mod_cache.c revision c51f2b89da23e3371959a74808dee1792d96f5c1
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
* Portions of this software are based upon public domain software
* originally written at the National Center for Supercomputing Applications,
* University of Illinois, Urbana-Champaign.
*/
#define CORE_PRIVATE
#include "mod_cache.h"
module AP_MODULE_DECLARE_DATA cache_module;
APR_OPTIONAL_FN_TYPE(ap_cache_generate_key) *cache_generate_key;
/* -------------------------------------------------------------- */
/*
* CACHE handler
* -------------
*
* Can we deliver this request from the cache?
* If yes:
* deliver the content by installing the CACHE_OUT filter.
* If no:
* check whether we're allowed to try cache it
* If yes:
* add CACHE_IN filter
* If No:
* oh well.
*/
static int cache_url_handler(request_rec *r, int lookup)
{
apr_status_t rv;
const char *cc_in, *pragma, *auth;
apr_uri_t uri = r->parsed_uri;
char *url = r->unparsed_uri;
apr_size_t urllen;
char *path = uri.path;
const char *types;
cache_info *info = NULL;
cache_request_rec *cache;
cache_server_conf *conf;
conf = (cache_server_conf *) ap_get_module_config(r->server->module_config,
&cache_module);
/* we don't handle anything but GET */
if (r->method_number != M_GET) {
return DECLINED;
}
/*
* Which cache module (if any) should handle this request?
*/
if (!(types = ap_cache_get_cachetype(r, conf, path))) {
return DECLINED;
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"cache: URL %s is being handled by %s", path, types);
urllen = strlen(url);
if (urllen > MAX_URL_LENGTH) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"cache: URL exceeds length threshold: %s", url);
return DECLINED;
}
/* DECLINE urls ending in / */
if (url[urllen-1] == '/') {
return DECLINED;
}
/* make space for the per request config */
cache = (cache_request_rec *) ap_get_module_config(r->request_config,
&cache_module);
if (!cache) {
cache = apr_pcalloc(r->pool, sizeof(cache_request_rec));
ap_set_module_config(r->request_config, &cache_module, cache);
}
/* save away the type */
cache->types = types;
/*
* Are we allowed to serve cached info at all?
*/
/* find certain cache controlling headers */
cc_in = apr_table_get(r->headers_in, "Cache-Control");
pragma = apr_table_get(r->headers_in, "Pragma");
auth = apr_table_get(r->headers_in, "Authorization");
/* first things first - does the request allow us to return
* cached information at all? If not, just decline the request.
*
* Note that there is a big difference between not being allowed
* to cache a request (no-store) and not being allowed to return
* a cached request without revalidation (max-age=0).
*
* Caching is forbidden under the following circumstances:
*
* - RFC2616 14.9.2 Cache-Control: no-store
* - Pragma: no-cache
* - Any requests requiring authorization.
*/
if (conf->ignorecachecontrol == 1 && auth == NULL) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"incoming request is asking for a uncached version of "
"%s, but we know better and are ignoring it", url);
}
else {
if (ap_cache_liststr(cc_in, "no-store", NULL) ||
ap_cache_liststr(pragma, "no-cache", NULL) || (auth != NULL)) {
/* delete the previously cached file */
cache_remove_url(r, cache->types, url);
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"cache: no-store forbids caching of %s", url);
return DECLINED;
}
}
/*
* Try to serve this request from the cache.
*
* If no existing cache file
* add cache_in filter
* If stale cache file
* If conditional request
* add cache_in filter
* If non-conditional request
* fudge response into a conditional
* add cache_conditional filter
* If fresh cache file
* clear filter stack
* add cache_out filter
*/
rv = cache_select_url(r, cache->types, url);
if (DECLINED == rv) {
if (!lookup) {
/* no existing cache file */
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"cache: no cache - add cache_in filter and DECLINE");
/* add cache_in filter to cache this request */
ap_add_output_filter("CACHE_IN", NULL, r, r->connection);
}
return DECLINED;
}
else if (OK == rv) {
/* RFC2616 13.2 - Check cache object expiration */
cache->fresh = ap_cache_check_freshness(cache, r);
if (cache->fresh) {
/* fresh data available */
apr_bucket_brigade *out;
conn_rec *c = r->connection;
if (lookup) {
return OK;
}
rv = ap_meets_conditions(r);
if (rv != OK) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"cache: fresh cache - returning status %d", rv);
return rv;
}
/*
* Not a conditionl request. Serve up the content
*/
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"cache: fresh cache - add cache_out filter and "
"handle request");
/* We are in the quick handler hook, which means that no output
* filters have been set. So lets run the insert_filter hook.
