"""Helper functions and classes for bup."""
+from collections import namedtuple
+from ctypes import sizeof, c_void_p
+from os import environ
+from contextlib import contextmanager
import sys, os, pwd, subprocess, errno, socket, select, mmap, stat, re, struct
-import hashlib, heapq, operator, time, grp
-from bup import _version, _helpers
-import bup._helpers as _helpers
-import math
+import hashlib, heapq, math, operator, time, grp, tempfile
+
+from bup import _helpers
+
+sc_page_size = os.sysconf('SC_PAGE_SIZE')
+assert(sc_page_size > 0)
+
+sc_arg_max = os.sysconf('SC_ARG_MAX')
+if sc_arg_max == -1: # "no definite limit" - let's choose 2M
+ sc_arg_max = 2 * 1024 * 1024
# 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.
buglvl = atoi(os.environ.get('BUP_DEBUG', 0))
-# If the platform doesn't have fdatasync (OS X), fall back to fsync.
-try:
- fdatasync = os.fdatasync
-except AttributeError:
- fdatasync = os.fsync
+if sys.platform.startswith('darwin'):
+ # Apparently fsync on OS X doesn't guarantee to sync all the way down
+ import fcntl
+ fdatasync = lambda fd : fcntl.fcntl(fd, fcntl.F_FULLFSYNC)
+else: # If the platform doesn't have fdatasync, fall back to fsync
+ try:
+ fdatasync = os.fdatasync
+ except AttributeError:
+ fdatasync = os.fsync
# Write (blockingly) to sockets that may or may not be in blocking mode.
raise IOError('select(fd) returned without being writable')
try:
sz = os.write(fd, buf)
- except OSError, e:
+ except OSError as e:
if e.errno != errno.EAGAIN:
raise
assert(sz >= 0)
os.makedirs(d, mode)
else:
os.makedirs(d)
- except OSError, e:
+ except OSError as e:
if e.errno == errno.EEXIST:
pass
else:
raise
-def next(it):
- """Get the next item from an iterator, None if we reached the end."""
- try:
+_unspecified_next_default = object()
+
+def _fallback_next(it, default=_unspecified_next_default):
+ """Retrieve the next item from the iterator by calling its
+ next() method. If default is given, it is returned if the
+ iterator is exhausted, otherwise StopIteration is raised."""
+
+ if default is _unspecified_next_default:
return it.next()
- except StopIteration:
- return None
+ else:
+ try:
+ return it.next()
+ except StopIteration:
+ return default
+
+if sys.version_info < (2, 6):
+ next = _fallback_next
def merge_iter(iters, pfreq, pfunc, pfinal, key=None):
count = 0
total = sum(len(it) for it in iters)
iters = (iter(it) for it in iters)
- heap = ((next(it),it) for it in iters)
+ heap = ((next(it, None),it) for it in iters)
heap = [(e,it) for e,it in heap if e]
heapq.heapify(heap)
"""
try:
os.unlink(f)
- except OSError, e:
- if e.errno == errno.ENOENT:
- pass # it doesn't exist, that's what you asked for
+ except OSError as e:
+ if e.errno != errno.ENOENT:
+ raise
-def readpipe(argv):
+def readpipe(argv, preexec_fn=None):
"""Run a subprocess and return its output."""
- p = subprocess.Popen(argv, stdout=subprocess.PIPE)
+ p = subprocess.Popen(argv, stdout=subprocess.PIPE, preexec_fn=preexec_fn)
out, err = p.communicate()
if p.returncode != 0:
raise Exception('subprocess %r failed with status %d'
- % (' '.join(argv), p.retcode))
+ % (' '.join(argv), p.returncode))
return out
-def realpath(p):
- """Get the absolute path of a file.
