borg/dedupestore/archive.py

255 lines
9.1 KiB
Python

from datetime import datetime
import hashlib
import logging
import msgpack
import os
import stat
import sys
import zlib
from .cache import NS_ARCHIVES, NS_CHUNKS
from .chunkifier import chunkify
from .helpers import uid2user, user2uid, gid2group, group2gid
CHUNK_SIZE = 55001
class Archive(object):
def __init__(self, store, cache, name=None):
self.store = store
self.cache = cache
self.items = []
self.chunks = []
self.chunk_idx = {}
self.hard_links = {}
if name:
self.open(name)
def open(self, name):
id = self.cache.archives[name]
data = self.store.get(NS_ARCHIVES, id)
if hashlib.sha256(data).digest() != id:
raise Exception('Archive hash did not match')
archive = msgpack.unpackb(zlib.decompress(data))
version = archive.get('version')
if version != 1:
raise Exception('Archive version %r not supported' % version)
self.items = archive['items']
self.name = archive['name']
self.chunks = archive['chunks']
for i, chunk in enumerate(archive['chunks']):
self.chunk_idx[i] = chunk[0]
def save(self, name):
archive = {
'version': 1,
'name': name,
'cmdline': ' '.join(sys.argv),
'ts': datetime.utcnow().isoformat(),
'items': self.items,
'chunks': self.chunks
}
data = zlib.compress(msgpack.packb(archive))
self.id = hashlib.sha256(data).digest()
self.store.put(NS_ARCHIVES, 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):
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 self.cache.seen_chunk(id) == 1:
usize += size
return osize, csize, usize
def list(self):
for item in self.items:
print item['path']
def extract(self, dest=None):
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, call_utime=False)
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]
data = self.store.get(NS_CHUNKS, id)
cid = data[:32]
data = data[32:]
if hashlib.sha256(data).digest() != cid:
raise Exception('Invalid chunk checksum')
data = zlib.decompress(data)
fd.write(data)
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, call_utime=True):
os.lchmod(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 call_utime:
# FIXME: We should really call futimes here (c extension required)
os.utime(path, (item['ctime'], item['mtime']))
def verify(self):
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]
data = self.store.get(NS_CHUNKS, id)
cid = data[:32]
data = data[32:]
if (hashlib.sha256(data).digest() != cid):
logging.error('%s ... ERROR', item['path'])
break
else:
logging.info('%s ... OK', item['path'])
def delete(self, cache):
self.store.delete(NS_ARCHIVES, self.cache.archives[self.name])
for id, size in self.chunks:
cache.chunk_decref(id)
self.store.commit()
del cache.archives[self.name]
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):
if name in cache.archives:
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)
else:
logging.error('Unknown file type: %s', path)
self.save(name)
cache.archives[name] = self.id
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):
safe_path = path.lstrip('/\\:')
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
try:
fd = open(path, 'rb')
except IOError, e:
logging.error(e)
return
with fd:
logging.info(safe_path)
chunks = []
size = 0
for chunk in chunkify(fd, CHUNK_SIZE, 30):
chunks.append(self.process_chunk(chunk))
size += len(chunk)
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_chunk(self, data):
id = hashlib.sha256(data).digest()
try:
return self.chunk_idx[id]
except KeyError:
idx = len(self.chunks)
size = self.cache.add_chunk(id, data)
self.chunks.append((id, size))
self.chunk_idx[id] = idx
return idx