Several optimizations and speed improvements.
cstubs: Use Matrix type instead of float[4][4].
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index a3043d4..f66a82c 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -26,21 +26,76 @@
#include "allobjects.h"
+#ifdef COUNT_ALLOCS
+int null_strings, one_strings;
+#endif
+
+#ifdef __STDC__
+#include <limits.h>
+#else
+#ifndef UCHAR_MAX
+#define UCHAR_MAX 255
+#endif
+#endif
+
+static stringobject *characters[UCHAR_MAX + 1];
+static stringobject *nullstring;
+
+/*
+ Newsizedstringobject() and newstringobject() try in certain cases
+ to share string objects. When the size of the string is zero,
+ these routines always return a pointer to the same string object;
+ when the size is one, they return a pointer to an already existing
+ object if the contents of the string is known. For
+ newstringobject() this is always the case, for
+ newsizedstringobject() this is the case when the first argument in
+ not NULL.
+ A common practice to allocate a string and then fill it in or
+ change it must be done carefully. It is only allowed to change the
+ contents of the string if the obect was gotten from
+ newsizedstringobject() with a NULL first argument, because in the
+ future these routines may try to do even more sharing of objects.
+*/
object *
newsizedstringobject(str, size)
char *str;
int size;
{
- register stringobject *op = (stringobject *)
+ register stringobject *op;
+ if (size == 0 && (op = nullstring) != NULL) {
+#ifdef COUNT_ALLOCS
+ null_strings++;
+#endif
+ INCREF(op);
+ return op;
+ }
+ if (size == 1 && str != NULL && (op = characters[*str & UCHAR_MAX]) != NULL) {
+#ifdef COUNT_ALLOCS
+ one_strings++;
+#endif
+ INCREF(op);
+ return op;
+ }
+ op = (stringobject *)
malloc(sizeof(stringobject) + size * sizeof(char));
if (op == NULL)
return err_nomem();
op->ob_type = &Stringtype;
op->ob_size = size;
+#ifdef CACHE_HASH
+ op->ob_shash = -1;
+#endif
NEWREF(op);
if (str != NULL)
memcpy(op->ob_sval, str, size);
op->ob_sval[size] = '\0';
+ if (size == 0) {
+ nullstring = op;
+ INCREF(op);
+ } else if (size == 1 && str != NULL) {
+ characters[*str & UCHAR_MAX] = op;
+ INCREF(op);
+ }
return (object *) op;
}
@@ -49,14 +104,39 @@
char *str;
{
register unsigned int size = strlen(str);
- register stringobject *op = (stringobject *)
+ register stringobject *op;
+ if (size == 0 && (op = nullstring) != NULL) {
+#ifdef COUNT_ALLOCS
+ null_strings++;
+#endif
+ INCREF(op);
+ return op;
+ }
+ if (size == 1 && (op = characters[*str & UCHAR_MAX]) != NULL) {
+#ifdef COUNT_ALLOCS
+ one_strings++;
+#endif
+ INCREF(op);
+ return op;
+ }
+ op = (stringobject *)
malloc(sizeof(stringobject) + size * sizeof(char));
if (op == NULL)
return err_nomem();
op->ob_type = &Stringtype;
op->ob_size = size;
+#ifdef CACHE_HASH
+ op->ob_shash = -1;
+#endif
NEWREF(op);
strcpy(op->ob_sval, str);
+ if (size == 0) {
+ nullstring = op;
+ INCREF(op);
+ } else if (size == 1) {
+ characters[*str & UCHAR_MAX] = op;
+ INCREF(op);
+ }
return (object *) op;
}
@@ -189,6 +269,9 @@
return err_nomem();
op->ob_type = &Stringtype;
op->ob_size = size;
+#ifdef CACHE_HASH
+ op->ob_shash = -1;
+#endif
NEWREF(op);
memcpy(op->ob_sval, a->ob_sval, (int) a->ob_size);
memcpy(op->ob_sval + a->ob_size, b->ob_sval, (int) b->ob_size);
@@ -218,6 +301,9 @@
return err_nomem();
op->ob_type = &Stringtype;
op->ob_size = size;
+#ifdef CACHE_HASH
+ op->ob_shash = -1;
+#endif
NEWREF(op);
for (i = 0; i < size; i += a->ob_size)
memcpy(op->ob_sval+i, a->ob_sval, (int) a->ob_size);
@@ -247,16 +333,6 @@
return newsizedstringobject(a->ob_sval + i, (int) (j-i));
}
-#ifdef __STDC__
-#include <limits.h>
-#else
-#ifndef UCHAR_MAX
-#define UCHAR_MAX 255
-#endif
-#endif
-
-static object *characters[UCHAR_MAX + 1];
-
static object *
string_item(a, i)
stringobject *a;
@@ -269,12 +345,16 @@
return NULL;
}
c = a->ob_sval[i] & UCHAR_MAX;
- v = characters[c];
+ v = (object *) characters[c];
+#ifdef COUNT_ALLOCS
+ if (v != NULL)
+ one_strings++;
+#endif
if (v == NULL) {
v = newsizedstringobject((char *)NULL, 1);
if (v == NULL)
return NULL;
- characters[c] = v;
+ characters[c] = (stringobject *) v;
((stringobject *)v)->ob_sval[0] = c;
}
INCREF(v);
@@ -287,9 +367,14 @@
{
int len_a = a->ob_size, len_b = b->ob_size;
int min_len = (len_a < len_b) ? len_a : len_b;
- int cmp = memcmp(a->ob_sval, b->ob_sval, min_len);
- if (cmp != 0)
- return cmp;
+ int cmp;
+ if (min_len > 0) {
+ cmp = *a->ob_sval - *b->ob_sval;
+ if (cmp == 0)
+ cmp = memcmp(a->ob_sval, b->ob_sval, min_len);
+ if (cmp != 0)
+ return cmp;
+ }
return (len_a < len_b) ? -1 : (len_a > len_b) ? 1 : 0;
}
@@ -297,14 +382,25 @@
string_hash(a)
stringobject *a;
{
- register int len = a->ob_size;
- register unsigned char *p = (unsigned char *) a->ob_sval;
- register long x = *p << 7;
+ register int len;
+ register unsigned char *p;
+ register long x;
+
+#ifdef CACHE_HASH
+ if (a->ob_shash != -1)
+ return a->ob_shash;
+#endif
+ len = a->ob_size;
+ p = (unsigned char *) a->ob_sval;
+ x = *p << 7;
while (--len >= 0)
x = (x + x + x) ^ *p++;
x ^= a->ob_size;
if (x == -1)
x = -2;
+#ifdef CACHE_HASH
+ a->ob_shash = x;
+#endif
return x;
}