dvc/remote/base.py
from __future__ import unicode_literals
from operator import itemgetter
from multiprocessing import cpu_count
import json
import logging
import tempfile
import itertools
from functools import partial
from concurrent.futures import ThreadPoolExecutor
from copy import copy
from dvc.ignore import DvcIgnore
from dvc.utils.compat import str, basestring, urlparse, FileNotFoundError
from dvc.remote.slow_link_detection import slow_link_guard
import dvc.prompt as prompt
from dvc.config import Config
from dvc.exceptions import (
DvcException,
ConfirmRemoveError,
DvcIgnoreInCollectedDirError,
)
from dvc.progress import Tqdm
from dvc.utils import LARGE_DIR_SIZE, tmp_fname, move, relpath, makedirs
from dvc.state import StateNoop
from dvc.path_info import PathInfo, URLInfo
from dvc.utils.http import open_url
logger = logging.getLogger(__name__)
STATUS_OK = 1
STATUS_MISSING = 2
STATUS_NEW = 3
STATUS_DELETED = 4
STATUS_MAP = {
# (local_exists, remote_exists)
(True, True): STATUS_OK,
(False, False): STATUS_MISSING,
(True, False): STATUS_NEW,
(False, True): STATUS_DELETED,
}
class DataCloudError(DvcException):
""" Data Cloud exception """
def __init__(self, msg):
super(DataCloudError, self).__init__("Data sync error: {}".format(msg))
class RemoteCmdError(DvcException):
def __init__(self, remote, cmd, ret, err):
super(RemoteCmdError, self).__init__(
"{remote} command '{cmd}' finished with non-zero return code"
" {ret}': {err}".format(remote=remote, cmd=cmd, ret=ret, err=err)
)
class RemoteActionNotImplemented(DvcException):
def __init__(self, action, scheme):
m = "{} is not supported by {} remote".format(action, scheme)
super(RemoteActionNotImplemented, self).__init__(m)
class RemoteMissingDepsError(DvcException):
pass
class DirCacheError(DvcException):
def __init__(self, checksum, cause=None):
super(DirCacheError, self).__init__(
"Failed to load dir cache for checksum: '{}'.".format(checksum),
cause=cause,
)
class RemoteBASE(object):
scheme = "base"
path_cls = URLInfo
REQUIRES = {}
JOBS = 4 * cpu_count()
PARAM_RELPATH = "relpath"
CHECKSUM_DIR_SUFFIX = ".dir"
CHECKSUM_JOBS = max(1, min(4, cpu_count() // 2))
DEFAULT_CACHE_TYPES = ["copy"]
state = StateNoop()
def __init__(self, repo, config):
self.repo = repo
self._check_requires(config)
core = config.get(Config.SECTION_CORE, {})
self.checksum_jobs = core.get(
Config.SECTION_CORE_CHECKSUM_JOBS, self.CHECKSUM_JOBS
)
self.protected = False
self.no_traverse = config.get(Config.SECTION_REMOTE_NO_TRAVERSE, True)
self._dir_info = {}
types = config.get(Config.SECTION_CACHE_TYPE, None)
if types:
if isinstance(types, str):
types = [t.strip() for t in types.split(",")]
self.cache_types = types
else:
self.cache_types = copy(self.DEFAULT_CACHE_TYPES)
self.cache_type_confirmed = False
def _check_requires(self, config):
import importlib
missing = []
for package, module in self.REQUIRES.items():
try:
importlib.import_module(module)
except ImportError:
missing.append(package)
if not missing:
return
url = config.get(
Config.SECTION_REMOTE_URL, "{}://".format(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, basestring):
url = config
else:
url = config[Config.SECTION_REMOTE_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 ThreadPoolExecutor(max_workers=self.checksum_jobs) as executor:
tasks = executor.map(self.get_file_checksum, file_infos)
if len(file_infos) > LARGE_DIR_SIZE:
logger.info(
(
"Computing md5 for a large number of files. "
"This is only done once."
)
)
tasks = Tqdm(tasks, total=len(file_infos), unit="md5")
checksums = dict(zip(file_infos, tasks))
return checksums
def _collect_dir(self, path_info):
file_infos = set()
for root, _dirs, files in self.walk(path_info):
if DvcIgnore.DVCIGNORE_FILE in files:
raise DvcIgnoreInCollectedDirError(root)
file_infos.update(path_info / root / fname for fname in files)
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):
dir_info = self._collect_dir(path_info)
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)
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, cause=exc)
if not isinstance(d, list):
msg = "dir cache file format error '{}' [skipping the file]"
logger.error(msg.format(relpath(path_info)))
return []
for info in d:
# NOTE: here is a BUG, see comment to .as_posix() below
relative_path = PathInfo.from_posix(info[self.PARAM_RELPATH])
info[self.PARAM_RELPATH] = relative_path.fspath
return d
@classmethod
def is_dir_checksum(cls, checksum):
return checksum.endswith(cls.CHECKSUM_DIR_SUFFIX)
def get_checksum(self, path_info):
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):
assert path_info.scheme == self.scheme
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)
- Checksum is not computed (saving a new file)
- The checkusm stored in the State is different from the given one
- There's no file in the cache
Args:
path_info: dict with path information.
checksum: expected checksum for this data.
