mod_disk_cache.c

最新apache的源代码

}

static apr_status_t store_body(cache_handle_t *h, request_rec *r,
                               apr_bucket_brigade *bb)
{
    apr_bucket *e;
    apr_status_t rv;
    disk_cache_object_t *dobj = (disk_cache_object_t *) h->cache_obj->vobj;
    disk_cache_conf *conf = ap_get_module_config(r->server->module_config,
                                                 &disk_cache_module);

    /* We write to a temp file and then atomically rename the file over
     * in file_cache_el_final().
     */
    if (!dobj->tfd) {
        rv = apr_file_mktemp(&dobj->tfd, dobj->tempfile,
                             APR_CREATE | APR_WRITE | APR_BINARY |
                             APR_BUFFERED | APR_EXCL, r->pool);
        if (rv != APR_SUCCESS) {
            return rv;
        }
        dobj->file_size = 0;
    }

    for (e = APR_BRIGADE_FIRST(bb);
         e != APR_BRIGADE_SENTINEL(bb);
         e = APR_BUCKET_NEXT(e))
    {
        const char *str;
        apr_size_t length, written;
        apr_bucket_read(e, &str, &length, APR_BLOCK_READ);
        rv = apr_file_write_full(dobj->tfd, str, length, &written);
        if (rv != APR_SUCCESS) {
            ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
                         "cache_disk: Error when writing cache file for URL %s",
                         h->cache_obj->key);
            /* Remove the intermediate cache file and return non-APR_SUCCESS */
            file_cache_errorcleanup(dobj, r);
            return APR_EGENERAL;
        }
        dobj->file_size += written;
        if (dobj->file_size > conf->maxfs) {
            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                         "cache_disk: URL %s failed the size check (%lu>%lu)",
                         h->cache_obj->key, (unsigned long)dobj->file_size,
                         (unsigned long)conf->maxfs);
            /* Remove the intermediate cache file and return non-APR_SUCCESS */
            file_cache_errorcleanup(dobj, r);
            return APR_EGENERAL;
        }
    }

    /* Was this the final bucket? If yes, close the temp file and perform
     * sanity checks.
     */
    if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(bb))) {
        if (h->cache_obj->info.len <= 0) {
          /* If the target value of the content length is unknown
           * (h->cache_obj->info.len <= 0), check if connection has been
           * aborted by client to avoid caching incomplete request bodies.
           *
           * This can happen with large responses from slow backends like
           * Tomcat via mod_jk.
           */
          if (r->connection->aborted) {
            ap_log_error(APLOG_MARK, APLOG_INFO, 0, r->server,
                         "disk_cache: Discarding body for URL %s "
                         "because connection has been aborted.",
                         h->cache_obj->key);
            /* Remove the intermediate cache file and return non-APR_SUCCESS */
            file_cache_errorcleanup(dobj, r);
            return APR_EGENERAL;
          }
          /* XXX Fixme: file_size isn't constrained by size_t. */
          h->cache_obj->info.len = dobj->file_size;
        }
        else if (h->cache_obj->info.len != dobj->file_size) {
          /* "Content-Length" and actual content disagree in size. Log that. */
          ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
                       "disk_cache: URL %s failed the size check (%lu != %lu)",
                       h->cache_obj->key,
                       (unsigned long)h->cache_obj->info.len,
                       (unsigned long)dobj->file_size);
          /* Remove the intermediate cache file and return non-APR_SUCCESS */
          file_cache_errorcleanup(dobj, r);
          return APR_EGENERAL;
        }
        if (dobj->file_size < conf->minfs) {
          ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                     "cache_disk: URL %s failed the size check (%lu<%lu)",
                     h->cache_obj->key, (unsigned long)dobj->file_size, (unsigned long)conf->minfs);
          /* Remove the intermediate cache file and return non-APR_SUCCESS */
          file_cache_errorcleanup(dobj, r);
          return APR_EGENERAL;
        }

        /* All checks were fine. Move tempfile to final destination */
        /* Link to the perm file, and close the descriptor */
        file_cache_el_final(dobj, r);
        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                     "disk_cache: Body for URL %s cached.",  dobj->name);
    }

    return APR_SUCCESS;
}

static void *create_config(apr_pool_t *p, server_rec *s)
{
    disk_cache_conf *conf = apr_pcalloc(p, sizeof(disk_cache_conf));