*/
ap_run_insert_filter(r);
ap_add_output_filter("CACHE_OUT", NULL, r, r->connection);
/* kick off the filter stack */
out = apr_brigade_create(r->pool, c->bucket_alloc);
if (APR_SUCCESS
!= (rv = ap_pass_brigade(r->output_filters, out))) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,
"cache: error returned while trying to return %s "
"cached data",
cache->type);
return rv;
}
return OK;
}
else {
/* stale data available */
if (lookup) {
return DECLINED;
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"cache: stale cache - test conditional");
/* if conditional request */
if (ap_cache_request_is_conditional(r)) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0,
r->server,
"cache: conditional - add cache_in filter and "
"DECLINE");
/* Why not add CACHE_CONDITIONAL? */
ap_add_output_filter("CACHE_IN", NULL, r, r->connection);
return DECLINED;
}
/* else if non-conditional request */
else {
/* fudge response into a conditional */
if (info && info->etag) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0,
r->server,
"cache: nonconditional - fudge conditional "
"by etag");
/* if we have a cached etag */
apr_table_set(r->headers_in, "If-None-Match", info->etag);
}
else if (info && info->lastmods) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0,
r->server,
"cache: nonconditional - fudge conditional "
"by lastmod");
/* if we have a cached IMS */
apr_table_set(r->headers_in,
"If-Modified-Since",
info->lastmods);
}
else {
/* something else - pretend there was no cache */
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0,
r->server,
"cache: nonconditional - no cached "
"etag/lastmods - add cache_in and DECLINE");
ap_add_output_filter("CACHE_IN", NULL, r, r->connection);
return DECLINED;
}
/* add cache_conditional filter */
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0,
r->server,
"cache: nonconditional - add cache_conditional "
"and DECLINE");
ap_add_output_filter("CACHE_CONDITIONAL",
NULL,
r,
r->connection);
return DECLINED;
}
}
}
else {
/* error */
ap_log_error(APLOG_MARK, APLOG_ERR, rv,
r->server,
"cache: error returned while checking for cached file by "
"%s cache",
cache->type);
return DECLINED;
}
}
/*
* CACHE_OUT filter
* ----------------
*
* Deliver cached content (headers and body) up the stack.
*/
static int cache_out_filter(ap_filter_t *f, apr_bucket_brigade *bb)
{
request_rec *r = f->r;
cache_request_rec *cache;
cache = (cache_request_rec *) ap_get_module_config(r->request_config,
&cache_module);
if (!cache) {
/* user likely configured CACHE_OUT manually; they should use mod_cache
* configuration to do that */
ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
"CACHE_OUT enabled unexpectedly");
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r->server,
"cache: running CACHE_OUT filter");
/* cache_read_entity_headers() was called in cache_select_url() */
cache_read_entity_body(cache->handle, r->pool, bb);
/* This filter is done once it has served up its content */
ap_remove_output_filter(f);
ap_log_error(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r->server,
"cache: serving cached version of %s", r->uri);
return ap_pass_brigade(f->next, bb);
}
/*
* CACHE_CONDITIONAL filter
* ------------------------
*
* Decide whether or not cached content should be delivered
* based on our fudged conditional request.