Returns:
bool: True if data has changed, False otherwise.
"""
logger.debug(
"checking if '{}'('{}') has changed.".format(
path_info, checksum_info
)
)
if not self.exists(path_info):
logger.debug("'{}' doesn't exist.".format(path_info))
return True
checksum = checksum_info.get(self.PARAM_CHECKSUM)
if checksum is None:
logger.debug("checksum for '{}' is missing.".format(path_info))
return True
if self.changed_cache(checksum):
logger.debug(
"cache for '{}'('{}') has changed.".format(path_info, checksum)
)
return True
actual = self.save_info(path_info)[self.PARAM_CHECKSUM]
if checksum != actual:
logger.debug(
"checksum '{}'(actual '{}') for '{}' has changed.".format(
checksum, actual, path_info
)
)
return True
logger.debug("'{}' hasn't changed.".format(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)
@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.cache_type_confirmed = True
return
except DvcException as exc:
msg = "Cache type '{}' is not supported: {}"
logger.debug(msg.format(link_types[0], str(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("Link '{}' already exists!".format(to_info))
link_method(from_info, to_info)
if self.protected:
self.protect(to_info)
msg = "Created {}'{}': {} -> {}".format(
"protected " if self.protected else "",
self.cache_types[0],
from_info,
to_info,
)
logger.debug(msg)
def _save_file(self, path_info, checksum, save_link=True):
assert checksum
cache_info = self.checksum_to_path_info(checksum)
if self.changed_cache(checksum):
self.move(path_info, cache_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
self.state.save(path_info, checksum)
self.state.save(cache_info, checksum)
def _save_dir(self, path_info, checksum):
cache_info = self.checksum_to_path_info(checksum)
dir_info = self.get_dir_cache(checksum)
for entry in dir_info:
entry_info = path_info / entry[self.PARAM_RELPATH]
entry_checksum = entry[self.PARAM_CHECKSUM]
self._save_file(entry_info, entry_checksum, save_link=False)
self.state.save_link(path_info)
self.state.save(cache_info, checksum)
self.state.save(path_info, checksum)
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 walk(self, path_info):
raise NotImplementedError
@staticmethod
def protect(path_info):
pass
def save(self, path_info, checksum_info):
if path_info.scheme != self.scheme:
raise RemoteActionNotImplemented(
"save {} -> {}".format(path_info.scheme, self.scheme),
self.scheme,
)
checksum = checksum_info[self.PARAM_CHECKSUM]
if not self.changed_cache(checksum):
self._checkout(path_info, checksum)
return
self._save(path_info, checksum)
def _save(self, path_info, checksum):
to_info = self.checksum_to_path_info(checksum)
logger.debug("Saving '{}' to '{}'.".format(path_info, to_info))
if self.isdir(path_info):
self._save_dir(path_info, checksum)
return
self._save_file(path_info, checksum)
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 '{}' to '{}'".format(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:
msg = "failed to upload '{}' to '{}'"
logger.exception(msg.format(from_info, to_info))
return 1 # 1 fail
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
logger.debug("Downloading '{}' to '{}'".format(from_info, to_info))
name = name or to_info.name
makedirs(to_info.parent, exist_ok=True, mode=dir_mode)
tmp_file = tmp_fname(to_info)
try:
self._download(
from_info, tmp_file, name=name, no_progress_bar=no_progress_bar
)
except Exception:
msg = "failed to download '{}' to '{}'"
logger.exception(msg.format(from_info, to_info))
return 1 # 1 fail
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):
self.copy(from_info, to_info)
self.remove(from_info)
def copy(self, from_info, to_info):
raise RemoteActionNotImplemented("copy", 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("Bad cache file path")
return "".join(parts)
def checksum_to_path_info(self, checksum):
return self.path_info / checksum[0:2] / checksum[2:]
def list_cache_paths(self):
raise NotImplementedError
def all(self):
