odoo_source/odoo/api.py

# -*- coding: utf-8 -*-
# Part of Odoo. See LICENSE file for full copyright and licensing details.

"""The Odoo API module defines Odoo Environments and method decorators.

.. todo:: Document this module
"""

__all__ = [
    'Environment',
    'Meta',
    'model',
    'constrains', 'depends', 'onchange', 'returns',
    'call_kw',
]

import logging
import warnings
from collections import defaultdict
from collections.abc import Mapping
from contextlib import contextmanager
from inspect import signature
from pprint import pformat
from weakref import WeakSet

from decorator import decorate

from .exceptions import CacheMiss
from .tools import frozendict, classproperty, lazy_property, StackMap
from .tools.translate import _

_logger = logging.getLogger(__name__)

# The following attributes are used, and reflected on wrapping methods:
#  - method._constrains: set by @constrains, specifies constraint dependencies
#  - method._depends: set by @depends, specifies compute dependencies
#  - method._returns: set by @returns, specifies return model
#  - method._onchange: set by @onchange, specifies onchange fields
#  - method.clear_cache: set by @ormcache, used to clear the cache
#  - method._ondelete: set by @ondelete, used to raise errors for unlink operations
#
# On wrapping method only:
#  - method._api: decorator function, used for re-applying decorator
#

INHERITED_ATTRS = ('_returns',)


class Params(object):
    def __init__(self, args, kwargs):
        self.args = args
        self.kwargs = kwargs

    def __str__(self):
        params = []
        for arg in self.args:
            params.append(repr(arg))
        for item in sorted(self.kwargs.items()):
            params.append("%s=%r" % item)
        return ', '.join(params)


class Meta(type):
    """ Metaclass that automatically decorates traditional-style methods by
        guessing their API. It also implements the inheritance of the
        :func:`returns` decorators.
    """

    def __new__(meta, name, bases, attrs):
        # dummy parent class to catch overridden methods decorated with 'returns'
        parent = type.__new__(meta, name, bases, {})

        for key, value in list(attrs.items()):
            if not key.startswith('__') and callable(value):
                # make the method inherit from decorators
                value = propagate(getattr(parent, key, None), value)
                attrs[key] = value

        return type.__new__(meta, name, bases, attrs)


def attrsetter(attr, value):
    """ Return a function that sets ``attr`` on its argument and returns it. """
    return lambda method: setattr(method, attr, value) or method

def propagate(method1, method2):
    """ Propagate decorators from ``method1`` to ``method2``, and return the
        resulting method.
    """
    if method1:
        for attr in INHERITED_ATTRS:
            if hasattr(method1, attr) and not hasattr(method2, attr):
                setattr(method2, attr, getattr(method1, attr))
    return method2


def constrains(*args):
    """Decorate a constraint checker.

    Each argument must be a field name used in the check::

        @api.constrains('name', 'description')
        def _check_description(self):
            for record in self:
                if record.name == record.description:
                    raise ValidationError("Fields name and description must be different")

    Invoked on the records on which one of the named fields has been modified.

    Should raise :exc:`~odoo.exceptions.ValidationError` if the
    validation failed.

    .. warning::

        ``@constrains`` only supports simple field names, dotted names
        (fields of relational fields e.g. ``partner_id.customer``) are not
        supported and will be ignored.

        ``@constrains`` will be triggered only if the declared fields in the
        decorated method are included in the ``create`` or ``write`` call.
        It implies that fields not present in a view will not trigger a call
        during a record creation. A override of ``create`` is necessary to make
        sure a constraint will always be triggered (e.g. to test the absence of
        value).

    One may also pass a single function as argument.  In that case, the field
    names are given by calling the function with a model instance.

    """
    if args and callable(args[0]):
        args = args[0]
    return attrsetter('_constrains', args)


def ondelete(*, at_uninstall):
    """
    Mark a method to be executed during :meth:`~odoo.models.BaseModel.unlink`.

