from __future__ import with_statement from datetime import datetime, timedelta from getpass import getuser from itertools import izip_longest import msgpack import os import socket import stat import sys import time from cStringIO import StringIO from xattr import xattr, XATTR_NOFOLLOW from .chunker import chunkify from .helpers import uid2user, user2uid, gid2group, group2gid, \ encode_filename, Statistics ITEMS_BUFFER = 1024 * 1024 CHUNK_MIN = 1024 WINDOW_SIZE = 0xfff CHUNK_MASK = 0xffff have_lchmod = hasattr(os, 'lchmod') linux = sys.platform == 'linux2' class ItemIter(object): def __init__(self, unpacker, filter): self.unpacker = iter(unpacker) self.filter = filter self.stack = [] self.peeks = 0 self._peek = None self._peek_iter = None global foo foo = self def __iter__(self): return self def next(self): if self.stack: item = self.stack.pop(0) else: self._peek = None item = self.get_next() self.peeks = max(0, self.peeks - len(item.get('chunks', []))) return item def get_next(self): next = self.unpacker.next() while self.filter and not self.filter(next): next = self.unpacker.next() return next def peek(self): while True: while not self._peek or not self._peek_iter: if self.peeks > 100: raise StopIteration self._peek = self.get_next() self.stack.append(self._peek) if 'chunks' in self._peek: self._peek_iter = iter(self._peek['chunks']) else: self._peek_iter = None try: item = self._peek_iter.next() self.peeks += 1 return item except StopIteration: self._peek = None class Archive(object): class DoesNotExist(Exception): pass class AlreadyExists(Exception): pass def __init__(self, store, key, manifest, name, cache=None, create=False, checkpoint_interval=300, numeric_owner=False): if sys.platform == 'darwin': self.cwd = os.getcwdu() else: self.cwd = os.getcwd() self.key = key self.store = store self.cache = cache self.manifest = manifest self.items = StringIO() self.items_ids = [] self.hard_links = {} self.stats = Statistics() self.name = name self.checkpoint_interval = checkpoint_interval self.numeric_owner = numeric_owner if create: if name in manifest.archives: raise self.AlreadyExists(name) self.last_checkpoint = time.time() i = 0 while True: self.checkpoint_name = '%s.checkpoint%s' % (name, i and ('.%d' % i) or '') if not self.checkpoint_name in manifest.archives: break i += 1 else: if name not in self.manifest.archives: raise self.DoesNotExist(name) info = self.manifest.archives[name] self.load(info['id']) def load(self, id): self.id = id data = self.key.decrypt(self.id, self.store.get(self.id)) self.metadata = msgpack.unpackb(data) if self.metadata['version'] != 1: raise Exception('Unknown archive metadata version') self.name = self.metadata['name'] @property def ts(self): """Timestamp of archive creation in UTC""" t, f = self.metadata['time'].split('.', 1) return datetime.strptime(t, '%Y-%m-%dT%H:%M:%S') + timedelta(seconds=float('.' + f)) def __repr__(self): return 'Archive(%r)' % self.name def iter_items(self, filter=None): unpacker = msgpack.Unpacker(use_list=False) i = 0 n = 20 while True: items = self.metadata['items'][i:i + n] i += n if not items: break for id, chunk in [(id, chunk) for id, chunk in izip_longest(items, self.store.get_many(items))]: unpacker.feed(self.key.decrypt(id, chunk)) iter = ItemIter(unpacker, filter) for item in iter: yield item, iter.peek def add_item(self, item): self.items.write(msgpack.packb(item)) now = time.time() if now - self.last_checkpoint > self.checkpoint_interval: self.last_checkpoint = now self.write_checkpoint() if self.items.tell() > ITEMS_BUFFER: self.flush_items() def