Commit 43cf5345 authored by Justin Erenkrantz's avatar Justin Erenkrantz
Browse files

More work to properly handle revalidated responses correctly. 

* modules/cache/mod_cache.c: If we add a new Expires value, tell our client;
  merge in headers properly (or better than before) so that we can update the
  header fields on a revalidated but with updated header fields.
* modules/cache/mod_cache.h, modules/cache/cache_storage.c:
  Add preserve_orig flag to ap_cache_accept_headers to allow updating of fields.
* modules/cache/mod_disk_cache.c: Load status value from disk.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@152973 13f79535-47bb-0310-9956-ffa450edef68
parent b83ca006

modules/cache/cache_storage.c

+11 −3
Changes for modules/cache/cache_storage.c: 11 added lines, 3 removed lines.
Original line number Diff line number Diff line
@@ -105,9 +105,10 @@ static int set_cookie_doo_doo(void *v, const char *key, const char *val) 
    return 1;

}



CACHE_DECLARE(void) ap_cache_accept_headers(cache_handle_t *h, request_rec *r)

CACHE_DECLARE(void) ap_cache_accept_headers(cache_handle_t *h, request_rec *r,

                                            int preserve_orig)

{

    apr_table_t *cookie_table;

    apr_table_t *cookie_table, *hdr_copy;

    const char *v;



    v = apr_table_get(h->resp_hdrs, "Content-Type");
@@ -140,7 +141,14 @@ CACHE_DECLARE(void) ap_cache_accept_headers(cache_handle_t *h, request_rec *r) 
    apr_table_unset(r->err_headers_out, "Set-Cookie");

    apr_table_unset(h->resp_hdrs, "Set-Cookie");



    if (preserve_orig) {

        hdr_copy = apr_table_copy(r->pool, h->resp_hdrs);

        apr_table_overlap(hdr_copy, r->headers_out, APR_OVERLAP_TABLES_SET);

        r->headers_out = hdr_copy;

    }

    else {

        apr_table_overlap(r->headers_out, h->resp_hdrs, APR_OVERLAP_TABLES_SET);

    }

    if (!apr_is_empty_table(cookie_table)) {

        r->err_headers_out = apr_table_overlay(r->pool, r->err_headers_out,

                                               cookie_table);
@@ -274,7 +282,7 @@ int cache_select_url(request_rec *r, char *url) 
            }



            /* Okay, this response looks okay.  Merge in our stuff and go. */

            ap_cache_accept_headers(h, r);

            ap_cache_accept_headers(h, r, 0);



            cache->handle = h;

            return OK;

modules/cache/mod_cache.c

+41 −13
Changes for modules/cache/mod_cache.c: 41 added lines, 13 removed lines.
Original line number Diff line number Diff line
@@ -532,12 +532,6 @@ static int cache_save_filter(ap_filter_t *f, apr_bucket_brigade *in) 
            /* Oh, hey.  It isn't that stale!  Yay! */

            cache->handle = cache->stale_handle;

            info = &cache->handle->cache_obj->info;

            /* Load in the saved status. */

            r->status = info->status;

            /* The cached response will override our err_headers_out. */

            apr_table_clear(r->err_headers_out);

            /* Merge in our headers. */

            ap_cache_accept_headers(cache->handle, r);

            rv = OK;

        }

        else {
@@ -636,6 +630,8 @@ static int cache_save_filter(ap_filter_t *f, apr_bucket_brigade *in) 
     *      expire date = date + defaultexpire

     */

    if (exp == APR_DATE_BAD) {

        char expire_hdr[APR_RFC822_DATE_LEN];



        /* if lastmod == date then you get 0*conf->factor which results in

         *   an expiration time of now. This causes some problems with

         *   freshness calculations, so we choose the else path...
@@ -647,19 +643,50 @@ static int cache_save_filter(ap_filter_t *f, apr_bucket_brigade *in) 
                x = conf->maxex;

            }

            exp = date + x;

            apr_rfc822_date(expire_hdr, exp);

            apr_table_set(r->headers_out, "Expires", expire_hdr);

        }

        else {

            exp = date + conf->defex;

            apr_rfc822_date(expire_hdr, exp);

            apr_table_set(r->headers_out, "Expires", expire_hdr);

        }

    }

    info->expire = exp;



    /*

     * Write away header information to cache.

