"""Helper functions and classes for bup."""
+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 heapq, operator
-from bup import _version
+import hashlib, heapq, operator, time, grp, tempfile
+
+from bup import _helpers
+import bup._helpers as _helpers
+import math
# 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
+
+
# Write (blockingly) to sockets that may or may not be in blocking mode.
# We need this because our stderr is sometimes eaten by subprocesses
# (probably ssh) that sometimes make it nonblocking, if only temporarily,
assert(sz >= 0)
buf = buf[sz:]
+
+_last_prog = 0
def log(s):
"""Print a log message to stderr."""
+ global _last_prog
sys.stdout.flush()
_hard_write(sys.stderr.fileno(), s)
+ _last_prog = 0
def debug1(s):
log(s)
+istty1 = os.isatty(1) or (atoi(os.environ.get('BUP_FORCE_TTY')) & 1)
+istty2 = os.isatty(2) or (atoi(os.environ.get('BUP_FORCE_TTY')) & 2)
+_last_progress = ''
+def progress(s):
+ """Calls log() if stderr is a TTY. Does nothing otherwise."""
+ global _last_progress
+ if istty2:
+ log(s)
+ _last_progress = s
+
+
+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
+ now = time.time()
+ if now - _last_prog > 0.1:
+ progress(s)
+ _last_prog = now
+
+
+def reprogress():
+ """Calls progress() to redisplay the most recent progress message.
+
+ Useful after you've printed some other message that wipes out the
+ progress line.
+ """
+ if _last_progress and _last_progress.endswith('\r'):
+ progress(_last_progress)
+
+
def mkdirp(d, mode=None):
"""Recursively create directories on path 'd'.
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
+ 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)
- r = p.stdout.read()
- p.wait()
- return r
+ 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.returncode))
+ return out
+
+
+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=_helpers.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 realpath(p):
return out
+def detect_fakeroot():
+ "Return True if we appear to be running under fakeroot."
+ return os.getenv("FAKEROOTKEY") != None
+
+
+def is_superuser():
+ if sys.platform.startswith('cygwin'):
+ import ctypes
+ return ctypes.cdll.shell32.IsUserAnAdmin()
+ else:
+ return os.geteuid() == 0
+
+
+def _cache_key_value(get_value, key, cache):
+ """Return (value, was_cached). If there is a value in the cache
+ for key, use that, otherwise, call get_value(key) which should
+ throw a KeyError if there is no value -- in which case the cached
+ and returned value will be None.
+ """
+ try: # Do we already have it (or know there wasn't one)?
+ value = cache[key]
+ return value, True
+ except KeyError:
+ pass
+ value = None
+ try:
+ cache[key] = value = get_value(key)
+ except KeyError:
+ cache[key] = None
+ return value, False
+
+
+_uid_to_pwd_cache = {}
+_name_to_pwd_cache = {}
+
+def pwd_from_uid(uid):
+ """Return password database entry for uid (may be a cached value).
+ Return None if no entry is found.
+ """
+ global _uid_to_pwd_cache, _name_to_pwd_cache
+ entry, cached = _cache_key_value(pwd.getpwuid, uid, _uid_to_pwd_cache)
+ if entry and not cached:
+ _name_to_pwd_cache[entry.pw_name] = entry
+ return entry
+
+
+def pwd_from_name(name):
+ """Return password database entry for name (may be a cached value).
+ Return None if no entry is found.
+ """
+ global _uid_to_pwd_cache, _name_to_pwd_cache
+ entry, cached = _cache_key_value(pwd.getpwnam, name, _name_to_pwd_cache)
+ if entry and not cached:
+ _uid_to_pwd_cache[entry.pw_uid] = entry
+ return entry
+
+
+_gid_to_grp_cache = {}
+_name_to_grp_cache = {}
+
+def grp_from_gid(gid):
+ """Return password database entry for gid (may be a cached value).
+ Return None if no entry is found.
+ """
+ global _gid_to_grp_cache, _name_to_grp_cache
+ entry, cached = _cache_key_value(grp.getgrgid, gid, _gid_to_grp_cache)
+ if entry and not cached:
+ _name_to_grp_cache[entry.gr_name] = entry
+ return entry
+
+
+def grp_from_name(name):
+ """Return password database entry for name (may be a cached value).
+ Return None if no entry is found.