    The goal of this decorator is to allow client-side errors when unlinking
    records if, from a business point of view, it does not make sense to delete
    such records. For instance, a user should not be able to delete a validated
    sales order.

    While this could be implemented by simply overriding the method ``unlink``
    on the model, it has the drawback of not being compatible with module
    uninstallation. When uninstalling the module, the override could raise user
    errors, but we shouldn't care because the module is being uninstalled, and
    thus **all** records related to the module should be removed anyway.

    This means that by overriding ``unlink``, there is a big chance that some
    tables/records may remain as leftover data from the uninstalled module. This
    leaves the database in an inconsistent state. Moreover, there is a risk of
    conflicts if the module is ever reinstalled on that database.

    Methods decorated with ``@ondelete`` should raise an error following some
    conditions, and by convention, the method should be named either
    ``_unlink_if_<condition>`` or ``_unlink_except_<not_condition>``.

    .. code-block:: python

        @api.ondelete(at_uninstall=False)
        def _unlink_if_user_inactive(self):
            if any(user.active for user in self):
                raise UserError("Can't delete an active user!")

        # same as above but with _unlink_except_* as method name
        @api.ondelete(at_uninstall=False)
        def _unlink_except_active_user(self):
            if any(user.active for user in self):
                raise UserError("Can't delete an active user!")

    :param bool at_uninstall: Whether the decorated method should be called if
        the module that implements said method is being uninstalled. Should
        almost always be ``False``, so that module uninstallation does not
        trigger those errors.

    .. danger::
        The parameter ``at_uninstall`` should only be set to ``True`` if the
        check you are implementing also applies when uninstalling the module.

        For instance, it doesn't matter if when uninstalling ``sale``, validated
        sales orders are being deleted because all data pertaining to ``sale``
        should be deleted anyway, in that case ``at_uninstall`` should be set to
        ``False``.

        However, it makes sense to prevent the removal of the default language
        if no other languages are installed, since deleting the default language
        will break a lot of basic behavior. In this case, ``at_uninstall``
        should be set to ``True``.
    """
    return attrsetter('_ondelete', at_uninstall)


def onchange(*args):
    """Return a decorator to decorate an onchange method for given fields.

    In the form views where the field appears, the method will be called
    when one of the given fields is modified. The method is invoked on a
    pseudo-record that contains the values present in the form. Field
    assignments on that record are automatically sent back to the client.

    Each argument must be a field name::

        @api.onchange('partner_id')
        def _onchange_partner(self):
            self.message = "Dear %s" % (self.partner_id.name or "")

    .. code-block:: python

        return {
            'warning': {'title': "Warning", 'message': "What is this?", 'type': 'notification'},
        }

    If the type is set to notification, the warning will be displayed in a notification.
    Otherwise it will be displayed in a dialog as default.

    .. warning::

        ``@onchange`` only supports simple field names, dotted names
        (fields of relational fields e.g. ``partner_id.tz``) are not
        supported and will be ignored

    .. danger::

        Since ``@onchange`` returns a recordset of pseudo-records,
        calling any one of the CRUD methods
        (:meth:`create`, :meth:`read`, :meth:`write`, :meth:`unlink`)
        on the aforementioned recordset is undefined behaviour,
        as they potentially do not exist in the database yet.

        Instead, simply set the record's field like shown in the example
        above or call the :meth:`update` method.

    .. warning::

        It is not possible for a ``one2many`` or ``many2many`` field to modify
        itself via onchange. This is a webclient limitation - see `#2693 <https://github.com/odoo/odoo/issues/2693>`_.

    """
    return attrsetter('_onchange', args)


def depends(*args):
    """ Return a decorator that specifies the field dependencies of a "compute"
        method (for new-style function fields). Each argument must be a string
        that consists in a dot-separated sequence of field names::

            pname = fields.Char(compute='_compute_pname')

            @api.depends('partner_id.name', 'partner_id.is_company')
            def _compute_pname(self):
                for record in self:
                    if record.partner_id.is_company:
                        record.pname = (record.partner_id.name or "").upper()
                    else:
                        record.pname = record.partner_id.name

        One may also pass a single function as argument. In that case, the
        dependencies are given by calling the function with the field's model.
    """
    if args and callable(args[0]):
        args = args[0]
    elif any('id' in arg.split('.') for arg in args):
        raise NotImplementedError("Compute method cannot depend on field 'id'.")
    return attrsetter('_depends', args)


def depends_context(*args):
    """ Return a decorator that specifies the context dependencies of a
    non-stored "compute" method.  Each argument is a key in the context's
    dictionary::

        price = fields.Float(compute='_compute_product_price')

        @api.depends_context('pricelist')
        def _compute_product_price(self):
            for product in self:
                if product.env.context.get('pricelist'):
                    pricelist = self.env['product.pricelist'].browse(product.env.context['pricelist'])
                else:
                    pricelist = self.env['product.pricelist'].get_default_pricelist()
                product.price = pricelist._get_products_price(product).get(product.id, 0.0)

    All dependencies must be hashable.  The following keys have special
    support:

    * `company` (value in context or current company id),
    * `uid` (current user id and superuser flag),
    * `active_test` (value in env.context or value in field.context).
    """
    return attrsetter('_depends_context', args)


def returns(model, downgrade=None, upgrade=None):
    """ Return a decorator for methods that return instances of ``model``.

        :param model: a model name, or ``'self'`` for the current model

        :param downgrade: a function ``downgrade(self, value, *args, **kwargs)``
            to convert the record-style ``value`` to a traditional-style output

        :param upgrade: a function ``upgrade(self, value, *args, **kwargs)``
            to convert the traditional-style ``value`` to a record-style output

        The arguments ``self``, ``*args`` and ``**kwargs`` are the ones passed
        to the method in the record-style.

        The decorator adapts the method output to the api style: ``id``, ``ids`` or
        ``False`` for the traditional style, and recordset for the record style::

            @model
            @returns('res.partner')
            def find_partner(self, arg):
                ...     # return some record

            # output depends on call style: traditional vs record style
            partner_id = model.find_partner(cr, uid, arg, context=context)

            # recs = model.browse(cr, uid, ids, context)
            partner_record = recs.find_partner(arg)

        Note that the decorated method must satisfy that convention.

        Those decorators are automatically *inherited*: a method that overrides
        a decorated existing method will be decorated with the same
        ``@returns(model)``.
    """
    return attrsetter('_returns', (model, downgrade, upgrade))


def downgrade(method, value, self, args, kwargs):
    """ Convert ``value`` returned by ``method`` on ``self`` to traditional style. """
    spec = getattr(method, '_returns', None)
    if not spec:
        return value
    _, convert, _ = spec
    if convert and len(signature(convert).parameters) > 1:
        return convert(self, value, *args, **kwargs)
    elif convert:
        return convert(value)
    else:
        return value.ids


def split_context(method, args, kwargs):
    """ Extract the context from a pair of positional and keyword arguments.
        Return a triple ``context, args, kwargs``.
    """
    # altering kwargs is a cause of errors, for instance when retrying a request
    # after a serialization error: the retry is done without context!
    kwargs = kwargs.copy()
    return kwargs.pop('context', None), args, kwargs


def autovacuum(method):
    """
    Decorate a method so that it is called by the daily vacuum cron job (model
    ``ir.autovacuum``).  This is typically used for garbage-collection-like
    tasks that do not deserve a specific cron job.
    """
    assert method.__name__.startswith('_'), "%s: autovacuum methods must be private" % method.__name__
    method._autovacuum = True
    return method


def model(method):
    """ Decorate a record-style method where ``self`` is a recordset, but its
        contents is not relevant, only the model is. Such a method::

            @api.model
            def method(self, args):
                ...

