=None, finalize=None):
+ assert finalize
+ self.finalize = finalize
+ self.enter_result = enter_result
+ def __enter__(self):
+ return self.enter_result
+ def __exit__(self, exc_type, exc_value, traceback):
+ self.finalize(self.enter_result)
+
+def temp_dir(*args, **kwargs):
+ # This is preferable to tempfile.TemporaryDirectory because the
+ # latter uses @contextmanager, and so will always eventually be
+ # deleted if it's handed to an ExitStack, whenever the stack is
+ # gc'ed, even if you pop_all() (the new stack will also trigger
+ # the deletion) because
+ # https://github.com/python/cpython/issues/88458
+ return finalized(mkdtemp(*args, **kwargs), lambda x: rmtree(x))
+
sc_page_size = os.sysconf('SC_PAGE_SIZE')
assert(sc_page_size > 0)
def qprogress(s):
"""Calls progress() only if we haven't printed progress in a while.
-
+
This avoids overloading the stderr buffer with excess junk.
"""
global _last_prog
def quote(x):
if isinstance(x, bytes):
return bquote(x)
- if isinstance(x, compat.str_type):
+ if isinstance(x, str):
return squote(x)
assert False
+ # some versions of pylint get confused
+ return None
def shstr(cmd):
"""Return a shell quoted string for cmd if it's a sequence, else cmd.
call() and friends. e.g. log(shstr(cmd)); call(cmd)
"""
- if isinstance(cmd, (bytes, compat.str_type)):
+ if isinstance(cmd, (bytes, str)):
return cmd
elif all(isinstance(x, bytes) for x in cmd):
return b' '.join(map(bquote, cmd))
- elif all(isinstance(x, compat.str_type) for x in cmd):
+ elif all(isinstance(x, str) for x in cmd):
return ' '.join(map(squote, cmd))
raise TypeError('unsupported shstr argument: ' + repr(cmd))
base_size = 2048
for c in command:
base_size += len(command) + 1
- for k, v in compat.items(environ):
+ for k, v in environ.items():
base_size += len(k) + len(v) + 2 + sizeof(c_void_p)
return base_size
class BaseConn:
def __init__(self, outp):
+ self._base_closed = False
self.outp = outp
def close(self):
- while self._read(65536): pass
+ self._base_closed = True
+
+ def __enter__(self):
+ return self
+
+ def __exit__(self, exc_type, exc_value, tb):
+ with pending_raise(exc_value, rethrow=False):
+ self.close()
+
+ def __del__(self):
+ assert self._base_closed
def _read(self, size):
raise NotImplementedError("Subclasses must implement _read")
assert(rl[0] == self.infd)
ns = b''.join(checked_reader(self.infd, 5))
n, fdw = struct.unpack('!IB', ns)
- assert(n <= MAX_PACKET)
+ if n > MAX_PACKET:
+ # assume that something went wrong and print stuff
+ ns += os.read(self.infd, 1024)
+ stderr = byte_stream(sys.stderr)
+ stderr.write(ns)
+ stderr.flush()
+ raise Exception("Connection broken")
if fdw == 1:
self.reader = checked_reader(self.infd, n)
elif fdw == 2:
yield b
-@contextmanager
-def atomically_replaced_file(name, mode='w', buffering=-1):
- """Yield a file that will be atomically renamed name when leaving the block.
-
- This contextmanager yields an open file object that is backed by a
- temporary file which will be renamed (atomically) to the target
- name if everything succeeds.
-
- The mode and buffering arguments are handled exactly as with open,
- and the yielded file will have very restrictive permissions, as
- per mkstemp.
-
- E.g.::
-
- with atomically_replaced_file('foo.txt', 'w') as f:
- f.write('hello jack.')
