Tune the buffersizes a bit to also be good for bgzip

Author: rhpvorderman

src/isal/igzip.py

@@ -168,7 +168,7 @@ def __init__(self, filename=None, mode=None,
                                                   0)
         if self.mode == READ:
             raw = _IGzipReader(self.fileobj)
-            self._buffer = io.BufferedReader(raw, 128 * 1024)
+            self._buffer = io.BufferedReader(raw, 64 * 1024)
 
     def __repr__(self):
         s = repr(self.fileobj)

src/isal/isal_zlibmodule.c

@@ -1296,7 +1296,7 @@ IGzipReader__new__(PyTypeObject *type, PyObject *args, PyObject *kwargs)
         PyErr_SetString(PyExc_MemoryError, "Unable to allocate lock");
         return NULL;
     }
-    self->buffer_size = 128 * 1024;
+    self->buffer_size = 32 * 1024;
     self->input_buffer = PyMem_Malloc(self->buffer_size);
     if (self->input_buffer == NULL) {
         Py_DECREF(self);