    """
    if method.__name__ == 'create':
        return model_create_single(method)
    method._api = 'model'
    return method


_create_logger = logging.getLogger(__name__ + '.create')


def _model_create_single(create, self, arg):
    # 'create' expects a dict and returns a record
    if isinstance(arg, Mapping):
        return create(self, arg)
    if len(arg) > 1:
        _create_logger.debug("%s.create() called with %d dicts", self, len(arg))
    return self.browse().concat(*(create(self, vals) for vals in arg))


def model_create_single(method):
    """ Decorate a method that takes a dictionary and creates a single record.
        The method may be called with either a single dict or a list of dicts::

            record = model.create(vals)
            records = model.create([vals, ...])
    """
    _create_logger.warning("The model %s is not overriding the create method in batch", method.__module__)
    wrapper = decorate(method, _model_create_single)
    wrapper._api = 'model_create'
    return wrapper


def _model_create_multi(create, self, arg):
    # 'create' expects a list of dicts and returns a recordset
    if isinstance(arg, Mapping):
        return create(self, [arg])
    return create(self, arg)


def model_create_multi(method):
    """ Decorate a method that takes a list of dictionaries and creates multiple
        records. The method may be called with either a single dict or a list of
        dicts::

            record = model.create(vals)
            records = model.create([vals, ...])
    """
    wrapper = decorate(method, _model_create_multi)
    wrapper._api = 'model_create'
    return wrapper


def _call_kw_model(method, self, args, kwargs):
    context, args, kwargs = split_context(method, args, kwargs)
    recs = self.with_context(context or {})
    _logger.debug("call %s.%s(%s)", recs, method.__name__, Params(args, kwargs))
    result = method(recs, *args, **kwargs)
    return downgrade(method, result, recs, args, kwargs)


def _call_kw_model_create(method, self, args, kwargs):
    # special case for method 'create'
    context, args, kwargs = split_context(method, args, kwargs)
    recs = self.with_context(context or {})
    _logger.debug("call %s.%s(%s)", recs, method.__name__, Params(args, kwargs))
    result = method(recs, *args, **kwargs)
    return result.id if isinstance(args[0], Mapping) else result.ids


def _call_kw_multi(method, self, args, kwargs):
    ids, args = args[0], args[1:]
    context, args, kwargs = split_context(method, args, kwargs)
    recs = self.with_context(context or {}).browse(ids)
    _logger.debug("call %s.%s(%s)", recs, method.__name__, Params(args, kwargs))
    result = method(recs, *args, **kwargs)
    return downgrade(method, result, recs, args, kwargs)


def call_kw(model, name, args, kwargs):
    """ Invoke the given method ``name`` on the recordset ``model``. """
    method = getattr(type(model), name)
    api = getattr(method, '_api', None)
    if api == 'model':
        result = _call_kw_model(method, model, args, kwargs)
    elif api == 'model_create':
        result = _call_kw_model_create(method, model, args, kwargs)
    else:
        result = _call_kw_multi(method, model, args, kwargs)
    model.flush()
    return result


class Environment(Mapping):
    """ An environment wraps data for ORM records:

        - :attr:`cr`, the current database cursor;
        - :attr:`uid`, the current user id;
        - :attr:`context`, the current context dictionary;
        - :attr:`su`, whether in superuser mode.

        It provides access to the registry by implementing a mapping from model
        names to new api models. It also holds a cache for records, and a data
        structure to manage recomputations.
    """
    @classproperty
    def envs(cls):
        raise NotImplementedError(
            "Since Odoo 15.0, Environment.envs no longer works; "
            "use cr.transaction or env.transaction instead."
        )

    @classmethod
    @contextmanager
    def manage(cls):
        warnings.warn(
            "Since Odoo 15.0, Environment.manage() is useless.",
            DeprecationWarning, stacklevel=2,
        )
        yield

    def reset(self):
        """ Reset the transaction, see :meth:`Transaction.reset`. """
        self.transaction.reset()

    def __new__(cls, cr, uid, context, su=False):
        if uid == SUPERUSER_ID:
            su = True
        assert context is not None
        args = (cr, uid, context, su)

        # determine transaction object
        transaction = cr.transaction
        if transaction is None:
            transaction = cr.transaction = Transaction(Registry(cr.dbname))

