Enable function_descriptor in backend to replace the function_id (#3028)

python/ray/remote_function.py

@@ -3,11 +3,9 @@ from __future__ import division
 from __future__ import print_function
 
 import copy
-import hashlib
-import inspect
 import logging
 
-import ray.ray_constants as ray_constants
+from ray.function_manager import FunctionDescriptor
 import ray.signature
 
 # Default parameters for remote functions.
@@ -18,33 +16,6 @@ DEFAULT_REMOTE_FUNCTION_MAX_CALLS = 0
 logger = logging.getLogger(__name__)
 
 
-def compute_function_id(function):
-    """Compute an function ID for a function.
-
-    Args:
-        func: The actual function.
-
-    Returns:
-        Raw bytes of the function id
-    """
-    function_id_hash = hashlib.sha1()
-    # Include the function module and name in the hash.
-    function_id_hash.update(function.__module__.encode("ascii"))
-    function_id_hash.update(function.__name__.encode("ascii"))
-    try:
-        # If we are running a script or are in IPython, include the source code
-        # in the hash.
-        source = inspect.getsource(function).encode("ascii")
-        function_id_hash.update(source)
-    except (IOError, OSError, TypeError):
-        # Source code may not be available: e.g. Cython or Python interpreter.
-        pass
-    # Compute the function ID.
-    function_id = function_id_hash.digest()
-    assert len(function_id) == ray_constants.ID_SIZE
-    return function_id
-
-
 class RemoteFunction(object):
     """A remote function.
 
@@ -52,7 +23,7 @@ class RemoteFunction(object):
 
     Attributes:
         _function: The original function.
-        _function_id: The ID of the function.
+        _function_descriptor: The function descriptor.
         _function_name: The module and function name.
         _num_cpus: The default number of CPUs to use for invocations of this
             remote function.
@@ -70,10 +41,7 @@ class RemoteFunction(object):
     def __init__(self, function, num_cpus, num_gpus, resources,
                  num_return_vals, max_calls):
         self._function = function
-        # TODO(rkn): We store the function ID as a string, so that
-        # RemoteFunction objects can be pickled. We should undo this when
-        # we allow ObjectIDs to be pickled.
-        self._function_id = compute_function_id(function)
+        self._function_descriptor = FunctionDescriptor.from_function(function)
         self._function_name = (
             self._function.__module__ + '.' + self._function.__name__)
         self._num_cpus = (DEFAULT_REMOTE_FUNCTION_CPUS
@@ -147,7 +115,7 @@ class RemoteFunction(object):
             result = self._function(*copy.deepcopy(args))
             return result
         object_ids = worker.submit_task(
-            ray.ObjectID(self._function_id),
+            self._function_descriptor,
             args,
             num_return_vals=num_return_vals,
             resources=resources)