-
- """
-
- (ffd, tempname) = tempfile.mkstemp(dir=os.path.dirname(name),
- text=('b' not in mode))
- try:
- try:
- f = os.fdopen(ffd, mode, buffering)
- except:
- os.close(ffd)
- raise
- try:
- yield f
- finally:
- f.close()
- os.rename(tempname, name)
- finally:
- unlink(tempname) # nonexistant file is ignored
+class atomically_replaced_file:
+ def __init__(self, path, mode='w', buffering=-1):
+ """Return a context manager supporting the atomic replacement of a file.
+
+ The context manager yields an open file object that has been
+ created in a mkdtemp-style temporary directory in the same
+ directory as the path. The temporary file will be renamed to
+ the target path (atomically if the platform allows it) if
+ there are no exceptions, and the temporary directory will
+ always be removed. Calling cancel() will prevent the
+ replacement.
+
+ The file object will have a name attribute containing the
+ file's path, and the mode and buffering arguments will be
+ handled exactly as with open(). The resulting permissions
+ will also match those produced by open().
+
+ E.g.::
+
+ with atomically_replaced_file('foo.txt', 'w') as f:
+ f.write('hello jack.')
+
+ """
+ assert 'w' in mode
+ self.path = path
+ self.mode = mode
+ self.buffering = buffering
+ self.canceled = False
+ self.tmp_path = None
+ self.cleanup = ExitStack()
+ def __enter__(self):
+ with self.cleanup:
+ parent, name = os.path.split(self.path)
+ tmpdir = self.cleanup.enter_context(temp_dir(dir=parent,
+ prefix=name + b'-'))
+ self.tmp_path = tmpdir + b'/pending'
+ f = open(self.tmp_path, mode=self.mode, buffering=self.buffering)
+ f = self.cleanup.enter_context(f)
+ self.cleanup = self.cleanup.pop_all()
+ return f
+ def __exit__(self, exc_type, exc_value, traceback):
+ with self.cleanup:
+ if not (self.canceled or exc_type):
+ os.rename(self.tmp_path, self.path)
+ def cancel(self):
+ self.canceled = True
def slashappend(s):
# string has all the same behaviour of a zero-length map, ie. it has
# no elements :)
return ''
- map = mmap.mmap(f.fileno(), sz, flags, prot)
+ map = io.mmap(f.fileno(), sz, flags, prot)
if close:
f.close() # map will persist beyond file close
return map
page_count = (st.st_size + sc_page_size - 1) // sc_page_size;
chunk_count = (st.st_size + _fmincore_chunk_size - 1) // _fmincore_chunk_size
result = bytearray(page_count)
- for ci in compat.range(chunk_count):
+ for ci in range(chunk_count):
pos = _fmincore_chunk_size * ci;
msize = min(_fmincore_chunk_size, st.st_size - pos)
try:
- m = mmap.mmap(fd, msize, mmap.MAP_PRIVATE, 0, 0, pos)
+ m = io.mmap(fd, msize, mmap.MAP_PRIVATE, 0, 0, pos)
except mmap.error as ex:
- if ex.errno == errno.EINVAL or ex.errno == errno.ENODEV:
+ if ex.errno in (errno.EINVAL, errno.ENODEV):
# Perhaps the file was a pipe, i.e. "... | bup split ..."
return None
raise ex
- try:
- _mincore(m, msize, 0, result, ci * pages_per_chunk)
- except OSError as ex:
- if ex.errno == errno.ENOSYS:
- return None
- raise
+ with m:
+ try:
+ _mincore(m, msize, 0, result, ci * pages_per_chunk)
+ except OSError as ex:
+ if ex.errno == errno.ENOSYS:
+ return None
+ raise
return result
if exctype == KeyboardInterrupt:
log('\nInterrupted.\n')
else:
- return oldhook(exctype, value, traceback)
+ oldhook(exctype, value, traceback)
sys.excepthook = newhook
while len(l) % ncols:
l.append(nothing)
rows = len(l) // ncols
- for s in compat.range(0, len(l), rows):
+ for s in range(0, len(l), rows):
cols.append(l[s:s+rows])
out = nothing
fmt = b'%-*s' if binary else '%-*s'
projects / bup.git / blobdiff