956fd92e82
This change uses a cursor to download all the chunks in a GridFS file instead of using individual find_one operations to read each chunk. Detect truncated/missing/extra chunks in _GridOutChunkIterator. Only detect extra chunks after reading the final chunk, not on every call to read(). Retry once after CursorNotFound for backward compatibility.
804 lines
29 KiB
Python
804 lines
29 KiB
Python
# Copyright 2009-present MongoDB, Inc.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""Tools for representing files stored in GridFS."""
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import datetime
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import hashlib
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import math
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import os
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from bson.son import SON
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from bson.binary import Binary
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from bson.objectid import ObjectId
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from bson.py3compat import text_type, StringIO
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from gridfs.errors import CorruptGridFile, FileExists, NoFile
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from pymongo import ASCENDING
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from pymongo.collection import Collection
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from pymongo.cursor import Cursor
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from pymongo.errors import (ConfigurationError,
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CursorNotFound,
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DuplicateKeyError,
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OperationFailure)
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from pymongo.read_preferences import ReadPreference
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try:
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_SEEK_SET = os.SEEK_SET
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_SEEK_CUR = os.SEEK_CUR
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_SEEK_END = os.SEEK_END
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# before 2.5
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except AttributeError:
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_SEEK_SET = 0
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_SEEK_CUR = 1
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_SEEK_END = 2
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EMPTY = b""
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NEWLN = b"\n"
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"""Default chunk size, in bytes."""
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# Slightly under a power of 2, to work well with server's record allocations.
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DEFAULT_CHUNK_SIZE = 255 * 1024
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_C_INDEX = SON([("files_id", ASCENDING), ("n", ASCENDING)])
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_F_INDEX = SON([("filename", ASCENDING), ("uploadDate", ASCENDING)])
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def _grid_in_property(field_name, docstring, read_only=False,
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closed_only=False):
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"""Create a GridIn property."""
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def getter(self):
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if closed_only and not self._closed:
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raise AttributeError("can only get %r on a closed file" %
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field_name)
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# Protect against PHP-237
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if field_name == 'length':
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return self._file.get(field_name, 0)
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return self._file.get(field_name, None)
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def setter(self, value):
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if self._closed:
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self._coll.files.update_one({"_id": self._file["_id"]},
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{"$set": {field_name: value}})
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self._file[field_name] = value
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if read_only:
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docstring += "\n\nThis attribute is read-only."
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elif closed_only:
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docstring = "%s\n\n%s" % (docstring, "This attribute is read-only and "
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"can only be read after :meth:`close` "
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"has been called.")
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if not read_only and not closed_only:
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return property(getter, setter, doc=docstring)
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return property(getter, doc=docstring)
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def _grid_out_property(field_name, docstring):
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"""Create a GridOut property."""
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def getter(self):
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self._ensure_file()
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# Protect against PHP-237
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if field_name == 'length':
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return self._file.get(field_name, 0)
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return self._file.get(field_name, None)
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docstring += "\n\nThis attribute is read-only."
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return property(getter, doc=docstring)
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class GridIn(object):
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"""Class to write data to GridFS.
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"""
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def __init__(
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self, root_collection, session=None, disable_md5=False, **kwargs):
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"""Write a file to GridFS
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Application developers should generally not need to
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instantiate this class directly - instead see the methods
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provided by :class:`~gridfs.GridFS`.
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Raises :class:`TypeError` if `root_collection` is not an
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instance of :class:`~pymongo.collection.Collection`.
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Any of the file level options specified in the `GridFS Spec
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<http://dochub.mongodb.org/core/gridfsspec>`_ may be passed as
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keyword arguments. Any additional keyword arguments will be
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set as additional fields on the file document. Valid keyword
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arguments include:
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- ``"_id"``: unique ID for this file (default:
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:class:`~bson.objectid.ObjectId`) - this ``"_id"`` must
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not have already been used for another file
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- ``"filename"``: human name for the file
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- ``"contentType"`` or ``"content_type"``: valid mime-type
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for the file
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- ``"chunkSize"`` or ``"chunk_size"``: size of each of the
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chunks, in bytes (default: 255 kb)
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- ``"encoding"``: encoding used for this file. In Python 2,
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any :class:`unicode` that is written to the file will be
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converted to a :class:`str`. In Python 3, any :class:`str`
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that is written to the file will be converted to
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:class:`bytes`.
