1 """Helper functions and classes for bup."""
3 import sys, os, pwd, subprocess, errno, socket, select, mmap, stat, re
4 from bup import _version
6 # This function should really be in helpers, not in bup.options. But we
7 # want options.py to be standalone so people can include it in other projects.
8 from bup.options import _tty_width
13 """Convert the string 's' to an integer. Return 0 if s is not a number."""
21 """Convert the string 's' to a float. Return 0 if s is not a number."""
23 return float(s or '0')
28 buglvl = atoi(os.environ.get('BUP_DEBUG', 0))
31 # Write (blockingly) to sockets that may or may not be in blocking mode.
32 # We need this because our stderr is sometimes eaten by subprocesses
33 # (probably ssh) that sometimes make it nonblocking, if only temporarily,
34 # leading to race conditions. Ick. We'll do it the hard way.
35 def _hard_write(fd, buf):
37 (r,w,x) = select.select([], [fd], [], None)
39 raise IOError('select(fd) returned without being writable')
41 sz = os.write(fd, buf)
43 if e.errno != errno.EAGAIN:
49 """Print a log message to stderr."""
51 _hard_write(sys.stderr.fileno(), s)
64 def mkdirp(d, mode=None):
65 """Recursively create directories on path 'd'.
67 Unlike os.makedirs(), it doesn't raise an exception if the last element of
68 the path already exists.
76 if e.errno == errno.EEXIST:
83 """Get the next item from an iterator, None if we reached the end."""
91 """Delete a file at path 'f' if it currently exists.
93 Unlike os.unlink(), does not throw an exception if the file didn't already
99 if e.errno == errno.ENOENT:
100 pass # it doesn't exist, that's what you asked for
104 """Run a subprocess and return its output."""
105 p = subprocess.Popen(argv, stdout=subprocess.PIPE)
112 """Get the absolute path of a file.
114 Behaves like os.path.realpath, but doesn't follow a symlink for the last
115 element. (ie. if 'p' itself is a symlink, this one won't follow it, but it
116 will follow symlinks in p's directory)
122 if st and stat.S_ISLNK(st.st_mode):
123 (dir, name) = os.path.split(p)
124 dir = os.path.realpath(dir)
125 out = os.path.join(dir, name)
127 out = os.path.realpath(p)
128 #log('realpathing:%r,%r\n' % (p, out))
134 """Get the user's login name."""
139 _username = pwd.getpwuid(uid)[0]
141 _username = 'user%d' % uid
147 """Get the user's full name."""
149 if not _userfullname:
152 _userfullname = pwd.getpwuid(uid)[4].split(',')[0]
154 _userfullname = 'user%d' % uid
160 """Get the FQDN of this machine."""
163 _hostname = socket.getfqdn()
167 _resource_path = None
168 def resource_path(subdir=''):
169 global _resource_path
170 if not _resource_path:
171 _resource_path = os.environ.get('BUP_RESOURCE_PATH') or '.'
172 return os.path.join(_resource_path, subdir)
174 class NotOk(Exception):
178 """A helper class for bup's client-server protocol."""
179 def __init__(self, inp, outp):
183 def read(self, size):
184 """Read 'size' bytes from input stream."""
186 return self.inp.read(size)
189 """Read from input stream until a newline is found."""
191 return self.inp.readline()
193 def write(self, data):
194 """Write 'data' to output stream."""
195 #log('%d writing: %d bytes\n' % (os.getpid(), len(data)))
196 self.outp.write(data)
199 """Return true if input stream is readable."""
200 [rl, wl, xl] = select.select([self.inp.fileno()], [], [], 0)
202 assert(rl[0] == self.inp.fileno())
208 """Indicate end of output from last sent command."""
212 """Indicate server error to the client."""
213 s = re.sub(r'\s+', ' ', str(s))
214 self.write('\nerror %s\n' % s)
216 def _check_ok(self, onempty):
219 for rl in linereader(self.inp):
220 #log('%d got line: %r\n' % (os.getpid(), rl))
221 if not rl: # empty line
225 elif rl.startswith('error '):
226 #log('client: error: %s\n' % rl[6:])
230 raise Exception('server exited unexpectedly; see errors above')
232 def drain_and_check_ok(self):
233 """Remove all data for the current command from input stream."""
236 return self._check_ok(onempty)
239 """Verify that server action completed successfully."""
241 raise Exception('expected "ok", got %r' % rl)
242 return self._check_ok(onempty)
246 """Generate a list of input lines from 'f' without terminating newlines."""
254 def chunkyreader(f, count = None):
255 """Generate a list of chunks of data read from 'f'.
257 If count is None, read until EOF is reached.
259 If count is a positive integer, read 'count' bytes from 'f'. If EOF is
260 reached while reading, raise IOError.
264 b = f.read(min(count, 65536))
266 raise IOError('EOF with %d bytes remaining' % count)
277 """Append "/" to 's' if it doesn't aleady end in "/"."""
278 if s and not s.endswith('/'):
284 def _mmap_do(f, sz, flags, prot):
286 st = os.fstat(f.fileno())
289 # trying to open a zero-length map gives an error, but an empty
290 # string has all the same behaviour of a zero-length map, ie. it has
293 map = mmap.mmap(f.fileno(), sz, flags, prot)
294 f.close() # map will persist beyond file close
298 def mmap_read(f, sz = 0):
299 """Create a read-only memory mapped region on file 'f'.
