class Remote:
"""Cloud remote class.
Provides methods for indexing and garbage collecting trees which contain
DVC remotes.
"""
INDEX_CLS = RemoteIndex
def __init__(self, tree):
self.tree = tree
self.repo = tree.repo
config = tree.config
url = config.get("url")
if url:
index_name = hashlib.sha256(url.encode("utf-8")).hexdigest()
self.index = self.INDEX_CLS(
self.repo,
index_name,
dir_suffix=self.tree.CHECKSUM_DIR_SUFFIX)
else:
self.index = RemoteIndexNoop()
@property
def path_info(self):
return self.tree.path_info
def __repr__(self):
return "{class_name}: '{path_info}'".format(
class_name=type(self).__name__,
path_info=self.path_info or "No path",
)
@property
def cache(self):
return getattr(self.repo.cache, self.scheme)
@property
def scheme(self):
return self.tree.scheme
def is_dir_hash(self, hash_):
return self.tree.is_dir_hash(hash_)
def get_hash(self, path_info, **kwargs):
return self.tree.get_hash(path_info, **kwargs)
def hash_to_path_info(self, hash_):
return self.tree.hash_to_path_info(hash_)
def path_to_hash(self, path):
return self.tree.path_to_hash(path)
def save_info(self, path_info, **kwargs):
return self.tree.save_info(path_info, **kwargs)
def open(self, *args, **kwargs):
return self.tree.open(*args, **kwargs)
def hashes_exist(self, hashes, jobs=None, name=None):
"""Check if the given hashes are stored in the remote.
There are two ways of performing this check:
- Traverse method: Get a list of all the files in the remote
(traversing the cache directory) and compare it with
the given hashes. Cache entries will be retrieved in parallel
threads according to prefix (i.e. entries starting with, "00...",
"01...", and so on) and a progress bar will be displayed.
- Exists method: For each given hash, run the `exists`
method and filter the hashes that aren't on the remote.
This is done in parallel threads.
It also shows a progress bar when performing the check.
The reason for such an odd logic is that most of the remotes
take much shorter time to just retrieve everything they have under
a certain prefix (e.g. s3, gs, ssh, hdfs). Other remotes that can
check if particular file exists much quicker, use their own
implementation of hashes_exist (see ssh, local).
Which method to use will be automatically determined after estimating
the size of the remote cache, and comparing the estimated size with
len(hashes). To estimate the size of the remote cache, we fetch
a small subset of cache entries (i.e. entries starting with "00...").
Based on the number of entries in that subset, the size of the full
cache can be estimated, since the cache is evenly distributed according
to hash.
Returns:
A list with hashes that were found in the remote
"""
# Remotes which do not use traverse prefix should override
# hashes_exist() (see ssh, local)
assert self.tree.TRAVERSE_PREFIX_LEN >= 2
hashes = set(hashes)
indexed_hashes = set(self.index.intersection(hashes))
hashes -= indexed_hashes
logger.debug("Matched '{}' indexed hashes".format(len(indexed_hashes)))
if not hashes:
return indexed_hashes
if len(hashes) == 1 or not self.tree.CAN_TRAVERSE:
remote_hashes = self.tree.list_hashes_exists(hashes, jobs, name)
return list(indexed_hashes) + remote_hashes
# Max remote size allowed for us to use traverse method
remote_size, remote_hashes = self.tree.estimate_remote_size(
hashes, name)
