[Python-checkins] python/dist/src/Objects listobject.c,2.196,2.197

[rhettinger at users.sourceforge.net]

Update of /cvsroot/python/python/dist/src/Objects
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv24604/Objects

Modified Files:
	listobject.c 
Log Message:
list_resize() now has an "exact" option for bypassing the overallocation
scheme in situations that likely won't benefit from it.  This further
improves memory utilization from Py2.3 which always over-allocates 
except for PyList_New().

Situations expected to benefit from over-allocation:
    list.insert(), list.pop(), list.append(), and list.extend()

Situations deemed unlikely to benefit:
    list_inplace_repeat, list_ass_slice, list_ass_subscript

The most gray area was for listextend_internal() which only runs
when the argument is a list or a tuple.  This could be viewed as
a one-time fixed length addition or it could be viewed as wrapping
a series of appends.  I left its over-allocation turned on but 
could be convinced otherwise.



Index: listobject.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Objects/listobject.c,v
retrieving revision 2.196
retrieving revision 2.197
diff -C2 -d -r2.196 -r2.197
*** listobject.c	12 Mar 2004 16:38:17 -0000	2.196
--- listobject.c	14 Mar 2004 06:42:23 -0000	2.197
***************
*** 10,14 ****
  
  static int
! list_resize(PyListObject *self, int newsize)
  {
  	PyObject **items;
--- 10,14 ----
  
  static int
! list_resize(PyListObject *self, int newsize, int exact)
  {
  	PyObject **items;
***************
*** 34,38 ****
  	 * The growth pattern is:  0, 4, 8, 16, 25, 35, 46, 58, 72, 88, ...
  	 */
! 	_new_size = (newsize >> 3) + (self->ob_size < 8 ? 3 : 6) + newsize;
  	items = self->ob_item;
  	if (_new_size <= ((~(size_t)0) / sizeof(PyObject *)))
--- 34,41 ----
  	 * The growth pattern is:  0, 4, 8, 16, 25, 35, 46, 58, 72, 88, ...
  	 */
! 	if (exact)
! 		_new_size = newsize;
! 	else
! 		_new_size = (newsize>>3) + (self->ob_size < 8 ? 3 : 6) + newsize;
  	items = self->ob_item;
  	if (_new_size <= ((~(size_t)0) / sizeof(PyObject *)))
***************
*** 153,157 ****
  	}
  	
! 	if (list_resize(self, n+1) == -1)
  		return -1;
  
--- 156,160 ----
  	}
  	
! 	if (list_resize(self, n+1, 0) == -1)
  		return -1;
  
***************
*** 519,523 ****
  			memmove(&item[ihigh+d], &item[ihigh], 
  				(a->ob_size - ihigh)*sizeof(PyObject *));
! 			list_resize(a, a->ob_size + d);
  			item = a->ob_item;
  		}
--- 522,526 ----
  			memmove(&item[ihigh+d], &item[ihigh], 
  				(a->ob_size - ihigh)*sizeof(PyObject *));
! 			list_resize(a, a->ob_size + d, 1);
  			item = a->ob_item;
  		}
***************
*** 525,529 ****
  	else { /* Insert d items; recycle ihigh-ilow items */
  		s = a->ob_size;
! 		if (list_resize(a, s+d) == -1) {
  			if (recycle != NULL)
  				PyMem_DEL(recycle);
--- 528,532 ----
  	else { /* Insert d items; recycle ihigh-ilow items */
  		s = a->ob_size;
! 		if (list_resize(a, s+d, 1) == -1) {
  			if (recycle != NULL)
  				PyMem_DEL(recycle);
***************
*** 589,593 ****
  	}
  
! 	if (list_resize(self, size*n) == -1) 
  		return NULL;
  
--- 592,596 ----
  	}
  
! 	if (list_resize(self, size*n, 1) == -1) 
  		return NULL;
  
***************
*** 681,685 ****
  	}
  
! 	if (list_resize(self, selflen + blen) == -1) {
  		Py_DECREF(b);
  		return -1;
--- 684,688 ----
  	}
  
! 	if (list_resize(self, selflen + blen, 0) == -1) {
  		Py_DECREF(b);
  		return -1;
***************
*** 734,738 ****
  	m = self->ob_size;
  	mn = m + n;
! 	if (list_resize(self, mn) == -1)
  		goto error;
  	memset(&(self->ob_item[m]), 0, sizeof(*self->ob_item) * n);
--- 737,741 ----
  	m = self->ob_size;
  	mn = m + n;
! 	if (list_resize(self, mn, 0) == -1)
  		goto error;
  	memset(&(self->ob_item[m]), 0, sizeof(*self->ob_item) * n);
***************
*** 819,823 ****
  	v = self->ob_item[i];
  	if (i == self->ob_size - 1) {
! 		if (list_resize(self, self->ob_size - 1) == -1)
  			return NULL;
  		return v;
--- 822,826 ----
  	v = self->ob_item[i];
  	if (i == self->ob_size - 1) {
! 		if (list_resize(self, self->ob_size - 1, 0) == -1)
  			return NULL;
  		return v;
***************
*** 2518,2522 ****
  
  			self->ob_size -= slicelength;
! 			list_resize(self, self->ob_size);
  
  			for (i = 0; i < slicelength; i++) {
--- 2521,2525 ----
  
  			self->ob_size -= slicelength;
! 			list_resize(self, self->ob_size, 1);
  
  			for (i = 0; i < slicelength; i++) {