:: **Zploit** v1.0 | Current Path: **/usr/lib64/python3.6/site-packages/borg/**
:: Editing File: cache.py
import configparser import os import shutil import stat from binascii import unhexlify from collections import namedtuple from time import perf_counter from .logger import create_logger logger = create_logger() files_cache_logger = create_logger('borg.debug.files_cache') from .constants import CACHE_README, FILES_CACHE_MODE_DISABLED from .hashindex import ChunkIndex, ChunkIndexEntry, CacheSynchronizer from .helpers import Location from .helpers import Error from .helpers import Manifest from .helpers import get_cache_dir, get_security_dir from .helpers import int_to_bigint, bigint_to_int, bin_to_hex, parse_stringified_list from .helpers import format_file_size from .helpers import safe_ns from .helpers import yes, hostname_is_unique from .helpers import remove_surrogates from .helpers import ProgressIndicatorPercent, ProgressIndicatorMessage from .helpers import set_ec, EXIT_WARNING from .helpers import safe_unlink from .helpers import msgpack from .item import ArchiveItem, ChunkListEntry from .crypto.key import PlaintextKey from .crypto.file_integrity import IntegrityCheckedFile, DetachedIntegrityCheckedFile, FileIntegrityError from .locking import Lock from .platform import SaveFile from .remote import cache_if_remote from .repository import LIST_SCAN_LIMIT # note: cmtime might me either a ctime or a mtime timestamp FileCacheEntry = namedtuple('FileCacheEntry', 'age inode size cmtime chunk_ids') class SecurityManager: """ Tracks repositories. Ensures that nothing bad happens (repository swaps, replay attacks, unknown repositories etc.). This is complicated by the Cache being initially used for this, while only some commands actually use the Cache, which meant that other commands did not perform these checks. Further complications were created by the Cache being a cache, so it could be legitimately deleted, which is annoying because Borg didn't recognize repositories after that. Therefore a second location, the security database (see get_security_dir), was introduced which stores this information. However, this means that the code has to deal with a cache existing but no security DB entry, or inconsistencies between the security DB and the cache which have to be reconciled, and also with no cache existing but a security DB entry. """ def __init__(self, repository): self.repository = repository self.dir = get_security_dir(repository.id_str) self.cache_dir = cache_dir(repository) self.key_type_file = os.path.join(self.dir, 'key-type') self.location_file = os.path.join(self.dir, 'location') self.manifest_ts_file = os.path.join(self.dir, 'manifest-timestamp') @staticmethod def destroy(repository, path=None): """destroy the security dir for ``repository`` or at ``path``""" path = path or get_security_dir(repository.id_str) if os.path.exists(path): shutil.rmtree(path) def known(self): return all(os.path.exists(f) for f in (self.key_type_file, self.location_file, self.manifest_ts_file)) def key_matches(self, key): if not self.known(): return False try: with open(self.key_type_file, 'r') as fd: type = fd.read() return type == str(key.TYPE) except OSError as exc: logger.warning('Could not read/parse key type file: %s', exc) def save(self, manifest, key): logger.debug('security: saving state for %s to %s', self.repository.id_str, self.dir) current_location = self.repository._location.canonical_path() logger.debug('security: current location %s', current_location) logger.debug('security: key type %s', str(key.TYPE)) logger.debug('security: manifest timestamp %s', manifest.timestamp) with SaveFile(self.location_file) as fd: fd.write(current_location) with SaveFile(self.key_type_file) as fd: fd.write(str(key.TYPE)) with SaveFile(self.manifest_ts_file) as fd: fd.write(manifest.timestamp) def assert_location_matches(self, cache_config=None): # Warn user before sending data to a relocated repository try: with open(self.location_file) as fd: previous_location = fd.read() logger.debug('security: read previous location %r', previous_location) except FileNotFoundError: logger.debug('security: previous location file %s not found', self.location_file) previous_location = None except OSError as exc: logger.warning('Could not read previous location file: %s', exc) previous_location = None if cache_config and cache_config.previous_location and previous_location != cache_config.previous_location: # Reconcile cache and security dir; we take the cache location. previous_location = cache_config.previous_location logger.debug('security: using previous_location of cache: %r', previous_location) repository_location = self.repository._location.canonical_path() if previous_location and previous_location != repository_location: msg = ("Warning: The repository at location {} was previously located at {}\n".format( repository_location, previous_location) + "Do you want to continue? [yN] ") if not yes(msg, false_msg="Aborting.", invalid_msg="Invalid answer, aborting.", retry=False, env_var_override='BORG_RELOCATED_REPO_ACCESS_IS_OK'): raise Cache.RepositoryAccessAborted() # adapt on-disk config immediately if the new location was accepted logger.debug('security: updating location stored in cache and security dir') with SaveFile(self.location_file) as fd: fd.write(repository_location) if cache_config: cache_config.save() def assert_no_manifest_replay(self, manifest, key, cache_config=None): try: with open(self.manifest_ts_file) as fd: timestamp = fd.read() logger.debug('security: