mongo-python-driver/pymongo/database.py
2010-03-19 16:17:59 -04:00

636 lines
23 KiB
Python

# Copyright 2009-2010 10gen, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Database level operations."""
import warnings
from pymongo import helpers
from pymongo.code import Code
from pymongo.collection import Collection
from pymongo.dbref import DBRef
from pymongo.errors import (CollectionInvalid,
InvalidName,
OperationFailure)
from pymongo.son import SON
from pymongo.son_manipulator import (ObjectIdInjector,
ObjectIdShuffler)
def _check_name(name):
"""Check if a database name is valid.
"""
if not name:
raise InvalidName("database name cannot be the empty string")
for invalid_char in [" ", ".", "$", "/", "\\"]:
if invalid_char in name:
raise InvalidName("database names cannot contain the "
"character %r" % invalid_char)
class Database(object):
"""A Mongo database.
"""
def __init__(self, connection, name):
"""Get a database by connection and name.
Raises :class:`TypeError` if `name` is not an instance of
:class:`basestring`. Raises
:class:`~pymongo.errors.InvalidName` if `name` is not a valid
database name.
:Parameters:
- `connection`: a :class:`~pymongo.connection.Connection`
instance
- `name`: database name
.. mongodoc:: databases
"""
if not isinstance(name, basestring):
raise TypeError("name must be an instance of basestring")
_check_name(name)
self.__name = unicode(name)
self.__connection = connection
# TODO remove the callable_value wrappers after deprecation is complete
self.__name_w = helpers.callable_value(self.__name, "Database.name")
self.__connection_w = helpers.callable_value(self.__connection, "Database.connection")
self.__incoming_manipulators = []
self.__incoming_copying_manipulators = []
self.__outgoing_manipulators = []
self.__outgoing_copying_manipulators = []
self.add_son_manipulator(ObjectIdInjector())
self.__system_js = SystemJS(self)
def add_son_manipulator(self, manipulator):
"""Add a new son manipulator to this database.
Newly added manipulators will be applied before existing ones.
:Parameters:
- `manipulator`: the manipulator to add
"""
def method_overwritten(instance, method):
return getattr(instance, method) != getattr(super(instance.__class__, instance), method)
if manipulator.will_copy():
if method_overwritten(manipulator, "transform_incoming"):
self.__incoming_copying_manipulators.insert(0, manipulator)
if method_overwritten(manipulator, "transform_outgoing"):
self.__outgoing_copying_manipulators.insert(0, manipulator)
else:
if method_overwritten(manipulator, "transform_incoming"):
self.__incoming_manipulators.insert(0, manipulator)
if method_overwritten(manipulator, "transform_outgoing"):
self.__outgoing_manipulators.insert(0, manipulator)
@property
def system_js(self):
"""A :class:`SystemJS` helper for this :class:`Database`.
See the documentation for :class:`SystemJS` for more details.
.. versionadded:: 1.5
"""
return self.__system_js
@property
def connection(self):
"""The :class:`~pymongo.connection.Connection` instance for this
:class:`Database`.
.. versionchanged:: 1.3
``connection`` is now a property rather than a method. The
``connection()`` method is deprecated.
"""
return self.__connection_w
@property
def name(self):
"""The name of this :class:`Database`.
.. versionchanged:: 1.3
``name`` is now a property rather than a method. The
``name()`` method is deprecated.
"""
return self.__name_w
def __cmp__(self, other):
if isinstance(other, Database):
return cmp((self.__connection, self.__name),
(other.__connection, other.__name))
return NotImplemented
def __repr__(self):
return "Database(%r, %r)" % (self.__connection, self.__name)
def __getattr__(self, name):
"""Get a collection of this database by name.
Raises InvalidName if an invalid collection name is used.
:Parameters:
- `name`: the name of the collection to get
"""
return Collection(self, name)
def __getitem__(self, name):
"""Get a collection of this database by name.
Raises InvalidName if an invalid collection name is used.
:Parameters:
- `name`: the name of the collection to get
"""
return self.__getattr__(name)
def create_collection(self, name, options=None, **kwargs):
"""Create a new :class:`~pymongo.collection.Collection` in this
database.
Normally collection creation is automatic. This method should
only be used to specify options on
creation. :class:`~pymongo.errors.CollectionInvalid` will be
raised if the collection already exists.