traverse_pages = remote_size / self.tree.LIST_OBJECT_PAGE_SIZE
# For sufficiently large remotes, traverse must be weighted to account
# for performance overhead from large lists/sets.
# From testing with S3, for remotes with 1M+ files, object_exists is
# faster until len(hashes) is at least 10k~100k
if remote_size > self.tree.TRAVERSE_THRESHOLD_SIZE:
traverse_weight = (traverse_pages *
self.tree.TRAVERSE_WEIGHT_MULTIPLIER)
else:
traverse_weight = traverse_pages
if len(hashes) < traverse_weight:
logger.debug("Large remote ('{}' hashes < '{}' traverse weight), "
"using object_exists for remaining hashes".format(
len(hashes), traverse_weight))
return (list(indexed_hashes) + list(hashes & remote_hashes) +
self.tree.list_hashes_exists(hashes - remote_hashes, jobs,
name))
logger.debug("Querying '{}' hashes via traverse".format(len(hashes)))
remote_hashes = set(
self.tree.list_hashes_traverse(remote_size, remote_hashes, jobs,
name))
return list(indexed_hashes) + list(hashes & set(remote_hashes))
@classmethod
@index_locked
def gc(cls, named_cache, remote, jobs=None):
tree = remote.tree
used = set(named_cache.scheme_keys("local"))
if tree.scheme != "":
used.update(named_cache.scheme_keys(tree.scheme))
removed = False
# hashes must be sorted to ensure we always remove .dir files first
for hash_ in sorted(
tree.all(jobs, str(tree.path_info)),
key=tree.is_dir_hash,
reverse=True,
):
if hash_ in used:
continue
path_info = tree.hash_to_path_info(hash_)
if tree.is_dir_hash(hash_):
# backward compatibility
tree._remove_unpacked_dir(hash_)
tree.remove(path_info)
removed = True
if removed and hasattr(remote, "index"):
remote.index.clear()
return removed
class BaseRemote:
scheme = "base"
path_cls = URLInfo
REQUIRES = {}
JOBS = 4 * cpu_count()
INDEX_CLS = RemoteIndex
PARAM_RELPATH = "relpath"
CHECKSUM_DIR_SUFFIX = ".dir"
CHECKSUM_JOBS = max(1, min(4, cpu_count() // 2))
DEFAULT_CACHE_TYPES = ["copy"]
DEFAULT_VERIFY = False
LIST_OBJECT_PAGE_SIZE = 1000
TRAVERSE_WEIGHT_MULTIPLIER = 5
TRAVERSE_PREFIX_LEN = 3
TRAVERSE_THRESHOLD_SIZE = 500000
CAN_TRAVERSE = True
CACHE_MODE = None
SHARED_MODE_MAP = {None: (None, None), "group": (None, None)}
state = StateNoop()
def __init__(self, repo, config):
self.repo = repo
self._check_requires(config)
shared = config.get("shared")
self._file_mode, self._dir_mode = self.SHARED_MODE_MAP[shared]
self.checksum_jobs = (
config.get("checksum_jobs")
or (self.repo and self.repo.config["core"].get("checksum_jobs"))
or self.CHECKSUM_JOBS)
self.verify = config.get("verify", self.DEFAULT_VERIFY)
self._dir_info = {}
self.cache_types = config.get("type") or copy(self.DEFAULT_CACHE_TYPES)
self.cache_type_confirmed = False
url = config.get("url")
if url:
index_name = hashlib.sha256(url.encode("utf-8")).hexdigest()
self.index = self.INDEX_CLS(self.repo,
index_name,
dir_suffix=self.CHECKSUM_DIR_SUFFIX)
else:
self.index = RemoteIndexNoop()
@classmethod
def get_missing_deps(cls):
import importlib
missing = []
for package, module in cls.REQUIRES.items():
try:
importlib.import_module(module)
except ImportError:
missing.append(package)
return missing
def _check_requires(self, config):
missing = self.get_missing_deps()
if not missing:
return
url = config.get("url", f"{self.scheme}://")
msg = ("URL '{}' is supported but requires these missing "
"dependencies: {}. If you have installed dvc using pip, "
"choose one of these options to proceed: \n"
"\n"
" 1) Install specific missing dependencies:\n"
" pip install {}\n"
" 2) Install dvc package that includes those missing "
"dependencies: \n"
" pip install 'dvc[{}]'\n"
" 3) Install dvc package with all possible "
"dependencies included: \n"
" pip install 'dvc[all]'\n"
"\n"
"If you have installed dvc from a binary package and you "
"are still seeing this message, please report it to us "
"using https://github.com/iterative/dvc/issues. Thank you!"
).format(url, missing, " ".join(missing), self.scheme)
raise RemoteMissingDepsError(msg)
def __repr__(self):
return "{class_name}: '{path_info}'".format(
class_name=type(self).__name__,
path_info=self.path_info or "No path",
)
@classmethod
def supported(cls, config):
if isinstance(config, (str, bytes)):
url = config
else:
url = config["url"]
# NOTE: silently skipping remote, calling code should handle that
parsed = urlparse(url)
return parsed.scheme == cls.scheme
@property
def cache(self):
return getattr(self.repo.cache, self.scheme)
def get_file_checksum(self, path_info):
raise NotImplementedError
def _calculate_checksums(self, file_infos):
file_infos = list(file_infos)
with Tqdm(
total=len(file_infos),
unit="md5",
desc="Computing file/dir hashes (only done once)",
) as pbar:
worker = pbar.wrap_fn(self.get_file_checksum)
with ThreadPoolExecutor(
max_workers=self.checksum_jobs) as executor:
tasks = executor.map(worker, file_infos)
checksums = dict(zip(file_infos, tasks))
return checksums
def _collect_dir(self, path_info):
file_infos = set()
for fname in self.walk_files(path_info):
if DvcIgnore.DVCIGNORE_FILE == fname.name:
raise DvcIgnoreInCollectedDirError(fname.parent)
file_infos.add(fname)
checksums = {fi: self.state.get(fi) for fi in file_infos}
not_in_state = {
fi
for fi, checksum in checksums.items() if checksum is None
}
new_checksums = self._calculate_checksums(not_in_state)
checksums.update(new_checksums)
result = [
{
self.PARAM_CHECKSUM:
