cache_storage.c revision aa47ca787f4bd6305d93e9106815f82061d568eb
/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "mod_cache.h"
#include "cache_storage.h"
#include "cache_util.h"
/* -------------------------------------------------------------- */
/*
* delete all URL entities from the cache
*
*/
{
cache_handle_t *h;
/* Remove the stale cache entry if present. If not, we're
* being called from outside of a request; remove the
* non-stale handle.
*/
if (!h) {
return OK;
}
/* for each specified cache type, delete the URL */
while(list) {
}
return OK;
}
/*
* create a new URL entity in the cache
*
* It is possible to store more than once entity per URL. This
* function will always create a new entity, regardless of whether
* other entities already exist for the same URL.
*
* The size of the entity is provided so that a cache module can
* decide whether or not it wants to cache this particular entity.
* If the size is unknown, a size of -1 should be set.
*/
{
if (!cache) {
/* This should never happen */
"cache: No cache request information available for key"
" generation");
return APR_EGENERAL;
}
if (rv != APR_SUCCESS) {
return rv;
}
}
/* for each specified cache type, delete the URL */
while (list) {
case OK: {
return OK;
}
case DECLINED: {
continue;
}
default: {
return rv;
}
}
}
return DECLINED;
}
{
return 1;
}
/**
* Take headers from the cache, and overlap them over the existing response
* headers.
*/
int preserve_orig)
{
const char *v;
if (v) {
ap_set_content_type(r, v);
/*
* Also unset possible Content-Type headers in r->headers_out and
* r->err_headers_out as they may be different to what we have received
* from the cache.
* Actually they are not needed as r->content_type set by
* ap_set_content_type above will be used in the store_headers functions
* of the storage providers as a fallback and the HTTP_HEADER filter
* does overwrite the Content-Type header with r->content_type anyway.
*/
}
/* If the cache gave us a Last-Modified header, we can't just
* pass it on blindly because of restrictions on future values.
*/
if (v) {
ap_update_mtime(r, apr_date_parse_http(v));
}
/* The HTTP specification says that it is legal to merge duplicate
* headers into one. Some browsers that support Cookies don't like
* merged headers and prefer that each Set-Cookie header is sent
* separately. Lets humour those browsers by not merging.
* Oh what a pain it is.
*/
"Set-Cookie", NULL);
"Set-Cookie", NULL);
if (preserve_orig) {
r->headers_out = hdr_copy;
}
else {
}
if (!apr_is_empty_table(cookie_table)) {
}
}
/*
* select a specific URL entity in the cache
*
* It is possible to store more than one entity per URL. Content
* negotiation is used to select an entity. Once an entity is
* selected, details of it are stored in the per request
* config to save time when serving the request later.
*
* This function returns OK if successful, DECLINED if no
* cached entity fits the bill.
*/
{
cache_handle_t *h;
if (!cache) {
/* This should never happen */
"cache: No cache request information available for key"
" generation");
return DECLINED;
}
if (rv != APR_SUCCESS) {
return DECLINED;
}
}
if (!ap_cache_check_allowed(cache, r)) {
return DECLINED;
}
/* go through the cache types till we get a match */
while (list) {
case OK: {
/* try again with next cache type */
continue;
}
/*
* Check Content-Negotiation - Vary
*
* At this point we need to make sure that the object we found in
* the cache is the same object that would be delivered to the
* client, when the effects of content negotiation are taken into
* effect.
*
* In plain english, we want to make sure that a language-negotiated
* document in one language is not given to a client asking for a
* language negotiated document in a different language by mistake.
*
* This code makes the assumption that the storage manager will
* cache the req_hdrs if the response contains a Vary
* header.
*
* RFC2616 13.6 and 14.44 describe the Vary mechanism.
*/
/* isolate header name */
++vary;
*vary = '\0';
++vary;
}
/*
* is this header in the request and the header in the cached
* request identical? If not, we give up and do a straight get
*/
/* both headers NULL, so a match - do nothing */
}
/* both headers exist and are equal - do nothing */
}
else {
/* headers do not match, so Vary failed */
mismatch = 1;
break;
}
}
/* no vary match, try next provider */
if (mismatch) {
/* try again with next cache type */
continue;
}
/* Is our cached response fresh enough? */
if (!fresh) {
/* Cache-Control: only-if-cached and revalidation required, try
* the next provider
*/
/* try again with next cache type */
continue;
}
/* set aside the stale entry for accessing later */
r->headers_in);
cache->stale_handle = h;
"conditional request headers.", r->uri);
/* We can only revalidate with our own conditionals: remove the
* conditions from the original request.
*/
* our own conditionals.
*/
if (etag) {
}
if (lastmod) {
lastmod);
}
/*
* Do not do Range requests with our own conditionals: If
* we get 304 the Range does not matter and otherwise the
* entity changed and we want to have the complete entity
*/
}
/* ready to revalidate, pretend we were never here */
return DECLINED;
}
/* Okay, this response looks okay. Merge in our stuff and go. */
cache_accept_headers(h, r, 0);
return OK;
}
case DECLINED: {
/* try again with next cache type */
continue;
}
default: {
/* oo-er! an error */
return rv;
}
}
}
/* if Cache-Control: only-if-cached, and not cached, return 504 */
"cache: 'only-if-cached' requested and no cached entity, "
"returning 504 Gateway Timeout for: %s", r->uri);
return HTTP_GATEWAY_TIME_OUT;
}
return DECLINED;
}
{
int i;
const char *path;
char *querystring;
if (*key) {
/*
* We have been here before during the processing of this request.
*/
return APR_SUCCESS;
}
/*
* Get the module configuration. We need this for the CacheIgnoreQueryString
* option below.
