|
|
"""
|
|
|
Utilities for file-based Contents/Checkpoints managers.
|
|
|
"""
|
|
|
|
|
|
# Copyright (c) IPython Development Team.
|
|
|
# Distributed under the terms of the Modified BSD License.
|
|
|
|
|
|
import base64
|
|
|
from contextlib import contextmanager
|
|
|
import errno
|
|
|
import io
|
|
|
import os
|
|
|
import shutil
|
|
|
import tempfile
|
|
|
|
|
|
from tornado.web import HTTPError
|
|
|
|
|
|
from jupyter_notebook.utils import (
|
|
|
to_api_path,
|
|
|
to_os_path,
|
|
|
)
|
|
|
from IPython import nbformat
|
|
|
from IPython.utils.py3compat import str_to_unicode
|
|
|
|
|
|
|
|
|
def _copy_metadata(src, dst):
|
|
|
"""Copy the set of metadata we want for atomic_writing.
|
|
|
|
|
|
Permission bits and flags. We'd like to copy file ownership as well, but we
|
|
|
can't do that.
|
|
|
"""
|
|
|
shutil.copymode(src, dst)
|
|
|
st = os.stat(src)
|
|
|
if hasattr(os, 'chflags') and hasattr(st, 'st_flags'):
|
|
|
os.chflags(dst, st.st_flags)
|
|
|
|
|
|
@contextmanager
|
|
|
def atomic_writing(path, text=True, encoding='utf-8', **kwargs):
|
|
|
"""Context manager to write to a file only if the entire write is successful.
|
|
|
|
|
|
This works by creating a temporary file in the same directory, and renaming
|
|
|
it over the old file if the context is exited without an error. If other
|
|
|
file names are hard linked to the target file, this relationship will not be
|
|
|
preserved.
|
|
|
|
|
|
On Windows, there is a small chink in the atomicity: the target file is
|
|
|
deleted before renaming the temporary file over it. This appears to be
|
|
|
unavoidable.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
path : str
|
|
|
The target file to write to.
|
|
|
|
|
|
text : bool, optional
|
|
|
Whether to open the file in text mode (i.e. to write unicode). Default is
|
|
|
True.
|
|
|
|
|
|
encoding : str, optional
|
|
|
The encoding to use for files opened in text mode. Default is UTF-8.
|
|
|
|
|
|
**kwargs
|
|
|
Passed to :func:`io.open`.
|
|
|
"""
|
|
|
# realpath doesn't work on Windows: http://bugs.python.org/issue9949
|
|
|
# Luckily, we only need to resolve the file itself being a symlink, not
|
|
|
# any of its directories, so this will suffice:
|
|
|
if os.path.islink(path):
|
|
|
path = os.path.join(os.path.dirname(path), os.readlink(path))
|
|
|
|
|
|
dirname, basename = os.path.split(path)
|
|
|
tmp_dir = tempfile.mkdtemp(prefix=basename, dir=dirname)
|
|
|
tmp_path = os.path.join(tmp_dir, basename)
|
|
|
if text:
|
|
|
fileobj = io.open(tmp_path, 'w', encoding=encoding, **kwargs)
|
|
|
else:
|
|
|
fileobj = io.open(tmp_path, 'wb', **kwargs)
|
|
|
|
|
|
try:
|
|
|
yield fileobj
|
|
|
except:
|
|
|
fileobj.close()
|
|
|
shutil.rmtree(tmp_dir)
|
|
|
raise
|
|
|
|
|
|
# Flush to disk
|
|
|
fileobj.flush()
|
|
|
os.fsync(fileobj.fileno())
|
|
|
|
|
|
# Written successfully, now rename it
|
|
|
fileobj.close()
|
|
|
|
|
|
# Copy permission bits, access time, etc.
|
|
|
try:
|
|
|
_copy_metadata(path, tmp_path)
|
|
|
except OSError:
|
|
|
# e.g. the file didn't already exist. Ignore any failure to copy metadata
|
|
|
pass
|
|
|
|
|
|
if os.name == 'nt' and os.path.exists(path):
|
|
|
# Rename over existing file doesn't work on Windows
|
|
|
os.remove(path)
|
|
|
|
|
|
os.rename(tmp_path, path)
|
|
|
shutil.rmtree(tmp_dir)
|
|
|
|
|
|
|
|
|
class FileManagerMixin(object):
|
|
|
"""
|
|
|
Mixin for ContentsAPI classes that interact with the filesystem.
|
|
|
|
|
|
Provides facilities for reading, writing, and copying both notebooks and
|
|
|
generic files.
|
|
|
|
|
|
Shared by FileContentsManager and FileCheckpoints.
|
|
|
|
|
|
Note
|
|
|
----
|
|
|
Classes using this mixin must provide the following attributes:
|
|
|
|
|
|
root_dir : unicode
|
|
|
A directory against against which API-style paths are to be resolved.
