[GitHub] piiswrong commented on a change in pull request #8642: ctypes speed improvement

[GitBox <gi...@apache.org>]

piiswrong commented on a change in pull request #8642: ctypes speed improvement
URL: https://github.com/apache/incubator-mxnet/pull/8642#discussion_r150751615
 
 

 ##########
 File path: python/mxnet/base.py
 ##########
 @@ -213,7 +248,55 @@ def c_array(ctype, values):
     >>> x[1]
     2.0
     """
-    return (ctype * len(values))(*values)
+    out = (ctype * len(values))()
+    out[:] = values
+    return out
+
+
+def c_array_buf(ctype, buf):
+    """Create ctypes array from a Python buffer.
+    For primitive types, using the buffer created with array.array is faster
+    than a c_array call.
+
+    Parameters
+    ----------
+    ctype : ctypes data type
+        Data type of the array we want to convert to, such as mx_float.
+
+    buf : buffer type
+        Data content.
+
+    Returns
+    -------
+    out : ctypes array
+        Created ctypes array.
+
+    Examples
+    --------
+    >>> x = mx.base.c_array_buf(mx.base.mx_float, array.array('i', [1, 2, 3]))
+    >>> print len(x)
+    3
+    >>> x[1]
+    2.0
+    """
+    return (ctype * len(buf)).from_buffer(buf)
+
+def c_handle_array(objs):
 
 Review comment:
   I don't think these new functions are necessary.

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