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:Parameters:
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- `root_collection`: root collection to write to
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- `session` (optional): a
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:class:`~pymongo.client_session.ClientSession` to use for all
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commands
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- `disable_md5` (optional): When True, an MD5 checksum will not be
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computed for the uploaded file. Useful in environments where
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MD5 cannot be used for regulatory or other reasons. Defaults to
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False.
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- `**kwargs` (optional): file level options (see above)
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.. versionchanged:: 3.6
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Added ``session`` parameter.
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.. versionchanged:: 3.0
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`root_collection` must use an acknowledged
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:attr:`~pymongo.collection.Collection.write_concern`
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"""
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if not isinstance(root_collection, Collection):
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raise TypeError("root_collection must be an "
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"instance of Collection")
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if not root_collection.write_concern.acknowledged:
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raise ConfigurationError('root_collection must use '
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'acknowledged write_concern')
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# Handle alternative naming
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if "content_type" in kwargs:
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kwargs["contentType"] = kwargs.pop("content_type")
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if "chunk_size" in kwargs:
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kwargs["chunkSize"] = kwargs.pop("chunk_size")
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coll = root_collection.with_options(
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read_preference=ReadPreference.PRIMARY)
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if not disable_md5:
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kwargs["md5"] = hashlib.md5()
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# Defaults
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kwargs["_id"] = kwargs.get("_id", ObjectId())
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kwargs["chunkSize"] = kwargs.get("chunkSize", DEFAULT_CHUNK_SIZE)
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object.__setattr__(self, "_session", session)
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object.__setattr__(self, "_coll", coll)
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object.__setattr__(self, "_chunks", coll.chunks)
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object.__setattr__(self, "_file", kwargs)
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object.__setattr__(self, "_buffer", StringIO())
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object.__setattr__(self, "_position", 0)
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object.__setattr__(self, "_chunk_number", 0)
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object.__setattr__(self, "_closed", False)
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object.__setattr__(self, "_ensured_index", False)
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def __create_index(self, collection, index_key, unique):
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doc = collection.find_one(projection={"_id": 1}, session=self._session)
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if doc is None:
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try:
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index_keys = [index_spec['key'] for index_spec in
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collection.list_indexes(session=self._session)]
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except OperationFailure:
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index_keys = []
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if index_key not in index_keys:
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collection.create_index(
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index_key.items(), unique=unique, session=self._session)
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def __ensure_indexes(self):
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if not object.__getattribute__(self, "_ensured_index"):
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self.__create_index(self._coll.files, _F_INDEX, False)
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self.__create_index(self._coll.chunks, _C_INDEX, True)
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object.__setattr__(self, "_ensured_index", True)
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def abort(self):
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"""Remove all chunks/files that may have been uploaded and close.
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"""
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self._coll.chunks.delete_many(
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{"files_id": self._file['_id']}, session=self._session)
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self._coll.files.delete_one(
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{"_id": self._file['_id']}, session=self._session)
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object.__setattr__(self, "_closed", True)
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@property
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def closed(self):
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"""Is this file closed?
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"""
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return self._closed
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_id = _grid_in_property("_id", "The ``'_id'`` value for this file.",
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read_only=True)
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filename = _grid_in_property("filename", "Name of this file.")
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name = _grid_in_property("filename", "Alias for `filename`.")
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content_type = _grid_in_property("contentType", "Mime-type for this file.")
