use numpy for faster de/serialization

gdsii/record.py

@@ -27,6 +27,7 @@ from . import exceptions, tags, types
 from datetime import datetime
 import math
 import struct
+import numpy
 
 __all__ = [
     'Record',
@@ -76,7 +77,7 @@ def _parse_int2(data):
     data_len = len(data)
     if not data_len or (data_len % 2):
         raise exceptions.IncorrectDataSize('INT2')
-    return struct.unpack('>%dh' % (data_len//2), data)
+    return numpy.frombuffer(data, dtype='>i2', count=data_len // 2)
 
 def _parse_int4(data):
     """
@@ -96,7 +97,7 @@ def _parse_int4(data):
     data_len = len(data)
     if not data_len or (data_len % 4):
         raise exceptions.IncorrectDataSize('INT4')
-    return struct.unpack('>%dl' % (data_len//4), data)
+    return numpy.frombuffer(data, dtype='>i4', count=data_len // 4)
 
 def _int_to_real(num):
     """
@@ -208,7 +209,7 @@ def _pack_int2(data):
         6
     """
     size = len(data)
-    return struct.pack('>{0}h'.format(size), *data)
+    return numpy.array(data).astype('>i2').tobytes()
 
 def _pack_int4(data):
     """
@@ -223,7 +224,7 @@ def _pack_int4(data):
         12
     """
     size = len(data)
-    return struct.pack('>{0}l'.format(size), *data)
+    return numpy.array(data).astype('>i4').tobytes()
 
 def _real_to_int(fnum):
     """
@@ -344,12 +345,7 @@ class Record(object):
         if data is not None:
             self.data = data
         elif points is not None:
-            new_data = []
-            # TODO make it faster
-            for point in points:
-                new_data.append(point[0])
-                new_data.append(point[1])
-            self.data = new_data
+            self.data = numpy.ravel(points)
         elif times is not None:
             mod_time = times[0]
             acc_time = times[1]
@@ -503,7 +499,7 @@ class Record(object):
         data_size = len(self.data)
         if not data_size or (data_size % 2):
             raise exceptions.DataSizeError(self.tag)
-        return [(self.data[i], self.data[i+1]) for i in range(0, data_size, 2)]
+        return numpy.array(self.data).reshape(-1, 2)
 
     @property
     def times(self):