cache_util.h

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/* 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.
 */
 
#ifndef CACHE_UTIL_H
#define CACHE_UTIL_H
 
#ifdef __cplusplus
extern "C" {
#endif
 
#include "mod_cache.h"
 
#include "apr_hooks.h"
#include "apr.h"
#include "apr_lib.h"
#include "apr_strings.h"
#include "apr_buckets.h"
#include "apr_md5.h"
#include "apr_pools.h"
#include "apr_strings.h"
#include "apr_optional.h"
#define APR_WANT_STRFUNC
#include "apr_want.h"
 
#include "httpd.h"
#include "http_config.h"
#include "ap_config.h"
#include "http_core.h"
#include "http_protocol.h"
#include "http_request.h"
#include "http_vhost.h"
#include "http_main.h"
#include "http_log.h"
#include "http_connection.h"
#include "util_filter.h"
#include "apr_uri.h"
 
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
 
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
 
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
 
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
 
#include "apr_atomic.h"
 
#ifndef MAX
#define MAX(a,b)                ((a) > (b) ? (a) : (b))
#endif
#ifndef MIN
#define MIN(a,b)                ((a) < (b) ? (a) : (b))
#endif
 
#define MSEC_ONE_DAY    ((apr_time_t)(86400*APR_USEC_PER_SEC)) /* one day, in microseconds */
#define MSEC_ONE_HR     ((apr_time_t)(3600*APR_USEC_PER_SEC))  /* one hour, in microseconds */
#define MSEC_ONE_MIN    ((apr_time_t)(60*APR_USEC_PER_SEC))    /* one minute, in microseconds */
#define MSEC_ONE_SEC    ((apr_time_t)(APR_USEC_PER_SEC))       /* one second, in microseconds */
 
#define DEFAULT_CACHE_MAXEXPIRE MSEC_ONE_DAY
#define DEFAULT_CACHE_MINEXPIRE 0
#define DEFAULT_CACHE_EXPIRE    MSEC_ONE_HR
#define DEFAULT_CACHE_LMFACTOR  (0.1)
#define DEFAULT_CACHE_MAXAGE    5
#define DEFAULT_X_CACHE         0
#define DEFAULT_X_CACHE_DETAIL  0
#define DEFAULT_CACHE_STALE_ON_ERROR 1
#define DEFAULT_CACHE_LOCKPATH "/mod_cache-lock"
#define CACHE_LOCKNAME_KEY "mod_cache-lockname"
#define CACHE_LOCKFILE_KEY "mod_cache-lockfile"
#define CACHE_CTX_KEY "mod_cache-ctx"
#define CACHE_SEPARATOR ", \t"
 
struct cache_enable {
    apr_uri_t url;
    const char *type;
    apr_size_t pathlen;
};
 
struct cache_disable {
    apr_uri_t url;
    apr_size_t pathlen;
};
 
/* static information about the local cache */
typedef struct {
    apr_array_header_t *cacheenable;    /* URLs to cache */
    apr_array_header_t *cachedisable;   /* URLs not to cache */
    apr_array_header_t *ignore_headers;
    apr_array_header_t *ignore_session_id;
    const char *lockpath;
    apr_time_t lockmaxage;
    apr_uri_t *base_uri;
    unsigned int ignorecachecontrol:1;
    unsigned int ignorequerystring:1;
    unsigned int quick:1;
    /* thundering herd lock */
    unsigned int lock:1;
    unsigned int x_cache:1;
    unsigned int x_cache_detail:1;
    /* flag if CacheIgnoreHeader has been set */
    #define CACHE_IGNORE_HEADERS_SET   1
    #define CACHE_IGNORE_HEADERS_UNSET 0
    unsigned int ignore_headers_set:1;
    /* flag if CacheIgnoreURLSessionIdentifiers has been set */
    #define CACHE_IGNORE_SESSION_ID_SET   1
    #define CACHE_IGNORE_SESSION_ID_UNSET 0
    unsigned int ignore_session_id_set:1;
    unsigned int base_uri_set:1;
    unsigned int ignorecachecontrol_set:1;
    unsigned int ignorequerystring_set:1;
    unsigned int quick_set:1;
    unsigned int lock_set:1;
    unsigned int lockpath_set:1;
    unsigned int lockmaxage_set:1;
    unsigned int x_cache_set:1;
    unsigned int x_cache_detail_set:1;
} cache_server_conf;
 