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length = _grid_in_property("length", "Length (in bytes) of this file.",
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closed_only=True)
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chunk_size = _grid_in_property("chunkSize", "Chunk size for this file.",
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read_only=True)
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upload_date = _grid_in_property("uploadDate",
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"Date that this file was uploaded.",
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closed_only=True)
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md5 = _grid_in_property("md5", "MD5 of the contents of this file "
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"if an md5 sum was created.",
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closed_only=True)
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def __getattr__(self, name):
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if name in self._file:
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return self._file[name]
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raise AttributeError("GridIn object has no attribute '%s'" % name)
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def __setattr__(self, name, value):
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# For properties of this instance like _buffer, or descriptors set on
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# the class like filename, use regular __setattr__
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if name in self.__dict__ or name in self.__class__.__dict__:
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object.__setattr__(self, name, value)
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else:
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# All other attributes are part of the document in db.fs.files.
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# Store them to be sent to server on close() or if closed, send
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# them now.
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self._file[name] = value
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if self._closed:
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self._coll.files.update_one({"_id": self._file["_id"]},
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{"$set": {name: value}})
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def __flush_data(self, data):
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"""Flush `data` to a chunk.
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"""
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self.__ensure_indexes()
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if 'md5' in self._file:
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self._file['md5'].update(data)
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if not data:
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return
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assert(len(data) <= self.chunk_size)
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chunk = {"files_id": self._file["_id"],
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"n": self._chunk_number,
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"data": Binary(data)}
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try:
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self._chunks.insert_one(chunk, session=self._session)
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except DuplicateKeyError:
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self._raise_file_exists(self._file['_id'])
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self._chunk_number += 1
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self._position += len(data)
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def __flush_buffer(self):
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"""Flush the buffer contents out to a chunk.
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"""
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self.__flush_data(self._buffer.getvalue())
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self._buffer.close()
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self._buffer = StringIO()
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def __flush(self):
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"""Flush the file to the database.
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"""
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try:
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self.__flush_buffer()
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if "md5" in self._file:
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self._file["md5"] = self._file["md5"].hexdigest()
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self._file["length"] = self._position
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self._file["uploadDate"] = datetime.datetime.utcnow()
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return self._coll.files.insert_one(
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self._file, session=self._session)
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except DuplicateKeyError:
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self._raise_file_exists(self._id)
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def _raise_file_exists(self, file_id):
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"""Raise a FileExists exception for the given file_id."""
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raise FileExists("file with _id %r already exists" % file_id)
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def close(self):
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"""Flush the file and close it.
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A closed file cannot be written any more. Calling
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:meth:`close` more than once is allowed.
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"""
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if not self._closed:
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self.__flush()
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object.__setattr__(self, "_closed", True)
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def write(self, data):
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"""Write data to the file. There is no return value.
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`data` can be either a string of bytes or a file-like object
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(implementing :meth:`read`). If the file has an
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:attr:`encoding` attribute, `data` can also be a
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:class:`unicode` (:class:`str` in python 3) instance, which
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will be encoded as :attr:`encoding` before being written.
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Due to buffering, the data may not actually be written to the
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database until the :meth:`close` method is called. Raises
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:class:`ValueError` if this file is already closed. Raises
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:class:`TypeError` if `data` is not an instance of
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:class:`str` (:class:`bytes` in python 3), a file-like object,
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or an instance of :class:`unicode` (:class:`str` in python 3).
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Unicode data is only allowed if the file has an :attr:`encoding`
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attribute.
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:Parameters:
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- `data`: string of bytes or file-like object to be written
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to the file
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"""
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if self._closed:
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raise ValueError("cannot write to a closed file")
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try:
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# file-like
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read = data.read
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except AttributeError:
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# string
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if not isinstance(data, (text_type, bytes)):
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raise TypeError("can only write strings or file-like objects")
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if isinstance(data, text_type):
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try:
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data = data.encode(self.encoding)
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except AttributeError:
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raise TypeError("must specify an encoding for file in "
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"order to write %s" % (text_type.__name__,))
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read = StringIO(data).read
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if self._buffer.tell() > 0:
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# Make sure to flush only when _buffer is complete
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space = self.chunk_size - self._buffer.tell()
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if space:
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try:
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to_write = read(space)
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except:
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self.abort()
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raise
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self._buffer.write(to_write)
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if len(to_write) < space:
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return # EOF or incomplete
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self.__flush_buffer()
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to_write = read(self.chunk_size)
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while to_write and len(to_write) == self.chunk_size:
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self.__flush_data(to_write)
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to_write = read(self.chunk_size)
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self._buffer.write(to_write)
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def writelines(self, sequence):
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"""Write a sequence of strings to the file.
