first add files

1 files changed, 254 insertions, 0 deletions

diff --git a/lib/sqlalchemy/orm/identity.py b/lib/sqlalchemy/orm/identity.py
new file mode 100644
index 0000000..7de8e2c
--- /dev/null
+++ b/lib/sqlalchemy/orm/identity.py
@@ -0,0 +1,254 @@
+# orm/identity.py
+# Copyright (C) 2005-2022 the SQLAlchemy authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: https://www.opensource.org/licenses/mit-license.php
+
+import weakref
+
+from . import util as orm_util
+from .. import exc as sa_exc
+from .. import util
+
+
+class IdentityMap(object):
+    def __init__(self):
+        self._dict = {}
+        self._modified = set()
+        self._wr = weakref.ref(self)
+
+    def _kill(self):
+        self._add_unpresent = _killed
+
+    def keys(self):
+        return self._dict.keys()
+
+    def replace(self, state):
+        raise NotImplementedError()
+
+    def add(self, state):
+        raise NotImplementedError()
+
+    def _add_unpresent(self, state, key):
+        """optional inlined form of add() which can assume item isn't present
+        in the map"""
+        self.add(state)
+
+    def update(self, dict_):
+        raise NotImplementedError("IdentityMap uses add() to insert data")
+
+    def clear(self):
+        raise NotImplementedError("IdentityMap uses remove() to remove data")
+
+    def _manage_incoming_state(self, state):
+        state._instance_dict = self._wr
+
+        if state.modified:
+            self._modified.add(state)
+
+    def _manage_removed_state(self, state):
+        del state._instance_dict
+        if state.modified:
+            self._modified.discard(state)
+
+    def _dirty_states(self):
+        return self._modified
+
+    def check_modified(self):
+        """return True if any InstanceStates present have been marked
+        as 'modified'.
+
+        """
+        return bool(self._modified)
+
+    def has_key(self, key):
+        return key in self
+
+    def popitem(self):
+        raise NotImplementedError("IdentityMap uses remove() to remove data")
+
+    def pop(self, key, *args):
+        raise NotImplementedError("IdentityMap uses remove() to remove data")
+
+    def setdefault(self, key, default=None):
+        raise NotImplementedError("IdentityMap uses add() to insert data")
+
+    def __len__(self):
+        return len(self._dict)
+
+    def copy(self):
+        raise NotImplementedError()
+
+    def __setitem__(self, key, value):
+        raise NotImplementedError("IdentityMap uses add() to insert data")
+
+    def __delitem__(self, key):
+        raise NotImplementedError("IdentityMap uses remove() to remove data")
+
+
+class WeakInstanceDict(IdentityMap):
+    def __getitem__(self, key):
+        state = self._dict[key]
+        o = state.obj()
+        if o is None:
+            raise KeyError(key)
+        return o
+
+    def __contains__(self, key):
+        try:
+            if key in self._dict:
+                state = self._dict[key]
+                o = state.obj()
+            else:
+                return False
+        except KeyError:
+            return False
+        else:
+            return o is not None
+
+    def contains_state(self, state):
+        if state.key in self._dict:
+            try:
+                return self._dict[state.key] is state
+            except KeyError:
+                return False
+        else:
+            return False
+
+    def replace(self, state):
+        if state.key in self._dict:
+            try:
+                existing = self._dict[state.key]
+            except KeyError:
+                # catch gc removed the key after we just checked for it
+                pass
+            else:
+                if existing is not state:
+                    self._manage_removed_state(existing)
+                else:
+                    return None
+        else:
+            existing = None
+
+        self._dict[state.key] = state
+        self._manage_incoming_state(state)
+        return existing
+
+    def add(self, state):
+        key = state.key
+        # inline of self.__contains__
+        if key in self._dict:
+            try:
+                existing_state = self._dict[key]
+            except KeyError:
+                # catch gc removed the key after we just checked for it
+                pass
+            else:
+                if existing_state is not state:
+                    o = existing_state.obj()
+                    if o is not None:
+                        raise sa_exc.InvalidRequestError(
+                            "Can't attach instance "
+                            "%s; another instance with key %s is already "
+                            "present in this session."
+                            % (orm_util.state_str(state), state.key)
+                        )
+                else:
+                    return False
+        self._dict[key] = state
+        self._manage_incoming_state(state)
+        return True
+
+    def _add_unpresent(self, state, key):
+        # inlined form of add() called by loading.py
+        self._dict[key] = state
+        state._instance_dict = self._wr
+
+    def get(self, key, default=None):
+        if key not in self._dict:
+            return default
+        try:
+            state = self._dict[key]
+        except KeyError:
+            # catch gc removed the key after we just checked for it
+            return default
+        else:
+            o = state.obj()
+            if o is None:
+                return default
+            return o
+
+    def items(self):
+        values = self.all_states()
+        result = []
+        for state in values:
+            value = state.obj()
+            if value is not None:
+                result.append((state.key, value))
+        return result
+
+    def values(self):
+        values = self.all_states()
+        result = []
+        for state in values:
+            value = state.obj()
+            if value is not None:
+                result.append(value)
+
+        return result
+
+    def __iter__(self):
+        return iter(self.keys())
+
+    if util.py2k:
+
+        def iteritems(self):
+            return iter(self.items())
+
+        def itervalues(self):
+            return iter(self.values())
+
+    def all_states(self):
+        if util.py2k:
+            return self._dict.values()
+        else:
+            return list(self._dict.values())
+
+    def _fast_discard(self, state):
+        # used by InstanceState for state being
+        # GC'ed, inlines _managed_removed_state
+        try:
+            st = self._dict[state.key]
+        except KeyError:
+            # catch gc removed the key after we just checked for it
+            pass
+        else:
+            if st is state:
+                self._dict.pop(state.key, None)
+
+    def discard(self, state):
+        self.safe_discard(state)
+
+    def safe_discard(self, state):
+        if state.key in self._dict:
+            try:
+                st = self._dict[state.key]
+            except KeyError:
+                # catch gc removed the key after we just checked for it
+                pass
+            else:
+                if st is state:
+                    self._dict.pop(state.key, None)
+                    self._manage_removed_state(state)
+
+
+def _killed(state, key):
+    # external function to avoid creating cycles when assigned to
+    # the IdentityMap
+    raise sa_exc.InvalidRequestError(
+        "Object %s cannot be converted to 'persistent' state, as this "
+        "identity map is no longer valid.  Has the owning Session "
+        "been closed?" % orm_util.state_str(state),
+        code="lkrp",
+    )