Rename ReshapeableDevicesSharding to PositionalSharding and add an alias NamedSharding for MeshPspecSharding.

`MeshPspecSharding` name will be replaced with `NamedSharding` in 3 months.

PiperOrigin-RevId: 485753078

CHANGELOG.md

@@ -25,6 +25,9 @@ Remember to align the itemized text with the first line of an item within a list
     * Functions in {mod}`jax.numpy.linalg` and {mod}`jax.numpy.fft` now uniformly
       require inputs to be array-like: i.e. lists and tuples cannot be used in place
       of arrays. Part of {jax-issue}`#7737`.
+* Deprecations
+  * `jax.sharding.MeshPspecSharding` has been renamed to `jax.sharding.NamedSharding`.
+    `jax.sharding.MeshPspecSharding` name will be removed in 3 months.
 
 ## jaxlib 0.3.24
 * Changes

jax/_src/sharding.py

@@ -194,7 +194,7 @@ class MeshPspecSharding(XLACompatibleSharding):
     _check_mesh_resource_axis(self.mesh, self._parsed_pspec)
 
   def __repr__(self):
-    return f'MeshPspecSharding(mesh={dict(self.mesh.shape)}, partition_spec={self.spec})'
+    return f'NamedSharding(mesh={dict(self.mesh.shape)}, partition_spec={self.spec})'
 
   def __hash__(self):
     if not hasattr(self, '_hash'):
@@ -253,6 +253,10 @@ class MeshPspecSharding(XLACompatibleSharding):
     return sharding_spec.sharding_proto(special_axes=special_axes)
 
 
+# New name of MeshPspecSharding to match with PositionalSharding below.
+NamedSharding = MeshPspecSharding
+
+
 @functools.lru_cache()
 def _get_replicated_op_sharding():
   proto = xc.OpSharding()
@@ -383,7 +387,7 @@ class PmapSharding(XLACompatibleSharding):
     return global_shape[:sharded_dim] + global_shape[sharded_dim+1:]
 
 
-class ReshapeableDevicesSharding(XLACompatibleSharding):
+class PositionalSharding(XLACompatibleSharding):
   _devices: List[xc.Device]
   _ids: np.ndarray  # dtype DeviceIdSet
 
@@ -423,8 +427,8 @@ class ReshapeableDevicesSharding(XLACompatibleSharding):
     return self.remake(self._devices, new_ids)
 
   @classmethod
-  def remake(cls, devices: List[xc.Device], ids: np.ndarray
-             ) -> ReshapeableDevicesSharding:
+  def remake(
+      cls, devices: List[xc.Device], ids: np.ndarray) -> PositionalSharding:
     self = cls.__new__(cls)
     self._devices = devices
     self._ids = ids
@@ -436,7 +440,7 @@ class ReshapeableDevicesSharding(XLACompatibleSharding):
     return id(self._devices)
 
   def __eq__(self, other) -> bool:
-    return (isinstance(other, ReshapeableDevicesSharding) and
+    return (isinstance(other, PositionalSharding) and
             id(self._devices) == id(other._devices) and
             bool(np.all(self._ids == other._ids)))
 

jax/sharding.py

@@ -15,9 +15,12 @@
 from jax._src.sharding import (
     Sharding as Sharding,
     XLACompatibleSharding as XLACompatibleSharding,
+    # TODO(yashkatariya): Deprecate MeshPspecSharding in 3 months.
     MeshPspecSharding as MeshPspecSharding,
+    # New name of MeshPspecSharding to match PositionalSharding below.
+    NamedSharding as NamedSharding,
     SingleDeviceSharding as SingleDeviceSharding,
     PmapSharding as PmapSharding,
     OpShardingSharding as OpShardingSharding,
-    ReshapeableDevicesSharding as ReshapeableDevicesSharding,
+    PositionalSharding as PositionalSharding,
 )

tests/api_test.py

@@ -1577,8 +1577,8 @@ class APITest(jtu.JaxTestCase):
     with self.assertRaisesRegex(
         ValueError,
         "device_put device specification must be a tree prefix of the "
-        r"corresponding value, got specification \(\(MeshPspecSharding\(.*\), "
-        r"MeshPspecSharding\(.*\)\), MeshPspecSharding\(.*\)\) for value tree "
+        r"corresponding value, got specification \(\(NamedSharding\(.*\), "
+        r"NamedSharding\(.*\)\), NamedSharding\(.*\)\) for value tree "
         r"PyTreeDef\(\(\*, \(\*, \*\)\)\)."
     ):
       jax.device_put((x, (y, z)), device=((s1, s2), s2))
@@ -1599,8 +1599,8 @@ class APITest(jtu.JaxTestCase):
     with self.assertRaisesRegex(
         ValueError,
         "device_put device specification must be a tree prefix of the "
-        r"corresponding value, got specification \(MeshPspecSharding\(.*\), "
-        r"MeshPspecSharding\(.*\)\) for value tree PyTreeDef\(\(\*, \*, \*\)\)."
+        r"corresponding value, got specification \(NamedSharding\(.*\), "
+        r"NamedSharding\(.*\)\) for value tree PyTreeDef\(\(\*, \*, \*\)\)."
     ):
       jax.device_put((x, y, z), device=(s1, s2))
 

tests/array_test.py

@@ -692,7 +692,7 @@ class ShardingTest(jtu.JaxTestCase):
 
     with self.assertRaisesRegex(
         ValueError,
-        r"Sharding MeshPspecSharding\(mesh={'replica': 1, 'data': 1, 'mdl': 2}, "
+        r"Sharding NamedSharding\(mesh={'replica': 1, 'data': 1, 'mdl': 2}, "
         r"partition_spec=PartitionSpec\(None, \('mdl',\), None, None\)\) is only "
         "valid for values of rank at least 4, but was applied to a value of rank 2"):
       new_mps.is_compatible_aval(shape)
@@ -733,9 +733,9 @@ class ShardingTest(jtu.JaxTestCase):
     value_shape = (8, 4)
 
     mesh = jtu.create_global_mesh((4, 2), ('x', 'y'))
-    mps = sharding.MeshPspecSharding(mesh, pspec)
+    mps = sharding.NamedSharding(mesh, pspec)
 
-    devices_sharding = sharding.ReshapeableDevicesSharding(jax.devices())
+    devices_sharding = sharding.PositionalSharding(jax.devices())
     devices_sharding = devices_sharding.reshape(shape).replicate(axes)
     if transpose:
       devices_sharding = devices_sharding.T
@@ -753,7 +753,7 @@ class ShardingTest(jtu.JaxTestCase):
     mesh = jtu.create_global_mesh((4, 2), ('x', 'y'))
     mps = sharding.MeshPspecSharding(mesh, P('x', 'y'))
 
-    devices_sharding = sharding.ReshapeableDevicesSharding(mesh.devices)
+    devices_sharding = sharding.PositionalSharding(mesh.devices)
 
     op1 = mps._to_xla_op_sharding(len(value_shape))
     op2 = devices_sharding._to_xla_op_sharding(len(value_shape))

tests/pjit_test.py

@@ -1084,7 +1084,7 @@ class PJitTest(jtu.BufferDonationTestCase):
       with self.assertRaisesRegex(
           ValueError,
           r"One of with_sharding_constraint.*Sharding "
-          r"MeshPspecSharding\(mesh={'replica': 1, 'data': 1, 'mdl': 2}, "
+          r"NamedSharding\(mesh={'replica': 1, 'data': 1, 'mdl': 2}, "
           r"partition_spec=PartitionSpec\(None, \('mdl',\), None, None\)\) is only "
           "valid for values of rank at least 4, but was applied to a value of rank 1"):
         pjit_f(jnp.array([1, 2, 3]))