        # if env already exists, return it
        for env in transaction.envs:
            if env.args == args:
                return env

        # otherwise create environment, and add it in the set
        self = object.__new__(cls)
        args = (cr, uid, frozendict(context), su)
        self.cr, self.uid, self.context, self.su = self.args = args

        self.transaction = self.all = transaction
        self.registry = transaction.registry
        self.cache = transaction.cache
        self._cache_key = {}                    # memo {field: cache_key}
        self._protected = transaction.protected
        transaction.envs.add(self)
        return self

    #
    # Mapping methods
    #

    def __contains__(self, model_name):
        """ Test whether the given model exists. """
        return model_name in self.registry

    def __getitem__(self, model_name):
        """ Return an empty recordset from the given model. """
        return self.registry[model_name]._browse(self, (), ())

    def __iter__(self):
        """ Return an iterator on model names. """
        return iter(self.registry)

    def __len__(self):
        """ Return the size of the model registry. """
        return len(self.registry)

    def __eq__(self, other):
        return self is other

    def __ne__(self, other):
        return self is not other

    def __hash__(self):
        return object.__hash__(self)

    def __call__(self, cr=None, user=None, context=None, su=None):
        """ Return an environment based on ``self`` with modified parameters.

            :param cr: optional database cursor to change the current cursor
            :param user: optional user/user id to change the current user
            :param context: optional context dictionary to change the current context
            :param su: optional boolean to change the superuser mode
            :type context: dict
            :type user: int or :class:`~odoo.addons.base.models.res_users`
            :type su: bool
        """
        cr = self.cr if cr is None else cr
        uid = self.uid if user is None else int(user)
        context = self.context if context is None else context
        su = (user is None and self.su) if su is None else su
        return Environment(cr, uid, context, su)

    def ref(self, xml_id, raise_if_not_found=True):
        """Return the record corresponding to the given ``xml_id``."""
        res_model, res_id = self['ir.model.data']._xmlid_to_res_model_res_id(
            xml_id, raise_if_not_found=raise_if_not_found
        )

        if res_model and res_id:
            record = self[res_model].browse(res_id)
            if record.exists():
                return record
            if raise_if_not_found:
                raise ValueError('No record found for unique ID %s. It may have been deleted.' % (xml_id))
        return None

    def is_superuser(self):
        """ Return whether the environment is in superuser mode. """
        return self.su

    def is_admin(self):
        """ Return whether the current user has group "Access Rights", or is in
            superuser mode. """
        return self.su or self.user._is_admin()

    def is_system(self):
        """ Return whether the current user has group "Settings", or is in
            superuser mode. """
        return self.su or self.user._is_system()

    @lazy_property
    def user(self):
        """Return the current user (as an instance).

        :returns: current user - sudoed
        :rtype: :class:`~odoo.addons.base.models.res_users`"""
        return self(su=True)['res.users'].browse(self.uid)

    @lazy_property
    def company(self):
        """Return the current company (as an instance).

        If not specified in the context (`allowed_company_ids`),
        fallback on current user main company.

        :raise AccessError: invalid or unauthorized `allowed_company_ids` context key content.
        :return: current company (default=`self.user.company_id`), with the current environment
        :rtype: res.company

        .. warning::

            No sanity checks applied in sudo mode !
            When in sudo mode, a user can access any company,
            even if not in his allowed companies.

            This allows to trigger inter-company modifications,
            even if the current user doesn't have access to
            the targeted company.
        """
        company_ids = self.context.get('allowed_company_ids', [])
        if company_ids:
            if not self.su:
                user_company_ids = self.user.company_ids.ids
                if any(cid not in user_company_ids for cid in company_ids):
                    raise AccessError(_("Access to unauthorized or invalid companies."))
            return self['res.company'].browse(company_ids[0])
        return self.user.company_id.with_env(self)

    @lazy_property
    def companies(self):
        """Return a recordset of the enabled companies by the user.

        If not specified in the context(`allowed_company_ids`),
        fallback on current user companies.