checksums[fi],
# NOTE: this is lossy transformation:
# "hey\there" -> "hey/there"
# "hey/there" -> "hey/there"
# The latter is fine filename on Windows, which
# will transform to dir/file on back transform.
#
# Yes, this is a BUG, as long as we permit "/" in
# filenames on Windows and "\" on Unix
self.PARAM_RELPATH:
fi.relative_to(path_info).as_posix(),
} for fi in file_infos
]
# Sorting the list by path to ensure reproducibility
return sorted(result, key=itemgetter(self.PARAM_RELPATH))
def get_dir_checksum(self, path_info):
if not self.cache:
raise RemoteCacheRequiredError(path_info)
dir_info = self._collect_dir(path_info)
return self._save_dir_info(dir_info, path_info)
def _save_dir_info(self, dir_info, path_info=None):
checksum, tmp_info = self._get_dir_info_checksum(dir_info)
new_info = self.cache.checksum_to_path_info(checksum)
if self.cache.changed_cache_file(checksum):
self.cache.makedirs(new_info.parent)
self.cache.move(tmp_info, new_info, mode=self.CACHE_MODE)
if path_info:
self.state.save(path_info, checksum)
self.state.save(new_info, checksum)
return checksum
def _get_dir_info_checksum(self, dir_info):
tmp = tempfile.NamedTemporaryFile(delete=False).name
with open(tmp, "w+") as fobj:
json.dump(dir_info, fobj, sort_keys=True)
from_info = PathInfo(tmp)
to_info = self.cache.path_info / tmp_fname("")
self.cache.upload(from_info, to_info, no_progress_bar=True)
checksum = self.get_file_checksum(to_info) + self.CHECKSUM_DIR_SUFFIX
return checksum, to_info
def get_dir_cache(self, checksum):
assert checksum
dir_info = self._dir_info.get(checksum)
if dir_info:
return dir_info
try:
dir_info = self.load_dir_cache(checksum)
except DirCacheError:
dir_info = []
self._dir_info[checksum] = dir_info
return dir_info
def load_dir_cache(self, checksum):
path_info = self.checksum_to_path_info(checksum)
try:
with self.cache.open(path_info, "r") as fobj:
d = json.load(fobj)
except (ValueError, FileNotFoundError) as exc:
raise DirCacheError(checksum) from exc
if not isinstance(d, list):
logger.error(
"dir cache file format error '%s' [skipping the file]",
path_info,
)
return []
if self.path_cls == WindowsPathInfo:
# only need to convert it for Windows
for info in d:
# NOTE: here is a BUG, see comment to .as_posix() below
info[self.PARAM_RELPATH] = info[self.PARAM_RELPATH].replace(
"/", self.path_cls.sep)
return d
@classmethod
def is_dir_checksum(cls, checksum):
if not checksum:
return False
return checksum.endswith(cls.CHECKSUM_DIR_SUFFIX)
def get_checksum(self, path_info):
assert isinstance(path_info, str) or path_info.scheme == self.scheme
if not self.exists(path_info):
return None
checksum = self.state.get(path_info)
# If we have dir checksum in state db, but dir cache file is lost,
# then we need to recollect the dir via .get_dir_checksum() call below,
# see https://github.com/iterative/dvc/issues/2219 for context
if (checksum and self.is_dir_checksum(checksum) and
not self.exists(self.cache.checksum_to_path_info(checksum))):
checksum = None
if checksum:
return checksum
if self.isdir(path_info):
checksum = self.get_dir_checksum(path_info)
else:
checksum = self.get_file_checksum(path_info)
if checksum:
self.state.save(path_info, checksum)
return checksum
def save_info(self, path_info):
return {self.PARAM_CHECKSUM: self.get_checksum(path_info)}
def changed(self, path_info, checksum_info):
"""Checks if data has changed.
A file is considered changed if:
- It doesn't exist on the working directory (was unlinked)
- Hash value is not computed (saving a new file)
- The hash value stored is different from the given one
- There's no file in the cache
Args:
path_info: dict with path information.
checksum: expected hash value for this data.
Returns:
bool: True if data has changed, False otherwise.
"""
logger.debug("checking if '%s'('%s') has changed.", path_info,
checksum_info)
if not self.exists(path_info):
logger.debug("'%s' doesn't exist.", path_info)
return True
checksum = checksum_info.get(self.PARAM_CHECKSUM)
if checksum is None:
logger.debug("hash value for '%s' is missing.", path_info)
return True
if self.changed_cache(checksum):
logger.debug("cache for '%s'('%s') has changed.", path_info,
checksum)
return True
actual = self.get_checksum(path_info)
if checksum != actual:
logger.debug(
"hash value '%s' for '%s' has changed (actual '%s').",
checksum,
actual,
path_info,
)
return True
logger.debug("'%s' hasn't changed.", path_info)
return False
def link(self, from_info, to_info):
self._link(from_info, to_info, self.cache_types)
def _link(self, from_info, to_info, link_types):
assert self.isfile(from_info)
self.makedirs(to_info.parent)
self._try_links(from_info, to_info, link_types)
def _verify_link(self, path_info, link_type):
if self.cache_type_confirmed:
return
is_link = getattr(self, f"is_{link_type}", None)
if is_link and not is_link(path_info):
self.remove(path_info)
raise DvcException(f"failed to verify {link_type}")
self.cache_type_confirmed = True
@slow_link_guard
def _try_links(self, from_info, to_info, link_types):
while link_types:
link_method = getattr(self, link_types[0])
try:
self._do_link(from_info, to_info, link_method)
self._verify_link(to_info, link_types[0])
return
except DvcException as exc:
logger.debug("Cache type '%s' is not supported: %s",
link_types[0], exc)
del link_types[0]
raise DvcException("no possible cache types left to try out.")
