Rewrote translate() as follows:

	- 'delete' is a C++ keyword; use 'del_table' instead
	- apply Py_CHARMASK() to del_table[i] before using it as an index
	  *** this fixes a bug that was just reported on the list ***
	- if the translation didn't make any changes, INCREF and return
	  the original string
	- when del_table is empty or omitted, don't copy the translation
	  table to a table of ints (should be a bit faster)

Rewrote maketrans() to avoid copying the table (2-3% faster).

diff --git a/Modules/stropmodule.c b/Modules/stropmodule.c
index d84b55f55c3932b6529229ce885e3a785bd3fafe..9251b034b6e3243839d2b797151465afa194ff60 100644 (file)
--- a/Modules/stropmodule.c
+++ b/Modules/stropmodule.c
@@ -661,8 +661,9 @@ strop_maketrans(self, args)
        PyObject *self; /* Not used */
        PyObject *args;
 {
-       unsigned char c[256], *from=NULL, *to=NULL;
+       unsigned char *c, *from=NULL, *to=NULL;
        int i, fromlen=0, tolen=0;
+       PyObject *result;
 
        if (!PyArg_ParseTuple(args, "s#s#", &from, &fromlen, &to, &tolen))
                return NULL;
@@ -672,12 +673,17 @@ strop_maketrans(self, args)
                                "maketrans arguments must have same length");
                return NULL;
        }
+
+       result = PyString_FromStringAndSize((char *)NULL, 256);
+       if (result == NULL)
+               return NULL;
+       c = (unsigned char *) PyString_AS_STRING((PyStringObject *)result);
        for (i = 0; i < 256; i++)
                c[i]=(unsigned char)i;
        for (i = 0; i < fromlen; i++)
                c[from[i]]=to[i];
 
-       return PyString_FromStringAndSize((char *)c, 256);
+       return result;
 }
 
 
@@ -686,48 +692,66 @@ strop_translate(self, args)
        PyObject *self;
        PyObject *args;
 {
-       char *input, *table, *output, *output_start, *delete=NULL;
+       register char *input, *table, *output;
+       register int i, c, changed = 0;
+       PyObject *input_obj;
+       char *table1, *output_start, *del_table=NULL;
        int inlen, tablen, dellen = 0;
        PyObject *result;
-       int i, trans_table[256];
+       int trans_table[256];
 
-       if (!PyArg_ParseTuple(args, "s#s#|s#", &input, &inlen,
-                             &table, &tablen, &delete, &dellen))
+       if (!PyArg_ParseTuple(args, "Ss#|s#", &input_obj,
+                             &table1, &tablen, &del_table, &dellen))
                return NULL;
        if (tablen != 256) {
                PyErr_SetString(PyExc_ValueError,
                              "translation table must be 256 characters long");
                return NULL;
        }
-       for (i = 0; i < 256; i++)
-               trans_table[i] = Py_CHARMASK(table[i]);
-
-       if (delete != NULL) {
-               for (i = 0; i < dellen; i++) 
-                       trans_table[(int)delete[i]] = -1;
-       }
 
+       table = table1;
+       inlen = PyString_Size(input_obj);
        result = PyString_FromStringAndSize((char *)NULL, inlen);
        if (result == NULL)
                return NULL;
        output_start = output = PyString_AsString(result);
-
-       if (delete != NULL && dellen != 0) {
-               for (i = 0; i < inlen; i++) {
-                       int c = Py_CHARMASK(*input++);
-                       if (trans_table[c] != -1) 
-                               *output++ = (char)trans_table[c];
-               }
-               /* Fix the size of the resulting string */
-               if (inlen > 0 &&_PyString_Resize(&result, output-output_start))
-                       return NULL; 
-       } else {
-               /* If no deletions are required, use a faster loop */
-               for (i = 0; i < inlen; i++) {
-                       int c = Py_CHARMASK(*input++);
-                       *output++ = (char)trans_table[c];
+       input = PyString_AsString(input_obj);
+
+       if (dellen == 0) {
+               /* If no deletions are required, use faster code */
+               for (i = inlen; --i >= 0; ) {
+                       c = Py_CHARMASK(*input++);
+                       if (Py_CHARMASK((*output++ = table[c])) != c)
+                               changed = 1;
                }
+               if (changed)
+                       return result;
+               Py_DECREF(result);
+               Py_INCREF(input_obj);
+               return input_obj;
+       }
+
+       for (i = 0; i < 256; i++)
+               trans_table[i] = Py_CHARMASK(table[i]);
+
+       for (i = 0; i < dellen; i++) 
+               trans_table[Py_CHARMASK(del_table[i])] = -1;
+
+       for (i = inlen; --i >= 0; ) {
+               c = Py_CHARMASK(*input++);
+               if (trans_table[c] != -1)
+                       if (Py_CHARMASK(*output++ = (char)trans_table[c]) == c)
+                               continue;
+               changed = 1;
+       }
+       if (!changed) {
+               Py_DECREF(result);
+               Py_INCREF(input_obj);
+               return input_obj;
        }
+       /* Fix the size of the resulting string */
+       if (inlen > 0 &&_PyString_Resize(&result, output-output_start))
+               return NULL; 
        return result;
 }