--- /dev/null
+/* 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
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ */
+
+#define CORE_PRIVATE
+
+#include "mod_cache.h"
+
+extern APR_OPTIONAL_FN_TYPE(ap_cache_generate_key) *cache_generate_key;
+
+extern module AP_MODULE_DECLARE_DATA cache_module;
+
+/* -------------------------------------------------------------- */
+
+/*
+ * delete all URL entities from the cache
+ *
+ */
+int cache_remove_url(request_rec *r, char *url)
+{
+ cache_provider_list *list;
+ apr_status_t rv;
+ char *key;
+ cache_request_rec *cache = (cache_request_rec *)
+ ap_get_module_config(r->request_config, &cache_module);
+
+ rv = cache_generate_key(r,r->pool,&key);
+ if (rv != APR_SUCCESS) {
+ return rv;
+ }
+
+ list = cache->providers;
+
+ /* for each specified cache type, delete the URL */
+ while(list) {
+ list->provider->remove_url(key);
+ list = list->next;
+ }
+ 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.
+ */
+int cache_create_entity(request_rec *r, char *url, apr_off_t size)
+{
+ cache_provider_list *list;
+ cache_handle_t *h = apr_pcalloc(r->pool, sizeof(cache_handle_t));
+ char *key;
+ apr_status_t rv;
+ cache_request_rec *cache = (cache_request_rec *)
+ ap_get_module_config(r->request_config, &cache_module);
+
+ rv = cache_generate_key(r,r->pool,&key);
+ if (rv != APR_SUCCESS) {
+ return rv;
+ }
+
+ list = cache->providers;
+ /* for each specified cache type, delete the URL */
+ while (list) {
+ switch (rv = list->provider->create_entity(h, r, key, size)) {
+ case OK: {
+ cache->handle = h;
+ cache->provider = list->provider;
+ cache->provider_name = list->provider_name;
+ return OK;
+ }
+ case DECLINED: {
+ list = list->next;
+ continue;
+ }
+ default: {
+ return rv;
+ }
+ }
+ }
+ return DECLINED;
+}
+
+static int set_cookie_doo_doo(void *v, const char *key, const char *val)
+{
+ apr_table_addn(v, key, val);
+ return 1;
+}
+
+static void accept_headers(cache_handle_t *h, request_rec *r)
+{
+ apr_table_t *cookie_table;
+ const char *v;
+
+ v = apr_table_get(h->resp_hdrs, "Content-Type");
+ if (v) {
+ ap_set_content_type(r, v);
+ apr_table_unset(h->resp_hdrs, "Content-Type");
+ }
+
+ /* If the cache gave us a Last-Modified header, we can't just
+ * pass it on blindly because of restrictions on future values.
+ */
+ v = apr_table_get(h->resp_hdrs, "Last-Modified");
+ if (v) {
+ ap_update_mtime(r, apr_date_parse_http(v));
+ ap_set_last_modified(r);
+ apr_table_unset(h->resp_hdrs, "Last-Modified");
+ }
+
+ /* 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.
+ */
+ cookie_table = apr_table_make(r->pool, 2);
+ apr_table_do(set_cookie_doo_doo, cookie_table, r->err_headers_out,
+ "Set-Cookie", NULL);
+ apr_table_do(set_cookie_doo_doo, cookie_table, h->resp_hdrs,
+ "Set-Cookie", NULL);
+ apr_table_unset(r->err_headers_out, "Set-Cookie");
+ apr_table_unset(h->resp_hdrs, "Set-Cookie");
+
+ apr_table_overlap(r->headers_out, h->resp_hdrs,
+ APR_OVERLAP_TABLES_SET);
+ apr_table_overlap(r->err_headers_out, h->resp_err_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);
+ }
+}
+
+/*
+ * 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.