* If response HTTP_NOT_MODIFIED
* replace ourselves with cache_out filter
* Otherwise
* replace ourselves with cache_in filter
*/
static int cache_conditional_filter(ap_filter_t *f, apr_bucket_brigade *in)
{
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, f->r->server,
"cache: running CACHE_CONDITIONAL filter");
if (f->r->status == HTTP_NOT_MODIFIED) {
/* replace ourselves with CACHE_OUT filter */
ap_add_output_filter("CACHE_OUT", NULL, f->r, f->r->connection);
}
else {
/* replace ourselves with CACHE_IN filter */
ap_add_output_filter("CACHE_IN", NULL, f->r, f->r->connection);
}
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, in);
}
/*
* CACHE_IN filter
* ---------------
*
* Decide whether or not this content should be cached.
* If we decide no it should:
* remove the filter from the chain
* If we decide yes it should:
* pass the data to the storage manager
* pass the data to the next filter (the network)
*
*/
static int cache_in_filter(ap_filter_t *f, apr_bucket_brigade *in)
{
int rv;
request_rec *r = f->r;
char *url = r->unparsed_uri;
const char *cc_out = apr_table_get(r->headers_out, "Cache-Control");
const char *exps, *lastmods, *dates, *etag;
apr_time_t exp, date, lastmod, now;
apr_size_t size;
cache_info *info;
void *sconf = r->server->module_config;
cache_server_conf *conf =
(cache_server_conf *) ap_get_module_config(sconf, &cache_module);
void *scache = r->request_config;
cache_request_rec *cache =
(cache_request_rec *) ap_get_module_config(scache, &cache_module);
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, f->r->server,
"cache: running CACHE_IN filter");
/* check first whether running this filter has any point or not */
if(r->no_cache) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, in);
}
/* make space for the per request config
* We hit this code path when CACHE_IN has been installed by someone
* other than the cache handler
*/
if (!cache) {
cache = apr_pcalloc(r->pool, sizeof(cache_request_rec));
ap_set_module_config(r->request_config, &cache_module, cache);
}
/*
* Pass Data to Cache
* ------------------
* This section passes the brigades into the cache modules, but only
* if the setup section (see below) is complete.
*/
/* have we already run the cachability check and set up the cached file
* handle?
*/
if (cache->in_checked) {
/* pass the brigades into the cache, then pass them
* up the filter stack
*/
rv = cache_write_entity_body(cache->handle, r, in);
if (rv != APR_SUCCESS) {
ap_remove_output_filter(f);
}
return ap_pass_brigade(f->next, in);
}
/*
* Setup Data in Cache
* -------------------
* This section opens the cache entity and sets various caching parameters,
* and decides whether this URL should be cached at all. This section is
* run before the above section.
*/
info = apr_pcalloc(r->pool, sizeof(cache_info));
/* read expiry date; if a bad date, then leave it so the client can
* read it
*/
exps = apr_table_get(r->headers_out, "Expires");
if (exps != NULL) {
if (APR_DATE_BAD == (exp = apr_date_parse_http(exps))) {
exps = NULL;
}
}
else {
exp = APR_DATE_BAD;
}
/* read the last-modified date; if the date is bad, then delete it */
lastmods = apr_table_get(r->headers_out, "Last-Modified");
if (lastmods != NULL) {
if (APR_DATE_BAD == (lastmod = apr_date_parse_http(lastmods))) {
lastmods = NULL;
}
}
else {
lastmod = APR_DATE_BAD;
}
/* read the etag from the entity */
etag = apr_table_get(r->headers_out, "Etag");
/*
* what responses should we not cache?
*
* At this point we decide based on the response headers whether it
* is appropriate _NOT_ to cache the data from the server. There are
* a whole lot of conditions that prevent us from caching this data.
* They are tested here one by one to be clear and unambiguous.
*/
/* RFC2616 13.4 we are allowed to cache 200, 203, 206, 300, 301 or 410
* We don't cache 206, because we don't (yet) cache partial responses.
* We include 304 Not Modified here too as this is the origin server
* telling us to serve the cached copy.
*/
if ((r->status != HTTP_OK && r->status != HTTP_NON_AUTHORITATIVE
&& r->status != HTTP_MULTIPLE_CHOICES
&& r->status != HTTP_MOVED_PERMANENTLY
&& r->status != HTTP_NOT_MODIFIED)
/* if a broken Expires header is present, don't cache it */
|| (exps != NULL && exp == APR_DATE_BAD)
/* if the server said 304 Not Modified but we have no cache
* file - pass this untouched to the user agent, it's not for us.