*/
&cache_module);
/*
* Use the canonical name to improve cache hit rate, but only if this is
* not a proxy request or if this is a reverse proxy request.
* We need to handle both cases in the same manner as for the reverse proxy
* case we have the following situation:
*
* If a cached entry is looked up by mod_cache's quick handler r->proxyreq
* is still unset in the reverse proxy case as it only gets set in the
* translate name hook (either by ProxyPass or mod_rewrite) which is run
* after the quick handler hook. This is different to the forward proxy
* case where it gets set before the quick handler is run (in the
* post_read_request hook).
* If a cache entry is created by the CACHE_SAVE filter we always have
* r->proxyreq set correctly.
* So we must ensure that in the reverse proxy case we use the same code
* path and using the canonical name seems to be the right thing to do
* in the reverse proxy case.
*/
}
else {
/* Use _default_ as the hostname if none present, as in mod_vhost */
hostname = ap_get_server_name(r);
if (!hostname) {
hostname = "_default_";
}
}
}
else if (parsed_uri->hostname) {
/* Copy the parsed uri hostname */
/* const work-around */
}
else {
/* We are a proxied request, with no hostname. Unlikely
* to get very far - but just in case */
hostname = "_default_";
}
/*
* Copy the scheme, ensuring that it is lower case. If the parsed uri
* contains no string or if this is not a proxy request get the http
* scheme for this request. As r->parsed_uri.scheme is not set if this
* is a reverse proxy request, it is ensured that the cases
* "no proxy request" and "reverse proxy request" are handled in the same
* manner (see above why this is needed).
*/
/* Copy the scheme and lower-case it */
/* const work-around */
}
else {
}
else {
scheme = ap_http_scheme(r);
}
}
/*
* If this is a proxy request, but not a reverse proxy request (see comment
* above why these cases must be handled in the same manner), copy the
* URI's port-string (which may be a service name). If the URI contains
* no port-string, use apr-util's notion of the default port for that
* scheme - if available. Otherwise use the port-number of the current
* server.
*/
if (parsed_uri->port_str) {
port_str[0] = ':';
for (i = 0; parsed_uri->port_str[i]; i++) {
}
}
else if (apr_uri_port_of_scheme(scheme)) {
}
else {
/* No port string given in the AbsoluteUri, and we have no
* idea what the default port for the scheme is. Leave it
* blank and live with the inefficiency of some extra cached
* entities.
*/
port_str = "";
}
}
else {
}
port_str = "";
}
else {
/* Use the server port */
}
}
/*
* Check if we need to ignore session identifiers in the URL and do so
* if needed.
*/
int i;
char **identifier;
int len;
char *param;
/*
* Check that we have a parameter separator in the last segment
* of the path and that the parameter matches our identifier
*/
continue;
}
/*
* Check if the identifier is in the querystring and cut it out.
*/
if (querystring) {
/*
* First check if the identifier is at the beginning of the
* querystring and followed by a '='
*/
param = querystring;
}
else {
char *complete;
/*
* In order to avoid subkey matching (PR 48401) prepend
* identifier with a '&' and append a '='
*/
/* If we found something we are sitting on the '&' */
if (param) {
param++;
}
}
if (param) {
char *amp;
if (querystring != param) {
param - querystring);
}
else {
querystring = "";
}
NULL);
}
else {
/*
* If querystring is not "", then we have the case
* that the identifier parameter we removed was the
* last one in the original querystring. Hence we have
* a trailing '&' which needs to be removed.
*/
if (*querystring) {
}
}
}
}
}
}
/* Key format is a URI, optionally without the query-string */
if (conf->ignorequerystring) {
NULL);
}
else {
querystring, NULL);
}
/*
* Store the key in the request_config for the cache as r->parsed_uri
* might have changed in the time from our first visit here triggered by the
* quick handler and our possible second visit triggered by the CACHE_SAVE
* filter (e.g. r->parsed_uri got unescaped). In this case we would save the
* resource in the cache under a key where it is never found by the quick
* handler during following requests.
*/
APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, r, APLOGNO(00698) "cache: Key for entity %s?%s is %s", uri, parsed_uri->query, *key);
return APR_SUCCESS;
}
const char **key)
{
}
/*
* Invalidate a specific URL entity in all caches
*
* All cached entities for this URL are removed, usually in
*
* This function returns OK if at least one entity was found and
* removed, and DECLINED if no cached entities were removed.
*/
{
cache_handle_t *h;
if (!cache) {
/* This should never happen */
APLOG_MARK, APLOG_ERR, APR_EGENERAL, r, APLOGNO(00697) "cache: No cache request information available for key"
" generation");
return DECLINED;
}
if (rv != APR_SUCCESS) {
return DECLINED;
}
}
if (location) {
|| APR_SUCCESS
location_key = NULL;
}
}
if (content_location) {
if (APR_SUCCESS
|| APR_SUCCESS
}
}
/* go through the cache types */
while (list) {
/* invalidate the request uri */
}
APLOG_MARK, APLOG_DEBUG, rv, r, APLOGNO(02468) "cache: Attempted to invalidate cached entity with key: %s", cache->key);
/* invalidate the Location */
if (location_key) {
}
APLOG_MARK, APLOG_DEBUG, rv, r, APLOGNO(02469) "cache: Attempted to invalidate cached entity with key: %s", location_key);
}
/* invalidate the Content-Location */
if (content_location_key) {
}
APLOG_MARK, APLOG_DEBUG, rv, r, APLOGNO(02470) "cache: Attempted to invalidate cached entity with key: %s", content_location_key);
}
}
return status;
}