def _do_link(self, from_info, to_info, link_method):
if self.exists(to_info):
raise DvcException(f"Link '{to_info}' already exists!")
link_method(from_info, to_info)
logger.debug(
"Created '%s': %s -> %s",
self.cache_types[0],
from_info,
to_info,
)
def _save_file(self, path_info, checksum, save_link=True, tree=None):
assert checksum
cache_info = self.checksum_to_path_info(checksum)
if tree:
if self.changed_cache(checksum):
with tree.open(path_info, mode="rb") as fobj:
self.copy_fobj(fobj, cache_info)
else:
if self.changed_cache(checksum):
self.move(path_info, cache_info, mode=self.CACHE_MODE)
self.link(cache_info, path_info)
elif self.iscopy(path_info) and self._cache_is_copy(path_info):
# Default relink procedure involves unneeded copy
self.unprotect(path_info)
else:
self.remove(path_info)
self.link(cache_info, path_info)
if save_link:
self.state.save_link(path_info)
# we need to update path and cache, since in case of reflink,
# or copy cache type moving original file results in updates on
# next executed command, which causes md5 recalculation
if not tree or is_working_tree(tree):
self.state.save(path_info, checksum)
self.state.save(cache_info, checksum)
def _cache_is_copy(self, path_info):
"""Checks whether cache uses copies."""
if self.cache_type_confirmed:
return self.cache_types[0] == "copy"
if set(self.cache_types) <= {"copy"}:
return True
workspace_file = path_info.with_name("." + uuid())
test_cache_file = self.path_info / ".cache_type_test_file"
if not self.exists(test_cache_file):
with self.open(test_cache_file, "wb") as fobj:
fobj.write(bytes(1))
try:
self.link(test_cache_file, workspace_file)
finally:
self.remove(workspace_file)
self.remove(test_cache_file)
self.cache_type_confirmed = True
return self.cache_types[0] == "copy"
def _save_dir(self, path_info, checksum, save_link=True, tree=None):
if tree:
checksum = self._save_tree(path_info, tree)
else:
dir_info = self.get_dir_cache(checksum)
for entry in Tqdm(dir_info,
desc="Saving " + path_info.name,
unit="file"):
entry_info = path_info / entry[self.PARAM_RELPATH]
entry_checksum = entry[self.PARAM_CHECKSUM]
self._save_file(entry_info, entry_checksum, save_link=False)
if save_link:
self.state.save_link(path_info)
cache_info = self.checksum_to_path_info(checksum)
self.state.save(cache_info, checksum)
if not tree or is_working_tree(tree):
self.state.save(path_info, checksum)
def _save_tree(self, path_info, tree):
# save tree directory to cache, collect dir cache during walk and
# return the resulting dir checksum
dir_info = []
for fname in tree.walk_files(path_info):
checksum = tree.get_file_checksum(fname)
file_info = {
self.PARAM_CHECKSUM: checksum,
self.PARAM_RELPATH: fname.relative_to(path_info).as_posix(),
}
self._save_file(fname, checksum, tree=tree)
dir_info.append(file_info)
return self._save_dir_info(
sorted(dir_info, key=itemgetter(self.PARAM_RELPATH)))
def is_empty(self, path_info):
return False
def isfile(self, path_info):
"""Optional: Overwrite only if the remote has a way to distinguish
between a directory and a file.
"""
return True
def isdir(self, path_info):
"""Optional: Overwrite only if the remote has a way to distinguish
between a directory and a file.
"""
return False
def iscopy(self, path_info):
"""Check if this file is an independent copy."""
