Line data    Source code

       1             : /* stringlib: replace implementation */
       2             : 
       3             : #ifndef STRINGLIB_FASTSEARCH_H
       4             : #error must include "stringlib/fastsearch.h" before including this module
       5             : #endif
       6             : 
       7             : Py_LOCAL_INLINE(void)
       8       35157 : STRINGLIB(replace_1char_inplace)(STRINGLIB_CHAR* s, STRINGLIB_CHAR* end,
       9             :                                  Py_UCS4 u1, Py_UCS4 u2, Py_ssize_t maxcount)
      10             : {
      11       35157 :     *s = u2;
      12       65081 :     while (--maxcount && ++s != end) {
      13             :         /* Find the next character to be replaced.
      14             : 
      15             :            If it occurs often, it is faster to scan for it using an inline
      16             :            loop.  If it occurs seldom, it is faster to scan for it using a
      17             :            function call; the overhead of the function call is amortized
      18             :            across the many characters that call covers.  We start with an
      19             :            inline loop and use a heuristic to determine whether to fall back
      20             :            to a function call. */
      21       64645 :         if (*s != u1) {
      22       52900 :             int attempts = 10;
      23             :             /* search u1 in a dummy loop */
      24             :             while (1) {
      25      389347 :                 if (++s == end)
      26       22455 :                     return;
      27      366892 :                 if (*s == u1)
      28       15148 :                     break;
      29      351744 :                 if (!--attempts) {
      30             :                     /* if u1 was not found for attempts iterations,
      31             :                        use FASTSEARCH() or memchr() */
      32             : #ifdef STRINGLIB_FAST_MEMCHR
      33       15291 :                     s++;
      34       15291 :                     s = STRINGLIB_FAST_MEMCHR(s, u1, end - s);
      35       15291 :                     if (s == NULL)
      36       12264 :                         return;
      37             : #else
      38             :                     Py_ssize_t i;
      39           6 :                     STRINGLIB_CHAR ch1 = (STRINGLIB_CHAR) u1;
      40           6 :                     s++;
      41           6 :                     i = FASTSEARCH(s, end - s, &ch1, 1, 0, FAST_SEARCH);
      42           6 :                     if (i < 0)
      43           2 :                         return;
      44           4 :                     s += i;
      45             : #endif
      46             :                     /* restart the dummy loop */
      47        3031 :                     break;
      48             :                 }
      49             :             }
      50             :         }
      51       29924 :         *s = u2;
      52             :     }
      53             : }