/* 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 APR_MEMCACHE_H
#define APR_MEMCACHE_H
/**
* @file apr_memcache.h
* @brief Client interface for memcached
* @remark To use this interface you must have a separate memcached
* server running. See the memcached website at http://www.danga.com/memcached/
* for more information.
*/
#include "apr.h"
#include "apr_pools.h"
#include "apr_time.h"
#include "apr_strings.h"
#include "apr_network_io.h"
#include "apr_ring.h"
#include "apr_buckets.h"
#include "apr_reslist.h"
#include "apr_hash.h"
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**
* @defgroup APR_Util_MC Memcached Client Routines
* @ingroup APR_Util
* @{
*/
/** Specifies the status of a memcached server */
typedef enum
{
APR_MC_SERVER_LIVE, /**< Server is alive and responding to requests */
APR_MC_SERVER_DEAD /**< Server is not responding to requests */
} apr_memcache_server_status_t;
/** Opaque memcache client connection object */
typedef struct apr_memcache_conn_t apr_memcache_conn_t;
/** Memcache Server Info Object */
typedef struct apr_memcache_server_t apr_memcache_server_t;
struct apr_memcache_server_t
{
const char *host; /**< Hostname of this Server */
apr_port_t port; /**< Port of this Server */
apr_memcache_server_status_t status; /**< @see apr_memcache_server_status_t */
#if APR_HAS_THREADS || defined(DOXYGEN)
apr_reslist_t *conns; /**< Resource list of actual client connections */
#else
apr_memcache_conn_t *conn;
#endif
apr_pool_t *p; /** Pool to use for private allocations */
#if APR_HAS_THREADS
apr_thread_mutex_t *lock;
#endif
apr_time_t btime;
};
/* Custom hash callback function prototype, user for server selection.
* @param baton user selected baton
* @param data data to hash
* @param data_len length of data
*/
typedef apr_uint32_t (*apr_memcache_hash_func)(void *baton,
const char *data,
const apr_size_t data_len);
typedef struct apr_memcache_t apr_memcache_t;
/* Custom Server Select callback function prototype.
* @param baton user selected baton
* @param mc memcache instance, use mc->live_servers to select a node
* @param hash hash of the selected key.
*/
typedef apr_memcache_server_t* (*apr_memcache_server_func)(void *baton,
apr_memcache_t *mc,
const apr_uint32_t hash);
/** Container for a set of memcached servers */
struct apr_memcache_t
{
apr_uint32_t flags; /**< Flags, Not currently used */
apr_uint16_t nalloc; /**< Number of Servers Allocated */
apr_uint16_t ntotal; /**< Number of Servers Added */
apr_memcache_server_t **live_servers; /**< Array of Servers */
apr_pool_t *p; /** Pool to use for allocations */
void *hash_baton;
apr_memcache_hash_func hash_func;
void *server_baton;
apr_memcache_server_func server_func;
};
/** Returned Data from a multiple get */
typedef struct
{
apr_status_t status;
const char* key;
apr_size_t len;
char *data;
apr_uint16_t flags;
} apr_memcache_value_t;
/**
* Creates a crc32 hash used to split keys between servers
* @param mc The memcache client object to use
* @param data Data to be hashed
* @param data_len Length of the data to use
* @return crc32 hash of data
* @remark The crc32 hash is not compatible with old memcached clients.
*/
APU_DECLARE(apr_uint32_t) apr_memcache_hash(apr_memcache_t *mc,
const char *data,
const apr_size_t data_len);
/**
* Pure CRC32 Hash. Used by some clients.
*/
APU_DECLARE(apr_uint32_t) apr_memcache_hash_crc32(void *baton,
const char *data,
const apr_size_t data_len);
/**
* hash compatible with the standard Perl Client.
*/
APU_DECLARE(apr_uint32_t) apr_memcache_hash_default(void *baton,
const char *data,
const apr_size_t data_len);
/**
* Picks a server based on a hash
* @param mc The memcache client object to use
* @param hash Hashed value of a Key
* @return server that controls specified hash
* @see apr_memcache_hash
*/
APU_DECLARE(apr_memcache_server_t *) apr_memcache_find_server_hash(apr_memcache_t *mc,
const apr_uint32_t hash);
/**
* server selection compatible with the standard Perl Client.