301 If sz is 0, the region will cover the entire file.
303 return _mmap_do(f, sz, mmap.MAP_PRIVATE, mmap.PROT_READ)
306 def mmap_readwrite(f, sz = 0):
307 """Create a read-write memory mapped region on file 'f'.
309 If sz is 0, the region will cover the entire file.
311 return _mmap_do(f, sz, mmap.MAP_SHARED, mmap.PROT_READ|mmap.PROT_WRITE)
315 """Parse data size information into a float number.
317 Here are some examples of conversions:
318 199.2k means 203981 bytes
319 1GB means 1073741824 bytes
320 2.1 tb means 2199023255552 bytes
322 g = re.match(r'([-+\d.e]+)\s*(\w*)', str(s))
324 raise ValueError("can't parse %r as a number" % s)
325 (val, unit) = g.groups()
328 if unit in ['t', 'tb']:
329 mult = 1024*1024*1024*1024
330 elif unit in ['g', 'gb']:
331 mult = 1024*1024*1024
332 elif unit in ['m', 'mb']:
334 elif unit in ['k', 'kb']:
336 elif unit in ['', 'b']:
339 raise ValueError("invalid unit %r in number %r" % (unit, s))
344 """Count the number of elements in an iterator. (consumes the iterator)"""
345 return reduce(lambda x,y: x+1, l)
350 """Append an error message to the list of saved errors.
352 Once processing is able to stop and output the errors, the saved errors are
353 accessible in the module variable helpers.saved_errors.
355 saved_errors.append(e)
358 istty = os.isatty(2) or atoi(os.environ.get('BUP_FORCE_TTY'))
360 """Calls log(s) if stderr is a TTY. Does nothing otherwise."""
366 """Replace the default exception handler for KeyboardInterrupt (Ctrl-C).
368 The new exception handler will make sure that bup will exit without an ugly
369 stacktrace when Ctrl-C is hit.
371 oldhook = sys.excepthook
372 def newhook(exctype, value, traceback):
373 if exctype == KeyboardInterrupt:
374 log('Interrupted.\n')
376 return oldhook(exctype, value, traceback)
377 sys.excepthook = newhook
380 def columnate(l, prefix):
381 """Format elements of 'l' in columns with 'prefix' leading each line.
383 The number of columns is determined automatically based on the string
389 clen = max(len(s) for s in l)
390 ncols = (tty_width() - len(prefix)) / (clen + 2)
395 while len(l) % ncols:
398 for s in range(0, len(l), rows):
399 cols.append(l[s:s+rows])
401 for row in zip(*cols):
402 out += prefix + ''.join(('%-*s' % (clen+2, s)) for s in row) + '\n'
405 def parse_date_or_fatal(str, fatal):
406 """Parses the given date or calls Option.fatal().
407 For now we expect a string that contains a float."""
410 except ValueError, e:
411 raise fatal('invalid date format (should be a float): %r' % e)
415 def strip_path(prefix, path):
416 """Strips a given prefix from a path.
418 First both paths are normalized.
420 Raises an Exception if no prefix is given.
423 raise Exception('no path given')
425 normalized_prefix = realpath(prefix)
426 debug2("normalized_prefix: %s\n" % normalized_prefix)
427 normalized_path = realpath(path)
428 debug2("normalized_path: %s\n" % normalized_path)
429 if normalized_path.startswith(normalized_prefix):
430 return normalized_path[len(normalized_prefix):]
434 def strip_base_path(path, base_paths):
435 """Strips the base path from a given path.
438 Determines the base path for the given string and the strips it
440 Iterates over all base_paths from long to short, to prevent that
441 a too short base_path is removed.
443 sorted_base_paths = sorted(base_paths, key=len, reverse=True)
444 for bp in sorted_base_paths:
445 if path.startswith(realpath(bp)):
446 return strip_path(bp, path)
449 def graft_path(graft_points, path):
450 normalized_path = realpath(path)
451 for graft_point in graft_points:
452 old_prefix, new_prefix = graft_point
453 if normalized_path.startswith(old_prefix):
454 return re.sub(r'^' + old_prefix, new_prefix, normalized_path)
455 return normalized_path
458 # hashlib is only available in python 2.5 or higher, but the 'sha' module
459 # produces a DeprecationWarning in python 2.6 or higher. We want to support
460 # python 2.4 and above without any stupid warnings, so let's try using hashlib
461 # first, and downgrade if it fails.
472 """Format bup's version date string for output."""
473 return _version.DATE.split(' ')[0]
475 def version_commit():
476 """Get the commit hash of bup's current version."""
477 return _version.COMMIT
480 """Format bup's version tag (the official version number).
482 When generated from a commit other than one pointed to with a tag, the
483 returned string will be "unknown-" followed by the first seven positions of
486 names = _version.NAMES.strip()
487 assert(names[0] == '(')
488 assert(names[-1] == ')')
490 l = [n.strip() for n in names.split(',')]
492 if n.startswith('tag: bup-'):
494 return 'unknown-%s' % _version.COMMIT[:7]