Issue #1380: Validate python parameters passed to SP compute method

src/nupic/bindings/algorithms.i

@@ -1163,11 +1163,11 @@ void forceRetentionOfImageSensorLiteLibrary(void) {
       self._initFromCapnpPyBytes(proto.as_builder().to_bytes()) # copy * 2
   %}
 
-  inline void compute(PyObject *py_x, bool learn, PyObject *py_y)
+  inline void compute(PyObject *py_inputArray, bool learn, PyObject *py_activeArray)
   {
-    PyArrayObject* x = (PyArrayObject*) py_x;
-    PyArrayObject* y = (PyArrayObject*) py_y;
-    self->compute((nupic::UInt*) PyArray_DATA(x), (bool)learn, (nupic::UInt*) PyArray_DATA(y));
+    nupic::CheckedNumpyVectorWeakRefT<nupic::UInt> inputArray(py_inputArray);
+    nupic::CheckedNumpyVectorWeakRefT<nupic::UInt> activeArray(py_activeArray);
+    self->compute(inputArray.begin(), learn, activeArray.begin());
   }
 
   inline void stripUnlearnedColumns(PyObject *py_x)

src/nupic/py_support/NumpyVector.hpp

@@ -31,6 +31,7 @@
 #include <nupic/types/Types.hpp> // For nupic::Real.
 #include <nupic/utils/Log.hpp> // For NTA_ASSERT
 #include <algorithm> // For std::copy.
+#include <boost/type_index/stl_type_index.hpp> // for 'type_id'
 
 namespace nupic {
 
@@ -438,6 +439,31 @@ namespace nupic {
     PyArrayObject* pyArray_;
   };
 
+  /**
+   * Similar to NumpyVectorWeakRefT but also provides extra type checking
+   */  
+  template<typename T>
+  class CheckedNumpyVectorWeakRefT : public NumpyVectorWeakRefT<T>
+  {
+    public:
+      CheckedNumpyVectorWeakRefT(PyObject* pyArray) 
+        : NumpyVectorWeakRefT<T>(pyArray)
+      {
+        if (PyArray_NDIM(this->pyArray_) != 1)
+        {
+          NTA_THROW << "Expecting 1D array " 
+                    << "but got " << PyArray_NDIM(this->pyArray_) << "D array";
+        }
+        if (!PyArray_EquivTypenums(
+              PyArray_TYPE(this->pyArray_), LookupNumpyDType((const T *) 0)))
+        {
+          boost::typeindex::stl_type_index expectedType = 
+            boost::typeindex::stl_type_index::type_id<T>();
+          NTA_THROW << "Expecting '" << expectedType.pretty_name() << "' "
+                    << "but got '" << PyArray_DTYPE(this->pyArray_)->type << "'";
+        }
+      }
+  };
 } // End namespace nupic.
 
 #endif