*/
APU_DECLARE(apr_memcache_server_t *) apr_memcache_find_server_hash_default(void *baton,
apr_memcache_t *mc,
const apr_uint32_t hash);
/**
* Adds a server to a client object
* @param mc The memcache client object to use
* @param server Server to add
* @remark Adding servers is not thread safe, and should be done once at startup.
* @warning Changing servers after startup may cause keys to go to
* different servers.
*/
APU_DECLARE(apr_status_t) apr_memcache_add_server(apr_memcache_t *mc,
apr_memcache_server_t *server);
/**
* Finds a Server object based on a hostname/port pair
* @param mc The memcache client object to use
* @param host Hostname of the server
* @param port Port of the server
* @return Server with matching Hostname and Port, or NULL if none was found.
*/
APU_DECLARE(apr_memcache_server_t *) apr_memcache_find_server(apr_memcache_t *mc,
const char *host,
apr_port_t port);
/**
* Enables a Server for use again
* @param mc The memcache client object to use
* @param ms Server to Activate
*/
APU_DECLARE(apr_status_t) apr_memcache_enable_server(apr_memcache_t *mc,
apr_memcache_server_t *ms);
/**
* Disable a Server
* @param mc The memcache client object to use
* @param ms Server to Disable
*/
APU_DECLARE(apr_status_t) apr_memcache_disable_server(apr_memcache_t *mc,
apr_memcache_server_t *ms);
/**
* Creates a new Server Object
* @param p Pool to use
* @param host hostname of the server
* @param port port of the server
* @param min minimum number of client sockets to open
* @param smax soft maximum number of client connections to open
* @param max hard maximum number of client connections
* @param ttl time to live in microseconds of a client connection
* @param ns location of the new server object
* @see apr_reslist_create
* @remark min, smax, and max are only used when APR_HAS_THREADS
*/
APU_DECLARE(apr_status_t) apr_memcache_server_create(apr_pool_t *p,
const char *host,
apr_port_t port,
apr_uint32_t min,
apr_uint32_t smax,
apr_uint32_t max,
apr_uint32_t ttl,
apr_memcache_server_t **ns);
/**
* Creates a new memcached client object
* @param p Pool to use
* @param max_servers maximum number of servers
* @param flags Not currently used
* @param mc location of the new memcache client object
*/
APU_DECLARE(apr_status_t) apr_memcache_create(apr_pool_t *p,
apr_uint16_t max_servers,
apr_uint32_t flags,
apr_memcache_t **mc);
/**
* Gets a value from the server, allocating the value out of p
* @param mc client to use
* @param p Pool to use
* @param key null terminated string containing the key
* @param baton location of the allocated value
* @param len length of data at baton
* @param flags any flags set by the client for this key
* @return
*/
APU_DECLARE(apr_status_t) apr_memcache_getp(apr_memcache_t *mc,
apr_pool_t *p,
const char* key,
char **baton,
apr_size_t *len,
apr_uint16_t *flags);
/**
* Add a key to a hash for a multiget query
* if the hash (*value) is NULL it will be created
* @param data_pool pool from where the hash and their items are created from
* @param key null terminated string containing the key
* @param values hash of keys and values that this key will be added to
* @return
*/
APU_DECLARE(void) apr_memcache_add_multget_key(apr_pool_t *data_pool,
const char* key,
apr_hash_t **values);
/**
* Gets multiple values from the server, allocating the values out of p
* @param mc client to use
* @param temp_pool Pool used for temporary allocations. May be cleared inside this
* call.
* @param data_pool Pool used to allocate data for the returned values.
* @param values hash of apr_memcache_value_t keyed by strings, contains the
* result of the multiget call.