Options should be passed as keyword arguments to this
method. Any of the following options are valid:
- "size": desired initial size for the collection (in
bytes). must be less than or equal to 10000000000. For
capped collections this size is the max size of the
collection.
- "capped": if True, this is a capped collection
- "max": maximum number of objects if capped (optional)
:Parameters:
- `name`: the name of the collection to create
- `options`: DEPRECATED options to use on the new collection
- `**kwargs` (optional): additional keyword arguments will
be passed as options for the create collection command
.. versionchanged:: 1.5
deprecating `options` in favor of kwargs
"""
opts = {"create": True}
if options is not None:
warnings.warn("the options argument to create_collection is "
"deprecated and will be removed. please use "
"kwargs instead.", DeprecationWarning)
opts.update(options)
opts.update(kwargs)
if name in self.collection_names():
raise CollectionInvalid("collection %s already exists" % name)
return Collection(self, name, **opts)
def _fix_incoming(self, son, collection):
"""Apply manipulators to an incoming SON object before it gets stored.
:Parameters:
- `son`: the son object going into the database
- `collection`: the collection the son object is being saved in
"""
for manipulator in self.__incoming_manipulators:
son = manipulator.transform_incoming(son, collection)
for manipulator in self.__incoming_copying_manipulators:
son = manipulator.transform_incoming(son, collection)
return son
def _fix_outgoing(self, son, collection):
"""Apply manipulators to a SON object as it comes out of the database.
:Parameters:
- `son`: the son object coming out of the database
- `collection`: the collection the son object was saved in
"""
for manipulator in reversed(self.__outgoing_manipulators):
son = manipulator.transform_outgoing(son, collection)
for manipulator in reversed(self.__outgoing_copying_manipulators):
son = manipulator.transform_outgoing(son, collection)
return son
def _command(self, command, allowable_errors=[], check=True, sock=None):
warnings.warn("The '_command' method is deprecated. "
"Please use 'command' instead.", DeprecationWarning)
return self.command(command, check=check,
allowable_errors=allowable_errors, _sock=sock)
def command(self, command, value=1,
check=True, allowable_errors=[], _sock=None, **kwargs):
"""Issue a MongoDB command.
Send command `command` to the database and return the
response. If `command` is an instance of :class:`basestring`
then the command {`command`: `value`} will be sent. Otherwise,
`command` must be an instance of :class:`dict` and will be
sent as is.
Any additional keyword arguments will be added to the final
command document before it is sent.
For example, a command like ``{buildinfo: 1}`` can be sent
using:
>>> db.command("buildinfo")
For a command where the value matters, like ``{collstats:
collection_name}`` we can do:
>>> db.command("collstats", collection_name)
For commands that take additional arguments we can use
kwargs. So ``{filemd5: object_id, root: file_root}`` becomes:
>>> db.command("filemd5", object_id, root=file_root)
:Parameters:
- `command`: document representing the command to be issued,
or the name of the command (for simple commands only).
.. note:: the order of keys in the `command` document is
significant (the "verb" must come first), so commands
which require multiple keys (e.g. `findandmodify`)
should use an instance of :class:`~pymongo.son.SON` or
a string and kwargs instead of a Python `dict`.
- `value` (optional): value to use for the command verb when
`command` is passed as a string
- `check` (optional): check the response for errors, raising
:class:`~pymongo.errors.OperationFailure` if there are any
- `allowable_errors`: if `check` is ``True``, error messages
in this list will be ignored by error-checking
- `**kwargs` (optional): additional keyword arguments will
be added to the command document before it is sent
.. versionchanged:: 1.5.1+
Added the `value` argument for string commands, and keyword
arguments for additional command options.
.. versionchanged:: 1.5
`command` can be a string in addition to a full document.
.. versionadded:: 1.4
.. mongodoc:: commands
"""
if isinstance(command, basestring):
command = SON([(command, value)])
command.update(kwargs)
result = self["$cmd"].find_one(command, _sock=_sock,
_must_use_master=True,
_is_command=True)
if check and result["ok"] != 1:
if result["errmsg"] in allowable_errors:
return result
raise OperationFailure("command %r failed: %s" %
(command, result["errmsg"]))
return result
def collection_names(self):
"""Get a list of all the collection names in this database.
"""
results = self["system.namespaces"].find(_must_use_master=True)
names = [r["name"] for r in results]
names = [n[len(self.__name) + 1:] for n in names
if n.startswith(self.__name + ".")]
names = [n for n in names if "$" not in n]
return names
def drop_collection(self, name_or_collection):
"""Drop a collection.