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Does not add seperators.
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"""
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for line in sequence:
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self.write(line)
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def __enter__(self):
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"""Support for the context manager protocol.
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"""
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return self
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def __exit__(self, exc_type, exc_val, exc_tb):
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"""Support for the context manager protocol.
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Close the file and allow exceptions to propagate.
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"""
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self.close()
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# propagate exceptions
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return False
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class GridOut(object):
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"""Class to read data out of GridFS.
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"""
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def __init__(self, root_collection, file_id=None, file_document=None,
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session=None):
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"""Read a file from GridFS
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Application developers should generally not need to
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instantiate this class directly - instead see the methods
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provided by :class:`~gridfs.GridFS`.
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Either `file_id` or `file_document` must be specified,
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`file_document` will be given priority if present. Raises
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:class:`TypeError` if `root_collection` is not an instance of
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:class:`~pymongo.collection.Collection`.
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:Parameters:
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- `root_collection`: root collection to read from
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- `file_id` (optional): value of ``"_id"`` for the file to read
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- `file_document` (optional): file document from
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`root_collection.files`
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- `session` (optional): a
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:class:`~pymongo.client_session.ClientSession` to use for all
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commands
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.. versionchanged:: 3.8
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For better performance and to better follow the GridFS spec,
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:class:`GridOut` now uses a single cursor to read all the chunks in
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the file.
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.. versionchanged:: 3.6
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Added ``session`` parameter.
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.. versionchanged:: 3.0
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Creating a GridOut does not immediately retrieve the file metadata
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from the server. Metadata is fetched when first needed.
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"""
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if not isinstance(root_collection, Collection):
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raise TypeError("root_collection must be an "
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"instance of Collection")
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self.__chunks = root_collection.chunks
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self.__files = root_collection.files
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self.__file_id = file_id
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self.__buffer = EMPTY
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self.__chunk_iter = None
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self.__position = 0
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self._file = file_document
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self._session = session
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_id = _grid_out_property("_id", "The ``'_id'`` value for this file.")
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filename = _grid_out_property("filename", "Name of this file.")
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name = _grid_out_property("filename", "Alias for `filename`.")
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content_type = _grid_out_property("contentType", "Mime-type for this file.")
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length = _grid_out_property("length", "Length (in bytes) of this file.")
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chunk_size = _grid_out_property("chunkSize", "Chunk size for this file.")
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upload_date = _grid_out_property("uploadDate",
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"Date that this file was first uploaded.")
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aliases = _grid_out_property("aliases", "List of aliases for this file.")
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metadata = _grid_out_property("metadata", "Metadata attached to this file.")
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md5 = _grid_out_property("md5", "MD5 of the contents of this file "
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"if an md5 sum was created.")
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def _ensure_file(self):
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if not self._file:
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self._file = self.__files.find_one({"_id": self.__file_id},
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session=self._session)
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if not self._file:
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raise NoFile("no file in gridfs collection %r with _id %r" %
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(self.__files, self.__file_id))
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def __getattr__(self, name):
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self._ensure_file()
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if name in self._file:
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return self._file[name]
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raise AttributeError("GridOut object has no attribute '%s'" % name)
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def readchunk(self):
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"""Reads a chunk at a time. If the current position is within a
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chunk the remainder of the chunk is returned.
