archive/php-src
1
0
Fork 0
mirror of https://github.com/php/php-src.git synced 2025-08-16 05:58:45 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

Optimize stripos/stristr

Browse source 
Closes GH-7847
Closes GH-7852

Previously stripos/stristr would lowercase both the haystack and the
needle to reuse strpos. The approach in this PR is similar to strpos.
memchr is highly optimized so we're using it to search for the first
character of the needle in the haystack. If we find it we compare the
remaining characters of the needle manually.

The new implementation seems to perform about half as well as strpos (as
two memchr calls are necessary to find the next candidate).
This commit is contained in:
Ilija Tovilo 2021-12-29 12:51:18 +01:00
parent 70f712ce04
commit 2f5295692f
No known key found for this signature in database
GPG key ID: A4F5D403F118200A
9 changed files with 79 additions and 46 deletions
Download patch file Download diff file Expand all files Collapse all files

5
ext/libxml/libxml.c
View file

@ -378,9 +378,9 @@ php_libxml_input_buffer_create_filename(const char *URI, xmlCharEncoding enc)
const char buf[] = "Content-Type:";
if (Z_TYPE_P(header) == IS_STRING &&
!zend_binary_strncasecmp(Z_STRVAL_P(header), Z_STRLEN_P(header), buf, sizeof(buf)-1, sizeof(buf)-1)) {
char *needle = estrdup("charset=");
char needle[] = "charset=";
char *haystack = estrndup(Z_STRVAL_P(header), Z_STRLEN_P(header));
char *encoding = php_stristr(haystack, needle, Z_STRLEN_P(header), sizeof("charset=")-1);
char *encoding = php_stristr(haystack, needle, Z_STRLEN_P(header), strlen(needle));
if (encoding) {
char *end;
@ -408,7 +408,6 @@ php_libxml_input_buffer_create_filename(const char *URI, xmlCharEncoding enc)
}
}
efree(haystack);
efree(needle);
break; /* found content-type */
}
} ZEND_HASH_FOREACH_END();