return False # We can't be sure by default
def walk_files(self, path_info):
"""Return a generator with `PathInfo`s to all the files"""
raise NotImplementedError
@staticmethod
def protect(path_info):
pass
def save(self, path_info, checksum_info, save_link=True, tree=None):
if path_info.scheme != self.scheme:
raise RemoteActionNotImplemented(
f"save {path_info.scheme} -> {self.scheme}",
self.scheme,
)
if tree:
# save checksum will be computed during tree walk
checksum = None
else:
checksum = checksum_info[self.PARAM_CHECKSUM]
self._save(path_info, checksum, save_link, tree)
def _save(self, path_info, checksum, save_link=True, tree=None):
if tree:
logger.debug("Saving tree path '%s' to cache.", path_info)
else:
to_info = self.checksum_to_path_info(checksum)
logger.debug("Saving '%s' to '%s'.", path_info, to_info)
if tree:
isdir = tree.isdir
save_link = False
else:
isdir = self.isdir
if isdir(path_info):
self._save_dir(path_info, checksum, save_link, tree)
return
self._save_file(path_info, checksum, save_link, tree)
def _handle_transfer_exception(self, from_info, to_info, exception,
operation):
if isinstance(exception, OSError) and exception.errno == errno.EMFILE:
raise exception
logger.exception("failed to %s '%s' to '%s'", operation, from_info,
to_info)
return 1
def upload(self, from_info, to_info, name=None, no_progress_bar=False):
if not hasattr(self, "_upload"):
raise RemoteActionNotImplemented("upload", self.scheme)
if to_info.scheme != self.scheme:
raise NotImplementedError
if from_info.scheme != "local":
raise NotImplementedError
logger.debug("Uploading '%s' to '%s'", from_info, to_info)
name = name or from_info.name
try:
self._upload(
from_info.fspath,
to_info,
name=name,
no_progress_bar=no_progress_bar,
)
except Exception as e:
return self._handle_transfer_exception(from_info, to_info, e,
"upload")
return 0
def download(
self,
from_info,
to_info,
name=None,
no_progress_bar=False,
file_mode=None,
dir_mode=None,
):
if not hasattr(self, "_download"):
raise RemoteActionNotImplemented("download", self.scheme)
if from_info.scheme != self.scheme:
raise NotImplementedError
if to_info.scheme == self.scheme != "local":
self.copy(from_info, to_info)
return 0
if to_info.scheme != "local":
raise NotImplementedError
if self.isdir(from_info):
return self._download_dir(from_info, to_info, name,
no_progress_bar, file_mode, dir_mode)
return self._download_file(from_info, to_info, name, no_progress_bar,
file_mode, dir_mode)
def _download_dir(self, from_info, to_info, name, no_progress_bar,
file_mode, dir_mode):
from_infos = list(self.walk_files(from_info))
to_infos = (to_info / info.relative_to(from_info)
for info in from_infos)
with Tqdm(
total=len(from_infos),
desc="Downloading directory",
unit="Files",
disable=no_progress_bar,
) as pbar:
download_files = pbar.wrap_fn(
partial(
self._download_file,
name=name,
no_progress_bar=True,
file_mode=file_mode,
dir_mode=dir_mode,
))
with ThreadPoolExecutor(max_workers=self.JOBS) as executor:
futures = executor.map(download_files, from_infos, to_infos)
return sum(futures)
def _download_file(self, from_info, to_info, name, no_progress_bar,
file_mode, dir_mode):
makedirs(to_info.parent, exist_ok=True, mode=dir_mode)
logger.debug("Downloading '%s' to '%s'", from_info, to_info)
name = name or to_info.name
tmp_file = tmp_fname(to_info)
try:
self._download(from_info,
tmp_file,
name=name,
no_progress_bar=no_progress_bar)
except Exception as e:
return self._handle_transfer_exception(from_info, to_info, e,
"download")
move(tmp_file, to_info, mode=file_mode)
return 0
def open(self, path_info, mode="r", encoding=None):
if hasattr(self, "_generate_download_url"):
get_url = partial(self._generate_download_url, path_info)
return open_url(get_url, mode=mode, encoding=encoding)
raise RemoteActionNotImplemented("open", self.scheme)
def remove(self, path_info):
raise RemoteActionNotImplemented("remove", self.scheme)
def move(self, from_info, to_info, mode=None):
assert mode is None
self.copy(from_info, to_info)
self.remove(from_info)
def copy(self, from_info, to_info):
raise RemoteActionNotImplemented("copy", self.scheme)
def copy_fobj(self, fobj, to_info):
raise RemoteActionNotImplemented("copy_fobj", self.scheme)
def symlink(self, from_info, to_info):
raise RemoteActionNotImplemented("symlink", self.scheme)
def hardlink(self, from_info, to_info):
raise RemoteActionNotImplemented("hardlink", self.scheme)
def reflink(self, from_info, to_info):
raise RemoteActionNotImplemented("reflink", self.scheme)
def exists(self, path_info):
raise NotImplementedError
def path_to_checksum(self, path):
parts = self.path_cls(path).parts[-2:]
if not (len(parts) == 2 and parts[0] and len(parts[0]) == 2):
raise ValueError(f"Bad cache file path '{path}'")
return "".join(parts)
def checksum_to_path_info(self, checksum):
return self.path_info / checksum[0:2] / checksum[2:]
# Return path as a string instead of PathInfo for remotes which support
# string paths (see local)
checksum_to_path = checksum_to_path_info
def list_cache_paths(self, prefix=None, progress_callback=None):
raise NotImplementedError
def cache_checksums(self, prefix=None, progress_callback=None):
"""Iterate over remote cache checksums.
If `prefix` is specified, only checksums which begin with `prefix`
will be returned.
"""
for path in self.list_cache_paths(prefix, progress_callback):
try:
yield self.path_to_checksum(path)
except ValueError:
logger.debug("'%s' doesn't look like a cache file, skipping",
path)
def all(self, jobs=None, name=None):
"""Iterate over all checksums in the remote cache.
Checksums will be fetched in parallel threads according to prefix
(except for small remotes) and a progress bar will be displayed.