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"""
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received = len(self.__buffer)
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chunk_data = EMPTY
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chunk_size = int(self.chunk_size)
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if received > 0:
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chunk_data = self.__buffer
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elif self.__position < int(self.length):
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chunk_number = int((received + self.__position) / chunk_size)
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if self.__chunk_iter is None:
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self.__chunk_iter = _GridOutChunkIterator(
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self, self.__chunks, self._session, chunk_number)
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chunk = self.__chunk_iter.next()
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chunk_data = chunk["data"][self.__position % chunk_size:]
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if not chunk_data:
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raise CorruptGridFile("truncated chunk")
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self.__position += len(chunk_data)
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self.__buffer = EMPTY
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return chunk_data
|
|
|
|
def read(self, size=-1):
|
|
"""Read at most `size` bytes from the file (less if there
|
|
isn't enough data).
|
|
|
|
The bytes are returned as an instance of :class:`str` (:class:`bytes`
|
|
in python 3). If `size` is negative or omitted all data is read.
|
|
|
|
:Parameters:
|
|
- `size` (optional): the number of bytes to read
|
|
|
|
.. versionchanged:: 3.8
|
|
This method now only checks for extra chunks after reading the
|
|
entire file. Previously, this method would check for extra chunks
|
|
on every call.
|
|
"""
|
|
self._ensure_file()
|
|
|
|
remainder = int(self.length) - self.__position
|
|
if size < 0 or size > remainder:
|
|
size = remainder
|
|
|
|
if size == 0:
|
|
return EMPTY
|
|
|
|
received = 0
|
|
data = StringIO()
|
|
while received < size:
|
|
chunk_data = self.readchunk()
|
|
received += len(chunk_data)
|
|
data.write(chunk_data)
|
|
|
|
# Detect extra chunks after reading the entire file.
|
|
if size == remainder and self.__chunk_iter:
|
|
try:
|
|
self.__chunk_iter.next()
|
|
except StopIteration:
|
|
pass
|
|
|
|
self.__position -= received - size
|
|
|
|
# Return 'size' bytes and store the rest.
|
|
data.seek(size)
|
|
self.__buffer = data.read()
|
|
data.seek(0)
|
|
return data.read(size)
|
|
|
|
def readline(self, size=-1):
|
|
"""Read one line or up to `size` bytes from the file.
|
|
|
|
:Parameters:
|
|
- `size` (optional): the maximum number of bytes to read
|
|
"""
|
|
remainder = int(self.length) - self.__position
|
|
if size < 0 or size > remainder:
|
|
size = remainder
|
|
|
|
if size == 0:
|
|
return EMPTY
|
|
|
|
received = 0
|
|
data = StringIO()
|
|
while received < size:
|
|
chunk_data = self.readchunk()
|
|
pos = chunk_data.find(NEWLN, 0, size)
|
|
if pos != -1:
|
|
size = received + pos + 1
|
|
|
|
received += len(chunk_data)
|
|
data.write(chunk_data)
|
|
if pos != -1:
|
|
break
|
|
|
|
self.__position -= received - size
|
|
|
|
# Return 'size' bytes and store the rest.
|
|
data.seek(size)
|
|
self.__buffer = data.read()
|
|
data.seek(0)
|
|
return data.read(size)
|
|
|
|
def tell(self):
|
|
"""Return the current position of this file.
|
|
"""
|
|
return self.__position
|
|
|
|
def seek(self, pos, whence=_SEEK_SET):
|
|
"""Set the current position of this file.
|
|
|
|
:Parameters:
|
|
- `pos`: the position (or offset if using relative
|
|
positioning) to seek to
|
|
- `whence` (optional): where to seek
|
|
from. :attr:`os.SEEK_SET` (``0``) for absolute file
|
|
positioning, :attr:`os.SEEK_CUR` (``1``) to seek relative
|
|
to the current position, :attr:`os.SEEK_END` (``2``) to
|
|
seek relative to the file's end.
