def get_last_version(self, filename):
"""Get a file from GridFS by ``"filename"``.
Returns the most recently uploaded file in GridFS with the
name `filename` as an instance of
:class:`~gridfs.grid_file.GridOut`. Raises
:class:`~gridfs.errors.NoFile` if no such file exists.
An index on ``{filename: 1, uploadDate: -1}`` will
automatically be created when this method is called the first
time.
:Parameters:
- `filename`: ``"filename"`` of the file to get
.. versionadded:: 1.6
"""
self.__files.ensure_index(
filter.sort(ASCENDING("filename") + DESCENDING("uploadDate")))
doc = yield self.__files.find_one({"filename": filename},
filter=filter.sort(
DESCENDING("uploadDate")))
if doc is None:
raise NoFile("TxMongo: no file in gridfs with filename {0}".format(
repr(filename)))
defer.returnValue(GridOut(self.__collection, doc))
def get_last_version(self, filename):
"""Get a file from GridFS by ``"filename"``.
Returns the most recently uploaded file in GridFS with the
name `filename` as an instance of
:class:`~gridfs.grid_file.GridOut`. Raises
:class:`~gridfs.errors.NoFile` if no such file exists.
An index on ``{filename: 1, uploadDate: -1}`` will
automatically be created when this method is called the first
time.
:Parameters:
- `filename`: ``"filename"`` of the file to get
.. versionadded:: 1.6
"""
self.__files.ensure_index(filter.sort(ASCENDING("filename") + \
DESCENDING("uploadDate")))
d = self.__files.find({"filename": filename},
filter=filter.sort(DESCENDING('uploadDate')))
d.addCallback(self._cb_get_last_version, filename)
return d
def get_version(self, filename=None, version=-1):
"""Get a file from GridFS by ``"filename"``.
Returns a version of the file in GridFS whose filename matches
`filename` and whose metadata fields match the supplied keyword
arguments, as an instance of :class:`~gridfs.grid_file.GridOut`.
Version numbering is a convenience atop the GridFS API provided
by MongoDB. If more than one file matches the query (either by
`filename` alone, by metadata fields, or by a combination of
both), then version ``-1`` will be the most recently uploaded
matching file, ``-2`` the second most recently
uploaded, etc. Version ``0`` will be the first version
uploaded, ``1`` the second version, etc. So if three versions
have been uploaded, then version ``0`` is the same as version
``-3``, version ``1`` is the same as version ``-2``, and
version ``2`` is the same as version ``-1``. Note that searching by
random (unindexed) meta data is not supported here.
Raises :class:`~gridfs.errors.NoFile` if no such version of
that file exists.
:Parameters:
- `filename`: ``"filename"`` of the file to get, or `None`
- `version` (optional): version of the file to get (defaults
to -1, the most recent version uploaded)
"""
query = {"filename": filename}
skip = abs(version)
if version < 0:
skip -= 1
myorder = DESCENDING("uploadDate")
else:
myorder = ASCENDING("uploadDate")
def ok(cursor):
if cursor:
return GridOut(self.__collection, cursor[0])
raise NoFile("no version %d for filename %r" % (version, filename))
return self.__files.find(query, filter=filter.sort(myorder), limit=1, skip=skip)\
.addCallback(ok)
def query(self, filter, limit=None):
"""
Return matching results.
"""
if limit == 0:
return succeed([])
# The txmongo API differs from pymongo with regard to sorting.
# To sort results when making a query using txmongo, a query
# filter needs to be created and passed to collection.find().
sort_filter = orderby(DESCENDING('sort$timestamp'))
# Do not include the '_id' and 'sort$timestamp' fields in the
# results as these are not part of the original document.
find_args = dict(filter=sort_filter,
fields={
'_id': False,
'sort$timestamp': False
})
if limit:
find_args['limit'] = limit
return self.collection.find(filter, **find_args)
def sortdesc(field):
return mongosort(DESCENDING(field))