+ """
+ global _gid_to_grp_cache, _name_to_grp_cache
+ entry, cached = _cache_key_value(grp.getgrnam, name, _name_to_grp_cache)
+ if entry and not cached:
+ _gid_to_grp_cache[entry.gr_gid] = entry
+ return entry
+
+
_username = None
def username():
"""Get the user's login name."""
global _username
if not _username:
uid = os.getuid()
- try:
- _username = pwd.getpwuid(uid)[0]
- except KeyError:
- _username = 'user%d' % uid
+ _username = pwd_from_uid(uid)[0] or 'user%d' % uid
return _username
global _userfullname
if not _userfullname:
uid = os.getuid()
- try:
- _userfullname = pwd.getpwuid(uid)[4].split(',')[0]
- except KeyError:
+ entry = pwd_from_uid(uid)
+ if entry:
+ _userfullname = entry[4].split(',')[0] or entry[0]
+ if not _userfullname:
_userfullname = 'user%d' % uid
return _userfullname
_resource_path = os.environ.get('BUP_RESOURCE_PATH') or '.'
return os.path.join(_resource_path, subdir)
+def format_filesize(size):
+ unit = 1024.0
+ size = float(size)
+ if size < unit:
+ return "%d" % (size)
+ exponent = int(math.log(size) / math.log(unit))
+ size_prefix = "KMGTPE"[exponent - 1]
+ return "%.1f%s" % (size / math.pow(unit, exponent), size_prefix)
+
class NotOk(Exception):
pass
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)
+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,
+throw a ValueError that may contain additional information."""
+ ns_per = {'s' : 1000000000,
+ 'ms' : 1000000,
+ 'us' : 1000,
+ 'ns' : 1}
+ match = re.match(r'^((?:[-+]?[0-9]+)?)(s|ms|us|ns)$', epoch_str)
+ if not match:
+ if re.match(r'^([-+]?[0-9]+)$', epoch_str):
+ raise ValueError('must include units, i.e. 100ns, 100ms, ...')
+ raise ValueError()
+ (n, units) = match.group(1, 2)
+ if not n:
+ n = 1
+ n = int(n)
+ return n * ns_per[units]
+
+
def parse_num(s):
"""Parse data size information into a float number.
log('%-70s\n' % e)
-istty = os.isatty(2) or atoi(os.environ.get('BUP_FORCE_TTY'))
-def progress(s):
- """Calls log(s) if stderr is a TTY. Does nothing otherwise."""
- if istty:
- log(s)
+def clear_errors():
+ global saved_errors
+ saved_errors = []
def handle_ctrl_c():
oldhook = sys.excepthook
def newhook(exctype, value, traceback):
if exctype == KeyboardInterrupt:
- log('Interrupted.\n')
+ log('\nInterrupted.\n')
else:
return oldhook(exctype, value, traceback)
sys.excepthook = newhook
return date
-def strip_path(prefix, path):
- """Strips a given prefix from a path.
-
- First both paths are normalized.
+def parse_excludes(options, fatal):
+ """Traverse the options and extract all excludes, or call Option.fatal()."""
+ excluded_paths = []
- Raises an Exception if no prefix is given.
- """
- if prefix == None:
- raise Exception('no path given')
-
- normalized_prefix = os.path.realpath(prefix)
- debug2("normalized_prefix: %s\n" % normalized_prefix)
- normalized_path = os.path.realpath(path)
- debug2("normalized_path: %s\n" % normalized_path)
- if normalized_path.startswith(normalized_prefix):
- return normalized_path[len(normalized_prefix):]
- else:
- return path
-
-
-def strip_base_path(path, base_paths):
- """Strips the base path from a given path.
-
-
- Determines the base path for the given string and then strips it
- using strip_path().
- Iterates over all base_paths from long to short, to prevent that
- a too short base_path is removed.
- """
- normalized_path = os.path.realpath(path)
- sorted_base_paths = sorted(base_paths, key=len, reverse=True)
- for bp in sorted_base_paths:
- if normalized_path.startswith(os.path.realpath(bp)):
- return strip_path(bp, normalized_path)
- return path
-
-
-def graft_path(graft_points, path):
- normalized_path = os.path.realpath(path)
+ for flag in options:
+ (option, parameter) = flag
+ if option == '--exclude':
+ excluded_paths.append(realpath(parameter))
+ elif option == '--exclude-from':
+ try:
+ f = open(realpath(parameter))
+ except IOError, e:
+ raise fatal("couldn't read %s" % parameter)
+ for exclude_path in f.readlines():
+ # FIXME: perhaps this should be rstrip('\n')
+ exclude_path = realpath(exclude_path.strip())
+ if exclude_path:
+ excluded_paths.append(exclude_path)
+ return sorted(frozenset(excluded_paths))
+
+
+def parse_rx_excludes(options, fatal):
+ """Traverse the options and extract all rx excludes, or call
+ Option.fatal()."""
+ excluded_patterns = []
+
+ for flag in options:
+ (option, parameter) = flag
+ if option == '--exclude-rx':
+ try:
+ excluded_patterns.append(re.compile(parameter))
+ except re.error, ex:
+ fatal('invalid --exclude-rx pattern (%s): %s' % (parameter, ex))
+ elif option == '--exclude-rx-from':
+ try:
+ f = open(realpath(parameter))
+ except IOError, 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:
+ fatal('invalid --exclude-rx pattern (%s): %s' % (spattern, ex))
+ return excluded_patterns
+
+
+def should_rx_exclude_path(path, exclude_rxs):
+ """Return True if path matches a regular expression in exclude_rxs."""