+ */
+int cache_select_url(request_rec *r, char *url)
+{
+ cache_provider_list *list;
+ apr_status_t rv;
+ cache_handle_t *h;
+ char *key;
+ cache_request_rec *cache = (cache_request_rec *)
+ ap_get_module_config(r->request_config, &cache_module);
+
+ rv = cache_generate_key(r, r->pool, &key);
+ if (rv != APR_SUCCESS) {
+ return rv;
+ }
+ /* go through the cache types till we get a match */
+ h = apr_palloc(r->pool, sizeof(cache_handle_t));
+
+ list = cache->providers;
+
+ while (list) {
+ switch ((rv = list->provider->open_entity(h, r, key))) {
+ case OK: {
+ char *vary = NULL;
+ const char *varyhdr = NULL;
+ int fresh;
+
+ if (list->provider->recall_headers(h, r) != APR_SUCCESS) {
+ /* TODO: Handle this error */
+ return DECLINED;
+ }
+
+ /*
+ * 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.
+ */
+ if ((varyhdr = apr_table_get(h->resp_err_hdrs, "Vary")) == NULL) {
+ varyhdr = apr_table_get(h->resp_hdrs, "Vary");
+ }
+ vary = apr_pstrdup(r->pool, varyhdr);
+ while (vary && *vary) {
+ char *name = vary;
+ const char *h1, *h2;
+
+ /* isolate header name */
+ while (*vary && !apr_isspace(*vary) && (*vary != ','))
+ ++vary;
+ while (*vary && (apr_isspace(*vary) || (*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
+ */
+ h1 = apr_table_get(r->headers_in, name);
+ h2 = apr_table_get(h->req_hdrs, name);
+ if (h1 == h2) {
+ /* both headers NULL, so a match - do nothing */
+ }
+ else if (h1 && h2 && !strcmp(h1, h2)) {
+ /* both headers exist and are equal - do nothing */
+ }
+ else {
+ /* headers do not match, so Vary failed */
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS,
+ r->server,
+ "cache_select_url(): Vary header mismatch.");
+ return DECLINED;
+ }
+ }
+
+ cache->provider = list->provider;
+ cache->provider_name = list->provider_name;
+
+ /* Is our cached response fresh enough? */
+ fresh = ap_cache_check_freshness(h, r);
+ if (!fresh) {
+ cache_info *info = &(h->cache_obj->info);
+
+ /* Make response into a conditional */
+ /* FIXME: What if the request is already conditional? */
+ if (info && info->etag) {
+ /* if we have a cached etag */
+ cache->stale_headers = apr_table_copy(r->pool,
+ r->headers_in);
+ apr_table_set(r->headers_in, "If-None-Match", info->etag);
+ cache->stale_handle = h;
+ }
+ else if (info && info->lastmods) {
+ /* if we have a cached Last-Modified header */
+ cache->stale_headers = apr_table_copy(r->pool,
+ r->headers_in);
+ apr_table_set(r->headers_in, "If-Modified-Since",
+ info->lastmods);
+ cache->stale_handle = h;
+ }
+
+ return DECLINED;
+ }
+
+ /* Okay, this response looks okay. Merge in our stuff and go. */
+ apr_table_setn(r->headers_out, "Content-Type",
+ ap_make_content_type(r, h->content_type));
+ r->filename = apr_pstrdup(r->pool, h->cache_obj->info.filename);
+ accept_headers(h, r);
+
+ cache->handle = h;
+ return OK;
+ }
+ case DECLINED: {
+ /* try again with next cache type */
+ list = list->next;
+ continue;
+ }
+ default: {
+ /* oo-er! an error */
+ return rv;
+ }
+ }
+ }
+ return DECLINED;
+}
+
+apr_status_t cache_generate_key_default( request_rec *r, apr_pool_t*p, char**key )
+{
+ if (r->hostname) {
+ *key = apr_pstrcat(p, r->hostname, r->uri, "?", r->args, NULL);
+ }
+ else {
+ *key = apr_pstrcat(p, r->uri, "?", r->args, NULL);
+ }
+ return APR_SUCCESS;
+}
+
Code Review / bottlenecks.git / blobdiff