"""
logger.debug("Fetching all checksums from '{}'".format(
name if name else "remote cache"))
if not self.CAN_TRAVERSE:
return self.cache_checksums()
remote_size, remote_checksums = self._estimate_cache_size(name=name)
return self._cache_checksums_traverse(remote_size, remote_checksums,
jobs, name)
@index_locked
def gc(self, named_cache, jobs=None):
used = self.extract_used_local_checksums(named_cache)
if self.scheme != "":
used.update(named_cache.scheme_keys(self.scheme))
removed = False
# checksums must be sorted to ensure we always remove .dir files first
for checksum in sorted(
self.all(jobs, str(self.path_info)),
key=self.is_dir_checksum,
reverse=True,
):
if checksum in used:
continue
path_info = self.checksum_to_path_info(checksum)
if self.is_dir_checksum(checksum):
self._remove_unpacked_dir(checksum)
self.remove(path_info)
removed = True
if removed:
self.index.clear()
return removed
def is_protected(self, path_info):
return False
def changed_cache_file(self, checksum):
"""Compare the given checksum with the (corresponding) actual one.
- Use `State` as a cache for computed checksums
+ The entries are invalidated by taking into account the following:
* mtime
* inode
* size
* checksum
- Remove the file from cache if it doesn't match the actual checksum
"""
# Prefer string path over PathInfo when possible due to performance
cache_info = self.checksum_to_path(checksum)
if self.is_protected(cache_info):
logger.debug("Assuming '%s' is unchanged since it is read-only",
cache_info)
return False
actual = self.get_checksum(cache_info)
logger.debug(
"cache '%s' expected '%s' actual '%s'",
cache_info,
checksum,
actual,
)
if not checksum or not actual:
return True
if actual.split(".")[0] == checksum.split(".")[0]:
# making cache file read-only so we don't need to check it
# next time
self.protect(cache_info)
return False
if self.exists(cache_info):
logger.warning("corrupted cache file '%s'.", cache_info)
self.remove(cache_info)
return True
def _changed_dir_cache(self, checksum, path_info=None, filter_info=None):
if self.changed_cache_file(checksum):
return True
if not (path_info
and filter_info) and not self._changed_unpacked_dir(checksum):
return False
for entry in self.get_dir_cache(checksum):
entry_checksum = entry[self.PARAM_CHECKSUM]
if path_info and filter_info:
entry_info = path_info / entry[self.PARAM_RELPATH]
if not entry_info.isin_or_eq(filter_info):
continue
if self.changed_cache_file(entry_checksum):
return True
if not (path_info and filter_info):
self._update_unpacked_dir(checksum)
return False
def changed_cache(self, checksum, path_info=None, filter_info=None):
if self.is_dir_checksum(checksum):
return self._changed_dir_cache(checksum,
path_info=path_info,
filter_info=filter_info)
return self.changed_cache_file(checksum)
def cache_exists(self, checksums, jobs=None, name=None):
"""Check if the given checksums are stored in the remote.
There are two ways of performing this check:
- Traverse method: Get a list of all the files in the remote
(traversing the cache directory) and compare it with
the given checksums. Cache entries will be retrieved in parallel
threads according to prefix (i.e. entries starting with, "00...",
"01...", and so on) and a progress bar will be displayed.
- Exists method: For each given checksum, run the `exists`
method and filter the checksums that aren't on the remote.
This is done in parallel threads.
It also shows a progress bar when performing the check.
The reason for such an odd logic is that most of the remotes
take much shorter time to just retrieve everything they have under
a certain prefix (e.g. s3, gs, ssh, hdfs). Other remotes that can
check if particular file exists much quicker, use their own
implementation of cache_exists (see ssh, local).
Which method to use will be automatically determined after estimating
the size of the remote cache, and comparing the estimated size with
len(checksums). To estimate the size of the remote cache, we fetch
a small subset of cache entries (i.e. entries starting with "00...").
Based on the number of entries in that subset, the size of the full
cache can be estimated, since the cache is evenly distributed according
to checksum.
Returns:
A list with checksums that were found in the remote
"""
# Remotes which do not use traverse prefix should override
# cache_exists() (see ssh, local)
assert self.TRAVERSE_PREFIX_LEN >= 2
checksums = set(checksums)
indexed_checksums = set(self.index.intersection(checksums))
checksums -= indexed_checksums
logger.debug("Matched '{}' indexed checksums".format(
len(indexed_checksums)))
if not checksums:
return indexed_checksums
if len(checksums) == 1 or not self.CAN_TRAVERSE:
remote_checksums = self._cache_object_exists(checksums, jobs, name)
return list(indexed_checksums) + remote_checksums
# Max remote size allowed for us to use traverse method
remote_size, remote_checksums = self._estimate_cache_size(
checksums, name)
