NF: Implement a readinto method for Opener.

Author: arokem

nibabel/openers.py

@@ -209,6 +209,9 @@ def fileno(self):
     def read(self, *args, **kwargs):
         return self.fobj.read(*args, **kwargs)
 
+    def readinto(self, *args, **kwargs):
+        return self.fobj.readinto(*args, **kwargs)
+
     def write(self, *args, **kwargs):
         return self.fobj.write(*args, **kwargs)
 

nibabel/streamlines/trk.py

@@ -557,10 +557,10 @@ def _read_header(fileobj):
 
         with Opener(fileobj) as f:
 
-            # Read the header in one block.
-            header_str = f.read(header_2_dtype.itemsize)
-            header_rec = np.frombuffer(buffer=bytearray(header_str),
-                                       dtype=header_2_dtype)
+            # Read the header into a bytearray.
+            header_buf = bytearray(header_2_dtype.itemsize)
+            n_read = f.readinto(header_buf)
+            header_rec = np.frombuffer(buffer=header_buf, dtype=header_2_dtype)
             # Check endianness
             endianness = native_code
             if header_rec['hdr_size'] != TrkFile.HEADER_SIZE: