diff options
Diffstat (limited to 'modules/cache/mod_socache_dc.c')
| -rw-r--r-- | modules/cache/mod_socache_dc.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/modules/cache/mod_socache_dc.c b/modules/cache/mod_socache_dc.c new file mode 100644 index 0000000..1fc52a7 --- /dev/null +++ b/modules/cache/mod_socache_dc.c @@ -0,0 +1,198 @@ +/* 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. + */ + +#include "httpd.h" +#include "http_log.h" +#include "http_request.h" +#include "http_config.h" +#include "http_protocol.h" +#include "mod_status.h" + +#include "apr_strings.h" +#include "apr_time.h" + +#include "ap_socache.h" + +#include "distcache/dc_client.h" + +#if !defined(DISTCACHE_CLIENT_API) || (DISTCACHE_CLIENT_API < 0x0001) +#error "You must compile with a more recent version of the distcache-base package" +#endif + +struct ap_socache_instance_t { + /* Configured target server: */ + const char *target; + /* distcache client context: */ + DC_CTX *dc; +}; + +static const char *socache_dc_create(ap_socache_instance_t **context, + const char *arg, + apr_pool_t *tmp, apr_pool_t *p) +{ + struct ap_socache_instance_t *ctx; + + ctx = *context = apr_palloc(p, sizeof *ctx); + + ctx->target = apr_pstrdup(p, arg); + + return NULL; +} + +static apr_status_t socache_dc_init(ap_socache_instance_t *ctx, + const char *namespace, + const struct ap_socache_hints *hints, + server_rec *s, apr_pool_t *p) +{ +#if 0 + /* If a "persistent connection" mode of operation is preferred, you *must* + * also use the PIDCHECK flag to ensure fork()'d processes don't interlace + * comms on the same connection as each other. */ +#define SESSION_CTX_FLAGS SESSION_CTX_FLAG_PERSISTENT | \ + SESSION_CTX_FLAG_PERSISTENT_PIDCHECK | \ + SESSION_CTX_FLAG_PERSISTENT_RETRY | \ + SESSION_CTX_FLAG_PERSISTENT_LATE +#else + /* This mode of operation will open a temporary connection to the 'target' + * for each cache operation - this makes it safe against fork() + * automatically. This mode is preferred when running a local proxy (over + * unix domain sockets) because overhead is negligible and it reduces the + * performance/stability danger of file-descriptor bloatage. */ +#define SESSION_CTX_FLAGS 0 +#endif + ctx->dc = DC_CTX_new(ctx->target, SESSION_CTX_FLAGS); + if (!ctx->dc) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(00738) "distributed scache failed to obtain context"); + return APR_EGENERAL; + } + ap_log_error(APLOG_MARK, APLOG_INFO, 0, s, APLOGNO(00739) "distributed scache context initialised"); + + return APR_SUCCESS; +} + +static void socache_dc_destroy(ap_socache_instance_t *ctx, server_rec *s) +{ + if (ctx && ctx->dc) { + DC_CTX_free(ctx->dc); + ctx->dc = NULL; + } +} + +static apr_status_t socache_dc_store(ap_socache_instance_t *ctx, server_rec *s, + const unsigned char *id, unsigned int idlen, + apr_time_t expiry, + unsigned char *der, unsigned int der_len, + apr_pool_t *p) +{ + /* !@#$%^ - why do we deal with *absolute* time anyway??? + * Uhm - because most things expire things at a specific time? + * Were the API were thought out expiry - r->request_time is a good approximation + */ + expiry -= apr_time_now(); + /* Send the serialised session to the distributed cache context */ + if (!DC_CTX_add_session(ctx->dc, id, idlen, der, der_len, + apr_time_msec(expiry))) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(00740) "distributed scache 'store' failed"); + return APR_EGENERAL; + } + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(00741) "distributed scache 'store' successful"); + return APR_SUCCESS; +} + +static apr_status_t socache_dc_retrieve(ap_socache_instance_t *ctx, server_rec *s, + const unsigned char *id, unsigned int idlen, + unsigned char *dest, unsigned int *destlen, + apr_pool_t *p) +{ + unsigned int data_len; + + /* Retrieve any corresponding session from the distributed cache context */ + if (!DC_CTX_get_session(ctx->dc, id, idlen, dest, *destlen, &data_len)) { + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(00742) "distributed scache 'retrieve' MISS"); + return APR_NOTFOUND; + } + if (data_len > *destlen) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(00743) "distributed scache 'retrieve' OVERFLOW"); + return APR_ENOSPC; + } + *destlen = data_len; + ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(00744) "distributed scache 'retrieve' HIT"); + return APR_SUCCESS; +} + +static apr_status_t socache_dc_remove(ap_socache_instance_t *ctx, + server_rec *s, const unsigned char *id, + unsigned int idlen, apr_pool_t *p) +{ + /* Remove any corresponding session from the distributed cache context */ + if (!DC_CTX_remove_session(ctx->dc, id, idlen)) { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(00745) "distributed scache 'remove' MISS"); + return APR_NOTFOUND; + } + else { + ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(00746) "distributed scache 'remove' HIT"); + return APR_SUCCESS; + } +} + +static void socache_dc_status(ap_socache_instance_t *ctx, request_rec *r, int flags) +{ + ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00747) + "distributed scache 'socache_dc_status'"); + if (!(flags & AP_STATUS_SHORT)) { + ap_rprintf(r, "cache type: <b>DC (Distributed Cache)</b>, " + " target: <b>%s</b><br>", ctx->target); + } + else { + ap_rputs("CacheType: DC\n", r); + ap_rvputs(r, "CacheTarget: ", ctx->target, "\n", NULL); + } +} + +static apr_status_t socache_dc_iterate(ap_socache_instance_t *instance, + server_rec *s, void *userctx, + ap_socache_iterator_t *iterator, + apr_pool_t *pool) +{ + return APR_ENOTIMPL; +} + +static const ap_socache_provider_t socache_dc = { + "distcache", + 0, + socache_dc_create, + socache_dc_init, + socache_dc_destroy, + socache_dc_store, + socache_dc_retrieve, + socache_dc_remove, + socache_dc_status, + socache_dc_iterate +}; + +static void register_hooks(apr_pool_t *p) +{ + ap_register_provider(p, AP_SOCACHE_PROVIDER_GROUP, "dc", + AP_SOCACHE_PROVIDER_VERSION, + &socache_dc); +} + +AP_DECLARE_MODULE(socache_dc) = { + STANDARD20_MODULE_STUFF, + NULL, NULL, NULL, NULL, NULL, + register_hooks +}; + |