Commit be9d0259 authored by Justin Erenkrantz's avatar Justin Erenkrantz
Browse files

The ap_add_input_filter/ap_add_output_filter functions do an O(n) scan 

through the list of registered filters.  This patch replaces the linear
list with a hash table for better performance.
Submitted by:	Brian Pane <bpane@pacbell.net>
Reviewed by:	Justin Erenkrantz


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@90888 13f79535-47bb-0310-9956-ffa450edef68
parent 21398356

server/util_filter.c

+30 −10
Original line number Diff line number Diff line
@@ -54,16 +54,18 @@ 


#define APR_WANT_STRFUNC

#include "apr_want.h"

#include "apr_lib.h"

#include "apr_hash.h"

#include "apr_strings.h"



#include "httpd.h"

#include "http_log.h"

#include "util_filter.h"



/* ### make this visible for direct manipulation?

 * ### use a hash table

 */

static ap_filter_rec_t *registered_output_filters = NULL;

static ap_filter_rec_t *registered_input_filters = NULL;

static apr_hash_t *registered_output_filters = NULL;

static apr_hash_t *registered_input_filters = NULL;



/* NOTE: Apache's current design doesn't allow a pool to be passed thu,

   so we depend on a global to hold the correct pool
@@ -92,16 +94,20 @@ static apr_status_t filter_cleanup(void *ctx) 
static void register_filter(const char *name,

                            ap_filter_func filter_func,

                            ap_filter_type ftype,

                            ap_filter_rec_t **reg_filter_list)

                            apr_hash_t **reg_filter_set)

{

    ap_filter_rec_t *frec = apr_palloc(FILTER_POOL, sizeof(*frec));



    frec->name = name;

    if (!*reg_filter_set) {

        *reg_filter_set = apr_hash_make(FILTER_POOL);

    }



    frec->name = apr_pstrdup(FILTER_POOL, name);

    ap_str_tolower((char *)frec->name);

    frec->filter_func = filter_func;

    frec->ftype = ftype;



    frec->next = *reg_filter_list;

    *reg_filter_list = frec;

    apr_hash_set(*reg_filter_set, frec->name, APR_HASH_KEY_STRING, frec);



    apr_pool_cleanup_register(FILTER_POOL, NULL, filter_cleanup, apr_pool_cleanup_null);

}
@@ -126,12 +132,26 @@ AP_DECLARE(void) ap_register_output_filter(const char *name, 


static ap_filter_t *add_any_filter(const char *name, void *ctx, 

				   request_rec *r, conn_rec *c, 

				   ap_filter_rec_t *frec,

                   apr_hash_t *reg_filter_set,

				   ap_filter_t **r_filters,

				   ap_filter_t **c_filters)

{

    for (; frec != NULL; frec = frec->next) {

        if (!strcasecmp(name, frec->name)) {

    if (reg_filter_set) {

        ap_filter_rec_t *frec;

        int len = strlen(name);

        int size = len + 1;

        char name_lower[size];

        char *dst = name_lower;

        const char *src = name;



        /* Normalize the name to all lowercase to match register_filter() */

        do {

            *dst++ = apr_tolower(*src++);

        } while (--size);



        frec = (ap_filter_rec_t *)apr_hash_get(reg_filter_set,

                                               name_lower, len);

        if (frec) {

            apr_pool_t *p = r ? r->pool : c->pool;

            ap_filter_t *f = apr_pcalloc(p, sizeof(*f));

            ap_filter_t **outf = r ? r_filters : c_filters;