typedef struct {
    /* Minimum time to keep cached files in msecs */
    apr_time_t minex;
    /* Maximum time to keep cached files in msecs */
    apr_time_t maxex;
    /* default time to keep cached file in msecs */
    apr_time_t defex;
    /* factor for estimating expires date */
    double factor;
    /* cache enabled for this location */
    apr_array_header_t *cacheenable;
    /* cache disabled for this location */
    unsigned int disable:1;
    /* set X-Cache headers */
    unsigned int x_cache:1;
    unsigned int x_cache_detail:1;
    /* serve stale on error */
    unsigned int stale_on_error:1;
    unsigned int no_last_mod_ignore:1;
    unsigned int store_expired:1;
    unsigned int store_private:1;
    unsigned int store_nostore:1;
    unsigned int minex_set:1;
    unsigned int maxex_set:1;
    unsigned int defex_set:1;
    unsigned int factor_set:1;
    unsigned int x_cache_set:1;
    unsigned int x_cache_detail_set:1;
    unsigned int stale_on_error_set:1;
    unsigned int no_last_mod_ignore_set:1;
    unsigned int store_expired_set:1;
    unsigned int store_private_set:1;
    unsigned int store_nostore_set:1;
    unsigned int enable_set:1;
    unsigned int disable_set:1;
} cache_dir_conf;
 
/* A linked-list of authn providers. */
typedef struct cache_provider_list cache_provider_list;
 
struct cache_provider_list {
    const char *provider_name;
    const cache_provider *provider;
    cache_provider_list *next;
};
 
/* per request cache information */
typedef struct {
    cache_provider_list *providers;     /* possible cache providers */
    const cache_provider *provider;     /* current cache provider */
    const char *provider_name;          /* current cache provider name */
    int fresh;                          /* is the entity fresh? */
    cache_handle_t *handle;             /* current cache handle */
    cache_handle_t *stale_handle;       /* stale cache handle */
    apr_table_t *stale_headers;         /* original request headers. */
    int in_checked;                     /* CACHE_SAVE must cache the entity */
    int block_response;                 /* CACHE_SAVE must block response. */
    apr_bucket_brigade *saved_brigade;  /* copy of partial response */
    apr_off_t saved_size;               /* length of saved_brigade */
    apr_time_t exp;                     /* expiration */
    apr_time_t lastmod;                 /* last-modified time */
    cache_info *info;                   /* current cache info */
    ap_filter_t *save_filter;           /* Enable us to restore the filter on error */
    ap_filter_t *remove_url_filter;     /* Enable us to remove the filter */
    const char *key;                    /* The cache key created for this
                                         * request
                                         */
    apr_off_t size;                     /* the content length from the headers, or -1 */
    apr_bucket_brigade *out;            /* brigade to reuse for upstream responses */
    cache_control_t control_in;         /* cache control incoming */
} cache_request_rec;
 
int ap_cache_check_no_cache(cache_request_rec *cache, request_rec *r);
 
int ap_cache_check_no_store(cache_request_rec *cache, request_rec *r);
 
int cache_check_freshness(cache_handle_t *h, cache_request_rec *cache,
        request_rec *r);
 
apr_status_t cache_try_lock(cache_server_conf *conf, cache_request_rec *cache,
        request_rec *r);
 
apr_status_t cache_remove_lock(cache_server_conf *conf,
        cache_request_rec *cache, request_rec *r, apr_bucket_brigade *bb);
 
cache_provider_list *cache_get_providers(request_rec *r,
                                         cache_server_conf *conf);
 
const char *cache_table_getm(apr_pool_t *p, const apr_table_t *t,
        const char *key);
 
char *cache_strqtok(char *str, const char *sep, char **last);
 
apr_table_t *cache_merge_headers_out(request_rec *r);
 
int cache_use_early_url(request_rec *r);
 
#ifdef __cplusplus
}
#endif
 
#endif /* !CACHE_UTIL_H */