| /* Locale dependent memory area transformation for comparison. |
| Copyright (C) 2009-2020 Free Software Foundation, Inc. |
| Written by Bruno Haible <bruno@clisp.org>, 2009. |
| |
| This program is free software: you can redistribute it and/or modify it |
| under the terms of the GNU Lesser General Public License as published |
| by the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| |
| #include <config.h> |
| |
| /* Specification. */ |
| #include "amemxfrm.h" |
| |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| char * |
| amemxfrm (char *s, size_t n, char *resultbuf, size_t *lengthp) |
| { |
| /* Result accumulator. */ |
| char *result; |
| size_t length; |
| size_t allocated; |
| |
| char orig_sentinel; |
| |
| /* Initial memory allocation. */ |
| if (resultbuf != NULL && *lengthp > 0) |
| { |
| result = resultbuf; |
| allocated = *lengthp; |
| } |
| else |
| { |
| allocated = (n > 0 ? n : 1); |
| result = (char *) malloc (allocated); |
| if (result == NULL) |
| goto out_of_memory_2; |
| } |
| length = 0; |
| |
| /* Add sentinel.byte. */ |
| orig_sentinel = s[n]; |
| s[n] = '\0'; |
| |
| /* Iterate through S, transforming each NUL terminated segment. |
| Accumulate the resulting transformed segments in result, separated by |
| NULs. */ |
| { |
| const char *p_end = s + n + 1; |
| const char *p; |
| |
| p = s; |
| for (;;) |
| { |
| /* Search next NUL byte. */ |
| size_t l = strlen (p); |
| |
| for (;;) |
| { |
| size_t k; |
| |
| /* A call to strxfrm costs about 20 times more than a call to |
| strdup of the result. Therefore it is worth to try to avoid |
| calling strxfrm more than once on a given string, by making |
| enough room before calling strxfrm. |
| The size of the strxfrm result, k, is likely to be between |
| l and 3 * l. */ |
| if (3 * l >= allocated - length) |
| { |
| /* Grow the result buffer. */ |
| size_t new_allocated; |
| char *new_result; |
| |
| new_allocated = length + 3 * l + 1; |
| if (new_allocated < 2 * allocated) |
| new_allocated = 2 * allocated; |
| if (new_allocated < 64) |
| new_allocated = 64; |
| if (result == resultbuf) |
| new_result = (char *) malloc (new_allocated); |
| else |
| new_result = (char *) realloc (result, new_allocated); |
| if (new_result != NULL) |
| { |
| allocated = new_allocated; |
| result = new_result; |
| } |
| } |
| |
| errno = 0; |
| k = strxfrm (result + length, p, allocated - length); |
| if (errno != 0) |
| goto fail; |
| if (k >= allocated - length) |
| { |
| /* Grow the result buffer. */ |
| size_t new_allocated; |
| char *new_result; |
| |
| new_allocated = length + k + 1; |
| if (new_allocated < 2 * allocated) |
| new_allocated = 2 * allocated; |
| if (new_allocated < 64) |
| new_allocated = 64; |
| if (result == resultbuf) |
| new_result = (char *) malloc (new_allocated); |
| else |
| new_result = (char *) realloc (result, new_allocated); |
| if (new_result == NULL) |
| goto out_of_memory_1; |
| allocated = new_allocated; |
| result = new_result; |
| } |
| else |
| { |
| length += k; |
| break; |
| } |
| } |
| |
| p = p + l + 1; |
| if (p == p_end) |
| break; |
| result[length] = '\0'; |
| length++; |
| } |
| } |
| |
| /* Shrink the allocated memory if possible. |
| It is not worth calling realloc when length + 1 == allocated; it would |
| save just one byte. */ |
| if (result != resultbuf && length + 1 < allocated) |
| { |
| if ((length > 0 ? length : 1) <= *lengthp) |
| { |
| memcpy (resultbuf, result, length); |
| free (result); |
| result = resultbuf; |
| } |
| else |
| { |
| char *memory = (char *) realloc (result, length > 0 ? length : 1); |
| if (memory != NULL) |
| result = memory; |
| } |
| } |
| |
| s[n] = orig_sentinel; |
| *lengthp = length; |
| return result; |
| |
| fail: |
| { |
| int saved_errno = errno; |
| if (result != resultbuf) |
| free (result); |
| s[n] = orig_sentinel; |
| errno = saved_errno; |
| return NULL; |
| } |
| |
| out_of_memory_1: |
| if (result != resultbuf) |
| free (result); |
| s[n] = orig_sentinel; |
| out_of_memory_2: |
| errno = ENOMEM; |
| return NULL; |
| } |