read manifest timestamp %r', timestamp) except FileNotFoundError: logger.debug('security: manifest timestamp file %s not found', self.manifest_ts_file) timestamp = '' except OSError as exc: logger.warning('Could not read previous location file: %s', exc) timestamp = '' if cache_config: timestamp = max(timestamp, cache_config.timestamp or '') logger.debug('security: determined newest manifest timestamp as %s', timestamp) # If repository is older than the cache or security dir something fishy is going on if timestamp and timestamp > manifest.timestamp: if isinstance(key, PlaintextKey): raise Cache.RepositoryIDNotUnique() else: raise Cache.RepositoryReplay() def assert_key_type(self, key, cache_config=None): # Make sure an encrypted repository has not been swapped for an unencrypted repository if cache_config and cache_config.key_type is not None and cache_config.key_type != str(key.TYPE): raise Cache.EncryptionMethodMismatch() if self.known() and not self.key_matches(key): raise Cache.EncryptionMethodMismatch() def assert_secure(self, manifest, key, *, cache_config=None, warn_if_unencrypted=True, lock_wait=None): # warn_if_unencrypted=False is only used for initializing a new repository. # Thus, avoiding asking about a repository that's currently initializing. self.assert_access_unknown(warn_if_unencrypted, manifest, key) if cache_config: self._assert_secure(manifest, key, cache_config) else: cache_config = CacheConfig(self.repository, lock_wait=lock_wait) if cache_config.exists(): with cache_config: self._assert_secure(manifest, key, cache_config) else: self._assert_secure(manifest, key) logger.debug('security: repository checks ok, allowing access') def _assert_secure(self, manifest, key, cache_config=None): self.assert_location_matches(cache_config) self.assert_key_type(key, cache_config) self.assert_no_manifest_replay(manifest, key, cache_config) if not self.known(): logger.debug('security: remembering previously unknown repository') self.save(manifest, key) def assert_access_unknown(self, warn_if_unencrypted, manifest, key): # warn_if_unencrypted=False is only used for initializing a new repository. # Thus, avoiding asking about a repository that's currently initializing. if not key.logically_encrypted and not self.known(): msg = ("Warning: Attempting to access a previously unknown unencrypted repository!\n" + "Do you want to continue? [yN] ") allow_access = not warn_if_unencrypted or yes(msg, false_msg="Aborting.", invalid_msg="Invalid answer, aborting.", retry=False, env_var_override='BORG_UNKNOWN_UNENCRYPTED_REPO_ACCESS_IS_OK') if allow_access: if warn_if_unencrypted: logger.debug('security: remembering unknown unencrypted repository (explicitly allowed)') else: logger.debug('security: initializing unencrypted repository') self.save(manifest, key) else: raise Cache.CacheInitAbortedError() def assert_secure(repository, manifest, lock_wait): sm = SecurityManager(repository) sm.assert_secure(manifest, manifest.key, lock_wait=lock_wait) def recanonicalize_relative_location(cache_location, repository): # borg < 1.0.8rc1 had different canonicalization for the repo location (see #1655 and #1741). repo_location = repository._location.canonical_path() rl = Location(repo_location) cl = Location(cache_location) if cl.proto == rl.proto and cl.user == rl.user and cl.host == rl.host and cl.port == rl.port \ and \ cl.path and rl.path and \ cl.path.startswith('/~/') and rl.path.startswith('/./') and cl.path[3:] == rl.path[3:]: # everything is same except the expected change in relative path canonicalization, # update previous_location to avoid warning / user query about changed location: return repo_location else: return cache_location def cache_dir(repository, path=None): return path or os.path.join(get_cache_dir(), repository.id_str) def files_cache_name(): suffix = os.environ.get('BORG_FILES_CACHE_SUFFIX', '') return 'files.' + suffix if suffix else 'files' def discover_files_cache_name(path): return [fn for fn in os.listdir(path) if fn == 'files' or fn.startswith('files.')][0] class CacheConfig: def __init__(self, repository, path=None, lock_wait=None): self.repository = repository self.path = cache_dir(repository, path) self.config_path = os.path.join(self.path, 'config') self.lock = None self.lock_wait = lock_wait def __enter__(self): self.open() return self def __exit__(self, exc_type, exc_val, exc_tb): self.close() def exists(self): return os.path.exists(self.config_path) def create(self): assert not self.exists() config = configparser.ConfigParser(interpolation=None) config.add_section('cache') config.set('cache', 'version', '1') config.set('cache', 'repository', self.repository.id_str) config.set('cache', 'manifest', '') config.add_section('integrity') config.set('integrity', 'manifest', '') with SaveFile(self.config_path) as fd: config.write(fd) def open(self): self.lock = Lock(os.path.join(self.path, 'lock'), exclusive=True, timeout=self.lock_wait, kill_stale_locks=hostname_is_unique()).acquire() self.load() def load(self): self._config = configparser.ConfigParser(interpolation=None) with open(self.config_path) as fd: self._config.read_file(fd) self._check_upgrade(self.config_path) self.id = self._config.get('cache', 'repository') self.manifest_id = unhexlify(self._config.get('cache', 'manifest')) self.timestamp = self._config.get('cache', 'timestamp', fallback=None) self.key_type = self._config.get('cache', 'key_type', fallback=None) self.ignored_features = set(parse_stringified_list(self._config.get('cache', 