        :raise AccessError: invalid or unauthorized `allowed_company_ids` context key content.
        :return: current companies (default=`self.user.company_ids`), with the current environment
        :rtype: res.company

        .. warning::

            No sanity checks applied in sudo mode !
            When in sudo mode, a user can access any company,
            even if not in his allowed companies.

            This allows to trigger inter-company modifications,
            even if the current user doesn't have access to
            the targeted company.
        """
        company_ids = self.context.get('allowed_company_ids', [])
        if company_ids:
            if not self.su:
                user_company_ids = self.user.company_ids.ids
                if any(cid not in user_company_ids for cid in company_ids):
                    raise AccessError(_("Access to unauthorized or invalid companies."))
            return self['res.company'].browse(company_ids)
        # By setting the default companies to all user companies instead of the main one
        # we save a lot of potential trouble in all "out of context" calls, such as
        # /mail/redirect or /web/image, etc. And it is not unsafe because the user does
        # have access to these other companies. The risk of exposing foreign records
        # (wrt to the context) is low because all normal RPCs will have a proper
        # allowed_company_ids.
        # Examples:
        #   - when printing a report for several records from several companies
        #   - when accessing to a record from the notification email template
        #   - when loading an binary image on a template
        return self.user.company_ids.with_env(self)

    @property
    def lang(self):
        """Return the current language code.

        :rtype: str
        """
        return self.context.get('lang')

    def clear(self):
        """ Clear all record caches, and discard all fields to recompute.
            This may be useful when recovering from a failed ORM operation.
        """
        lazy_property.reset_all(self)
        self.transaction.clear()

    def clear_upon_failure(self):
        """ Context manager that rolls back the environments (caches and pending
            computations and updates) upon exception.
        """
        warnings.warn(
            "Since Odoo 15.0, use cr.savepoint() instead of env.clear_upon_failure().",
            DeprecationWarning, stacklevel=2,
        )
        return self.cr.savepoint()

    def is_protected(self, field, record):
        """ Return whether `record` is protected against invalidation or
            recomputation for `field`.
        """
        return record.id in self._protected.get(field, ())

    def protected(self, field):
        """ Return the recordset for which ``field`` should not be invalidated or recomputed. """
        return self[field.model_name].browse(self._protected.get(field, ()))

    @contextmanager
    def protecting(self, what, records=None):
        """ Prevent the invalidation or recomputation of fields on records.
        The parameters are either:

        - ``what`` a collection of fields and ``records`` a recordset, or
        - ``what`` a collection of pairs ``(fields, records)``.
        """
        protected = self._protected
        try:
            protected.pushmap()
            if records is not None:  # Handle first signature
                ids_by_field = {field: records._ids for field in what}
            else:  # Handle second signature
                ids_by_field = defaultdict(list)
                for fields, what_records in what:
                    for field in fields:
                        ids_by_field[field].extend(what_records._ids)

            for field, rec_ids in ids_by_field.items():
                ids = protected.get(field)
                protected[field] = ids.union(rec_ids) if ids else frozenset(rec_ids)
            yield
        finally:
            protected.popmap()

    def fields_to_compute(self):
        """ Return a view on the field to compute. """
        return self.all.tocompute.keys()

    def records_to_compute(self, field):
        """ Return the records to compute for ``field``. """
        ids = self.all.tocompute.get(field, ())
        return self[field.model_name].browse(ids)

    def is_to_compute(self, field, record):
        """ Return whether ``field`` must be computed on ``record``. """
        return record.id in self.all.tocompute.get(field, ())

    def not_to_compute(self, field, records):
        """ Return the subset of ``records`` for which ``field`` must not be computed. """
        ids = self.all.tocompute.get(field, ())
        return records.browse(id_ for id_ in records._ids if id_ not in ids)

    def add_to_compute(self, field, records):
        """ Mark ``field`` to be computed on ``records``. """
        if not records:
            return records
        self.all.tocompute[field].update(records._ids)

    def remove_to_compute(self, field, records):
        """ Mark ``field`` as computed on ``records``. """
        if not records:
            return
        ids = self.all.tocompute.get(field, None)
        if ids is None:
            return
        ids.difference_update(records._ids)
        if not ids:
            del self.all.tocompute[field]

