Commit 1d2261ff authored by Brian Pane's avatar Brian Pane
Browse files

Performance fix: When a BrowserMatch or SetEnvIf pattern doesn't 

actually require regular expression parsing, use a fast string search
instead.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@95027 13f79535-47bb-0310-9956-ffa450edef68
parent 606428ce

modules/metadata/mod_setenvif.c

+77 −1
Changes for modules/metadata/mod_setenvif.c: 77 added lines, 1 removed line.
Original line number Diff line number Diff line
@@ -123,6 +123,7 @@ 


#include "apr.h"

#include "apr_strings.h"

#include "apr_strmatch.h"



#define APR_WANT_STRFUNC

#include "apr_want.h"
@@ -149,6 +150,7 @@ typedef struct { 
    regex_t *pnamereg;          /* compiled header name regex */

    char *regex;                /* regex to match against */

    regex_t *preg;              /* compiled regex */

    const apr_strmatch_pattern *pattern; /* non-regex pattern to match */

    apr_table_t *features;      /* env vars to set (or unset) */

    enum special special_type;  /* is it a "special" header ? */

    int icase;                  /* ignoring case? */
@@ -219,10 +221,68 @@ static int is_header_regex(apr_pool_t *p, const char* name) 
    }

    return 0;

}



/* If the input string does not take advantage of regular

 * expression metacharacters, return a pointer to an equivalent

 * string that can be searched using apr_strmatch().  (The

 * returned string will often be the input string.  But if

 * the input string contains escaped characters, the returned

 * string will be a copy with the escapes removed.)

 */

static const char *non_regex_pattern(apr_pool_t *p, const char *s)

{

    const char *src = s;

    int escapes_found = 0;

    int in_escape = 0;



    while (*src) {

        if (in_escape) {

            in_escape = 0;

        }

        else {

            switch (*src) {

            case '^':

            case '.':

            case '$':

            case '|':

            case '(':

            case ')':

            case '[':

            case ']':

            case '*':

            case '+':

            case '?':

            case '{':

            case '}':

                return NULL;

            case '\\':

                in_escape = 1;

                escapes_found = 1;

            }

        }

        src++;

    }

    if (!escapes_found) {

        return s;

    }

    else {

        char *unescaped = (char *)apr_palloc(p, src - s + 1);

        char *dst = unescaped;

        src = s;

        do {

            if (*src == '\\') {

                src++;

            }

        } while ((*dst++ = *src++));

        return unescaped;

    }

}



static const char *add_setenvif_core(cmd_parms *cmd, void *mconfig,

				     char *fname, const char *args)

{

    char *regex;

    const char *simple_pattern;

    const char *feature;

    sei_cfg_rec *sconf;

    sei_entry *new;
@@ -279,6 +339,16 @@ static const char *add_setenvif_core(cmd_parms *cmd, void *mconfig, 
	new->name = fname;

	new->regex = regex;

	new->icase = icase;

        if ((simple_pattern = non_regex_pattern(cmd->pool, regex))) {

            new->pattern = apr_strmatch_precompile(cmd->pool,

                                                   simple_pattern, 1);

            if (new->pattern == NULL) {

                return apr_pstrcat(cmd->pool, cmd->cmd->name,

                                   " pattern could not be compiled.", NULL);

            }

            new->preg = NULL;

        }

        else {

            new->preg = ap_pregcomp(cmd->pool, regex,

                                    (REG_EXTENDED | REG_NOSUB

                                     | (icase ? REG_ICASE : 0)));
@@ -286,6 +356,8 @@ static const char *add_setenvif_core(cmd_parms *cmd, void *mconfig, 
                return apr_pstrcat(cmd->pool, cmd->cmd->name,

                                   " regex could not be compiled.", NULL);

            }

            new->pattern = NULL;

        }

	new->features = apr_table_make(cmd->pool, 2);



	if (!strcasecmp(fname, "remote_addr")) {
@@ -408,6 +480,7 @@ static int match_headers(request_rec *r) 
    sei_entry *entries;

    const apr_table_entry_t *elts;

    const char *val;

    apr_size_t val_len = 0;

    int i, j;

    char *last_name;
@@ -477,6 +550,7 @@ static int match_headers(request_rec *r) 
                    }

                }

	    }

            val_len = val ? strlen(val) : 0;

        }



	/*
@@ -487,9 +561,11 @@ static int match_headers(request_rec *r) 
	 */

        if (val == NULL) {

            val = "";

            val_len = 0;

        }



        if (!ap_regexec(b->preg, val, 0, NULL, 0)) {

        if (b->pattern ? apr_strmatch(b->pattern, val, val_len) :

            !ap_regexec(b->preg, val, 0, NULL, 0)) {

	    const apr_array_header_t *arr = apr_table_elts(b->features);

            elts = (const apr_table_entry_t *) arr->elts;