*/
|| (r->status == HTTP_NOT_MODIFIED && (NULL == cache->handle))
/* 200 OK response from HTTP/1.0 and up without a Last-Modified
* header/Etag
*/
/* XXX mod-include clears last_modified/expires/etags - this
* is why we have an optional function for a key-gen ;-)
*/
|| (r->status == HTTP_OK && lastmods == NULL && etag == NULL
&& (conf->no_last_mod_ignore ==0))
/* HEAD requests */
|| r->header_only
/* RFC2616 14.9.2 Cache-Control: no-store response indicating do not
* cache, or stop now if you are trying to cache it */
|| ap_cache_liststr(cc_out, "no-store", NULL)
/* RFC2616 14.9.1 Cache-Control: private
* this object is marked for this user's eyes only. Behave
* as a tunnel.
*/
|| ap_cache_liststr(cc_out, "private", NULL)
/* RFC2616 14.8 Authorisation:
* if authorisation is included in the request, we don't cache,
* but we can cache if the following exceptions are true:
* 1) If Cache-Control: s-maxage is included
* 2) If Cache-Control: must-revalidate is included
* 3) If Cache-Control: public is included
*/
|| (apr_table_get(r->headers_in, "Authorization") != NULL
&& !(ap_cache_liststr(cc_out, "s-maxage", NULL)
|| ap_cache_liststr(cc_out, "must-revalidate", NULL)
|| ap_cache_liststr(cc_out, "public", NULL)))
/* or we've been asked not to cache it above */
|| r->no_cache) {
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"cache: response is not cachable");
/* remove this object from the cache
* BillS Asks.. Why do we need to make this call to remove_url?
* leave it in for now..
*/
cache_remove_url(r, cache->types, url);
/* remove this filter from the chain */
ap_remove_output_filter(f);
/* ship the data up the stack */
return ap_pass_brigade(f->next, in);
}
cache->in_checked = 1;
/* Set the content length if known. We almost certainly do NOT want to
* cache streams with unknown content lengths in the in-memory cache.
* Streams with unknown content length should be first cached in the
* file system. If they are withing acceptable limits, then they can be
* moved to the in-memory cache.
*/
{
const char* cl;
cl = apr_table_get(r->headers_out, "Content-Length");
if (cl) {
size = apr_atoll(cl);
}
else {
/* if we don't get the content-length, see if we have all the
* buckets and use their length to calculate the size
*/
apr_bucket *e;
int all_buckets_here=0;
size=0;
APR_BRIGADE_FOREACH(e, in) {
if (APR_BUCKET_IS_EOS(e)) {
all_buckets_here=1;
break;
}
if (APR_BUCKET_IS_FLUSH(e)) {
continue;
}
if (e->length < 0) {
break;
}
size += e->length;
}
if (!all_buckets_here) {
size = -1;
}
}
}
/* It's safe to cache the response.
*
* There are two possiblities at this point:
* - cache->handle == NULL. In this case there is no previously
* cached entity anywhere on the system. We must create a brand
* new entity and store the response in it.
* - cache->handle != NULL. In this case there is a stale
* entity in the system which needs to be replaced by new
* content (unless the result was 304 Not Modified, which means
* the cached entity is actually fresh, and we should update
* the headers).
*/
/* no cache handle, create a new entity */
if (!cache->handle) {
rv = cache_create_entity(r, cache->types, url, size);
}
/* pre-existing cache handle and 304, make entity fresh */
else if (r->status == HTTP_NOT_MODIFIED) {
/* update headers */
/* remove this filter ??? */
/* XXX is this right? we must set rv to something other than OK
* in this path
*/
rv = HTTP_NOT_MODIFIED;
}
/* pre-existing cache handle and new entity, replace entity
* with this one
*/
else {
cache_remove_entity(r, cache->types, cache->handle);
rv = cache_create_entity(r, cache->types, url, size);
}
if (rv != OK) {
/* Caching layer declined the opportunity to cache the response */
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, in);
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"cache: Caching url: %s", url);
/*
* We now want to update the cache file header information with
* the new date, last modified, expire and content length and write
* it away to our cache file. First, we determine these values from
* the response, using heuristics if appropriate.