    /* We found a stale entry which wasn't really stale. */

    if (cache->stale_handle) {

        /* Load in the saved status and clear the status line. */

        r->status = info->status;

        r->status_line = NULL;



        /* RFC 2616 10.3.5 states that entity headers are not supposed

         * to be in the 304 response.  Therefore, we need to load in the

         * cached headers before we update the cached headers.

         *

         * However, before doing that, we need to first merge in

         * err_headers_out and we also need to strip any hop-by-hop

         * headers that might have snuck in.

         */

        r->headers_out = apr_table_overlay(r->pool, r->headers_out,

                                           r->err_headers_out);

        r->headers_out = ap_cache_cacheable_hdrs_out(r->pool, r->headers_out,

                                                     r->server);

        apr_table_clear(r->err_headers_out);



        /* Merge in our cached headers.  However, keep any updated values. */

        ap_cache_accept_headers(cache->handle, r, 1);

    }



    /* Write away header information to cache. */

    rv = cache->provider->store_headers(cache->handle, r, info);



    /* Did we actually find an entity before, but it wasn't really stale? */

    /* Did we just update the cached headers on a revalidated response?

     *

     * If so, we can now decide what to serve to the client:

     * - If the original request was conditional and is satisified, send 304.

     * - Otherwise, send the cached body.

    */

    if (rv == APR_SUCCESS && cache->stale_handle) {

        apr_bucket_brigade *bb;

        apr_bucket *bkt;
@@ -668,14 +695,15 @@ static int cache_save_filter(ap_filter_t *f, apr_bucket_brigade *in) 


        /* Were we initially a conditional request? */

        if (ap_cache_request_is_conditional(cache->stale_headers)) {

            /* FIXME: Should we now go and make sure it's really not

             * modified since what the user thought?

             */

            /* FIXME: We must ensure that the request meets conditions. */



            /* Set the status to be a 304. */

            r->status = HTTP_NOT_MODIFIED;



            bkt = apr_bucket_flush_create(bb->bucket_alloc);

            APR_BRIGADE_INSERT_TAIL(bb, bkt);

        }

        else {

            r->status = info->status;

            cache->provider->recall_body(cache->handle, r->pool, bb);

        }

modules/cache/mod_cache.h

+9 −1
Changes for modules/cache/mod_cache.h: 9 added lines, 1 removed line.
Original line number Diff line number Diff line
@@ -241,7 +241,15 @@ CACHE_DECLARE(apr_time_t) ap_cache_current_age(cache_info *info, const apr_time_ 
 */

CACHE_DECLARE(int) ap_cache_check_freshness(cache_handle_t *h, request_rec *r);



CACHE_DECLARE(void) ap_cache_accept_headers(cache_handle_t *h, request_rec *r);

/**

 * Merge in cached headers into the response

 * @param h cache_handle_t

 * @param r request_rec

 * @param preserve_orig If 1, the values in r->headers_out are preserved.

 *        Otherwise, they are overwritten by the cached value.

 */

CACHE_DECLARE(void) ap_cache_accept_headers(cache_handle_t *h, request_rec *r,

                                            int preserve_orig);



CACHE_DECLARE(apr_time_t) ap_cache_hex2usec(const char *x);

CACHE_DECLARE(void) ap_cache_usec2hex(apr_time_t j, char *y);

modules/cache/mod_disk_cache.c

+1 −0
Changes for modules/cache/mod_disk_cache.c: 1 added line, 0 removed lines.
Original line number Diff line number Diff line
@@ -221,6 +221,7 @@ static int file_cache_recall_mydata(apr_file_t *fd, cache_info *info, 
    /* Store it away so we can get it later. */

    dobj->disk_info = disk_info;



    info->status = disk_info.status;

    info->date = disk_info.date;

    info->expire = disk_info.expire;

    info->request_time = disk_info.request_time;