[nnx] use HashableMapping instead of FrozenDict

flax/nnx/graph.py

@@ -24,7 +24,6 @@
 import numpy as np
 import typing_extensions as tpe
 
-from flax.core.frozen_dict import FrozenDict
 from flax.nnx import filterlib, reprlib
 from flax.nnx.proxy_caller import (
   ApplyCaller,
@@ -183,7 +182,7 @@ def get_node_impl_for_type(x: type[Node]) -> NodeImpl[Node, tp.Any, tp.Any]:
   return _node_impl_for_type[x]
 
 
-class _HashableMapping(tp.Mapping[HA, HB], tp.Hashable):
+class HashableMapping(tp.Mapping[HA, HB], tp.Hashable):
   def __init__(self, mapping: tp.Mapping[HA, HB] | tp.Iterable[tuple[HA, HB]]):
     self._mapping = dict(mapping)
 
@@ -204,7 +203,7 @@ def __hash__(self) -> int:
 
   def __eq__(self, other: tp.Any) -> bool:
     return (
-      isinstance(other, _HashableMapping) and self._mapping == other._mapping
+      isinstance(other, HashableMapping) and self._mapping == other._mapping
     )
 
   def __repr__(self) -> str:
@@ -246,7 +245,7 @@ def __treescope_repr__(self, path, subtree_renderer):
 class VariableDef(reprlib.Representable):
   type: type[Variable]
   index: int
-  metadata: FrozenDict[str, tp.Any]
+  metadata: HashableMapping[str, tp.Any]
 
   def __nnx_repr__(self):
     yield reprlib.Object(type=type(self))
@@ -272,7 +271,7 @@ def __treescope_repr__(self, path, subtree_renderer):
 jax.tree_util.register_static(VariableDef)
 
 
-@dataclasses.dataclass(frozen=True, repr=False)
+@dataclasses.dataclass(frozen=True, repr=False, slots=True)
 class NodeDef(GraphDef[Node], reprlib.Representable):
   """A dataclass that denotes the tree structure of a
   :class:`Module`. A ``GraphDef`` can be generated by either
@@ -281,11 +280,11 @@ class NodeDef(GraphDef[Node], reprlib.Representable):
   type: tp.Type[Node]
   index: int
   attributes: tuple[Key, ...]
-  subgraphs: _HashableMapping[Key, NodeDef[tp.Any] | NodeRef[tp.Any]]
-  static_fields: _HashableMapping[Key, tp.Any]
-  leaves: _HashableMapping[Key, VariableDef | NodeRef[tp.Any]]
+  subgraphs: HashableMapping[Key, NodeDef[tp.Any] | NodeRef[tp.Any]]
+  static_fields: HashableMapping[Key, tp.Any]
+  leaves: HashableMapping[Key, VariableDef | NodeRef[tp.Any]]
   metadata: tp.Any
-  index_mapping: FrozenDict[Index, Index] | None
+  index_mapping: HashableMapping[Index, Index] | None
 
   @classmethod
   def create(
@@ -303,11 +302,11 @@ def create(
       type=type,
       index=index,
       attributes=attributes,
-      subgraphs=_HashableMapping(subgraphs),
-      static_fields=_HashableMapping(static_fields),
-      leaves=_HashableMapping(leaves),
+      subgraphs=HashableMapping(subgraphs),
+      static_fields=HashableMapping(static_fields),
+      leaves=HashableMapping(leaves),
       metadata=metadata,
-      index_mapping=FrozenDict(index_mapping)
+      index_mapping=HashableMapping(index_mapping)
       if index_mapping is not None
       else None,
     )
@@ -424,7 +423,7 @@ def _graph_flatten(
         flat_state[(*path, key)] = value.to_state()
         variable_index = ref_index[value] = len(ref_index)
         variabledef = VariableDef(
-          type(value), variable_index, FrozenDict(value.get_metadata())
+          type(value), variable_index, HashableMapping(value.get_metadata())
         )
         leaves.append((key, variabledef))
     else:
@@ -794,7 +793,7 @@ def split(
       if ctx.index_ref is not None and isinstance(graphdef, NodeDef):
         index_to_index = compose_mapping(ctx.index_ref, self.ref_index)
         graphdef = dataclasses.replace(
-          graphdef, index_mapping=FrozenDict(index_to_index)
+          graphdef, index_mapping=HashableMapping(index_to_index)
         )
 
     return graphdef, *states
@@ -984,7 +983,7 @@ def split(
     if self.index_ref is not None and isinstance(graphdef, NodeDef):
       index_to_index = compose_mapping(self.index_ref, ref_index)
       graphdef = dataclasses.replace(
-        graphdef, index_mapping=FrozenDict(index_to_index)
+        graphdef, index_mapping=HashableMapping(index_to_index)
       )
 
     self.flatten_end(ref_index)

flax/nnx/transforms/autodiff.py

@@ -19,7 +19,6 @@
 
 
 from flax import struct
-from flax.core.frozen_dict import FrozenDict
 from flax.nnx import (
   extract,
   filterlib,
@@ -428,7 +427,7 @@ def _custom_vjp_split_fn(
   nondiff_argnums: tuple[int, ...] = struct.field(pytree_node=False)
   tangent_tree_node_args: tuple[tp.Any, ...] = struct.field(pytree_node=False)
 
