def add_file_entry(self, path:str, script_path:str, source_url: Optional[str] = None) -> Dict[str, str]:
"""
Add a file entry to the config file
:param path: The path to the data file
:param script_path: The path to the script that used it
:param source_url: The source to download file from
:return:
"""
# path relative to the config file
path_rel = str(self.path_relative_to_config(path))
script_path_rel = str(self.path_relative_to_config(script_path))
sha256 = calculate_file_sha256(path)
result = {
"path": path_rel,
"hash": sha256,
"usage": script_path_rel,
}
if source_url is not None:
result['source_url'] = source_url
self.config["files"].append(result)
self.save_config()
return result
def download_to_local(self, config: Config, local: LocalStorage,
sha256: str, **kwargs):
try:
transfer = boto3.s3.transfer.S3Transfer(self.client)
local_path = local.hash_to_file(sha256)
remote_path = local.hash_to_remote_path(sha256)
s3_key = str(PurePosixPath(self.path_prefix, remote_path))
local_path.parent.mkdir(parents=True, exist_ok=True)
real_path = [
e["path"] for e in config.config["files"]
if e["hash"] == sha256
]
if len(real_path) > 0:
real_path = real_path[-1]
else:
# file no longer in config? this shouldn't happen but don't fail.
real_path = ""
print("Downloading `%s`" % real_path)
transfer.download_file(self.bucket_name, s3_key, str(local_path))
# make sure the sha256 of the just downloaded file is correct
downloaded_sha256 = calculate_file_sha256(str(local_path))
if sha256 != downloaded_sha256:
raise RuntimeError(
"Hash for the downloaded file `%s` is incorrect. File might be corrupted in the remote storage backend."
% str(local_path))
except botocore.exceptions.NoCredentialsError:
raise RuntimeError(
"Download failed. AWS credentials not found. Run `lazydata config aws` to configure them."
)
def store_file(self, path:str):
"""
Store a file in the local backend.
:ivar path: The path to the file to store
:return:
"""
stat = os.stat(path)
abspath = Path(path).resolve()
sha256 = calculate_file_sha256(path)
# see if we stored this file already
datapath = self.hash_to_file(sha256)
# copy over the the cache,
# TODO: option to hardlink
datapath.parent.mkdir(parents=True, exist_ok=True)
shutil.copyfile(str(abspath), str(datapath))
# Store in the metadata DB if doesn't exist already
existing_entries = DataFile.select().where(
(
(DataFile.abspath == abspath) &
(DataFile.sha256 == sha256) &
(DataFile.mtime == stat.st_mtime) &
(DataFile.size == stat.st_size)
)
)
if existing_entries.count() == 0:
DataFile.create(abspath=abspath, sha256=sha256, mtime=stat.st_mtime, size=stat.st_size)
def download_to_local(config: Config,
local: LocalStorage,
sha256: Optional[str] = None,
source_url: Optional[str] = None,
path: Optional[str] = None):
if sha256 is not None:
local_path = local.hash_to_file(sha256)
source_url = config.source_url(sha256=sha256)
if source_url is None:
raise RuntimeError(
"Cannot find source_url for file with hash `%s`. "
"See `lazydata add-source` command." % sha256)
if path is None:
path = config.path(sha256=sha256)
if path is None:
raise RuntimeError(
"Cannot find path for downloading a file.")
elif source_url is not None:
if path is None:
path = config.path(source_url=source_url)
if path is None:
raise RuntimeError(
"Cannot find path for downloading a file.")
local_path = Path(path)
else:
raise RuntimeError(
"Cannot download a file without sha256 and source_url specified."
)
local_path.parent.mkdir(parents=True, exist_ok=True)
f = SmartDL(urls=source_url, dest=str(local_path), progress_bar=False)
print("Downloading `%s`" % path)
f.start()
# make sure the sha256 of the just downloaded file is correct
downloaded_sha256 = calculate_file_sha256(str(local_path))
if sha256 is not None and sha256 != downloaded_sha256:
raise RuntimeError(
"Hash for the downloaded file `%s` is incorrect. "
"File might be corrupted in the remote storage backend." %
str(local_path))
local.store_file(path=path)
def add_file_entry(self, path:str, script_path:str):
"""
Add a file entry to the config file
:param path: The path to the data file
:param script_path: The path to the script that used it
:return:
"""
# path relative to the config file
path_rel = str(self.path_relative_to_config(path))
script_path_rel = str(self.path_relative_to_config(script_path))
sha256 = calculate_file_sha256(path)
self.config["files"].append({
"path": path_rel,
"hash": sha256,
"usage": script_path_rel,
})
self.save_config()
def track(path:str) -> str:
"""
Track a file using lazydata.
:param path: a path to the file to be tracked
:return: Returns the path string that is now tracked
"""
stack = traceback.extract_stack()
script_location = ""
if len(stack) >= 2:
script_location = stack[-2].filename
# remove the ipython hash because it's going to be changing all the time
if script_location.startswith("<ipython-input") or script_location.startswith("<stdin"):
script_location = ""
path_obj = Path(path)
# 1) Check if the path exists
path_exists = path_obj.exists()
if path_exists and path_obj.is_dir():
raise NotImplementedError("Tracking directories is not currently supported: `%s`" % path)
# 2) Check it's present in the config file
config = Config()
latest, older = config.get_latest_and_all_file_entries(path)
if path_exists and latest is None:
# CASE: Start tracking a new file
print("LAZYDATA: Tracking new file `%s`" % path)
local = LocalStorage()
local.store_file(path)
config.add_file_entry(path, script_location)
elif path_exists and latest:
# CASE: Check for change or stale version
# check if it has changed
local = LocalStorage()
cached_sha256 = local.get_file_sha256(path)
# compare with the value in config
if latest["hash"] in cached_sha256:
# file is at the latest version!
# just make sure the usage is recorded
config.add_usage(latest, script_location)
return path
# check if it's one of the stale versions
matching_old = [e for e in older if e["hash"] in cached_sha256]
if matching_old:
print("LAZYDATA: Detected an old version of `%s`, updating to the latest..." % path)
fetch_file(config, local, latest["hash"], path)
# make sure usage is recorded
config.add_usage(latest, script_location)
else:
# It's not a stale version...
# So now recalculate the SHA256 to see if the file really changed
path_sha256 = calculate_file_sha256(path)
if latest["hash"] != path_sha256:
print("LAZYDATA: Tracked file `%s` changed, recording a new version..." % path)
local.store_file(path)
config.add_file_entry(path, script_location)
# make sure usage is recorded
config.add_usage(latest, script_location)
else:
# the file hasn't changed but the metadata was missing locally, so add it...
local.store_file(path)
# make sure usage is recorded
config.add_usage(latest, script_location)
elif not path_exists and latest:
# CASE: Remote download
print("LAZYDATA: Getting latest version of tracked file `%s`..." % path)
local = LocalStorage()
fetch_file(config, local, latest["hash"], path)
# make sure usage is recorded
config.add_usage(latest, script_location)
elif not path_exists and not latest:
# CASE: Trying to track non-existing
raise RuntimeError("Cannot track file, because file is not found: %s" % path)
return path
