borg/darc/archive.py

323 lines
12 KiB
Python

from datetime import datetime
from getpass import getuser
import logging
import msgpack
import os
import socket
import stat
import sys
from . import NS_ARCHIVE_METADATA, NS_ARCHIVE_ITEMS, NS_ARCHIVE_CHUNKS, NS_CHUNK
from .chunkifier import chunkify
from .helpers import uid2user, user2uid, gid2group, group2gid, \
IntegrityError, format_file_mode, format_time
CHUNK_SIZE = 55001
have_lchmod = hasattr(os, 'lchmod')
class Archive(object):
def __init__(self, store, crypto, name=None):
self.crypto = crypto
self.store = store
self.items = []
self.chunks = []
self.chunk_idx = {}
self.hard_links = {}
if name:
self.load(self.crypto.id_hash(name))
def load(self, id):
self.id = id
data, self.hash = self.crypto.decrypt(self.store.get(NS_ARCHIVE_METADATA, self.id))
self.metadata = msgpack.unpackb(data)
assert self.metadata['version'] == 1
def get_items(self):
data, chunks_hash = self.crypto.decrypt(self.store.get(NS_ARCHIVE_CHUNKS, self.id))
chunks = msgpack.unpackb(data)
assert chunks['version'] == 1
assert self.metadata['chunks_hash'] == chunks_hash
self.chunks = chunks['chunks']
data, items_hash = self.crypto.decrypt(self.store.get(NS_ARCHIVE_ITEMS, self.id))
items = msgpack.unpackb(data)
assert items['version'] == 1
assert self.metadata['items_hash'] == items_hash
self.items = items['items']
for i, chunk in enumerate(self.chunks):
self.chunk_idx[i] = chunk[0]
def save(self, name):
self.id = self.crypto.id_hash(name)
chunks = {'version': 1, 'chunks': self.chunks}
data, chunks_hash = self.crypto.encrypt_create(msgpack.packb(chunks))
self.store.put(NS_ARCHIVE_CHUNKS, self.id, data)
items = {'version': 1, 'items': self.items}
data, items_hash = self.crypto.encrypt_read(msgpack.packb(items))
self.store.put(NS_ARCHIVE_ITEMS, self.id, data)
metadata = {
'version': 1,
'name': name,
'chunks_hash': chunks_hash,
'items_hash': items_hash,
'cmdline': sys.argv,
'hostname': socket.gethostname(),
'username': getuser(),
'time': datetime.utcnow().isoformat(),
}
data, self.hash = self.crypto.encrypt_read(msgpack.packb(metadata))
self.store.put(NS_ARCHIVE_METADATA, self.id, data)
self.store.commit()
def add_chunk(self, id, size):
try:
return self.chunk_idx[id]
except KeyError:
idx = len(self.chunks)
self.chunks.append((id, size))
self.chunk_idx[id] = idx
return idx
def stats(self, cache):
self.get_items()
osize = csize = usize = 0
for item in self.items:
if item['type'] == 'FILE':
osize += item['size']
for id, size in self.chunks:
csize += size
if cache.seen_chunk(id) == 1:
usize += size
return osize, csize, usize
def list(self):
tmap = dict(FILE='-', DIRECTORY='d', SYMLINK='l')
self.get_items()
for item in self.items:
type = tmap[item['type']]
mode = format_file_mode(item['mode'])
size = item.get('size', 0)
mtime = format_time(datetime.fromtimestamp(item['mtime']))
print '%s%s %-6s %-6s %8d %s %s' % (type, mode, item['user'],
item['group'], size, mtime, item['path'])
def extract(self, dest=None):
self.get_items()
dest = dest or os.getcwdu()
dir_stat_queue = []
for item in self.items:
assert item['path'][0] not in ('/', '\\', ':')
path = os.path.join(dest, item['path'].decode('utf-8'))
if item['type'] == 'DIRECTORY':
logging.info(path)
if not os.path.exists(path):
os.makedirs(path)
dir_stat_queue.append((path, item))
continue
elif item['type'] == 'SYMLINK':
if not os.path.exists(os.path.dirname(path)):
os.makedirs(os.path.dirname(path))
source = item['source']
logging.info('%s -> %s', path, source)
if os.path.exists(path):
os.unlink(path)
os.symlink(source, path)
self.restore_stat(path, item, symlink=True)
elif item['type'] == 'HARDLINK':
if not os.path.exists(os.path.dirname(path)):
os.makedirs(os.path.dirname(path))
source = os.path.join(dest, item['source'])
logging.info('%s => %s', path, source)
if os.path.exists(path):
os.unlink(path)
os.link(source, path)
elif item['type'] == 'FILE':
logging.info(path)
if not os.path.exists(os.path.dirname(path)):
os.makedirs(os.path.dirname(path))
with open(path, 'wb') as fd:
for chunk in item['chunks']:
id = self.chunk_idx[chunk]
try:
data, hash = self.crypto.decrypt(self.store.get(NS_CHUNK, id))
if self.crypto.id_hash(data) != id:
raise IntegrityError('chunk id did not match')
fd.write(data)
except ValueError:
raise Exception('Invalid chunk checksum')
self.restore_stat(path, item)
else:
raise Exception('Unknown archive item type %r' % item['type'])
if dir_stat_queue and not path.startswith(dir_stat_queue[-1][0]):
self.restore_stat(*dir_stat_queue.pop())
def restore_stat(self, path, item, symlink=False):
if have_lchmod:
os.lchmod(path, item['mode'])
elif not symlink:
os.chmod(path, item['mode'])
uid = user2uid(item['user']) or item['uid']
gid = group2gid(item['group']) or item['gid']
try:
os.lchown(path, uid, gid)
except OSError:
pass
if not symlink:
# FIXME: We should really call futimes here (c extension required)
os.utime(path, (item['ctime'], item['mtime']))
def verify(self):
self.get_items()
for item in self.items:
if item['type'] == 'FILE':
item['path'] = item['path'].decode('utf-8')
for chunk in item['chunks']:
id = self.chunk_idx[chunk]
try:
data, hash = self.crypto.decrypt(self.store.get(NS_CHUNK, id))
if self.crypto.id_hash(data) != id:
raise IntegrityError('chunk id did not match')
except IntegrityError:
logging.error('%s ... ERROR', item['path'])
break
else:
logging.info('%s ... OK', item['path'])
def delete(self, cache):
self.get_items()
self.store.delete(NS_ARCHIVE_CHUNKS, self.id)
self.store.delete(NS_ARCHIVE_ITEMS, self.id)
self.store.delete(NS_ARCHIVE_METADATA, self.id)
for id, size in self.chunks:
cache.chunk_decref(id)
self.store.commit()
cache.save()
def _walk(self, path):
st = os.lstat(path)
yield path, st
if stat.S_ISDIR(st.st_mode):
for f in os.listdir(path):
for x in self._walk(os.path.join(path, f)):
yield x
def create(self, name, paths, cache):
id = self.crypto.id_hash(name)
try:
self.store.get(NS_ARCHIVE_METADATA, id)
except self.store.DoesNotExist:
pass
else:
raise NameError('Archive already exists')
for path in paths:
for path, st in self._walk(unicode(path)):
if stat.S_ISDIR(st.st_mode):
self.process_dir(path, st)
elif stat.S_ISLNK(st.st_mode):
self.process_symlink(path, st)
elif stat.S_ISREG(st.st_mode):
self.process_file(path, st, cache)
else:
logging.error('Unknown file type: %s', path)
self.save(name)
cache.save()
def process_dir(self, path, st):
path = path.lstrip('/\\:')
logging.info(path)
self.items.append({
'type': 'DIRECTORY', 'path': path,
'mode': st.st_mode,
'uid': st.st_uid, 'user': uid2user(st.st_uid),
'gid': st.st_gid, 'group': gid2group(st.st_gid),
'ctime': st.st_ctime, 'mtime': st.st_mtime,
})
def process_symlink(self, path, st):
source = os.readlink(path)
path = path.lstrip('/\\:')
logging.info('%s -> %s', path, source)
self.items.append({
'type': 'SYMLINK', 'path': path, 'source': source,
'mode': st.st_mode,
'uid': st.st_uid, 'user': uid2user(st.st_uid),
'gid': st.st_gid, 'group': gid2group(st.st_gid),
'ctime': st.st_ctime, 'mtime': st.st_mtime,
})
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:
logging.info('%s => %s', path, source)
self.items.append({ 'type': 'HARDLINK',
'path': path, 'source': source})
return
else:
self.hard_links[st.st_ino, st.st_dev] = safe_path
logging.info(safe_path)
path_hash = self.crypto.id_hash(path.encode('utf-8'))
ids, size = cache.file_known_and_unchanged(path_hash, st)
if ids is not None:
# Make sure all ids are available
for id in ids:
if not cache.seen_chunk(id):
ids = None
break
else:
chunks = [self.process_chunk2(id, cache) for id in ids]
# Only chunkify the file if needed
if ids is None:
try:
fd = open(path, 'rb')
except IOError, e:
logging.error(e)
return
with fd:
size = 0
ids = []
chunks = []
for chunk in chunkify(fd, CHUNK_SIZE, 30):
id = self.crypto.id_hash(chunk)
ids.append(id)
try:
chunks.append(self.chunk_idx[id])
except KeyError:
chunks.append(self.process_chunk(id, chunk, cache))
size += len(chunk)
cache.memorize_file_chunks(path_hash, st, ids)
self.items.append({
'type': 'FILE', 'path': safe_path, 'chunks': chunks, 'size': size,
'mode': st.st_mode,
'uid': st.st_uid, 'user': uid2user(st.st_uid),
'gid': st.st_gid, 'group': gid2group(st.st_gid),
'ctime': st.st_ctime, 'mtime': st.st_mtime,
})
def process_chunk2(self, id, cache):
try:
return self.chunk_idx[id]
except KeyError:
idx = len(self.chunks)
size = cache.chunk_incref(id)
self.chunks.append((id, size))
self.chunk_idx[id] = idx
return idx
def process_chunk(self, id, data, cache):
idx = len(self.chunks)
size = cache.add_chunk(id, data)
self.chunks.append((id, size))
self.chunk_idx[id] = idx
return idx
@staticmethod
def list_archives(store, crypto):
for id in list(store.list(NS_ARCHIVE_METADATA)):
archive = Archive(store, crypto)
archive.load(id)
yield archive