Move more code to cython

Author: kshedden

pandas/io/sas/sas7bdat.py

@@ -20,7 +20,7 @@
 import numpy as np
 import struct
 import pandas.io.sas.sas_constants as const
-from .saslib import (_rle_decompress, _rdc_decompress, _readline)
+from .saslib import (_rle_decompress, _rdc_decompress, _do_read)
 
 
 class _subheader_pointer(object):
@@ -549,10 +549,7 @@ def read(self, nrows=None):
         self._byte_chunk = np.empty((nd, 8 * nrows), dtype=np.uint8)
 
         self._current_row_in_chunk_index = 0
-        for i in range(nrows):
-            done = _readline(self)
-            if done:
-                break
+        _do_read(self, nrows)
 
         rslt = self._chunk_to_dataframe()
         if self.index is not None:

pandas/io/sas/saslib.pyx

@@ -194,6 +194,15 @@ def _rdc_decompress(int result_length, np.ndarray[uint8_t, ndim=1] inbuff):
     return np.asarray(outbuff).tostring()
 
 
+def _do_read(parser, int nrows):
+    cdef int i
+
+    for i in range(nrows):
+        done = _readline(parser)
+        if done:
+            break
+
+
 def _readline(parser):
 
     cdef int offset