'ignored_features', fallback=''))) self.mandatory_features = set(parse_stringified_list(self._config.get('cache', 'mandatory_features', fallback=''))) try: self.integrity = dict(self._config.items('integrity')) if self._config.get('cache', 'manifest') != self.integrity.pop('manifest'): # The cache config file is updated (parsed with ConfigParser, the state of the ConfigParser # is modified and then written out.), not re-created. # Thus, older versions will leave our [integrity] section alone, making the section's data invalid. # Therefore, we also add the manifest ID to this section and # can discern whether an older version interfered by comparing the manifest IDs of this section # and the main [cache] section. self.integrity = {} logger.warning('Cache integrity data not available: old Borg version modified the cache.') except configparser.NoSectionError: logger.debug('Cache integrity: No integrity data found (files, chunks). Cache is from old version.') self.integrity = {} previous_location = self._config.get('cache', 'previous_location', fallback=None) if previous_location: self.previous_location = recanonicalize_relative_location(previous_location, self.repository) else: self.previous_location = None self._config.set('cache', 'previous_location', self.repository._location.canonical_path()) def save(self, manifest=None, key=None): if manifest: self._config.set('cache', 'manifest', manifest.id_str) self._config.set('cache', 'timestamp', manifest.timestamp) self._config.set('cache', 'ignored_features', ','.join(self.ignored_features)) self._config.set('cache', 'mandatory_features', ','.join(self.mandatory_features)) if not self._config.has_section('integrity'): self._config.add_section('integrity') for file, integrity_data in self.integrity.items(): self._config.set('integrity', file, integrity_data) self._config.set('integrity', 'manifest', manifest.id_str) if key: self._config.set('cache', 'key_type', str(key.TYPE)) with SaveFile(self.config_path) as fd: self._config.write(fd) def close(self): if self.lock is not None: self.lock.release() self.lock = None def _check_upgrade(self, config_path): try: cache_version = self._config.getint('cache', 'version') wanted_version = 1 if cache_version != wanted_version: self.close() raise Exception('%s has unexpected cache version %d (wanted: %d).' % (config_path, cache_version, wanted_version)) except configparser.NoSectionError: self.close() raise Exception('%s does not look like a Borg cache.' % config_path) from None class Cache: """Client Side cache """ class RepositoryIDNotUnique(Error): """Cache is newer than repository - do you have multiple, independently updated repos with same ID?""" class RepositoryReplay(Error): """Cache, or information obtained from the security directory is newer than repository - this is either an attack or unsafe (multiple repos with same ID)""" class CacheInitAbortedError(Error): """Cache initialization aborted""" class RepositoryAccessAborted(Error): """Repository access aborted""" class EncryptionMethodMismatch(Error): """Repository encryption method changed since last access, refusing to continue""" @staticmethod def break_lock(repository, path=None): path = cache_dir(repository, path) Lock(os.path.join(path, 'lock'), exclusive=True).break_lock() @staticmethod def destroy(repository, path=None): """destroy the cache for ``repository`` or at ``path``""" path = path or os.path.join(get_cache_dir(), repository.id_str) config = os.path.join(path, 'config') if os.path.exists(config): os.remove(config) # kill config first shutil.rmtree(path) def __new__(cls, repository, key, manifest, path=None, sync=True, do_files=False, warn_if_unencrypted=True, progress=False, lock_wait=None, permit_adhoc_cache=False, cache_mode=FILES_CACHE_MODE_DISABLED, ignore_inode=False): if not do_files and 'd' not in cache_mode: cache_mode = 'd' elif ignore_inode and 'i' in cache_mode: cache_mode = ''.join(set(cache_mode) - set('i')) def local(): return LocalCache(repository=repository, key=key, manifest=manifest, path=path, sync=sync, warn_if_unencrypted=warn_if_unencrypted, progress=progress, lock_wait=lock_wait, cache_mode=cache_mode) def adhoc(): return AdHocCache(repository=repository, key=key, manifest=manifest, lock_wait=lock_wait) if not permit_adhoc_cache: return local() # ad-hoc cache may be permitted, but if the local cache is in sync it'd be stupid to invalidate # it by needlessly using the ad-hoc cache. # Check if the local cache exists and is in sync. cache_config = CacheConfig(repository, path, lock_wait) if cache_config.exists(): with cache_config: cache_in_sync = cache_config.manifest_id == manifest.id # Don't nest cache locks if cache_in_sync: # Local cache is in sync, use it logger.debug('Cache: choosing local cache (in sync)') return local() logger.debug('Cache: choosing ad-hoc cache (local cache does not exist or is not in sync)') return adhoc() class CacheStatsMixin: str_format = """\ All archives: {0.total_size:>20s} {0.total_csize:>20s} {0.unique_csize:>20s} Unique chunks Total chunks Chunk index: {0.total_unique_chunks:20d} {0.total_chunks:20d}""" def __str__(self): return self.str_format.format(self.format_tuple()) Summary = namedtuple('Summary', ['total_size', 'total_csize', 'unique_size', 'unique_csize', 'total_unique_chunks', 'total_chunks']) def stats(self): # XXX: this should really be moved down to `hashindex.pyx` stats = self.Summary(*self.chunks.summarize())._asdict() return stats def format_tuple(self): stats = self.stats() for field in ['total_size', 'total_csize', 'unique_csize']: stats[field] = format_file_size(stats[field]) return self.Summary(**stats) def chunks_stored_size(self): return self.stats()['unique_csize'] class LocalCache(CacheStatsMixin): """ Persistent, local (client-side) cache. """ def __init__(self, repository, key, manifest, path=None, sync=True, warn_if_unencrypted=True, progress=False, lock_wait=None, cache_mode=FILES_CACHE_MODE_DISABLED): """ :param warn_if_unencrypted: print warning if accessing unknown unencrypted repository :param lock_wait: timeout for lock acquisition (int [s] or None [wait forever]) :param sync: do :meth:`.sync` :param cache_mode: what shall be compared in the file stat infos vs. cached stat infos comparison """ self.repository = repository self.key = key self.manifest = manifest self.progress = progress self.cache_mode = cache_mode self.timestamp = None self.txn_active = False self.path = cache_dir(repository, path) self.security_manager = SecurityManager(repository) self.cache_config = CacheConfig(self.repository, self.path, lock_wait) # Warn user before sending data to a never seen before unencrypted repository if not os.path.exists(self.path): self.security_manager.assert_access_unknown(warn_if_unencrypted, manifest, key) self.create() self.open() try: self.security_manager.assert_secure(manifest, key, cache_config=self.cache_config) if not self.check_cache_compatibility(): self.wipe_cache() self.update_compatibility() if sync and self.manifest.id != self.cache_config.manifest_id: self.sync() self.commit() except: self.close() raise def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): self.close() def create(self): """Create a new empty cache at `self.path` """ os.makedirs(self.path) with open(os.path.join(self.path, 'README'), 'w') as fd: fd.write(CACHE_README) self.cache_config.create() ChunkIndex().write(os.path.join(self.path, 'chunks')) os.makedirs(os.path.join(self.path, 'chunks.archive.d')) with SaveFile(os.path.join(self.path, files_cache_name()), binary=True): pass # empty file def _do_open(self): self.cache_config.load() with IntegrityCheckedFile(path=os.path.join(self.path, 'chunks'), write=False, integrity_data=self.cache_config.integrity.get('chunks')) as fd: self.chunks = ChunkIndex.read(fd) if 'd' in self.cache_mode: # d(isabled) self.files = None else: self._read_files() def open(self): if not os.path.isdir(self.path): raise Exception('%s Does not look like a Borg cache' % self.path) self.cache_config.open() self.rollback() def close(self): if self.cache_config is not None: self.cache_config.close() self.cache_config = None def _read_files(self): self.files = {} self._newest_cmtime = None logger.debug('Reading files cache ...') files_cache_logger.debug("FILES-CACHE-LOAD: starting...") msg = None try: with IntegrityCheckedFile(path=os.path.join(self.path, files_cache_name()), write=False, integrity_data=self.cache_config.integrity.get(files_cache_name())) as fd: u = msgpack.Unpacker(use_list=True) while True: data = fd.read(64 * 1024) if not data: break u.feed(data) try: for path_hash, item in u: entry = FileCacheEntry(*item) # in the end, this takes about 240 Bytes per file self.files[path_hash] = msgpack.packb(entry._replace(age=entry.age + 1)) except (TypeError, ValueError) as exc: msg = "The files cache seems invalid. [%s]" % str(exc) break except OSError as exc: msg = "The files cache can't be read. [%s]" % str(exc) except FileIntegrityError as fie: msg = "The files cache is corrupted. [%s]" % str(fie) if msg is not None: logger.warning(msg) logger.warning('Continuing without files cache - expect lower performance.') self.files = {} files_cache_logger.debug("FILES-CACHE-LOAD: finished, %d entries loaded.", len(self.files)) def begin_txn(self): # Initialize transaction snapshot pi = ProgressIndicatorMessage(msgid='cache.begin_transaction') txn_dir = os.path.join(self.path, 'txn.tmp') os.mkdir(txn_dir) pi.output('Initializing cache transaction: Reading config') shutil.copy(os.path.join(self.path, 'config'), txn_dir) pi.output('Initializing cache transaction: Reading chunks') shutil.copy(os.path.join(self.path, 'chunks'), txn_dir) pi.output('Initializing cache transaction: Reading files') try: shutil.copy(os.path.join(self.path, files_cache_name()), txn_dir) except FileNotFoundError: with SaveFile(os.path.join(txn_dir, files_cache_name()), binary=True): pass # empty file os.rename(os.path.join(self.path, 'txn.tmp'), os.path.join(self.path, 'txn.active')) self.txn_active = True pi.finish() def commit(self): """Commit transaction """ if not self.txn_active: return self.security_manager.save(self.manifest, self.key) pi = ProgressIndicatorMessage(msgid='cache.commit') if self.files is not None: if self._newest_cmtime is None: # was never set because no files were modified/added self._newest_cmtime = 2 ** 63 - 1 # nanoseconds, good until y2262 ttl = int(os.environ.get('BORG_FILES_CACHE_TTL', 20)) pi.output('Saving files cache') files_cache_logger.debug("FILES-CACHE-SAVE: starting...") with IntegrityCheckedFile(path=os.path.join(self.path, files_cache_name()), write=True) as fd: entry_count = 0 for path_hash, item in self.files.items(): # Only keep files seen in this backup that are older than newest cmtime seen in this backup - # this is to avoid issues with filesystem snapshots and cmtime granularity. # Also keep files from older backups that have not reached BORG_FILES_CACHE_TTL yet. entry = FileCacheEntry(*msgpack.unpackb(item)) if entry.age == 0 and bigint_to_int(entry.cmtime) < self._newest_cmtime or \ entry.age > 0 and entry.age < ttl: msgpack.pack((path_hash, entry), fd) entry_count += 1 files_cache_logger.debug("FILES-CACHE-KILL: removed all old entries with age >= TTL [%d]", ttl) files_cache_logger.debug("FILES-CACHE-KILL: removed all current entries with newest cmtime %d", self._newest_cmtime) files_cache_logger.debug("FILES-CACHE-SAVE: finished, %d remaining entries saved.", entry_count) self.cache_config.integrity[files_cache_name()] = fd.integrity_data pi.output('Saving chunks cache') with IntegrityCheckedFile(path=os.path.join(self.path, 'chunks'), write=True) as fd: self.chunks.write(fd) self.cache_config.integrity['chunks'] = fd.integrity_data pi.output('Saving cache config') self.cache_config.save(self.manifest, self.key) os.rename(os.path.join(self.path, 'txn.active'), os.path.join(self.path, 'txn.tmp')) shutil.rmtree(os.path.join(self.path, 'txn.tmp')) self.txn_active = False pi.finish() def rollback(self): """Roll back partial and aborted transactions """ # Remove partial transaction if os.path.exists(os.path.join(self.path, 'txn.tmp')): shutil.rmtree(os.path.join(self.path, 'txn.tmp')) # Roll back active transaction txn_dir = os.path.join(self.path, 'txn.active') if os.path.exists(txn_dir): shutil.copy(os.path.join(txn_dir, 'config'), self.path) shutil.copy(os.path.join(txn_dir, 'chunks'), self.path) shutil.copy(os.path.join(txn_dir, discover_files_cache_name(txn_dir)), self.path) os.rename(txn_dir, os.path.join(self.path, 'txn.tmp')) if os.path.exists(os.path.join(self.path, 'txn.tmp')): shutil.rmtree(os.path.join(self.path, 'txn.tmp')) self.txn_active = False self._do_open() def sync(self): """Re-synchronize chunks cache with repository. Maintains a directory with known backup archive indexes, so it only needs to fetch infos from repo and build a chunk index once per backup archive. If out of sync, missing archive indexes get added, outdated indexes get removed and a new master chunks index is built by merging all archive indexes. """ archive_path = os.path.join(self.path, 'chunks.archive.d') # An index of chunks whose size had to be fetched chunks_fetched_size_index = ChunkIndex() # Instrumentation processed_item_metadata_bytes = 0 processed_item_metadata_chunks = 0 compact_chunks_archive_saved_space = 0 fetched_chunks_for_csize = 0 fetched_bytes_for_csize = 0 def mkpath(id, suffix=''): id_hex = bin_to_hex(id) path = os.path.join(archive_path, id_hex + suffix) return path def cached_archives(): if self.do_cache: fns = os.listdir(archive_path) # filenames with 64 hex digits == 256bit, # or compact indices which are 64 hex digits + ".compact" return set(unhexlify(fn) for fn in fns if len(fn) == 64) | \ set(unhexlify(fn[:64]) for fn in fns if len(fn) == 72 and fn.endswith('.compact')) else: return set() def repo_archives(): return set(info.id for info in self.manifest.archives.list()) def cleanup_outdated(ids): for id in ids: cleanup_cached_archive(id) def cleanup_cached_archive(id, cleanup_compact=True): try: os.unlink(mkpath(id)) os.unlink(mkpath(id) + '.integrity') except FileNotFoundError: pass if not cleanup_compact: return try: os.unlink(mkpath(id, suffix='.compact')) os.unlink(mkpath(id, suffix='.compact') + '.integrity') except FileNotFoundError: pass def fetch_missing_csize(chunk_idx): """ Archives created with AdHocCache will have csize=0 in all chunk list entries whose chunks were already in the repository. Scan *chunk_idx* for entries where csize=0 and fill in the correct information. """ nonlocal fetched_chunks_for_csize nonlocal fetched_bytes_for_csize all_missing_ids = chunk_idx.zero_csize_ids() fetch_ids = [] if len(chunks_fetched_size_index): for id_ in all_missing_ids: already_fetched_entry = chunks_fetched_size_index.get(id_) if already_fetched_entry: entry = chunk_idx[id_]._replace(csize=already_fetched_entry.csize) assert entry.size == already_fetched_entry.size, 'Chunk size mismatch' chunk_idx[id_] = entry else: fetch_ids.append(id_) else: fetch_ids = all_missing_ids # This is potentially a rather expensive operation, but it's hard to tell at this point # if it's a problem in practice (hence the experimental status of --no-cache-sync). for id_, data in zip(fetch_ids, decrypted_repository.repository.get_many(fetch_ids)): entry = chunk_idx[id_]._replace(csize=len(data)) chunk_idx[id_] = entry chunks_fetched_size_index[id_] = entry fetched_chunks_for_csize += 1 fetched_bytes_for_csize += len(data) def fetch_and_build_idx(archive_id, decrypted_repository, chunk_idx): nonlocal processed_item_metadata_bytes nonlocal processed_item_metadata_chunks csize, data = decrypted_repository.get(archive_id) chunk_idx.add(archive_id, 1, len(data), csize) archive, verified, _ = self.key.unpack_and_verify_archive(data, force_tam_not_required=True) archive = ArchiveItem(internal_dict=archive) if archive.version != 1: raise Exception('Unknown archive metadata version') sync = CacheSynchronizer(chunk_idx) for item_id, (csize, data) in zip(archive.items, decrypted_repository.get_many(archive.items)): chunk_idx.add(item_id, 1, len(data), csize) processed_item_metadata_bytes += len(data) processed_item_metadata_chunks += 1 sync.feed(data) if self.do_cache: fetch_missing_csize(chunk_idx) write_archive_index(archive_id, chunk_idx) def write_archive_index(archive_id, chunk_idx): nonlocal compact_chunks_archive_saved_space compact_chunks_archive_saved_space += chunk_idx.compact() fn = mkpath(archive_id, suffix='.compact') fn_tmp = mkpath(archive_id, suffix='.tmp') try: with DetachedIntegrityCheckedFile(path=fn_tmp, write=True, filename=bin_to_hex(archive_id) + '.compact') as