# NOTE: The list might be way too 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.
for path in self.list_cache_paths():
try:
yield self.path_to_checksum(path)
except ValueError:
# We ignore all the non-cache looking files
pass
def gc(self, cinfos):
used = self.extract_used_local_checksums(cinfos)
if self.scheme != "":
used |= {
info[self.PARAM_CHECKSUM]
for info in cinfos.get(self.scheme, [])
}
removed = False
for checksum in self.all():
if checksum in used:
continue
path_info = self.checksum_to_path_info(checksum)
self.remove(path_info)
removed = True
return removed
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
"""
cache_info = self.checksum_to_path_info(checksum)
actual = self.get_checksum(cache_info)
logger.debug(
"cache '{}' expected '{}' actual '{}'".format(
str(cache_info), checksum, actual
)
)
if not checksum or not actual:
return True
if actual.split(".")[0] == checksum.split(".")[0]:
return False
if self.exists(cache_info):
logger.warning("corrupted cache file '{}'.".format(cache_info))
self.remove(cache_info)
return True
def _changed_dir_cache(self, checksum):
if self.changed_cache_file(checksum):
return True
if not self._changed_unpacked_dir(checksum):
return False
for entry in self.get_dir_cache(checksum):
entry_checksum = entry[self.PARAM_CHECKSUM]
if self.changed_cache_file(entry_checksum):
return True
self._update_unpacked_dir(checksum)
return False
def changed_cache(self, checksum):
if self.is_dir_checksum(checksum):
return self._changed_dir_cache(checksum)
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: Get a list of all the files in the remote
(traversing the cache directory) and compare it with
the given checksums.
- No traverse: 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).
Returns:
A list with checksums that were found in the remote
"""
if not self.no_traverse:
return list(set(checksums) & set(self.all()))
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_desc(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,
save_link=True,
):
# NOTE: In case if path_info is already cached and path_info's
# link type matches cache link type, we would like to avoid
# relinking.
if self.changed(
path_info, {self.PARAM_CHECKSUM: checksum}
) or not self._link_matches(path_info):
self.safe_remove(path_info, force=force)
cache_info = self.checksum_to_path_info(checksum)
self.link(cache_info, path_info)
if save_link:
self.state.save_link(path_info)
self.state.save(path_info, checksum)
else:
# NOTE: performing (un)protection costs us +/- the same as checking
# if path_info is protected. Instead of implementing logic,
# just (un)protect according to self.protected.
if self.protected:
self.protect(path_info)
else:
# NOTE dont allow copy, because we checked before that link
# type matches cache, and we don't want data duplication
self.unprotect(path_info, allow_copy=False)
if progress_callback:
progress_callback(str(path_info))
def _link_matches(self, path_info):
return True
def makedirs(self, path_info):
"""Optional: Implement only if the remote needs to create
directories before copying/linking/moving data
"""
pass
def _checkout_dir(
self, path_info, checksum, force, progress_callback=None
):
# Create dir separately so that dir is created
# even if there are no files in it
if not self.exists(path_info):
self.makedirs(path_info)
dir_info = self.get_dir_cache(checksum)
logger.debug("Linking directory '{}'.".format(path_info))
for entry in dir_info:
relative_path = entry[self.PARAM_RELPATH]
entry_checksum = entry[self.PARAM_CHECKSUM]
entry_info = path_info / relative_path
self._checkout_file(
entry_info,
entry_checksum,
force,
progress_callback,
save_link=False,
)
self._remove_redundant_files(path_info, dir_info, force)
self.state.save_link(path_info)
self.state.save(path_info, checksum)
def _remove_redundant_files(self, path_info, dir_info, force):
existing_files = set(
path_info / root / fname
for root, _, files in self.walk(path_info)
for fname in files
)
needed_files = {
path_info / entry[self.PARAM_RELPATH] for entry in dir_info
}
for path in existing_files - needed_files:
self.safe_remove(path, force)
def checkout(
self, path_info, checksum_info, force=False, progress_callback=None
):
if path_info.scheme not in ["local", self.scheme]:
raise NotImplementedError
checksum = checksum_info.get(self.PARAM_CHECKSUM)
failed = None
if not checksum:
logger.warning(
"No checksum info found for '{}'. "
"It won't be created.".format(str(path_info))
)
self.safe_remove(path_info, force=force)
failed = path_info
elif self.changed_cache(checksum):
msg = "Cache '{}' not found. File '{}' won't be created."
logger.warning(msg.format(checksum, str(path_info)))
self.safe_remove(path_info, force=force)
failed = path_info
if failed:
if progress_callback:
progress_callback(
str(path_info), self.get_files_number(checksum)
)
return failed
msg = "Checking out '{}' with cache '{}'."
logger.debug(msg.format(str(path_info), checksum))
self._checkout(path_info, checksum, force, progress_callback)
return None
def _checkout(
self, path_info, checksum, force=False, progress_callback=None
):
if not self.is_dir_checksum(checksum):
return self._checkout_file(
path_info, checksum, force, progress_callback=progress_callback
)
return self._checkout_dir(
path_info, checksum, force, progress_callback=progress_callback
)
def get_files_number(self, checksum):
if not checksum:
return 0
if self.is_dir_checksum(checksum):
return len(self.get_dir_cache(checksum))
return 1
@staticmethod
def unprotect(path_info, allow_copy=True):
pass
def _get_unpacked_dir_names(self, checksums):
return set()
def extract_used_local_checksums(self, cinfos):
from dvc.remote import RemoteLOCAL
used = {info[RemoteLOCAL.PARAM_CHECKSUM] for info in cinfos["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