:Parameters:
- `name_or_collection`: the name of a collection to drop or the
collection object itself
"""
name = name_or_collection
if isinstance(name, Collection):
name = name.name
if not isinstance(name, basestring):
raise TypeError("name_or_collection must be an instance of "
"(Collection, str, unicode)")
self.__connection._purge_index(self.__name, name)
if name not in self.collection_names():
return
self.command("drop", unicode(name))
def validate_collection(self, name_or_collection):
"""Validate a collection.
Returns a string of validation info. Raises CollectionInvalid if
validation fails.
"""
name = name_or_collection
if isinstance(name, Collection):
name = name.name
if not isinstance(name, basestring):
raise TypeError("name_or_collection must be an instance of "
"(Collection, str, unicode)")
result = self.command("validate", unicode(name))
info = result["result"]
if info.find("exception") != -1 or info.find("corrupt") != -1:
raise CollectionInvalid("%s invalid: %s" % (name, info))
return info
def profiling_level(self):
"""Get the database's current profiling level.
Returns one of (:data:`~pymongo.OFF`,
:data:`~pymongo.SLOW_ONLY`, :data:`~pymongo.ALL`).
.. mongodoc:: profiling
"""
result = self.command("profile", -1)
assert result["was"] >= 0 and result["was"] <= 2
return result["was"]
def set_profiling_level(self, level):
"""Set the database's profiling level.
Raises :class:`ValueError` if level is not one of
(:data:`~pymongo.OFF`, :data:`~pymongo.SLOW_ONLY`,
:data:`~pymongo.ALL`).
:Parameters:
- `level`: the profiling level to use
.. mongodoc:: profiling
"""
if not isinstance(level, int) or level < 0 or level > 2:
raise ValueError("level must be one of (OFF, SLOW_ONLY, ALL)")
self.command("profile", level)
def profiling_info(self):
"""Returns a list containing current profiling information.
.. mongodoc:: profiling
"""
return list(self["system.profile"].find())
def error(self):
"""Get a database error if one occured on the last operation.
Return None if the last operation was error-free. Otherwise return the
error that occurred.
"""
error = self.command("getlasterror")
if error.get("err", 0) is None:
return None
if error["err"] == "not master":
self.__connection._reset()
return error
def last_status(self):
"""Get status information from the last operation.
Returns a SON object with status information.
"""
return self.command("getlasterror")
def previous_error(self):
"""Get the most recent error to have occurred on this database.
Only returns errors that have occurred since the last call to
`Database.reset_error_history`. Returns None if no such errors have
occurred.
"""
error = self.command("getpreverror")
if error.get("err", 0) is None:
return None
return error
def reset_error_history(self):
"""Reset the error history of this database.
Calls to `Database.previous_error` will only return errors that have
occurred since the most recent call to this method.
"""
self.command("reseterror")
def __iter__(self):
return self
def next(self):
raise TypeError("'Database' object is not iterable")
def add_user(self, name, password):
"""Create user `name` with password `password`.
Add a new user with permissions for this :class:`Database`.
.. note:: Will change the password if user `name` already exists.
:Parameters:
- `name`: the name of the user to create
- `password`: the password of the user to create
.. versionadded:: 1.4
"""
self.system.users.update({"user": name},
{"user": name,
"pwd": helpers._password_digest(name, password)},
upsert=True, safe=True)
def remove_user(self, name):
"""Remove user `name` from this :class:`Database`.
User `name` will no longer have permissions to access this
:class:`Database`.
:Paramaters:
- `name`: the name of the user to remove
.. versionadded:: 1.4
"""
self.system.users.remove({"user": name}, safe=True)
def authenticate(self, name, password):
"""Authenticate to use this database.
Once authenticated, the user has full read and write access to
this database. Raises :class:`TypeError` if either `name` or
`password` is not an instance of ``(str,
unicode)``. Authentication lasts for the life of the database
connection, or until :meth:`logout` is called.
The "admin" database is special. Authenticating on "admin"
gives access to *all* databases. Effectively, "admin" access
means root access to the database.
.. note:: Currently, authentication is per
:class:`~socket.socket`. This means that there are a couple
of situations in which re-authentication is necessary:
- On failover (when an
:class:`~pymongo.errors.AutoReconnect` exception is
raised).