traverse_pages = remote_size / self.LIST_OBJECT_PAGE_SIZE
# For sufficiently large remotes, traverse must be weighted to account
# for performance overhead from large lists/sets.
# From testing with S3, for remotes with 1M+ files, object_exists is
# faster until len(checksums) is at least 10k~100k
if remote_size > self.TRAVERSE_THRESHOLD_SIZE:
traverse_weight = traverse_pages * self.TRAVERSE_WEIGHT_MULTIPLIER
else:
traverse_weight = traverse_pages
if len(checksums) < traverse_weight:
logger.debug(
"Large remote ('{}' checksums < '{}' traverse weight), "
"using object_exists for remaining checksums".format(
len(checksums), traverse_weight))
return (list(indexed_checksums) +
list(checksums & remote_checksums) +
self._cache_object_exists(checksums - remote_checksums,
jobs, name))
logger.debug("Querying '{}' checksums via traverse".format(
len(checksums)))
remote_checksums = set(
self._cache_checksums_traverse(remote_size, remote_checksums, jobs,
name))
return list(indexed_checksums) + list(checksums
& set(remote_checksums))
def _checksums_with_limit(self,
limit,
prefix=None,
progress_callback=None):
count = 0
for checksum in self.cache_checksums(prefix, progress_callback):
yield checksum
count += 1
if count > limit:
logger.debug(
"`cache_checksums()` returned max '{}' checksums, "
"skipping remaining results".format(limit))
return
def _max_estimation_size(self, checksums):
# Max remote size allowed for us to use traverse method
return max(
self.TRAVERSE_THRESHOLD_SIZE,
len(checksums) / self.TRAVERSE_WEIGHT_MULTIPLIER *
self.LIST_OBJECT_PAGE_SIZE,
)
def _estimate_cache_size(self, checksums=None, name=None):
"""Estimate remote cache size based on number of entries beginning with
"00..." prefix.
"""
prefix = "0" * self.TRAVERSE_PREFIX_LEN
total_prefixes = pow(16, self.TRAVERSE_PREFIX_LEN)
if checksums:
max_checksums = self._max_estimation_size(checksums)
else:
max_checksums = None
with Tqdm(
desc="Estimating size of " +
(f"cache in '{name}'" if name else "remote cache"),
unit="file",
) as pbar:
def update(n=1):
pbar.update(n * total_prefixes)
if max_checksums:
checksums = self._checksums_with_limit(
max_checksums / total_prefixes, prefix, update)
else:
checksums = self.cache_checksums(prefix, update)
remote_checksums = set(checksums)
if remote_checksums:
remote_size = total_prefixes * len(remote_checksums)
else:
remote_size = total_prefixes
logger.debug(f"Estimated remote size: {remote_size} files")
return remote_size, remote_checksums
def _cache_checksums_traverse(self,
remote_size,
remote_checksums,
jobs=None,
name=None):
"""Iterate over all checksums in the remote cache.
Checksums are fetched in parallel according to prefix, except in
cases where the remote size is very small.
All checksums from the remote (including any from the size
estimation step passed via the `remote_checksums` argument) will be
returned.
NOTE: For large remotes the list of checksums will be very
big(e.g. 100M entries, md5 for each is 32 bytes, so ~3200Mb list)
and we don't really need all of it at the same time, so it makes
sense to use a generator to gradually iterate over it, without
keeping all of it in memory.
"""
num_pages = remote_size / self.LIST_OBJECT_PAGE_SIZE
if num_pages < 256 / self.JOBS:
# Fetching prefixes in parallel requires at least 255 more
# requests, for small enough remotes it will be faster to fetch
# entire cache without splitting it into prefixes.
#
# NOTE: this ends up re-fetching checksums that were already
# fetched during remote size estimation
traverse_prefixes = [None]
initial = 0
else:
yield from remote_checksums
initial = len(remote_checksums)
traverse_prefixes = [f"{i:02x}" for i in range(1, 256)]
if self.TRAVERSE_PREFIX_LEN > 2:
traverse_prefixes += [
"{0:0{1}x}".format(i, self.TRAVERSE_PREFIX_LEN)
for i in range(1, pow(16, self.TRAVERSE_PREFIX_LEN - 2))
]
with Tqdm(
desc="Querying " +
(f"cache in '{name}'" if name else "remote cache"),
total=remote_size,
initial=initial,
unit="file",
) as pbar:
def list_with_update(prefix):
return list(
self.cache_checksums(prefix=prefix,
progress_callback=pbar.update))
with ThreadPoolExecutor(max_workers=jobs or self.JOBS) as executor:
in_remote = executor.map(
list_with_update,
traverse_prefixes,
)
yield from itertools.chain.from_iterable(in_remote)
def _cache_object_exists(self, checksums, jobs=None, name=None):
logger.debug("Querying {} checksums via object_exists".format(
len(checksums)))
with Tqdm(
desc="Querying " +
("cache in " + name if name else "remote cache"),
total=len(checksums),
unit="file",
) as pbar:
def exists_with_progress(path_info):
ret = self.exists(path_info)
pbar.update_msg(str(path_info))
return ret
with ThreadPoolExecutor(max_workers=jobs or self.JOBS) as executor:
path_infos = map(self.checksum_to_path_info, checksums)
in_remote = executor.map(exists_with_progress, path_infos)
ret = list(itertools.compress(checksums, in_remote))
return ret
def already_cached(self, path_info):
current = self.get_checksum(path_info)
if not current:
return False
return not self.changed_cache(current)
def safe_remove(self, path_info, force=False):
if not self.exists(path_info):
return
if not force and not self.already_cached(path_info):
msg = ("file '{}' is going to be removed."