*
* In addition, we make HTTP/1.1 age calculations and write them away
* too.
*/
/* Read the date. Generate one if one is not supplied */
dates = apr_table_get(r->headers_out, "Date");
if (dates != NULL) {
info->date = apr_date_parse_http(dates);
}
else {
info->date = APR_DATE_BAD;
}
now = apr_time_now();
if (info->date == APR_DATE_BAD) { /* No, or bad date */
char *dates;
/* no date header! */
/* add one; N.B. use the time _now_ rather than when we were checking
* the cache
*/
date = now;
dates = apr_pcalloc(r->pool, MAX_STRING_LEN);
apr_rfc822_date(dates, now);
apr_table_set(r->headers_out, "Date", dates);
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"cache: Added date header");
info->date = date;
}
else {
date = info->date;
}
/* set response_time for HTTP/1.1 age calculations */
info->response_time = now;
/* get the request time */
info->request_time = r->request_time;
/* check last-modified date */
/* XXX FIXME we're referencing date on a path where we didn't set it */
if (lastmod != APR_DATE_BAD && lastmod > date) {
/* if it's in the future, then replace by date */
lastmod = date;
lastmods = dates;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0,
r->server,
"cache: Last modified is in the future, "
"replacing with now");
}
info->lastmod = lastmod;
/* if no expiry date then
* if lastmod
* expiry date = now + min((date - lastmod) * factor, maxexpire)
* else
* expire date = now + defaultexpire
*/
if (exp == APR_DATE_BAD) {
if (lastmod != APR_DATE_BAD) {
apr_time_t x = (apr_time_t) ((date - lastmod) * conf->factor);
if (x > conf->maxex) {
x = conf->maxex;
}
exp = now + x;
}
else {
exp = now + conf->defex;
}
}
info->expire = exp;
info->content_type = apr_pstrdup(r->pool, r->content_type);
info->filename = apr_pstrdup(r->pool, r->filename );
/*
* Write away header information to cache.
*/
rv = cache_write_entity_headers(cache->handle, r, info);
if (rv == APR_SUCCESS) {
rv = cache_write_entity_body(cache->handle, r, in);
}
if (rv != APR_SUCCESS) {
ap_remove_output_filter(f);
}
return ap_pass_brigade(f->next, in);
}
/* -------------------------------------------------------------- */
/* Setup configurable data */
static void * create_cache_config(apr_pool_t *p, server_rec *s)
{
cache_server_conf *ps = apr_pcalloc(p, sizeof(cache_server_conf));
/* 1 if the cache is enabled, 0 otherwise */
ps->cacheon = 0;
ps->cacheon_set = 0;
/* array of URL prefixes for which caching is enabled */
ps->cacheenable = apr_array_make(p, 10, sizeof(struct cache_enable));
/* array of URL prefixes for which caching is disabled */
ps->cachedisable = apr_array_make(p, 10, sizeof(struct cache_disable));
/* maximum time to cache a document */
ps->maxex = DEFAULT_CACHE_MAXEXPIRE;
ps->maxex_set = 0;
/* default time to cache a document */
ps->defex = DEFAULT_CACHE_EXPIRE;
ps->defex_set = 0;
/* factor used to estimate Expires date from LastModified date */
ps->factor = DEFAULT_CACHE_LMFACTOR;
ps->factor_set = 0;
/* default percentage to force cache completion */
ps->complete = DEFAULT_CACHE_COMPLETION;
ps->complete_set = 0;
ps->no_last_mod_ignore_set = 0;
ps->no_last_mod_ignore = 0;
ps->ignorecachecontrol = 0;
ps->ignorecachecontrol_set = 0 ;
return ps;
}
static void * merge_cache_config(apr_pool_t *p, void *basev, void *overridesv)
{
cache_server_conf *ps = apr_pcalloc(p, sizeof(cache_server_conf));
cache_server_conf *base = (cache_server_conf *) basev;
cache_server_conf *overrides = (cache_server_conf *) overridesv;
/* 1 if the cache is enabled, 0 otherwise */
ps->cacheon =
(overrides->cacheon_set == 0) ? base->cacheon : overrides->cacheon;
/* array of URL prefixes for which caching is disabled */
ps->cachedisable = apr_array_append(p,
base->cachedisable,
overrides->cachedisable);
/* array of URL prefixes for which caching is enabled */
ps->cacheenable = apr_array_append(p,
base->cacheenable,
