def test_obj_info_primary_vars(cls_info, obj_info):
assert isinstance(obj_info.primary_vars, tuple)
for column, variable in iter_zip(cls_info.primary_key,
obj_info.primary_vars):
assert obj_info.variables.get(column) == variable
assert len(obj_info.primary_vars) == len(cls_info.primary_key)
def __init__(self, local_key, remote_key, many, on_remote):
assert type(local_key) is tuple and type(remote_key) is tuple
self.local_key = local_key
self.remote_key = remote_key
self.local_cls = getattr(self.local_key[0], "cls", None)
self.remote_cls = self.remote_key[0].cls
self.remote_key_is_primary = False
primary_key = get_cls_info(self.remote_cls).primary_key
if len(primary_key) == len(self.remote_key):
for column1, column2 in iter_zip(self.remote_key, primary_key):
if column1.name != column2.name:
break
else:
self.remote_key_is_primary = True
self.many = many
self.on_remote = on_remote
# XXX These should probably be weak dictionaries.
self._local_columns = {}
self._remote_columns = {}
self._l_to_r = {}
self._r_to_l = {}
def get(self, name, namespace=None):
"""Translate a property name path to the actual property.
This method accepts a property name like C{"id"} or C{"Class.id"}
or C{"module.path.Class.id"}, and tries to find a unique
class/property with the given name.
When the C{namespace} argument is given, the registry will be
able to disambiguate names by choosing the one that is closer
to the given namespace. For instance C{get("Class.id", "a.b.c")}
will choose C{a.Class.id} rather than C{d.Class.id}.
"""
key = ".".join(reversed(name.split("."))) + "."
i = bisect_left(self._properties, (key, ))
l = len(self._properties)
best_props = []
if namespace is None:
while i < l and self._properties[i][0].startswith(key):
path, prop_ref = self._properties[i]
prop = prop_ref()
if prop is not None:
best_props.append((path, prop))
i += 1
else:
namespace_parts = ("." + namespace).split(".")
best_path_info = (0, sys.maxsize)
while i < l and self._properties[i][0].startswith(key):
path, prop_ref = self._properties[i]
prop = prop_ref()
if prop is None:
i += 1
continue
path_parts = path.split(".")
path_parts.reverse()
common_prefix = 0
for part, ns_part in iter_zip(path_parts, namespace_parts):
if part == ns_part:
common_prefix += 1
else:
break
path_info = (-common_prefix, len(path_parts) - common_prefix)
if path_info < best_path_info:
best_path_info = path_info
best_props = [(path, prop)]
elif path_info == best_path_info:
best_props.append((path, prop))
i += 1
if not best_props:
raise PropertyPathError("Path '%s' matches no known property." %
name)
elif len(best_props) > 1:
paths = [
".".join(reversed(path.split(".")[:-1]))
for path, prop in best_props
]
raise PropertyPathError("Path '%s' matches multiple "
"properties: %s" %
(name, ", ".join(paths)))
return best_props[0][1]
def _get_local_column(self, local_cls, remote_column):
try:
return self._r_to_l[local_cls].get(remote_column)
except KeyError:
map = {}
for local_prop, _remote_column in iter_zip(self.local_key,
self.remote_key):
map[_remote_column] = local_prop.__get__(None, local_cls)
return self._r_to_l.setdefault(local_cls, map).get(remote_column)
def _get_remote_column(self, local_cls, local_column):
try:
return self._l_to_r[local_cls].get(local_column)
except KeyError:
map = {}
for local_prop, _remote_column in iter_zip(self.local_key,
self.remote_key):
map[local_prop.__get__(None, local_cls)] = _remote_column
return self._l_to_r.setdefault(local_cls, map).get(local_column)
def get_insert_identity(self, primary_key, primary_variables):
equals = []
for column, variable in iter_zip(primary_key, primary_variables):
if not variable.is_defined():
# The Select here prevents PostgreSQL from going nuts and
# performing a sequential scan when there *is* an index.
# http://tinyurl.com/2n8mv3
variable = Select(currval(column))
equals.append(Eq(column, variable))
return And(*equals)
def execute(self, statement, params=None, noresult=False):
"""Execute a statement with the given parameters.
This extends the L{Connection.execute} method to add support
for automatic retrieval of inserted primary keys to link
in-memory objects with their specific rows.