|
|
"""
|
|
if whence == _SEEK_SET:
|
|
new_pos = pos
|
|
elif whence == _SEEK_CUR:
|
|
new_pos = self.__position + pos
|
|
elif whence == _SEEK_END:
|
|
new_pos = int(self.length) + pos
|
|
else:
|
|
raise IOError(22, "Invalid value for `whence`")
|
|
|
|
if new_pos < 0:
|
|
raise IOError(22, "Invalid value for `pos` - must be positive")
|
|
|
|
# Optimization, continue using the same buffer and chunk iterator.
|
|
if new_pos == self.__position:
|
|
return
|
|
|
|
self.__position = new_pos
|
|
self.__buffer = EMPTY
|
|
if self.__chunk_iter:
|
|
self.__chunk_iter.close()
|
|
self.__chunk_iter = None
|
|
|
|
def __iter__(self):
|
|
"""Return an iterator over all of this file's data.
|
|
|
|
The iterator will return chunk-sized instances of
|
|
:class:`str` (:class:`bytes` in python 3). This can be
|
|
useful when serving files using a webserver that handles
|
|
such an iterator efficiently.
|
|
|
|
.. versionchanged:: 3.8
|
|
The iterator now raises :class:`CorruptGridFile` when encountering
|
|
any truncated, missing, or extra chunk in a file. The previous
|
|
behavior was to only raise :class:`CorruptGridFile` on a missing
|
|
chunk.
|
|
"""
|
|
return GridOutIterator(self, self.__chunks, self._session)
|
|
|
|
def close(self):
|
|
"""Make GridOut more generically file-like."""
|
|
if self.__chunk_iter:
|
|
self.__chunk_iter.close()
|
|
self.__chunk_iter = None
|
|
|
|
def __enter__(self):
|
|
"""Makes it possible to use :class:`GridOut` files
|
|
with the context manager protocol.
|
|
"""
|
|
return self
|
|
|
|
def __exit__(self, exc_type, exc_val, exc_tb):
|
|
"""Makes it possible to use :class:`GridOut` files
|
|
with the context manager protocol.
|
|
"""
|
|
self.close()
|
|
return False
|
|
|
|
|
|
class _GridOutChunkIterator(object):
|
|
"""Iterates over a file's chunks using a single cursor.
|
|
|
|
Raises CorruptGridFile when encountering any truncated, missing, or extra
|
|
chunk in a file.
|
|
"""
|
|
def __init__(self, grid_out, chunks, session, next_chunk):
|
|
self._id = grid_out._id
|
|
self._chunk_size = int(grid_out.chunk_size)
|
|
self._length = int(grid_out.length)
|
|
self._chunks = chunks
|
|
self._session = session
|
|
self._next_chunk = next_chunk
|
|
self._num_chunks = math.ceil(float(self._length) / self._chunk_size)
|
|
self._cursor = None
|
|
|
|
def expected_chunk_length(self, chunk_n):
|
|
if chunk_n < self._num_chunks - 1:
|
|
return self._chunk_size
|
|
return self._length - (self._chunk_size * (self._num_chunks - 1))
|
|
|
|
def __iter__(self):
|
|
return self
|
|
|
|
def _create_cursor(self):
|
|
filter = {"files_id": self._id}
|
|
if self._next_chunk > 0:
|
|
filter["n"] = {"$gte": self._next_chunk}
|
|
self._cursor = self._chunks.find(filter, sort=[("n", 1)],
|
|
session=self._session)
|
|
|
|
def _next_with_retry(self):
|
|
"""Return the next chunk and retry once on CursorNotFound.
|
|
|
|
We retry on CursorNotFound to maintain backwards compatibility in
|
|
cases where two calls to read occur more than 10 minutes apart (the
|
|
server's default cursor timeout).