fd: chunk_idx.write(fd) except Exception: safe_unlink(fn_tmp) else: os.rename(fn_tmp, fn) def read_archive_index(archive_id, archive_name): archive_chunk_idx_path = mkpath(archive_id) logger.info("Reading cached archive chunk index for %s ...", archive_name) try: try: # Attempt to load compact index first with DetachedIntegrityCheckedFile(path=archive_chunk_idx_path + '.compact', write=False) as fd: archive_chunk_idx = ChunkIndex.read(fd, permit_compact=True) # In case a non-compact index exists, delete it. cleanup_cached_archive(archive_id, cleanup_compact=False) # Compact index read - return index, no conversion necessary (below). return archive_chunk_idx except FileNotFoundError: # No compact index found, load non-compact index, and convert below. with DetachedIntegrityCheckedFile(path=archive_chunk_idx_path, write=False) as fd: archive_chunk_idx = ChunkIndex.read(fd) except FileIntegrityError as fie: logger.error('Cached archive chunk index of %s is corrupted: %s', archive_name, fie) # Delete corrupted index, set warning. A new index must be build. cleanup_cached_archive(archive_id) set_ec(EXIT_WARNING) return None # Convert to compact index. Delete the existing index first. logger.debug('Found non-compact index for %s, converting to compact.', archive_name) cleanup_cached_archive(archive_id) write_archive_index(archive_id, archive_chunk_idx) return archive_chunk_idx def get_archive_ids_to_names(archive_ids): # Pass once over all archives and build a mapping from ids to names. # The easier approach, doing a similar loop for each archive, has # square complexity and does about a dozen million functions calls # with 1100 archives (which takes 30s CPU seconds _alone_). archive_names = {} for info in self.manifest.archives.list(): if info.id in archive_ids: archive_names[info.id] = info.name assert len(archive_names) == len(archive_ids) return archive_names def create_master_idx(chunk_idx): logger.info('Synchronizing chunks cache...') cached_ids = cached_archives() archive_ids = repo_archives() logger.info('Archives: %d, w/ cached Idx: %d, w/ outdated Idx: %d, w/o cached Idx: %d.', len(archive_ids), len(cached_ids), len(cached_ids - archive_ids), len(archive_ids - cached_ids)) # deallocates old hashindex, creates empty hashindex: chunk_idx.clear() cleanup_outdated(cached_ids - archive_ids) # Explicitly set the initial hash table capacity to avoid performance issues # due to hash table "resonance". master_index_capacity = int(len(self.repository) / ChunkIndex.MAX_LOAD_FACTOR) if archive_ids: chunk_idx = None if not self.do_cache else ChunkIndex(master_index_capacity) pi = ProgressIndicatorPercent(total=len(archive_ids), step=0.1, msg='%3.0f%% Syncing chunks cache. Processing archive %s', msgid='cache.sync') archive_ids_to_names = get_archive_ids_to_names(archive_ids) for archive_id, archive_name in archive_ids_to_names.items(): pi.show(info=[remove_surrogates(archive_name)]) if self.do_cache: if archive_id in cached_ids: archive_chunk_idx = read_archive_index(archive_id, archive_name) if archive_chunk_idx is None: cached_ids.remove(archive_id) if archive_id not in cached_ids: # Do not make this an else branch; the FileIntegrityError exception handler # above can remove *archive_id* from *cached_ids*. logger.info('Fetching and building archive index for %s ...', archive_name) archive_chunk_idx = ChunkIndex() fetch_and_build_idx(archive_id, decrypted_repository, archive_chunk_idx) logger.info("Merging into master chunks index ...") chunk_idx.merge(archive_chunk_idx) else: chunk_idx = chunk_idx or ChunkIndex(master_index_capacity) logger.info('Fetching archive index for %s ...', archive_name) fetch_and_build_idx(archive_id, decrypted_repository, chunk_idx) if not self.do_cache: fetch_missing_csize(chunk_idx) pi.finish() logger.debug('Cache sync: had to fetch %s (%d chunks) because no archive had a csize set for them ' '(due to --no-cache-sync)', format_file_size(fetched_bytes_for_csize), fetched_chunks_for_csize) logger.debug('Cache sync: processed %s (%d chunks) of metadata', format_file_size(processed_item_metadata_bytes), processed_item_metadata_chunks) logger.debug('Cache sync: compact chunks.archive.d storage saved %s bytes', format_file_size(compact_chunks_archive_saved_space)) logger.info('Done.') return chunk_idx def legacy_cleanup(): """bring old cache dirs into the desired state (cleanup and adapt)""" try: os.unlink(os.path.join(self.path, 'chunks.archive')) except: pass try: os.unlink(os.path.join(self.path, 'chunks.archive.tmp')) except: pass try: os.mkdir(archive_path) except: pass # The cache can be used by a command that e.g. only checks against Manifest.Operation.WRITE, # which does not have to include all flags from Manifest.Operation.READ. # Since the sync will attempt to read archives, check compatibility with Manifest.Operation.READ. self.manifest.check_repository_compatibility((Manifest.Operation.READ, )) self.begin_txn() with cache_if_remote(self.repository, decrypted_cache=self.key) as decrypted_repository: legacy_cleanup() # TEMPORARY HACK: to avoid archive index caching, create a FILE named ~/.cache/borg/REPOID/chunks.archive.d - # this is only recommended if you have a fast, low latency connection to your repo (e.g. if repo is local disk) self.do_cache = os.path.isdir(archive_path) self.chunks = create_master_idx(self.chunks) def check_cache_compatibility(self): my_features = Manifest.SUPPORTED_REPO_FEATURES if self.cache_config.ignored_features & my_features: # The cache might not contain references of chunks