"""
if (isinstance(statement, Insert) and
self._database._version >= 80200 and
statement.primary_variables is not Undef and
statement.primary_columns is not Undef):
# Here we decorate the Insert statement with a Returning
# expression, so that we get back in the result the values
# for the primary key just inserted. This prevents a round
# trip to the database for obtaining these values.
result = Connection.execute(self, Returning(statement), params)
for variable, value in iter_zip(statement.primary_variables,
result.get_one()):
result.set_variable(variable, value)
return result
return Connection.execute(self, statement, params, noresult)
def assert_variables_equal(checked, expected):
assert len(checked) == len(expected)
for check, expect in iter_zip(checked, expected):
assert check.__class__ == expect.__class__
assert check.get() == expect.get()
def link(self, local, remote, setting=False):
"""Link objects to represent their relation.
@param local: Object representing the I{local} side of the reference.
@param remote: Object representing the I{remote} side of the reference,
or the actual value to be set as the local key.
@param setting: Pass true when the relationship is being newly created.
"""
local_info = get_obj_info(local)
try:
remote_info = get_obj_info(remote)
except ClassInfoError:
# Must be a plain key. Just set it.
# XXX I guess this is broken if self.on_remote is True.
local_variables = self.get_local_variables(local)
if type(remote) is not tuple:
remote = (remote,)
assert len(remote) == len(local_variables)
for variable, value in iter_zip(local_variables, remote):
variable.set(value)
return
local_store = Store.of(local)
remote_store = Store.of(remote)
if setting:
if local_store is None:
if remote_store is None:
local_info.event.hook("added", self._add_all, local_info)
remote_info.event.hook("added", self._add_all, local_info)
else:
remote_store.add(local)
local_store = remote_store
elif remote_store is None:
local_store.add(remote)
elif local_store is not remote_store:
raise WrongStoreError("%r and %r cannot be linked because they "
"are in different stores." %
(local, remote))
# In cases below, we maintain a reference to the remote object
# to make sure it won't get deallocated while the link is active.
relation_data = local_info.get(self)
if self.many:
if relation_data is None:
relation_data = local_info[self] = {"remote":
{remote_info: remote}}
else:
relation_data["remote"][remote_info] = remote
else:
if relation_data is None:
relation_data = local_info[self] = {"remote": remote}
else:
old_remote = relation_data.get("remote")
if old_remote is not None:
self.unlink(local_info, get_obj_info(old_remote))
relation_data["remote"] = remote
if setting:
local_vars = local_info.variables
remote_vars = remote_info.variables
pairs = iter_zip(self._get_local_columns(local.__class__),
self.remote_key)
if self.on_remote:
local_has_changed = False
for local_column, remote_column in pairs:
local_var = local_vars[local_column]
if not local_var.is_defined():
remote_vars[remote_column].set(PendingReferenceValue)
else:
remote_vars[remote_column].set(local_var.get())
if local_var.has_changed():
local_has_changed = True
if local_has_changed:
self._add_flush_order(local_info, remote_info)
local_info.event.hook("changed", self._track_local_changes,
remote_info)
local_info.event.hook("flushed", self._break_on_local_flushed,
remote_info)
#local_info.event.hook("removed", self._break_on_local_removed,
# remote_info)
remote_info.event.hook("removed", self._break_on_remote_removed,
weakref.ref(local_info))
else:
remote_has_changed = False
for local_column, remote_column in pairs:
remote_var = remote_vars[remote_column]
if not remote_var.is_defined():
local_vars[local_column].set(PendingReferenceValue)
else:
local_vars[local_column].set(remote_var.get())
if remote_var.has_changed():
remote_has_changed = True
if remote_has_changed:
self._add_flush_order(local_info, remote_info,
remote_first=True)
remote_info.event.hook("changed", self._track_remote_changes,
local_info)
remote_info.event.hook("flushed", self._break_on_remote_flushed,
local_info)
#local_info.event.hook("removed", self._break_on_remote_removed,
# local_info)
local_info.event.hook("changed", self._break_on_local_diverged,
remote_info)
else:
local_info.event.hook("changed", self._break_on_local_diverged,
remote_info)
remote_info.event.hook("changed", self._break_on_remote_diverged,
weakref.ref(local_info))
if self.on_remote:
remote_info.event.hook("removed", self._break_on_remote_removed,
weakref.ref(local_info))