    /* XXX: Set default values */
    conf->dirlevels = DEFAULT_DIRLEVELS;
    conf->dirlength = DEFAULT_DIRLENGTH;
    conf->space = DEFAULT_CACHE_SIZE;
    conf->maxfs = DEFAULT_MAX_FILE_SIZE;
    conf->minfs = DEFAULT_MIN_FILE_SIZE;
    conf->expirychk = 1;

    conf->cache_root = NULL;
    conf->cache_root_len = 0;

    return conf;
}

/*
 * mod_disk_cache configuration directives handlers.
 */
static const char
*set_cache_root(cmd_parms *parms, void *in_struct_ptr, const char *arg)
{
    disk_cache_conf *conf = ap_get_module_config(parms->server->module_config,
                                                 &disk_cache_module);
    conf->cache_root = arg;
    conf->cache_root_len = strlen(arg);
    /* TODO: canonicalize cache_root and strip off any trailing slashes */

    return NULL;
}
static const char
*set_cache_size(cmd_parms *parms, void *in_struct_ptr, const char *arg)
{
    disk_cache_conf *conf = ap_get_module_config(parms->server->module_config,
                                                 &disk_cache_module);
    conf->space = atoi(arg);
    return NULL;
}
static const char
*set_cache_gcint(cmd_parms *parms, void *in_struct_ptr, const char *arg)
{
/*
    disk_cache_conf *conf = ap_get_module_config(parms->server->module_config,
                                                 &disk_cache_module);
*/
    /* XXX */
    return NULL;
}
/*
 * Consider eliminating the next two directives in favor of
 * Ian's prime number hash...
 * key = hash_fn( r->uri)
 * filename = "/key % prime1 /key %prime2/key %prime3"
 */
static const char
*set_cache_dirlevels(cmd_parms *parms, void *in_struct_ptr, const char *arg)
{
    disk_cache_conf *conf = ap_get_module_config(parms->server->module_config,
                                                 &disk_cache_module);
    int val = atoi(arg);
    if (val < 1)
        return "CacheDirLevels value must be an integer greater than 0";
    if (val * conf->dirlength > CACHEFILE_LEN)
        return "CacheDirLevels*CacheDirLength value must not be higher than 20";
    conf->dirlevels = val;
    return NULL;
}
static const char
*set_cache_dirlength(cmd_parms *parms, void *in_struct_ptr, const char *arg)
{
    disk_cache_conf *conf = ap_get_module_config(parms->server->module_config,
                                                 &disk_cache_module);
    int val = atoi(arg);
    if (val < 1)
        return "CacheDirLength value must be an integer greater than 0";
    if (val * conf->dirlevels > CACHEFILE_LEN)
        return "CacheDirLevels*CacheDirLength value must not be higher than 20";

    conf->dirlength = val;
    return NULL;
}
static const char
*set_cache_exchk(cmd_parms *parms, void *in_struct_ptr, int flag)
{
    disk_cache_conf *conf = ap_get_module_config(parms->server->module_config,
                                                 &disk_cache_module);
    conf->expirychk = flag;