|
|
|
|
|
|
log : logging.Logger
|
|
|
"""
|
|
|
|
|
|
@contextmanager
|
|
|
def open(self, os_path, *args, **kwargs):
|
|
|
"""wrapper around io.open that turns permission errors into 403"""
|
|
|
with self.perm_to_403(os_path):
|
|
|
with io.open(os_path, *args, **kwargs) as f:
|
|
|
yield f
|
|
|
|
|
|
@contextmanager
|
|
|
def atomic_writing(self, os_path, *args, **kwargs):
|
|
|
"""wrapper around atomic_writing that turns permission errors to 403"""
|
|
|
with self.perm_to_403(os_path):
|
|
|
with atomic_writing(os_path, *args, **kwargs) as f:
|
|
|
yield f
|
|
|
|
|
|
@contextmanager
|
|
|
def perm_to_403(self, os_path=''):
|
|
|
"""context manager for turning permission errors into 403."""
|
|
|
try:
|
|
|
yield
|
|
|
except (OSError, IOError) as e:
|
|
|
if e.errno in {errno.EPERM, errno.EACCES}:
|
|
|
# make 403 error message without root prefix
|
|
|
# this may not work perfectly on unicode paths on Python 2,
|
|
|
# but nobody should be doing that anyway.
|
|
|
if not os_path:
|
|
|
os_path = str_to_unicode(e.filename or 'unknown file')
|
|
|
path = to_api_path(os_path, root=self.root_dir)
|
|
|
raise HTTPError(403, u'Permission denied: %s' % path)
|
|
|
else:
|
|
|
raise
|
|
|
|
|
|
def _copy(self, src, dest):
|
|
|
"""copy src to dest
|
|
|
|
|
|
like shutil.copy2, but log errors in copystat
|
|
|
"""
|
|
|
shutil.copyfile(src, dest)
|
|
|
try:
|
|
|
shutil.copystat(src, dest)
|
|
|
except OSError:
|
|
|
self.log.debug("copystat on %s failed", dest, exc_info=True)
|
|
|
|
|
|
def _get_os_path(self, path):
|
|
|
"""Given an API path, return its file system path.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
path : string
|
|
|
The relative API path to the named file.
|
|
|
|
|
|
Returns
|
|
|
-------
|
|
|
path : string
|
|
|
Native, absolute OS path to for a file.
|
|
|
|
|
|
Raises
|
|
|
------
|
|
|
404: if path is outside root
|
|
|
"""
|
|
|
root = os.path.abspath(self.root_dir)
|
|
|
os_path = to_os_path(path, root)
|
|
|
if not (os.path.abspath(os_path) + os.path.sep).startswith(root):
|
|
|
raise HTTPError(404, "%s is outside root contents directory" % path)
|
|
|
return os_path
|
|
|
|
|
|
def _read_notebook(self, os_path, as_version=4):
|
|
|
"""Read a notebook from an os path."""
|
|
|
with self.open(os_path, 'r', encoding='utf-8') as f:
|
|
|
try:
|
|
|
return nbformat.read(f, as_version=as_version)
|
|
|
except Exception as e:
|
|
|
raise HTTPError(
|
|
|
400,
|
|
|
u"Unreadable Notebook: %s %r" % (os_path, e),
|
|
|
)
|
|
|
|
|
|
def _save_notebook(self, os_path, nb):
|
|
|
"""Save a notebook to an os_path."""
|
|
|
with self.atomic_writing(os_path, encoding='utf-8') as f:
|
|
|
nbformat.write(nb, f, version=nbformat.NO_CONVERT)
|
|
|
|
|
|
def _read_file(self, os_path, format):
|
|
|
"""Read a non-notebook file.
|
|
|
|
|
|
os_path: The path to be read.
|
|
|
format:
|
|
|
If 'text', the contents will be decoded as UTF-8.
|
|
|
If 'base64', the raw bytes contents will be encoded as base64.
|
|
|
If not specified, try to decode as UTF-8, and fall back to base64
|
|
|
"""
|
|
|
if not os.path.isfile(os_path):
|
|
|
raise HTTPError(400, "Cannot read non-file %s" % os_path)
|
|
|
|
|
|
with self.open(os_path, 'rb') as f:
|
|
|
bcontent = f.read()
|
|
|
|
|
|
if format is None or format == 'text':
|
|
|
# Try to interpret as unicode if format is unknown or if unicode
|
|
|
# was explicitly requested.
|
|
|
try:
|
|
|
return bcontent.decode('utf8'), 'text'
|
|
|
except UnicodeError:
|
|
|
if format == 'text':
|
|
|
raise HTTPError(
|
|
|
400,
|
|
|
"%s is not UTF-8 encoded" % os_path,
|
|
|
reason='bad format',
|
|
|
)
|
|
|
return base64.encodestring(bcontent).decode('ascii'), 'base64'
|
|
|
|
|
|
def _save_file(self, os_path, content, format):
|
|
|
"""Save content of a generic file."""
|
|
|
if format not in {'text', 'base64'}:
|
|
|
raise HTTPError(
|
|
|
400,
|
|
|
"Must specify format of file contents as 'text' or 'base64'",
|
|
|
)
|
|
|
try:
|
|
|
if format == 'text':
|
|
|
bcontent = content.encode('utf8')
|
|
|
else:
|
|
|
b64_bytes = content.encode('ascii')
|
|
|
bcontent = base64.decodestring(b64_bytes)
|
|
|
except Exception as e:
|
|
|
raise HTTPError(
|
|
|
400, u'Encoding error saving %s: %s' % (os_path, e)
|
|
|
)
|
|
|
|
|
|
with self.atomic_writing(os_path, text=False) as f:
|
|
|
f.write(bcontent)
|
|
|
|