+def _argmax_base(command):
+ base_size = 2048
+ for c in command:
+ base_size += len(command) + 1
+ for k, v in environ.iteritems():
+ base_size += len(k) + len(v) + 2 + sizeof(c_void_p)
+ return base_size
+
+
+def _argmax_args_size(args):
+ return sum(len(x) + 1 + sizeof(c_void_p) for x in args)
+
+
+def batchpipe(command, args, preexec_fn=None, arg_max=sc_arg_max):
+ """If args is not empty, yield the output produced by calling the
+command list with args as a sequence of strings (It may be necessary
+to return multiple strings in order to respect ARG_MAX)."""
+ # The optional arg_max arg is a workaround for an issue with the
+ # current wvtest behavior.
+ base_size = _argmax_base(command)
+ while args:
+ room = arg_max - base_size
+ i = 0
+ while i < len(args):
+ next_size = _argmax_args_size(args[i:i+1])
+ if room - next_size < 0:
+ break
+ room -= next_size
+ i += 1
+ sub_args = args[:i]
+ args = args[i:]
+ assert(len(sub_args))
+ yield readpipe(command + sub_args, preexec_fn=preexec_fn)
+
+
+def resolve_parent(p):
+ """Return the absolute path of a file without following any final symlink.
Behaves like os.path.realpath, but doesn't follow a symlink for the last
element. (ie. if 'p' itself is a symlink, this one won't follow it, but it
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
+
+
def slashappend(s):
"""Append "/" to 's' if it doesn't aleady end in "/"."""
if s and not s.endswith('/'):
close)
+_mincore = getattr(_helpers, 'mincore', None)
+if _mincore:
+ # ./configure ensures that we're on Linux if MINCORE_INCORE isn't defined.
+ MINCORE_INCORE = getattr(_helpers, 'MINCORE_INCORE', 1)
+
+ _fmincore_chunk_size = None
+ def _set_fmincore_chunk_size():
+ global _fmincore_chunk_size
+ pref_chunk_size = 64 * 1024 * 1024
+ chunk_size = sc_page_size
+ if (sc_page_size < pref_chunk_size):
+ chunk_size = sc_page_size * (pref_chunk_size / sc_page_size)
+ _fmincore_chunk_size = chunk_size
+
+ def fmincore(fd):
+ """Return the mincore() data for fd as a bytearray whose values can be
+ tested via MINCORE_INCORE, or None if fd does not fully
+ support the operation."""
+ st = os.fstat(fd)
+ if (st.st_size == 0):
+ return bytearray(0)
+ if not _fmincore_chunk_size:
+ _set_fmincore_chunk_size()
+ pages_per_chunk = _fmincore_chunk_size / sc_page_size;
+ page_count = (st.st_size + sc_page_size - 1) / sc_page_size;
+ chunk_count = page_count / _fmincore_chunk_size
+ if chunk_count < 1:
+ chunk_count = 1
+ result = bytearray(page_count)
+ for ci in xrange(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)
+ except mmap.error as ex:
+ if ex.errno == errno.EINVAL or ex.errno == errno.ENODEV:
+ # Perhaps the file was a pipe, i.e. "... | bup split ..."
+ return None
+ raise ex
+ _mincore(m, msize, 0, result, ci * pages_per_chunk);
+ return result
+
+
def parse_timestamp(epoch_str):
"""Return the number of nanoseconds since the epoch that are described
by epoch_str (100ms, 100ns, ...); when epoch_str cannot be parsed,
"""Parses the given date or calls Option.fatal().