that need a feature that is mandatory for some operation # and which this version supports. To avoid corruption while executing that operation force rebuild. return False if not self.cache_config.mandatory_features <= my_features: # The cache was build with consideration to at least one feature that this version does not understand. # This client might misinterpret the cache. Thus force a rebuild. return False return True def wipe_cache(self): logger.warning("Discarding incompatible cache and forcing a cache rebuild") archive_path = os.path.join(self.path, 'chunks.archive.d') if os.path.isdir(archive_path): shutil.rmtree(os.path.join(self.path, 'chunks.archive.d')) os.makedirs(os.path.join(self.path, 'chunks.archive.d')) self.chunks = ChunkIndex() with SaveFile(os.path.join(self.path, files_cache_name()), binary=True): pass # empty file self.cache_config.manifest_id = '' self.cache_config._config.set('cache', 'manifest', '') self.cache_config.ignored_features = set() self.cache_config.mandatory_features = set() def update_compatibility(self): operation_to_features_map = self.manifest.get_all_mandatory_features() my_features = Manifest.SUPPORTED_REPO_FEATURES repo_features = set() for operation, features in operation_to_features_map.items(): repo_features.update(features) self.cache_config.ignored_features.update(repo_features - my_features) self.cache_config.mandatory_features.update(repo_features & my_features) def add_chunk(self, id, chunk, stats, overwrite=False, wait=True): if not self.txn_active: self.begin_txn() size = len(chunk) refcount = self.seen_chunk(id, size) if refcount and not overwrite: return self.chunk_incref(id, stats) data = self.key.encrypt(chunk) csize = len(data) self.repository.put(id, data, wait=wait) self.chunks.add(id, 1, size, csize) stats.update(size, csize, not refcount) return ChunkListEntry(id, size, csize) def seen_chunk(self, id, size=None): refcount, stored_size, _ = self.chunks.get(id, ChunkIndexEntry(0, None, None)) if size is not None and stored_size is not None and size != stored_size: # we already have a chunk with that id, but different size. # this is either a hash collision (unlikely) or corruption or a bug. raise Exception("chunk has same id [%r], but different size (stored: %d new: %d)!" % ( id, stored_size, size)) return refcount def chunk_incref(self, id, stats, size=None): if not self.txn_active: self.begin_txn() count, _size, csize = self.chunks.incref(id) stats.update(_size, csize, False) return ChunkListEntry(id, _size, csize) def chunk_decref(self, id, stats, wait=True): if not self.txn_active: self.begin_txn() count, size, csize = self.chunks.decref(id) if count == 0: del self.chunks[id] self.repository.delete(id, wait=wait) stats.update(-size, -csize, True) else: stats.update(-size, -csize, False) def file_known_and_unchanged(self, hashed_path, path_hash, st): """ Check if we know the file that has this path_hash (know == it is in our files cache) and whether it is unchanged (the size/inode number/cmtime is same for stuff we check in this cache_mode). :param hashed_path: the file's path as we gave it to hash(hashed_path) :param path_hash: hash(hashed_path), to save some memory in the files cache :param st: the file's stat() result :return: known, ids (known is True if we have infos about this file in the cache, ids is the list of chunk ids IF the file has not changed, otherwise None). """ if not stat.S_ISREG(st.st_mode): return False, None cache_mode = self.cache_mode if 'd' in cache_mode: # d(isabled) files_cache_logger.debug('UNKNOWN: files cache disabled') return False, None # note: r(echunk) does not need the files cache in this method, but the files cache will # be updated and saved to disk to memorize the files. To preserve previous generations in # the cache, this means that it also needs to get loaded from disk first. if 'r' in cache_mode: # r(echunk) files_cache_logger.debug('UNKNOWN: rechunking enforced') return False, None entry = self.files.get(path_hash) if not entry: files_cache_logger.debug('UNKNOWN: no file metadata in cache for: %r', hashed_path) return False, None # we know the file! entry = FileCacheEntry(*msgpack.unpackb(entry)) if 's' in cache_mode and entry.size != st.st_size: files_cache_logger.debug('KNOWN-CHANGED: file size has changed: %r', hashed_path) return True, None if 'i' in cache_mode and entry.inode != st.st_ino: files_cache_logger.debug('KNOWN-CHANGED: file inode number has changed: %r', hashed_path) return True, None if 'c' in cache_mode and bigint_to_int(entry.cmtime) != st.st_ctime_ns: files_cache_logger.debug('KNOWN-CHANGED: file ctime has changed: %r', hashed_path) return True, None elif 'm' in cache_mode and bigint_to_int(entry.cmtime) != st.st_mtime_ns: files_cache_logger.debug('KNOWN-CHANGED: file mtime has changed: %r', hashed_path) return True, None # we ignored the inode number in the comparison above or it is still same. # if it is still the same, replacing it in the tuple doesn't change it. # if we ignored it, a reason for doing that is that files were moved to a new # disk / new fs (so a one-time change of inode number is expected) and we wanted # to avoid everything getting chunked again. to be able to re-enable the inode # number comparison in a future backup run (and avoid chunking everything # again at that time), we need to update the inode number in the cache with what # we see in the filesystem. self.files[path_hash] = msgpack.packb(entry._replace(inode=st.st_ino, age=0)) return True, entry.chunk_ids def memorize_file(self, hashed_path, path_hash, st, ids): if