ap_ namespace, a dead giveaway that this information should reside

in the general include\ directory

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@664232 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 159 insertions, 0 deletions

diff --git a/include/ap_socache.h b/include/ap_socache.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.
+ */
+
+/**
+ * @file ap_socache.h
+ * @brief Small object cache provider interface.
+ *
+ * @defgroup AP_SOCACHE ap_socache
+ * @ingroup  APACHE_MODS
+ * @{
+ */
+
+#ifndef AP_SOCACHE_H
+#define AP_SOCACHE_H 
+
+#include "httpd.h"
+#include "ap_provider.h"
+#include "apr_pools.h"
+
+/** If this flag is set, the store/retrieve/delete/status interfaces
+ * of the provider are NOT safe to be called concurrently from
+ * multiple processes or threads, and an external global mutex must be
+ * used to serialize access to the provider. */
+#define AP_SOCACHE_FLAG_NOTMPSAFE (0x0001)
+
+/** A cache instance. */
+typedef struct ap_socache_instance_t ap_socache_instance_t;
+
+/** Hints which may be passed to the init function; providers may
+ * ignore some or all of these hints. */
+struct ap_socache_hints {
+    /** Approximate average length of IDs: */
+    apr_size_t avg_id_len;
+    /** Approximate average size of objects: */
+    apr_size_t avg_obj_size;
+    /** Interval (in seconds) after which an expiry run is
+     * necessary. */
+    time_t expiry_interval;
+};
+
+/** A socache provider structure.  socache providers are registered
+ * with the ap_provider.h interface using the AP_SOCACHE_PROVIDER_*
+ * constants. */
+typedef struct ap_socache_provider_t {
+    /** Canonical provider name: */
+    const char *name;
+
+    /** Bitmask of AP_SOCACHE_FLAG_* flags: */
+    unsigned int flags;
+
+    /** 
+     * Create a session cache based on the given configuration string.
+     * The instance pointer returned in the instance paramater will be
+     * passed as the first argument to subsequent invocations.
+     *
+     * @param instance Output parameter to which instance object is written.
+     * @param arg Used-specified configuration string
+     * @param tmp Pool to be used for any temporary allocations
+     * @param p Pool to be use for any allocations lasting as long as 
+     * the created instance
+     * @return NULL on success, or an error string on failure.
+     */
+    const char *(*create)(ap_socache_instance_t **instance, const char *arg, 
+                          apr_pool_t *tmp, apr_pool_t *p);
+
+    /* Initialize the cache.  NAMESPACE must given a unique string
+     * prefix for use with memcached; if hints is non-NULL, it gives a
+     * set of hints for the provider.  Return APR error code. 
+
+     * @param instance The cache instance
+     * @param namespace A unique string identifying the consumer of this API
+     * @param hints Optional hints argument describing expected cache use
+     * @param s Server structure to which the cache is associated
+     * @param pool Pool for long-lived allocations
+     * @return APR status value indicating success.
+     */
+    apr_status_t (*init)(ap_socache_instance_t *instance, const char *namespace, 
+                         const struct ap_socache_hints *hints,
+                         server_rec *s, apr_pool_t *pool);
+
+    /** 
+     * Destroy a given cache instance object.
+     * @param instance The cache instance to destroy.
+     * @param s Associated server structure (for logging purposes)
+     */
+    void (*destroy)(ap_socache_instance_t *instance, server_rec *s);
+
+    /** 
+     * Store an object in a cache instance.
+     * @param instance The cache instance
+     * @param s Associated server structure (for logging purposes)
+     * @param id Unique ID for the object; binary blob
+     * @param idlen Length of id blob
+     * @param expiry Absolute time at which the object expires
+     * @param data Data to store; binary blob
+     * @param datalen Length of data blob
+     */
+    apr_status_t (*store)(ap_socache_instance_t *instance, server_rec *s, 
+                          const unsigned char *id, unsigned int idlen, 
+                          time_t expiry, 
+                          unsigned char *data, unsigned int datalen);
+
+    /**
+     * Retrieve a cached object.
+     * @param instance The cache instance
+     * @param s Associated server structure (for logging purposes)
+     * @param id Unique ID for the object; binary blob
+     * @param idlen Length of id blob
+     * @param data Output buffer to place retrievd data (binary blob)
+     * @param datalen On entry, length of data buffer; on exit, the
+     * number of bytes written to the data buffer.
+     * @param pool Pool for temporary allocations.
+     */
+    apr_status_t (*retrieve)(ap_socache_instance_t *instance, server_rec *s,
+                             const unsigned char *id, unsigned int idlen,
+                             unsigned char *data, unsigned int *datalen,
+                             apr_pool_t *pool);
+
+    /* Remove an object from the cache
+     * @param instance The cache instance
+     * @param s Associated server structure (for logging purposes)
+     * @param id Unique ID for the object; binary blob
+     * @param idlen Length of id blob
+     * @param pool Pool for temporary allocations.
+     */
+    void (*delete)(ap_socache_instance_t *instance, server_rec *s,
+                   const unsigned char *id, unsigned int idlen,
+                   apr_pool_t *pool);
+
+    /** Dump the status of a cache instance for mod_status.  Will use
+     * the ap_r* interfaces to produce appropriate status output.
+     *
+     * @param instance The cache instance
+     * @param r The request structure
+     * @param flags The AP_STATUS_* constants used (see mod_status.h)
+     */
+    void (*status)(ap_socache_instance_t *instance, request_rec *r, int flags);
+} ap_socache_provider_t;
+
+/** The provider group used to register socache providers. */
+#define AP_SOCACHE_PROVIDER_GROUP "socache"
+/** The provider version used to register socache providers. */
+#define AP_SOCACHE_PROVIDER_VERSION "0"
+
+#endif /* AP_SOCACHE_H */
+/** @} */