NUP-2475: Make sure Network API links use the same dtype at both ends

bindings/py/tests/network_test.py

@@ -21,6 +21,7 @@
 
 import json
 import unittest
+import pytest
 
 try:
   # NOTE need to import capnp first to activate the magic necessary for
@@ -31,15 +32,67 @@
 else:
   from nupic.proto.NetworkProto_capnp import NetworkProto
 
+from nupic.bindings.regions.PyRegion import PyRegion
 
 import nupic.bindings.engine_internal as engine
 from nupic.bindings.tools.serialization_test_py_region import \
      SerializationTestPyRegion
 
 
+class TestLinks(PyRegion):
+  """
+  Test region used to test link validation
+  """
+  def __init__(self): pass
+  def initialize(self): pass
+  def compute(self): pass
+  def getOutputElementCount(self): pass
+  @classmethod
+  def getSpec(cls):
+    return {
+      "description": TestLinks.__doc__,
+      "singleNodeOnly": True,
+      "inputs": {
+        "UInt32": {
+          "description": "UInt32 Data",
+          "dataType": "UInt32",
+          "isDefaultInput": True,
+          "required": False,
+          "count": 0
+        },
+        "Real32": {
+          "description": "Real32 Data",
+          "dataType": "Real32",
+          "isDefaultInput": False,
+          "required": False,
+          "count": 0
+        },        
+      },
+      "outputs": {
+        "UInt32": {
+          "description": "UInt32 Data",
+          "dataType": "UInt32",
+          "isDefaultOutput": True,
+          "required": False,
+          "count": 0
+        },
+        "Real32": {
+          "description": "Real32 Data",
+          "dataType": "Real32",
+          "isDefaultOutput": False,
+          "required": False,
+          "count": 0
+        },              
+      },
+      "parameters": { }
+    }
 
 class NetworkTest(unittest.TestCase):
 
+  def setUp(self):
+    """Register test region"""
+    engine.Network.registerPyRegion(TestLinks.__module__, TestLinks.__name__)
+
 
   @unittest.skipUnless(
     capnp, "pycapnp is not installed, skipping serialization test.")
@@ -107,3 +160,21 @@ def testSimpleTwoRegionNetworkIntrospection(self):
       self.fail("Unable to iterate network links.")
 
 
+  def testNetworkLinkTypeValidation(self):
+    """
+    This tests whether the links source and destination dtypes match
+    """
+    network = engine.Network()
+    network.addRegion("from", "py.TestLinks", "")
+    network.addRegion("to", "py.TestLinks", "")
+
+    # Check for valid links
+    network.link("from", "to", "UniformLink", "", "UInt32", "UInt32")
+    network.link("from", "to", "UniformLink", "", "Real32", "Real32")
+
+    # Check for invalid links
+    with pytest.raises(RuntimeError):
+      network.link("from", "to", "UniformLink", "", "Real32", "UInt32")
+    with pytest.raises(RuntimeError):
+      network.link("from", "to", "UniformLink", "", "UInt32", "Real32")
+

src/nupic/engine/Input.cpp

@@ -124,6 +124,8 @@ const Array &Input::getData() const {
   return data_;
 }
 
+NTA_BasicType Input::getDataType() const { return data_.getType(); }
+
 Region &Input::getRegion() { return region_; }
 
 const std::vector<Link *> &Input::getLinks() { return links_; }

src/nupic/engine/Input.hpp

@@ -156,6 +156,11 @@ class Input {
    */
   const Array &getData() const;
 
+  /**
+   *  Get the data type
+   */
+  NTA_BasicType getDataType() const;
+
   /**
    *
    * Get the Region that the input belongs to.

src/nupic/engine/Network.cpp

@@ -30,6 +30,8 @@ Implementation of the Network class
 #include <stdexcept>
 
 #include <nupic/engine/Input.hpp>
+#include <nupic/engine/Output.hpp>
+#include <nupic/types/BasicType.hpp>
 #include <nupic/engine/Link.hpp>
 #include <nupic/engine/Network.hpp>
 #include <nupic/engine/NuPIC.hpp> // for register/unregister
@@ -41,6 +43,7 @@ Implementation of the Network class
 #include <nupic/os/Path.hpp>
 #include <nupic/proto/NetworkProto.capnp.h>
 #include <nupic/proto/RegionProto.capnp.h>
+#include <nupic/types/BasicType.hpp>
 #include <nupic/utils/Log.hpp>
 #include <nupic/utils/StringUtils.hpp>
 #include <yaml-cpp/yaml.h>
@@ -317,6 +320,11 @@ void Network::link(const std::string &srcRegionName,
               << " does not exist on region " << destRegionName;
   }
 
+  NTA_CHECK(srcOutput->getDataType() == destInput->getDataType())
+      << "Network::link -- Mismatched data types."
+      << BasicType::getName(srcOutput->getDataType())
+      << " != " << BasicType::getName(destInput->getDataType());
+
   // Create the link itself
   auto link =
       new Link(linkType, linkParams, srcOutput, destInput, propagationDelay);

src/nupic/engine/Output.cpp

@@ -108,4 +108,6 @@ size_t Output::getNodeOutputElementCount() const {
 
 bool Output::hasOutgoingLinks() { return (!links_.empty()); }
 
+NTA_BasicType Output::getDataType() const { return data_->getType(); }
+
 } // namespace nupic

src/nupic/engine/Output.hpp

@@ -135,6 +135,11 @@ class Output {
    */
   const Array &getData() const;
 
+  /**
+   *  Get the data type
+   */
+  NTA_BasicType getDataType() const;
+
   /**
    *
    * Tells whether the output is region level.