- After a call to
:meth:`~pymongo.connection.Connection.disconnect` or
:meth:`~pymongo.connection.Connection.end_request`.
- When sharing a :class:`~pymongo.connection.Connection`
between multiple threads, each thread will need to
authenticate separately.
.. warning:: Currently, calls to
:meth:`~pymongo.connection.Connection.end_request` will
lead to unpredictable behavior in combination with
auth. The :class:`~socket.socket` owned by the calling
thread will be returned to the pool, so whichever thread
uses that :class:`~socket.socket` next will have whatever
permissions were granted to the calling thread.
:Parameters:
- `name`: the name of the user to authenticate
- `password`: the password of the user to authenticate
.. mongodoc:: authenticate
"""
if not isinstance(name, basestring):
raise TypeError("name must be an instance of basestring")
if not isinstance(password, basestring):
raise TypeError("password must be an instance of basestring")
nonce = self.command("getnonce")["nonce"]
key = helpers._auth_key(nonce, name, password)
try:
self.command("authenticate", user=unicode(name), nonce=nonce, key=key)
return True
except OperationFailure:
return False
def logout(self):
"""Deauthorize use of this database for this connection.
Note that other databases may still be authorized.
"""
self.command("logout")
def dereference(self, dbref):
"""Dereference a DBRef, getting the SON object it points to.
Raises TypeError if `dbref` is not an instance of DBRef. Returns a SON
object or None if the reference does not point to a valid object. Raises
ValueError if `dbref` has a database specified that is different from
the current database.
:Parameters:
- `dbref`: the reference
"""
if not isinstance(dbref, DBRef):
raise TypeError("cannot dereference a %s" % type(dbref))
if dbref.database is not None and dbref.database != self.__name:
raise ValueError("trying to dereference a DBRef that points to "
"another database (%r not %r)" % (dbref.database,
self.__name))
return self[dbref.collection].find_one({"_id": dbref.id})
def eval(self, code, *args):
"""Evaluate a JavaScript expression on the Mongo server.
Useful if you need to touch a lot of data lightly; in such a scenario
the network transfer of the data could be a bottleneck. The `code`
argument must be a JavaScript function. Additional positional
arguments will be passed to that function when it is run on the
server.
Raises TypeError if `code` is not an instance of (str, unicode,
`Code`). Raises OperationFailure if the eval fails. Returns the result
of the evaluation.
:Parameters:
- `code`: string representation of JavaScript code to be evaluated
- `args` (optional): additional positional arguments are passed to
the `code` being evaluated
"""
if not isinstance(code, Code):
code = Code(code)
result = self.command("$eval", code, args=args)
return result.get("retval", None)
def __call__(self, *args, **kwargs):
"""This is only here so that some API misusages are easier to debug.
"""
raise TypeError("'Database' object is not callable. If you meant to "
"call the '%s' method on a 'Collection' object it is "
"failing because no such method exists." % self.__name)
class SystemJS(object):
"""Helper class for dealing with stored JavaScript.
"""
def __init__(self, database):
"""Get a system js helper for the database `database`.
An instance of :class:`SystemJS` is automatically created for
each :class:`Database` instance as :attr:`Database.system_js`,
manual instantiation of this class should not be necessary.
:class:`SystemJS` instances allow for easy manipulation and
access to `server-side JavaScript`_:
.. doctest::
>>> db.system_js.add1 = "function (x) { return x + 1; }"
>>> db.system.js.find({"_id": "add1"}).count()
1
>>> db.system_js.add1(5)
6.0
>>> del db.system_js.add1
>>> db.system.js.find({"_id": "add1"}).count()
0
.. note:: Requires server version **>= 1.1.1**
.. versionadded:: 1.5
.. _server-side JavaScript: http://www.mongodb.org/display/DOCS/Server-side+Code+Execution#Server-sideCodeExecution-Storingfunctionsserverside
"""
# can't just assign it since we've overridden __setattr__
object.__setattr__(self, "_database", database)
def __setattr__(self, name, code):
self._database.system.js.save({"_id": name, "value": Code(code)},
safe=True)
def __delattr__(self, name):
self._database.system.js.remove({"_id": name}, safe=True)
def __getattr__(self, name):
return lambda *args: self._database.eval("function() { return %s."
"apply(this, "
"arguments); }" % name,
*args)