+ for rx in exclude_rxs:
+ if rx.search(path):
+ debug1('Skipping %r: excluded by rx pattern %r.\n'
+ % (path, rx.pattern))
+ return True
+ return False
+
+
+# FIXME: Carefully consider the use of functions (os.path.*, etc.)
+# that resolve against the current filesystem in the strip/graft
+# functions for example, but elsewhere as well. I suspect bup's not
+# always being careful about that. For some cases, the contents of
+# the current filesystem should be irrelevant, and consulting it might
+# produce the wrong result, perhaps via unintended symlink resolution,
+# for example.
+
+def path_components(path):
+ """Break path into a list of pairs of the form (name,
+ full_path_to_name). Path must start with '/'.
+ Example:
+ '/home/foo' -> [('', '/'), ('home', '/home'), ('foo', '/home/foo')]"""
+ if not path.startswith('/'):
+ raise Exception, 'path must start with "/": %s' % path
+ # Since we assume path startswith('/'), we can skip the first element.
+ result = [('', '/')]
+ norm_path = os.path.abspath(path)
+ if norm_path == '/':
+ return result
+ full_path = ''
+ for p in norm_path.split('/')[1:]:
+ full_path += '/' + p
+ result.append((p, full_path))
+ return result
+
+
+def stripped_path_components(path, strip_prefixes):
+ """Strip any prefix in strip_prefixes from path and return a list
+ of path components where each component is (name,
+ none_or_full_fs_path_to_name). Assume path startswith('/').
+ See thelpers.py for examples."""
+ normalized_path = os.path.abspath(path)
+ 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 = []
+ for p in normalized_path[len(normalized_bp):].split('/'):
+ if p: # not root
+ prefix += '/'
+ prefix += p
+ result.append((p, prefix))
+ return result
+ # Nothing to strip.
+ return path_components(path)
+
+
+def grafted_path_components(graft_points, path):
+ # Create a result that consists of some number of faked graft
+ # directories before the graft point, followed by all of the real
+ # directories from path that are after the graft point. Arrange
+ # for the directory at the graft point in the result to correspond
+ # to the "orig" directory in --graft orig=new. See t/thelpers.py
+ # for some examples.
+
+ # Note that given --graft orig=new, orig and new have *nothing* to
+ # do with each other, even if some of their component names
+ # match. i.e. --graft /foo/bar/baz=/foo/bar/bax is semantically
+ # equivalent to --graft /foo/bar/baz=/x/y/z, or even
+ # /foo/bar/baz=/x.
+
+ # FIXME: This can't be the best solution...
+ clean_path = os.path.abspath(path)
for graft_point in graft_points:
old_prefix, new_prefix = graft_point
- if normalized_path.startswith(old_prefix):
- return re.sub(r'^' + old_prefix, new_prefix, normalized_path)
- return normalized_path
-
-
-# hashlib is only available in python 2.5 or higher, but the 'sha' module
-# produces a DeprecationWarning in python 2.6 or higher. We want to support
-# python 2.4 and above without any stupid warnings, so let's try using hashlib
-# first, and downgrade if it fails.
-try:
- import hashlib
-except ImportError:
- import sha
- Sha1 = sha.sha
-else:
- 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
-
-
-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]
+ # Expand prefixes iff not absolute paths.
+ old_prefix = os.path.normpath(old_prefix)
+ new_prefix = os.path.normpath(new_prefix)
+ if clean_path.startswith(old_prefix):
+ escaped_prefix = re.escape(old_prefix)
+ grafted_path = re.sub(r'^' + escaped_prefix, new_prefix, clean_path)
+ # Handle /foo=/ (at least) -- which produces //whatever.
+ grafted_path = '/' + grafted_path.lstrip('/')
+ clean_path_components = path_components(clean_path)
+ # Count the components that were stripped.
+ strip_count = 0 if old_prefix == '/' else old_prefix.count('/')
+ new_prefix_parts = new_prefix.split('/')
+ result_prefix = grafted_path.split('/')[:new_prefix.count('/')]
+ result = [(p, None) for p in result_prefix] \
+ + clean_path_components[strip_count:]
+ # Now set the graft point name to match the end of new_prefix.
+ graft_point = len(result_prefix)
+ result[graft_point] = \
+ (new_prefix_parts[-1], clean_path_components[strip_count][1])
+ if new_prefix == '/': # --graft ...=/ is a special case.
+ return result[1:]
+ return result
+ return path_components(clean_path)
+
+Sha1 = hashlib.sha1
projects / bup.git / blobdiff