For now we expect a string that contains a float."""
try:
- date = atof(str)
- except ValueError, e:
+ date = float(str)
+ except ValueError as e:
raise fatal('invalid date format (should be a float): %r' % e)
else:
return date
for flag in options:
(option, parameter) = flag
if option == '--exclude':
- excluded_paths.append(realpath(parameter))
+ excluded_paths.append(resolve_parent(parameter))
elif option == '--exclude-from':
try:
- f = open(realpath(parameter))
- except IOError, e:
+ f = open(resolve_parent(parameter))
+ except IOError as e:
raise fatal("couldn't read %s" % parameter)
for exclude_path in f.readlines():
- excluded_paths.append(realpath(exclude_path.strip()))
+ # FIXME: perhaps this should be rstrip('\n')
+ exclude_path = resolve_parent(exclude_path.strip())
+ if exclude_path:
+ excluded_paths.append(exclude_path)
return sorted(frozenset(excluded_paths))
if option == '--exclude-rx':
try:
excluded_patterns.append(re.compile(parameter))
- except re.error, ex:
+ except re.error as ex:
fatal('invalid --exclude-rx pattern (%s): %s' % (parameter, ex))
elif option == '--exclude-rx-from':
try:
- f = open(realpath(parameter))
- except IOError, e:
+ f = open(resolve_parent(parameter))
+ except IOError as e:
raise fatal("couldn't read %s" % parameter)
for pattern in f.readlines():
spattern = pattern.rstrip('\n')
+ if not spattern:
+ continue
try:
excluded_patterns.append(re.compile(spattern))
- except re.error, ex:
+ except re.error as ex:
fatal('invalid --exclude-rx pattern (%s): %s' % (spattern, ex))
return excluded_patterns
sorted_strip_prefixes = sorted(strip_prefixes, key=len, reverse=True)
for bp in sorted_strip_prefixes:
normalized_bp = os.path.abspath(bp)
+ if normalized_bp == '/':
+ continue
if normalized_path.startswith(normalized_bp):
prefix = normalized_path[:len(normalized_bp)]
result = []
return result
return path_components(clean_path)
-Sha1 = hashlib.sha1
-
-def version_date():
- """Format bup's version date string for output."""
- return _version.DATE.split(' ')[0]
-
-
-def version_commit():
- """Get the commit hash of bup's current version."""
- return _version.COMMIT
+Sha1 = hashlib.sha1
-def version_tag():
- """Format bup's version tag (the official version number).
- When generated from a commit other than one pointed to with a tag, the
- returned string will be "unknown-" followed by the first seven positions of
- the commit hash.
- """
- names = _version.NAMES.strip()
- assert(names[0] == '(')
- assert(names[-1] == ')')
- names = names[1:-1]
- l = [n.strip() for n in names.split(',')]
- for n in l:
- if n.startswith('tag: bup-'):
- return n[9:]
- return 'unknown-%s' % _version.COMMIT[:7]
+_localtime = getattr(_helpers, 'localtime', None)
+
+if _localtime:
+ bup_time = namedtuple('bup_time', ['tm_year', 'tm_mon', 'tm_mday',
+ 'tm_hour', 'tm_min', 'tm_sec',
+ 'tm_wday', 'tm_yday',
+ 'tm_isdst', 'tm_gmtoff', 'tm_zone'])
+
+# Define a localtime() that returns bup_time when possible. Note:
+# this means that any helpers.localtime() results may need to be
+# passed through to_py_time() before being passed to python's time
+# module, which doesn't appear willing to ignore the extra items.
+if _localtime:
+ def localtime(time):
+ return bup_time(*_helpers.localtime(time))
+ def utc_offset_str(t):
+ """Return the local offset from UTC as "+hhmm" or "-hhmm" for time t.
+ If the current UTC offset does not represent an integer number
+ of minutes, the fractional component will be truncated."""
+ off = localtime(t).tm_gmtoff
+ # Note: // doesn't truncate like C for negative values, it rounds down.
+ offmin = abs(off) // 60
+ m = offmin % 60
+ h = (offmin - m) // 60
+ return "%+03d%02d" % (-h if off < 0 else h, m)
+ def to_py_time(x):
+ if isinstance(x, time.struct_time):
+ return x
+ return time.struct_time(x[:9])
+else:
+ localtime = time.localtime
+ def utc_offset_str(t):
+ return time.strftime('%z', localtime(t))
+ def to_py_time(x):
+ return x
projects / bup.git / blobdiff