Changed how ray treats deserialization of custom classes (#333)

doc/remote-functions.md

@@ -68,11 +68,11 @@ class ExampleClass(object):
     # This example assumes that field1 and field2 are serializable types.
     self.field1 = field1
     self.field2 = field2
-
-  def deserialize(self, primitives):
+  
+  @staticmethod
+  def deserialize(primitives):
     (field1, field2) = primitives
-    self.field1 = field1
-    self.field2 = field2
+    return ExampleClass(field1, field2)
 
   def serialize(self):
     return (self.field1, self.field2)

lib/python/ray/array/distributed/core.py

@@ -9,7 +9,7 @@ __all__ = ["BLOCK_SIZE", "DistArray", "assemble", "zeros", "ones", "copy",
 BLOCK_SIZE = 10
 
 class DistArray(object):
-  def construct(self, shape, objectids=None):
+  def __init__(self, shape, objectids=None):
     self.shape = shape
     self.ndim = len(shape)
     self.num_blocks = [int(np.ceil(1.0 * a / BLOCK_SIZE)) for a in self.shape]
@@ -17,17 +17,14 @@ class DistArray(object):
     if self.num_blocks != list(self.objectids.shape):
       raise Exception("The fields `num_blocks` and `objectids` are inconsistent, `num_blocks` is {} and `objectids` has shape {}".format(self.num_blocks, list(self.objectids.shape)))
 
-  def deserialize(self, primitives):
+  @staticmethod
+  def deserialize(primitives):
     (shape, objectids) = primitives
-    self.construct(shape, objectids)
+    return DistArray(shape, objectids)
 
   def serialize(self):
     return (self.shape, self.objectids)
 
-  def __init__(self, shape=None):
-    if shape is not None:
-      self.construct(shape)
-
   @staticmethod
   def compute_block_lower(index, shape):
     if len(index) != len(shape):

lib/python/ray/array/distributed/linalg.py

@@ -46,8 +46,6 @@ def tsqr(a):
     current_rs = new_rs
   assert len(current_rs) == 1, "len(current_rs) = " + str(len(current_rs))
 
-  q_result = DistArray()
-
   # handle the special case in which the whole DistArray "a" fits in one block
   # and has fewer rows than columns, this is a bit ugly so think about how to
   # remove it
@@ -56,9 +54,8 @@ def tsqr(a):
   else:
     q_shape = [a.shape[0], a.shape[0]]
   q_num_blocks = DistArray.compute_num_blocks(q_shape)
-  q_result = DistArray()
   q_objectids = np.empty(q_num_blocks, dtype=object)
-  q_result.construct(q_shape, q_objectids)
+  q_result = DistArray(q_shape, q_objectids)
 
   # reconstruct output
   for i in range(num_blocks):
@@ -145,8 +142,7 @@ def qr(a):
   k = min(m, n)
 
   # we will store our scratch work in a_work
-  a_work = DistArray()
-  a_work.construct(a.shape, np.copy(a.objectids))
+  a_work = DistArray(a.shape, np.copy(a.objectids))
 
   result_dtype = np.linalg.qr(ray.get(a.objectids[0, 0]))[0].dtype.name
   r_res = ray.get(zeros.remote([k, n], result_dtype)) # TODO(rkn): It would be preferable not to get this right after creating it.

lib/python/ray/array/distributed/random.py

@@ -12,6 +12,5 @@ def normal(shape):
   objectids = np.empty(num_blocks, dtype=object)
   for index in np.ndindex(*num_blocks):
     objectids[index] = ra.random.normal.remote(DistArray.compute_block_shape(index, shape))
-  result = DistArray()
-  result.construct(shape, objectids)
+  result = DistArray(shape, objectids)
   return result

lib/python/ray/serialization.py

@@ -46,8 +46,7 @@ def from_primitive(primitive_obj):
     # This code assumes that the type module.__dict__[type_name] knows how to deserialize itself
     type_module, type_name = primitive_obj[0]
     module = importlib.import_module(type_module)
-    obj = module.__dict__[type_name]()
-    obj.deserialize(primitive_obj[1])
+    obj = module.__dict__[type_name].deserialize(primitive_obj[1])
   return obj
 
 def is_arrow_serializable(value):

lib/python/ray/worker.py

@@ -30,7 +30,7 @@ class RayFailedObject(object):
     error_message (str): The error message raised by the task that failed.
   """
 
-  def __init__(self, error_message=None):
+  def __init__(self, error_message):
     """Initialize a RayFailedObject.
 
     Args:
@@ -39,7 +39,8 @@ class RayFailedObject(object):
     """
     self.error_message = error_message
 
-  def deserialize(self, primitives):
+  @staticmethod
+  def deserialize(primitives):
     """Create a RayFailedObject from a primitive object.
 
     This initializes a RayFailedObject from a primitive object created by the
@@ -52,7 +53,7 @@ class RayFailedObject(object):
     Args:
       primitives (str): The object's error message.
     """
-    self.error_message = primitives
+    return RayFailedObject(primitives)
 
   def serialize(self):
     """Turn a RayFailedObject into a primitive object.

test/array_test.py

@@ -49,8 +49,7 @@ class DistributedArrayTest(unittest.TestCase):
       reload(module)
     ray.init(start_ray_local=True, num_workers=0)
 
-    x = da.DistArray()
-    x.construct([2, 3, 4], np.array([[[ray.put(0)]]]))
+    x = da.DistArray([2, 3, 4], np.array([[[ray.put(0)]]]))
     capsule, _ = ray.serialization.serialize(ray.worker.global_worker.handle, x)
     y = ray.serialization.deserialize(ray.worker.global_worker.handle, capsule)
     self.assertEqual(x.shape, y.shape)
@@ -65,8 +64,7 @@ class DistributedArrayTest(unittest.TestCase):
 
     a = ra.ones.remote([da.BLOCK_SIZE, da.BLOCK_SIZE])
     b = ra.zeros.remote([da.BLOCK_SIZE, da.BLOCK_SIZE])
-    x = da.DistArray()
-    x.construct([2 * da.BLOCK_SIZE, da.BLOCK_SIZE], np.array([[a], [b]]))
+    x = da.DistArray([2 * da.BLOCK_SIZE, da.BLOCK_SIZE], np.array([[a], [b]]))
     self.assertTrue(np.alltrue(x.assemble() == np.vstack([np.ones([da.BLOCK_SIZE, da.BLOCK_SIZE]), np.zeros([da.BLOCK_SIZE, da.BLOCK_SIZE])])))
 
     ray.services.cleanup()

test/runtest.py

@@ -23,7 +23,8 @@ class UserDefinedType(object):
   def __init__(self):
     pass
 
-  def deserialize(self, primitives):
+  @staticmethod
+  def deserialize(primitives):
     return "user defined type"
 
   def serialize(self):