flush_items(self, flush=False): if self.items.tell() == 0: return self.items.seek(0) chunks = list(str(s) for s in chunkify(self.items, WINDOW_SIZE, CHUNK_MASK, CHUNK_MIN, self.key.chunk_seed)) self.items.seek(0) self.items.truncate() for chunk in chunks[:-1]: id, _, _ = self.cache.add_chunk(self.key.id_hash(chunk), chunk, self.stats) self.items_ids.append(id) if flush or len(chunks) == 1: id, _, _ = self.cache.add_chunk(self.key.id_hash(chunks[-1]), chunks[-1], self.stats) self.items_ids.append(id) else: self.items.write(chunks[-1]) def write_checkpoint(self): self.save(self.checkpoint_name) del self.manifest.archives[self.checkpoint_name] self.cache.chunk_decref(self.id) def save(self, name=None): name = name or self.name if name in self.manifest.archives: raise self.AlreadyExists(name) self.flush_items(flush=True) metadata = { 'version': 1, 'name': name, 'items': self.items_ids, 'cmdline': sys.argv, 'hostname': socket.gethostname(), 'username': getuser(), 'time': datetime.utcnow().isoformat(), } data = msgpack.packb(metadata) self.id = self.key.id_hash(data) self.cache.add_chunk(self.id, data, self.stats) self.manifest.archives[name] = {'id': self.id, 'time': metadata['time']} self.manifest.write() self.store.commit() self.cache.commit() def calc_stats(self, cache): def add(id): count, size, csize = self.cache.chunks[id] stats.update(size, csize, count == 1) self.cache.chunks[id] = count - 1, size, csize # This function is a bit evil since it abuses the cache to calculate # the stats. The cache transaction must be rolled back afterwards unpacker = msgpack.Unpacker(use_list=False) cache.begin_txn() stats = Statistics() add(self.id) for id, chunk in izip_longest(self.metadata['items'], self.store.get_many(self.metadata['items'])): add(id) unpacker.feed(self.key.decrypt(id, chunk)) for item in unpacker: try: for id, size, csize in item['chunks']: add(id) stats.nfiles += 1 except KeyError: pass cache.rollback() return stats def extract_item(self, item, dest=None, restore_attrs=True, peek=None): dest = dest or self.cwd assert item['path'][0] not in ('/', '\\', ':') path = os.path.join(dest, encode_filename(item['path'])) # Attempt to remove existing files, ignore errors on failure try: st = os.lstat(path) if stat.S_ISDIR(st.st_mode): os.rmdir(path) else: os.unlink(path) except OSError: pass mode = item['mode'] if stat.S_ISDIR(mode): if not os.path.exists(path): os.makedirs(path) if restore_attrs: self.restore_attrs(path, item) elif stat.S_ISREG(mode): if not os.path.exists(os.path.dirname(path)): os.makedirs(os.path.dirname(path)) # Hard link? if 'source' in item: source = os.path.join(dest, item['source']) if os.path.exists(path): os.unlink(path) os.link(source, path) else: with open(path, 'wbx') as fd: ids = [id for id, size, csize in item['chunks']] for id, chunk in izip_longest(ids, self.store.get_many(ids, peek)): data = self.key.decrypt(id, chunk) fd.write(data) self.restore_attrs(path, item) elif stat.S_ISFIFO(mode): if not os.path.exists(os.path.dirname(path)): os.makedirs(os.path.dirname(path)) os.mkfifo(path) self.restore_attrs(path, item) elif stat.S_ISLNK(mode): if not os.path.exists(os.path.dirname(path)): os.makedirs(os.path.dirname(path)) source = item['source'] if os.path.exists(path): os.unlink(path) os.symlink(source, path) self.restore_attrs(path, item, symlink=True) elif stat.S_ISCHR(mode) or stat.S_ISBLK(mode): os.mknod(path, item['mode'], item['rdev']) self.restore_attrs(path, item) else: raise Exception('Unknown archive item type %r' % item['mode']) def restore_attrs(self, path, item, symlink=False): xattrs = item.get('xattrs') if xattrs: xa = xattr(path, XATTR_NOFOLLOW) for k, v in xattrs.items(): try: xa.set(k, v) except (IOError, KeyError): pass uid = gid = None if not self.numeric_owner: uid = user2uid(item['user']) gid = group2gid(item['group']) uid = uid or item['uid'] gid = gid or item['gid'] try: os.lchown(path, uid, gid) except OSError: pass if have_lchmod: os.lchmod(path, item['mode']) elif not symlink: os.chmod(path, item['mode']) if not symlink: # FIXME: We should really call futimes here (c extension required) os.utime(path, (item['mtime'], item['mtime'])) def verify_file(self, item, start, result, peek=None): if not item['chunks']: start(item) result(item, True) else: start(item) ids = [id for id, size, csize in item['chunks']] try: for id, chunk in izip_longest(ids, self.store.get_many(ids, peek)): self.key.decrypt(id, chunk) except Exception: result(item, False) return result(item, True) def delete(self, cache): unpacker = msgpack.Unpacker(use_list=False) for id in self.metadata['items']: unpacker.feed(self.key.decrypt(id, self.store.get(id))) for item in unpacker: try: for chunk_id, size, csize in item['chunks']: self.cache.chunk_decref(chunk_id) except KeyError: pass self.cache.chunk_decref(id) self.cache.chunk_decref(self.id) del self.manifest.archives[self.name] self.manifest.write() self.store.commit() cache.commit() def stat_attrs(self, st, path): item = { 'mode': st.st_mode, 'uid': st.st_uid, 'user': uid2user(st.st_uid), 'gid': st.st_gid, 'group': gid2group(st.st_gid), 'mtime': st.st_mtime, } if self.numeric_owner: item['user'] = item['group'] = None try: xa = xattr(path, XATTR_NOFOLLOW) xattrs = {} for key in xa: # Only store the user namespace on Linux if linux and not key.startswith('user'): continue xattrs[key] = xa[key] if xattrs: item['xattrs'] = xattrs except IOError: pass return item def process_item(self, path, st): item = {'path': path.lstrip('/\\:')} item.update(self.stat_attrs(st, path)) self.add_item(item) def process_dev(self, path, st): item = {'path': path.lstrip('/\\:'), 'rdev': st.st_rdev} item.update(self.stat_attrs(st, path)) self.add_item(item) def process_symlink(self, path, st): source = os.readlink(path) item = {'path': path.lstrip('/\\:'), 'source': source} item.update(self.stat_attrs(st, path)) self.add_item(item) def process_file(self, path, st, cache): safe_path = path.lstrip('/\\:') # Is it a hard link? if st.st_nlink > 1: source = self.hard_links.get((st.st_ino, st.st_dev)) if (st.st_ino, st.st_dev) in self.hard_links: item = self.stat_attrs(st, path) item.update({'path': safe_path, 'source': source}) self.add_item(item) return else: self.hard_links[st.st_ino, st.st_dev] = safe_path path_hash = self.key.id_hash(path) ids = cache.file_known_and_unchanged(path_hash, st) chunks = None if ids is not None: # Make sure all ids are available for id in ids: if not cache.seen_chunk(id): break else: chunks = [cache.chunk_incref(id, self.stats) for id in ids] # Only chunkify the file if needed if chunks is None: with open(path, 'rb') as fd: chunks = [] for chunk in chunkify(fd, WINDOW_SIZE, CHUNK_MASK, CHUNK_MIN, self.key.chunk_seed): chunks.append(cache.add_chunk(self.key.id_hash(chunk), chunk, self.stats)) ids = [id for id, _, _ in chunks] cache.memorize_file(path_hash, st, ids) item = {'path': safe_path, 'chunks': chunks} item.update(self.stat_attrs(st, path)) self.stats.nfiles += 1 self.add_item(item) @staticmethod def list_archives(store, key, manifest, cache=None): for name, info in manifest.archives.items(): yield Archive(store, key, manifest, name, cache=cache)