overrides->cacheenable);
/* maximum time to cache a document */
ps->maxex = (overrides->maxex_set == 0) ? base->maxex : overrides->maxex;
/* default time to cache a document */
ps->defex = (overrides->defex_set == 0) ? base->defex : overrides->defex;
/* factor used to estimate Expires date from LastModified date */
ps->factor =
(overrides->factor_set == 0) ? base->factor : overrides->factor;
/* default percentage to force cache completion */
ps->complete =
(overrides->complete_set == 0) ? base->complete : overrides->complete;
ps->no_last_mod_ignore =
(overrides->no_last_mod_ignore_set == 0)
? base->no_last_mod_ignore
: overrides->no_last_mod_ignore;
ps->ignorecachecontrol =
(overrides->ignorecachecontrol_set == 0)
? base->ignorecachecontrol
: overrides->ignorecachecontrol;
return ps;
}
static const char *set_cache_ignore_no_last_mod(cmd_parms *parms, void *dummy,
int flag)
{
cache_server_conf *conf;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
conf->no_last_mod_ignore = 1;
conf->no_last_mod_ignore_set = 1;
return NULL;
}
static const char *set_cache_on(cmd_parms *parms, void *dummy, int flag)
{
cache_server_conf *conf;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
conf->cacheon = 1;
conf->cacheon_set = 1;
return NULL;
}
static const char *set_cache_ignore_cachecontrol(cmd_parms *parms,
void *dummy, int flag)
{
cache_server_conf *conf;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
conf->ignorecachecontrol = 1;
conf->ignorecachecontrol_set = 1;
return NULL;
}
static const char *add_cache_enable(cmd_parms *parms, void *dummy,
const char *type,
const char *url)
{
cache_server_conf *conf;
struct cache_enable *new;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
new = apr_array_push(conf->cacheenable);
new->type = type;
new->url = url;
return NULL;
}
static const char *add_cache_disable(cmd_parms *parms, void *dummy,
const char *url)
{
cache_server_conf *conf;
struct cache_enable *new;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
new = apr_array_push(conf->cachedisable);
new->url = url;
return NULL;
}
static const char *set_cache_maxex(cmd_parms *parms, void *dummy,
const char *arg)
{
cache_server_conf *conf;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
conf->maxex = (apr_time_t) (atol(arg) * MSEC_ONE_SEC);
conf->maxex_set = 1;
return NULL;
}
static const char *set_cache_defex(cmd_parms *parms, void *dummy,
const char *arg)
{
cache_server_conf *conf;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
conf->defex = (apr_time_t) (atol(arg) * MSEC_ONE_SEC);
conf->defex_set = 1;
return NULL;
}
static const char *set_cache_factor(cmd_parms *parms, void *dummy,
const char *arg)
{
cache_server_conf *conf;
double val;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
if (sscanf(arg, "%lg", &val) != 1) {
return "CacheLastModifiedFactor value must be a float";
}
conf->factor = val;
conf->factor_set = 1;
return NULL;
}
static const char *set_cache_complete(cmd_parms *parms, void *dummy,
const char *arg)
{
cache_server_conf *conf;
int val;
conf =
(cache_server_conf *)ap_get_module_config(parms->server->module_config,
&cache_module);
if (sscanf(arg, "%u", &val) != 1) {
return "CacheForceCompletion value must be a percentage";
}
conf->complete = val;
conf->complete_set = 1;
return NULL;
}
static int cache_post_config(apr_pool_t *p, apr_pool_t *plog,
apr_pool_t *ptemp, server_rec *s)
{
/* This is the means by which unusual (non-unix) os's may find alternate
* means to run a given command (e.g. shebang/registry parsing on Win32)
*/
cache_generate_key = APR_RETRIEVE_OPTIONAL_FN(ap_cache_generate_key);
if (!cache_generate_key) {
cache_generate_key = cache_generate_key_default;
}
return OK;
}
static const command_rec cache_cmds[] =
{
/* XXX
* Consider a new config directive that enables loading specific cache
* implememtations (like mod_cache_mem, mod_cache_file, etc.).