" Are you sure you want to proceed?".format(str(path_info)))
if not prompt.confirm(msg):
raise ConfirmRemoveError(str(path_info))
self.remove(path_info)
def _checkout_file(self,
path_info,
checksum,
force,
progress_callback=None,
relink=False):
"""The file is changed we need to checkout a new copy"""
added, modified = True, False
cache_info = self.checksum_to_path_info(checksum)
if self.exists(path_info):
logger.debug("data '%s' will be replaced.", path_info)
self.safe_remove(path_info, force=force)
added, modified = False, True
self.link(cache_info, path_info)
self.state.save_link(path_info)
self.state.save(path_info, checksum)
if progress_callback:
progress_callback(str(path_info))
return added, modified and not relink
def makedirs(self, path_info):
"""Optional: Implement only if the remote needs to create
directories before copying/linking/moving data
"""
def _checkout_dir(
self,
path_info,
checksum,
force,
progress_callback=None,
relink=False,
filter_info=None,
):
added, modified = False, False
# Create dir separately so that dir is created
# even if there are no files in it
if not self.exists(path_info):
added = True
self.makedirs(path_info)
dir_info = self.get_dir_cache(checksum)
logger.debug("Linking directory '%s'.", path_info)
for entry in dir_info:
relative_path = entry[self.PARAM_RELPATH]
entry_checksum = entry[self.PARAM_CHECKSUM]
entry_cache_info = self.checksum_to_path_info(entry_checksum)
entry_info = path_info / relative_path
if filter_info and not entry_info.isin_or_eq(filter_info):
continue
entry_checksum_info = {self.PARAM_CHECKSUM: entry_checksum}
if relink or self.changed(entry_info, entry_checksum_info):
modified = True
self.safe_remove(entry_info, force=force)
self.link(entry_cache_info, entry_info)
self.state.save(entry_info, entry_checksum)
if progress_callback:
progress_callback(str(entry_info))
modified = (self._remove_redundant_files(path_info, dir_info, force)
or modified)
self.state.save_link(path_info)
self.state.save(path_info, checksum)
# relink is not modified, assume it as nochange
return added, not added and modified and not relink
def _remove_redundant_files(self, path_info, dir_info, force):
existing_files = set(self.walk_files(path_info))
needed_files = {
path_info / entry[self.PARAM_RELPATH]
for entry in dir_info
}
redundant_files = existing_files - needed_files
for path in redundant_files:
self.safe_remove(path, force)
return bool(redundant_files)
def checkout(
self,
path_info,
checksum_info,
force=False,
progress_callback=None,
relink=False,
filter_info=None,
):
if path_info.scheme not in ["local", self.scheme]:
raise NotImplementedError
checksum = checksum_info.get(self.PARAM_CHECKSUM)
failed = None
skip = False
if not checksum:
logger.warning(
"No file hash info found for '%s'. "
"It won't be created.",
path_info,
)
self.safe_remove(path_info, force=force)
failed = path_info
elif not relink and not self.changed(path_info, checksum_info):
logger.debug("Data '%s' didn't change.", path_info)
skip = True
elif self.changed_cache(checksum,
path_info=path_info,
filter_info=filter_info):
logger.warning(
"Cache '%s' not found. File '%s' won't be created.",
checksum,
path_info,
)
self.safe_remove(path_info, force=force)
failed = path_info
if failed or skip:
if progress_callback:
progress_callback(
str(path_info),
self.get_files_number(self.path_info, checksum,
filter_info),
)
if failed:
raise CheckoutError([failed])
return
logger.debug("Checking out '%s' with cache '%s'.", path_info, checksum)
return self._checkout(
path_info,
checksum,
force,
progress_callback,
relink,
filter_info,
)
def _checkout(
self,
path_info,
checksum,
force=False,
progress_callback=None,
relink=False,
filter_info=None,
):
if not self.is_dir_checksum(checksum):
return self._checkout_file(path_info, checksum, force,
progress_callback, relink)
return self._checkout_dir(path_info, checksum, force,
progress_callback, relink, filter_info)
def get_files_number(self, path_info, checksum, filter_info):
from funcy.py3 import ilen
if not checksum:
return 0
if not self.is_dir_checksum(checksum):
return 1
if not filter_info:
return len(self.get_dir_cache(checksum))
return ilen(
filter_info.isin_or_eq(path_info / entry[self.PARAM_CHECKSUM])
for entry in self.get_dir_cache(checksum))
@staticmethod
def unprotect(path_info):
pass
def _get_unpacked_dir_names(self, checksums):
return set()
def extract_used_local_checksums(self, named_cache):
used = set(named_cache.scheme_keys("local"))
unpacked = self._get_unpacked_dir_names(used)
return used | unpacked
def _changed_unpacked_dir(self, checksum):
return True
def _update_unpacked_dir(self, checksum):
pass
def _remove_unpacked_dir(self, checksum):
pass