    @contextmanager
    def norecompute(self):
        """ Delay recomputations (deprecated: this is not the default behavior). """
        yield

    def cache_key(self, field):
        """ Return the cache key of the given ``field``. """
        try:
            return self._cache_key[field]

        except KeyError:
            def get(key, get_context=self.context.get):
                if key == 'company':
                    return self.company.id
                elif key == 'uid':
                    return (self.uid, self.su)
                elif key == 'active_test':
                    return get_context('active_test', field.context.get('active_test', True))
                else:
                    val = get_context(key)
                    if type(val) is list:
                        val = tuple(val)
                    try:
                        hash(val)
                    except TypeError:
                        raise TypeError(
                            "Can only create cache keys from hashable values, "
                            "got non-hashable value {!r} at context key {!r} "
                            "(dependency of field {})".format(val, key, field)
                        ) from None  # we don't need to chain the exception created 2 lines above
                    else:
                        return val

            result = tuple(get(key) for key in self.registry.field_depends_context[field])
            self._cache_key[field] = result
            return result


class Transaction:
    """ A object holding ORM data structures for a transaction. """
    def __init__(self, registry):
        self.registry = registry
        # weak set of environments
        self.envs = WeakSet()
        # cache for all records
        self.cache = Cache()
        # fields to protect {field: ids}
        self.protected = StackMap()
        # pending computations {field: ids}
        self.tocompute = defaultdict(set)
        # pending updates {model: {id: {field: value}}}
        self.towrite = defaultdict(lambda: defaultdict(dict))

    def flush(self):
        """ Flush pending computations and updates in the transaction. """
        env_to_flush = None
        for env in self.envs:
            if isinstance(env.uid, int) or env.uid is None:
                env_to_flush = env
                if env.uid is not None:
                    break
        if env_to_flush is not None:
            env_to_flush['base'].flush()

    def clear(self):
        """ Clear the caches and pending computations and updates in the translations. """
        self.cache.invalidate()
        self.tocompute.clear()
        self.towrite.clear()

    def reset(self):
        """ Reset the transaction.  This clears the transaction, and reassigns
            the registry on all its environments.  This operation is strongly
            recommended after reloading the registry.
        """
        self.registry = Registry(self.registry.db_name)
        for env in self.envs:
            env.registry = self.registry
            lazy_property.reset_all(env)
        self.clear()


# sentinel value for optional parameters
NOTHING = object()
EMPTY_DICT = frozendict()


class Cache(object):
    """ Implementation of the cache of records. """
    def __init__(self):
        # {field: {record_id: value}, field: {context_key: {record_id: value}}}
        self._data = defaultdict(dict)

    def _get_field_cache(self, model, field):
        """ Return the field cache of the given field, but not for modifying it. """
        field_cache = self._data.get(field, EMPTY_DICT)
        if field_cache and model.pool.field_depends_context[field]:
            field_cache = field_cache.get(model.env.cache_key(field), EMPTY_DICT)
        return field_cache

    def _set_field_cache(self, model, field):
        """ Return the field cache of the given field for modifying it. """
        field_cache = self._data[field]
        if model.pool.field_depends_context[field]:
            field_cache = field_cache.setdefault(model.env.cache_key(field), {})
        return field_cache

    def contains(self, record, field):
        """ Return whether ``record`` has a value for ``field``. """
        return record.id in self._get_field_cache(record, field)

    def get(self, record, field, default=NOTHING):
        """ Return the value of ``field`` for ``record``. """
        try:
            field_cache = self._get_field_cache(record, field)
            return field_cache[record._ids[0]]
        except KeyError:
            if default is NOTHING:
                raise CacheMiss(record, field)
            return default