* Rather than using a LoadModule directive, admin would use something
* like CacheModule mem_cache_module | file_cache_module, etc,
* which would cause the approprpriate cache module to be loaded.
* This is more intuitive that requiring a LoadModule directive.
*/
AP_INIT_FLAG("CacheOn", set_cache_on, NULL, RSRC_CONF,
"On if the transparent cache should be enabled"),
AP_INIT_TAKE2("CacheEnable", add_cache_enable, NULL, RSRC_CONF,
"A cache type and partial URL prefix below which "
"caching is enabled"),
AP_INIT_TAKE1("CacheDisable", add_cache_disable, NULL, RSRC_CONF,
"A partial URL prefix below which caching is disabled"),
AP_INIT_TAKE1("CacheMaxExpire", set_cache_maxex, NULL, RSRC_CONF,
"The maximum time in seconds to cache a document"),
AP_INIT_TAKE1("CacheDefaultExpire", set_cache_defex, NULL, RSRC_CONF,
"The default time in seconds to cache a document"),
AP_INIT_FLAG("CacheIgnoreNoLastMod", set_cache_ignore_no_last_mod, NULL,
RSRC_CONF,
"Ignore Responses where there is no Last Modified Header"),
AP_INIT_FLAG("CacheIgnoreCacheControl", set_cache_ignore_cachecontrol,
NULL,
RSRC_CONF,
"Ignore requests from the client for uncached content"),
AP_INIT_TAKE1("CacheLastModifiedFactor", set_cache_factor, NULL, RSRC_CONF,
"The factor used to estimate Expires date from "
"LastModified date"),
AP_INIT_TAKE1("CacheForceCompletion", set_cache_complete, NULL, RSRC_CONF,
"Percentage of download to arrive for the cache to force "
"complete transfer"),
{NULL}
};
static void register_hooks(apr_pool_t *p)
{
/* cache initializer */
/* cache handler */
ap_hook_quick_handler(cache_url_handler, NULL, NULL, APR_HOOK_FIRST);
/* cache filters
* XXX The cache filters need to run right after the handlers and before
* any other filters. Consider creating AP_FTYPE_CACHE for this purpose.
* Make them AP_FTYPE_CONTENT for now.
* XXX ianhH:they should run AFTER all the other content filters.
*/
ap_register_output_filter("CACHE_IN",
cache_in_filter,
NULL,
AP_FTYPE_CONTENT_SET);
/* CACHE_OUT must go into the filter chain before SUBREQ_CORE to
* handle subrequsts. Decrementing filter type by 1 ensures this
* happens.
*/
ap_register_output_filter("CACHE_OUT",
cache_out_filter,
NULL,
AP_FTYPE_CONTENT_SET-1);
ap_register_output_filter("CACHE_CONDITIONAL",
cache_conditional_filter,
NULL,
AP_FTYPE_CONTENT_SET);
ap_hook_post_config(cache_post_config, NULL, NULL, APR_HOOK_REALLY_FIRST);
}
module AP_MODULE_DECLARE_DATA cache_module =
{
STANDARD20_MODULE_STUFF,
NULL, /* create per-directory config structure */
NULL, /* merge per-directory config structures */
create_cache_config, /* create per-server config structure */
merge_cache_config, /* merge per-server config structures */
cache_cmds, /* command apr_table_t */
register_hooks
};