|
|
"""
|
|
if self._cursor is None:
|
|
self._create_cursor()
|
|
|
|
try:
|
|
return self._cursor.next()
|
|
except CursorNotFound:
|
|
self._cursor.close()
|
|
self._create_cursor()
|
|
return self._cursor.next()
|
|
|
|
def next(self):
|
|
try:
|
|
chunk = self._next_with_retry()
|
|
except StopIteration:
|
|
if self._next_chunk >= self._num_chunks:
|
|
raise
|
|
raise CorruptGridFile("no chunk #%d" % self._next_chunk)
|
|
|
|
if chunk["n"] != self._next_chunk:
|
|
self.close()
|
|
raise CorruptGridFile(
|
|
"Missing chunk: expected chunk #%d but found "
|
|
"chunk with n=%d" % (self._next_chunk, chunk["n"]))
|
|
|
|
if chunk["n"] >= self._num_chunks:
|
|
# According to spec, ignore extra chunks if they are empty.
|
|
if len(chunk["data"]):
|
|
self.close()
|
|
raise CorruptGridFile(
|
|
"Extra chunk found: expected %d chunks but found "
|
|
"chunk with n=%d" % (self._num_chunks, chunk["n"]))
|
|
|
|
expected_length = self.expected_chunk_length(chunk["n"])
|
|
if len(chunk["data"]) != expected_length:
|
|
self.close()
|
|
raise CorruptGridFile(
|
|
"truncated chunk #%d: expected chunk length to be %d but "
|
|
"found chunk with length %d" % (
|
|
chunk["n"], expected_length, len(chunk["data"])))
|
|
|
|
self._next_chunk += 1
|
|
return chunk
|
|
|
|
__next__ = next
|
|
|
|
def close(self):
|
|
if self._cursor:
|
|
self._cursor.close()
|
|
self._cursor = None
|
|
|
|
|
|
class GridOutIterator(object):
|
|
def __init__(self, grid_out, chunks, session):
|
|
self.__chunk_iter = _GridOutChunkIterator(grid_out, chunks, session, 0)
|
|
|
|
def __iter__(self):
|
|
return self
|
|
|
|
def next(self):
|
|
chunk = self.__chunk_iter.next()
|
|
return bytes(chunk["data"])
|
|
|
|
__next__ = next
|
|
|
|
|
|
class GridOutCursor(Cursor):
|
|
"""A cursor / iterator for returning GridOut objects as the result
|
|
of an arbitrary query against the GridFS files collection.
|
|
"""
|
|
def __init__(self, collection, filter=None, skip=0, limit=0,
|
|
no_cursor_timeout=False, sort=None, batch_size=0,
|
|
session=None):
|
|
"""Create a new cursor, similar to the normal
|
|
:class:`~pymongo.cursor.Cursor`.
|
|
|
|
Should not be called directly by application developers - see
|
|
the :class:`~gridfs.GridFS` method :meth:`~gridfs.GridFS.find` instead.
|
|
|
|
.. versionadded 2.7
|
|
|
|
.. mongodoc:: cursors
|
|
"""
|
|
# Hold on to the base "fs" collection to create GridOut objects later.
|
|
self.__root_collection = collection
|
|
|
|
super(GridOutCursor, self).__init__(
|
|
collection.files, filter, skip=skip, limit=limit,
|
|
no_cursor_timeout=no_cursor_timeout, sort=sort,
|
|
batch_size=batch_size, session=session)
|
|
|
|
def next(self):
|
|
"""Get next GridOut object from cursor.
|
|
"""
|
|
# Work around "super is not iterable" issue in Python 3.x
|
|
next_file = super(GridOutCursor, self).next()
|
|
return GridOut(self.__root_collection, file_document=next_file,
|
|
session=self.session)
|
|
|
|
__next__ = next
|
|
|
|
def add_option(self, *args, **kwargs):
|
|
raise NotImplementedError("Method does not exist for GridOutCursor")
|
|
|
|
def remove_option(self, *args, **kwargs):
|
|
raise NotImplementedError("Method does not exist for GridOutCursor")
|
|
|
|
def _clone_base(self, session):
|
|
"""Creates an empty GridOutCursor for information to be copied into.
|
|
"""
|
|
return GridOutCursor(self.__root_collection, session=session)
|