-def _extract_index_mappings(x, *, index_mappings: deque[FrozenDict]):
+def _extract_index_mappings(x, *, index_mappings: deque[graph.HashableMapping]):
   if isinstance(x, graph.NodeDef):
     assert x.index_mapping is not None
     index_mappings.append(x.index_mapping)
@@ -466,7 +465,9 @@ def __call__(self, *pure_args):
       (args_out, out), ctxtag=self.ctxtag
     )
     # remove index_mapping from NodeDef's but store them in global context
-    index_mappings: deque[FrozenDict] = extract.get_broadcast_state(self.ctxtag)
+    index_mappings: deque[graph.HashableMapping] = extract.get_broadcast_state(
+      self.ctxtag
+    )
 
     pure_args_out, pure_out = jax.tree.map(
       functools.partial(_extract_index_mappings, index_mappings=index_mappings),
@@ -519,8 +520,8 @@ def __call__(self, *pure_args):
 
     if update_context_active:
       # remove index_mapping from NodeDef's but store them in global context
-      index_mappings: deque[FrozenDict] = extract.get_broadcast_state(
-        self.ctxtag
+      index_mappings: deque[graph.HashableMapping] = (
+        extract.get_broadcast_state(self.ctxtag)
       )
       pure_args_out, pure_out = jax.tree.map(
         functools.partial(
@@ -631,7 +632,7 @@ def __call__(
         for i, x in enumerate(tree_node_args)
         if i not in self.jax_nondiff_argnums
       )
-      index_mappings: deque[FrozenDict] = deque()
+      index_mappings: deque[graph.HashableMapping] = deque()
       with extract.broadcast_state(self.ctxtag, index_mappings):
         if self.fwd is None or self.bwd is None or self.symbolic_zeros is None:
           raise ValueError()
@@ -663,7 +664,7 @@ def __call__(
       # insert index_mappings
       def _insert_index_mappings(x):
         if isinstance(x, graph.NodeDef):
-          index_mapping: FrozenDict = index_mappings.popleft()
+          index_mapping: graph.HashableMapping = index_mappings.popleft()
           return dataclasses.replace(x, index_mapping=index_mapping)
         return x
 

flax/nnx/transforms/iteration.py

@@ -650,7 +650,7 @@ def check_carry_same_references(key_path, arg, out):
 
 def _extract_index_mappings(
   pure_carry_arg_out,
-  carry_index_mappings: list[FrozenDict[int, int]],
+  carry_index_mappings: list[graph.HashableMapping[int, int]],
   /,
 ):
   def extract_index_mappings(x):
@@ -675,7 +675,7 @@ def extract_index_mappings(x):
 
 def _insert_index_mappings(
   pure_carry_arg_out,
-  carry_index_mappings: deque[FrozenDict[int, int]],
+  carry_index_mappings: deque[graph.HashableMapping[int, int]],
   /,
 ):
   def insert_index_mappings(x):
@@ -1096,7 +1096,7 @@ def __call__(
 
     # next we have to remove all the index_mappings from the NodeDefs
     # in the carry outputs because they are not present in the inputs
-    carry_index_mappings: list[FrozenDict[int, int]] = []
+    carry_index_mappings: list[graph.HashableMapping[int, int]] = []
     pure_carry_arg_out = _extract_index_mappings(
       pure_carry_arg_out, carry_index_mappings
     )
@@ -1347,10 +1347,12 @@ def per_node_def(nd: graph.NodeDef | tp.Any):
       return
 
     per_node_def(ns._graphdef)
-    return dataclasses.replace(ns, _graphdef=dataclasses.replace(
-        ns._graphdef,
-        index_mapping=FrozenDict(global_index_mapping)
-      ))
+    return dataclasses.replace(
+      ns,
+      _graphdef=dataclasses.replace(
+        ns._graphdef, index_mapping=graph.HashableMapping(global_index_mapping)
+      ),
+    )
 
   return jax.tree.map(per_node_state, tree,
                       is_leaf=lambda x: isinstance(x, extract.NodeStates))