    return NULL;
}
static const char
*set_cache_minfs(cmd_parms *parms, void *in_struct_ptr, const char *arg)
{
    disk_cache_conf *conf = ap_get_module_config(parms->server->module_config,
                                                 &disk_cache_module);
    conf->minfs = atoi(arg);
    return NULL;
}
static const char
*set_cache_maxfs(cmd_parms *parms, void *in_struct_ptr, const char *arg)
{
    disk_cache_conf *conf = ap_get_module_config(parms->server->module_config,
                                                 &disk_cache_module);
    conf->maxfs = atoi(arg);
    return NULL;
}
static const char
*set_cache_minetm(cmd_parms *parms, void *in_struct_ptr, const char *arg)
{
    /* XXX
    disk_cache_conf *conf = ap_get_module_config(parms->server->module_config,
                                                 &disk_cache_module);
    */
    return NULL;
}
static const char
*set_cache_gctime(cmd_parms *parms, void *in_struct_ptr, const char *arg)
{
    /* XXX
    disk_cache_conf *conf = ap_get_module_config(parms->server->module_config,
                                                 &disk_cache_module);
    */
    return NULL;
}
static const char
*add_cache_gcclean(cmd_parms *parms, void *in_struct_ptr, const char *arg, const char *arg1)
{
    /* XXX
    disk_cache_conf *conf = ap_get_module_config(parms->server->module_config,
                                                 &disk_cache_module);
    */
    return NULL;
}
static const char
*add_cache_gcclnun(cmd_parms *parms, void *in_struct_ptr, const char *arg, const char *arg1)
{
    /* XXX
    disk_cache_conf *conf = ap_get_module_config(parms->server->module_config,
                                                 &disk_cache_module);
    */
    return NULL;
}
static const char
*set_cache_maxgcmem(cmd_parms *parms, void *in_struct_ptr, const char *arg)
{
    /* XXX
    disk_cache_conf *conf = ap_get_module_config(parms->server->module_config,
                                                 &disk_cache_module);
    */
    return NULL;
}

static const command_rec disk_cache_cmds[] =
{
    AP_INIT_TAKE1("CacheRoot", set_cache_root, NULL, RSRC_CONF,
                 "The directory to store cache files"),
    AP_INIT_TAKE1("CacheSize", set_cache_size, NULL, RSRC_CONF,
                  "The maximum disk space used by the cache in KB"),
    AP_INIT_TAKE1("CacheGcInterval", set_cache_gcint, NULL, RSRC_CONF,
                  "The interval between garbage collections, in hours"),
    AP_INIT_TAKE1("CacheDirLevels", set_cache_dirlevels, NULL, RSRC_CONF,
                  "The number of levels of subdirectories in the cache"),
    AP_INIT_TAKE1("CacheDirLength", set_cache_dirlength, NULL, RSRC_CONF,
                  "The number of characters in subdirectory names"),
    AP_INIT_FLAG("CacheExpiryCheck", set_cache_exchk, NULL, RSRC_CONF,
                 "on if cache observes Expires date when seeking files"),
    AP_INIT_TAKE1("CacheMinFileSize", set_cache_minfs, NULL, RSRC_CONF,
                  "The minimum file size to cache a document"),
    AP_INIT_TAKE1("CacheMaxFileSize", set_cache_maxfs, NULL, RSRC_CONF,
                  "The maximum file size to cache a document"),
    AP_INIT_TAKE1("CacheTimeMargin", set_cache_minetm, NULL, RSRC_CONF,
                  "The minimum time margin to cache a document"),
    AP_INIT_TAKE1("CacheGcDaily", set_cache_gctime, NULL, RSRC_CONF,
                  "The time of day for garbage collection (24 hour clock)"),
    AP_INIT_TAKE2("CacheGcUnused", add_cache_gcclnun, NULL, RSRC_CONF,
                  "The time in hours to retain unused file that match a url"),
    AP_INIT_TAKE2("CacheGcClean", add_cache_gcclean, NULL, RSRC_CONF,
                  "The time in hours to retain unchanged files that match a url"),
    AP_INIT_TAKE1("CacheGcMemUsage", set_cache_maxgcmem, NULL, RSRC_CONF,
                  "The maximum kilobytes of memory used for garbage collection"),
    {NULL}
};

static const cache_provider cache_disk_provider =
{
    &remove_entity,
    &store_headers,
    &store_body,
    &recall_headers,
    &recall_body,
    &create_entity,
    &open_entity,
    &remove_url,
};

static void disk_cache_register_hook(apr_pool_t *p)
{
    /* cache initializer */
    ap_register_provider(p, CACHE_PROVIDER_GROUP, "disk", "0",
                         &cache_disk_provider);
}

module AP_MODULE_DECLARE_DATA disk_cache_module = {
    STANDARD20_MODULE_STUFF,
    NULL,                       /* create per-directory config structure */
    NULL,                       /* merge per-directory config structures */
    create_config,              /* create per-server config structure */
    NULL,                       /* merge per-server config structures */
    disk_cache_cmds,	        /* command apr_table_t */
    disk_cache_register_hook	/* register hooks */
};