not stat.S_ISREG(st.st_mode): return cache_mode = self.cache_mode # note: r(echunk) modes will update the files cache, d(isabled) mode won't if 'd' in cache_mode: files_cache_logger.debug('FILES-CACHE-NOUPDATE: files cache disabled') return if 'c' in cache_mode: cmtime_type = 'ctime' cmtime_ns = safe_ns(st.st_ctime_ns) elif 'm' in cache_mode: cmtime_type = 'mtime' cmtime_ns = safe_ns(st.st_mtime_ns) entry = FileCacheEntry(age=0, inode=st.st_ino, size=st.st_size, cmtime=int_to_bigint(cmtime_ns), chunk_ids=ids) self.files[path_hash] = msgpack.packb(entry) self._newest_cmtime = max(self._newest_cmtime or 0, cmtime_ns) files_cache_logger.debug('FILES-CACHE-UPDATE: put %r [has %s] <- %r', entry._replace(chunk_ids='[%d entries]' % len(entry.chunk_ids)), cmtime_type, hashed_path) class AdHocCache(CacheStatsMixin): """ Ad-hoc, non-persistent cache. Compared to the standard LocalCache the AdHocCache does not maintain accurate reference count, nor does it provide a files cache (which would require persistence). Chunks that were not added during the current AdHocCache lifetime won't have correct size/csize set (0 bytes) and will have an infinite reference count (MAX_VALUE). """ str_format = """\ All archives: unknown unknown unknown Unique chunks Total chunks Chunk index: {0.total_unique_chunks:20d} unknown""" def __init__(self, repository, key, manifest, warn_if_unencrypted=True, lock_wait=None): self.repository = repository self.key = key self.manifest = manifest self._txn_active = False self.security_manager = SecurityManager(repository) self.security_manager.assert_secure(manifest, key, lock_wait=lock_wait) logger.warning('Note: --no-cache-sync is an experimental feature.') # Public API def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): pass files = None cache_mode = 'd' def file_known_and_unchanged(self, hashed_path, path_hash, st): files_cache_logger.debug("UNKNOWN: files cache not implemented") return False, None def memorize_file(self, hashed_path, path_hash, st, ids): pass def add_chunk(self, id, chunk, stats, overwrite=False, wait=True): assert not overwrite, 'AdHocCache does not permit overwrites — trying to use it for recreate?' if not self._txn_active: self._begin_txn() size = len(chunk) refcount = self.seen_chunk(id, size) if refcount: return self.chunk_incref(id, stats, size=size) data = self.key.encrypt(chunk) csize = len(data) self.repository.put(id, data, wait=wait) self.chunks.add(id, 1, size, csize) stats.update(size, csize, not refcount) return ChunkListEntry(id, size, csize) def seen_chunk(self, id, size=None): if not self._txn_active: self._begin_txn() entry = self.chunks.get(id, ChunkIndexEntry(0, None, None)) if entry.refcount and size and not entry.size: # The LocalCache has existing size information and uses *size* to make an effort at detecting collisions. # This is of course not possible for the AdHocCache. # Here *size* is used to update the chunk's size information, which will be zero for existing chunks. self.chunks[id] = entry._replace(size=size) return entry.refcount def chunk_incref(self, id, stats, size=None): if not self._txn_active: self._begin_txn() count, _size, csize = self.chunks.incref(id) # When _size is 0 and size is not given, then this chunk has not been locally visited yet (seen_chunk with # size or add_chunk); we can't add references to those (size=0 is invalid) and generally don't try to. size = _size or size assert size stats.update(size, csize, False) return ChunkListEntry(id, size, csize) def chunk_decref(self, id, stats, wait=True): if not self._txn_active: self._begin_txn() count, size, csize = self.chunks.decref(id) if count == 0: del self.chunks[id] self.repository.delete(id, wait=wait) stats.update(-size, -csize, True) else: stats.update(-size, -csize, False) def commit(self): if not self._txn_active: return self.security_manager.save(self.manifest, self.key) self._txn_active = False def rollback(self): self._txn_active = False del self.chunks # Private API def _begin_txn(self): self._txn_active = True # Explicitly set the initial hash table capacity to avoid performance issues # due to hash table "resonance". # Since we're creating an archive, add 10 % from the start. num_chunks = len(self.repository) capacity = int(num_chunks / ChunkIndex.MAX_LOAD_FACTOR * 1.1) self.chunks = ChunkIndex(capacity) pi = ProgressIndicatorPercent(total=num_chunks, msg='Downloading chunk list... %3.0f%%', msgid='cache.download_chunks') t0 = perf_counter() num_requests = 0 marker = None while True: result = self.repository.list(limit=LIST_SCAN_LIMIT, marker=marker) num_requests += 1 if not result: break pi.show(increase=len(result)) marker = result[-1] # All chunks from the repository have a refcount of MAX_VALUE, which is sticky, # therefore we can't/won't delete them. Chunks we added ourselves in this transaction # (e.g. checkpoint archives) are tracked correctly. init_entry = ChunkIndexEntry(refcount=ChunkIndex.MAX_VALUE, size=0, csize=0) for id_ in result: self.chunks[id_] = init_entry assert len(self.chunks) == num_chunks # LocalCache does not contain the manifest, either. del self.chunks[self.manifest.MANIFEST_ID] duration = perf_counter() - t0 or 0.01 pi.finish() logger.debug('AdHocCache: downloaded %d chunk IDs in %.2f s (%d requests), ~%s/s', num_chunks, duration, num_requests, format_file_size(num_chunks * 34 / duration)) # Chunk IDs in a list are encoded in 34 bytes: 1 byte msgpack header, 1 byte length, 32 ID bytes. # Protocol overhead is neglected in this calculation.