    def set(self, record, field, value):
        """ Set the value of ``field`` for ``record``. """
        field_cache = self._set_field_cache(record, field)
        field_cache[record._ids[0]] = value

    def update(self, records, field, values):
        """ Set the values of ``field`` for several ``records``. """
        field_cache = self._set_field_cache(records, field)
        field_cache.update(zip(records._ids, values))

    def remove(self, record, field):
        """ Remove the value of ``field`` for ``record``. """
        try:
            field_cache = self._set_field_cache(record, field)
            del field_cache[record._ids[0]]
        except KeyError:
            pass

    def get_values(self, records, field):
        """ Return the cached values of ``field`` for ``records``. """
        field_cache = self._get_field_cache(records, field)
        for record_id in records._ids:
            try:
                yield field_cache[record_id]
            except KeyError:
                pass

    def get_until_miss(self, records, field):
        """ Return the cached values of ``field`` for ``records`` until a value is not found. """
        field_cache = self._get_field_cache(records, field)
        vals = []
        for record_id in records._ids:
            try:
                vals.append(field_cache[record_id])
            except KeyError:
                break
        return vals

    def get_records_different_from(self, records, field, value):
        """ Return the subset of ``records`` that has not ``value`` for ``field``. """
        field_cache = self._get_field_cache(records, field)
        ids = []
        for record_id in records._ids:
            try:
                val = field_cache[record_id]
            except KeyError:
                ids.append(record_id)
            else:
                if val != value:
                    ids.append(record_id)
        return records.browse(ids)

    def get_fields(self, record):
        """ Return the fields with a value for ``record``. """
        for name, field in record._fields.items():
            if name != 'id' and record.id in self._get_field_cache(record, field):
                yield field

    def get_records(self, model, field):
        """ Return the records of ``model`` that have a value for ``field``. """
        field_cache = self._get_field_cache(model, field)
        return model.browse(field_cache)

    def get_missing_ids(self, records, field):
        """ Return the ids of ``records`` that have no value for ``field``. """
        field_cache = self._get_field_cache(records, field)
        for record_id in records._ids:
            if record_id not in field_cache:
                yield record_id

    def invalidate(self, spec=None):
        """ Invalidate the cache, partially or totally depending on ``spec``. """
        if spec is None:
            self._data.clear()
        elif spec:
            for field, ids in spec:
                if ids is None:
                    self._data.pop(field, None)
                    continue
                cache = self._data.get(field)
                if not cache:
                    continue
                caches = cache.values() if isinstance(next(iter(cache)), tuple) else [cache]
                for field_cache in caches:
                    for id_ in ids:
                        field_cache.pop(id_, None)

    def check(self, env):
        """ Check the consistency of the cache for the given environment. """
        # flush fields to be recomputed before evaluating the cache
        env['res.partner'].recompute()

        # make a copy of the cache, and invalidate it
        dump = dict(self._data)
        self.invalidate()

        depends_context = env.registry.field_depends_context

        # re-fetch the records, and compare with their former cache
        invalids = []

        def check(model, field, field_dump):
            records = env[field.model_name].browse(field_dump)
            for record in records:
                if not record.id:
                    continue
                try:
                    cached = field_dump[record.id]
                    value = field.convert_to_record(cached, record)
                    fetched = record[field.name]
                    if fetched != value:
                        info = {'cached': value, 'fetched': fetched}
                        invalids.append((record, field, info))
                except (AccessError, MissingError):
                    pass

        for field, field_dump in dump.items():
            model = env[field.model_name]
            if depends_context[field]:
                for context_keys, field_cache in field_dump.items():
                    context = dict(zip(depends_context[field], context_keys))
                    check(model.with_context(context), field, field_cache)
            else:
                check(model, field, field_dump)

        if invalids:
            raise UserError('Invalid cache for fields\n' + pformat(invalids))


# keep those imports here in order to handle cyclic dependencies correctly
from odoo import SUPERUSER_ID
from odoo.exceptions import UserError, AccessError, MissingError
from odoo.modules.registry import Registry