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-rw-r--r--modules/cache/mod_socache_dc.c198
1 files changed, 198 insertions, 0 deletions
diff --git a/modules/cache/mod_socache_dc.c b/modules/cache/mod_socache_dc.c
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+++ b/modules/cache/mod_socache_dc.c
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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.
+ */
+
+#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 negligable 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
+};
+