* @return
*/
APU_DECLARE(apr_status_t) apr_memcache_multgetp(apr_memcache_t *mc,
apr_pool_t *temp_pool,
apr_pool_t *data_pool,
apr_hash_t *values);
/**
* Sets a value by key on the server
* @param mc client to use
* @param key null terminated string containing the key
* @param baton data to store on the server
* @param data_size length of data at baton
* @param timeout time in seconds for the data to live on the server
* @param flags any flags set by the client for this key
*/
APU_DECLARE(apr_status_t) apr_memcache_set(apr_memcache_t *mc,
const char *key,
char *baton,
const apr_size_t data_size,
apr_uint32_t timeout,
apr_uint16_t flags);
/**
* Adds value by key on the server
* @param mc client to use
* @param key null terminated string containing the key
* @param baton data to store on the server
* @param data_size length of data at baton
* @param timeout time for the data to live on the server
* @param flags any flags set by the client for this key
* @return APR_SUCCESS if the key was added, APR_EEXIST if the key
* already exists on the server.
*/
APU_DECLARE(apr_status_t) apr_memcache_add(apr_memcache_t *mc,
const char *key,
char *baton,
const apr_size_t data_size,
apr_uint32_t timeout,
apr_uint16_t flags);
/**
* Replaces value by key on the server
* @param mc client to use
* @param key null terminated string containing the key
* @param baton data to store on the server
* @param data_size length of data at baton
* @param timeout time for the data to live on the server
* @param flags any flags set by the client for this key
* @return APR_SUCCESS if the key was added, APR_EEXIST if the key
* did not exist on the server.
*/
APU_DECLARE(apr_status_t) apr_memcache_replace(apr_memcache_t *mc,
const char *key,
char *baton,
const apr_size_t data_size,
apr_uint32_t timeout,
apr_uint16_t flags);
/**
* Deletes a key from a server
* @param mc client to use
* @param key null terminated string containing the key
* @param timeout time for the delete to stop other clients from adding
*/
APU_DECLARE(apr_status_t) apr_memcache_delete(apr_memcache_t *mc,
const char *key,
apr_uint32_t timeout);
/**
* Increments a value
* @param mc client to use
* @param key null terminated string containing the key
* @param n number to increment by
* @param nv new value after incrementing
*/
APU_DECLARE(apr_status_t) apr_memcache_incr(apr_memcache_t *mc,
const char *key,
apr_int32_t n,
apr_uint32_t *nv);
/**
* Decrements a value
* @param mc client to use
* @param key null terminated string containing the key
* @param n number to decrement by
* @param new_value new value after decrementing
*/
APU_DECLARE(apr_status_t) apr_memcache_decr(apr_memcache_t *mc,
const char *key,
apr_int32_t n,
apr_uint32_t *new_value);
/**
* Query a server's version
* @param ms server to query
* @param p Pool to allocate answer from
* @param baton location to store server version string
* @param len length of the server version string
*/
APU_DECLARE(apr_status_t) apr_memcache_version(apr_memcache_server_t *ms,
apr_pool_t *p,
char **baton);
typedef struct
{
/** Version string of this server */
const char *version;
/** Process id of this server process */
apr_uint32_t pid;
/** Number of seconds this server has been running */
apr_uint32_t uptime;
/** current UNIX time according to the server */
apr_time_t time;
/** The size of a pointer on the current machine */
apr_uint32_t pointer_size;
/** Accumulated user time for this process */
apr_time_t rusage_user;
/** Accumulated system time for this process */
apr_time_t rusage_system;
/** Current number of items stored by the server */
apr_uint32_t curr_items;
/** Total number of items stored by this server */
apr_uint32_t total_items;
/** Current number of bytes used by this server to store items */
apr_uint64_t bytes;
/** Number of open connections */
apr_uint32_t curr_connections;
/** Total number of connections opened since the server started running */
apr_uint32_t total_connections;
/** Number of connection structures allocated by the server */
apr_uint32_t connection_structures;
/** Cumulative number of retrieval requests */
apr_uint32_t cmd_get;
/** Cumulative number of storage requests */
apr_uint32_t cmd_set;
/** Number of keys that have been requested and found present */
apr_uint32_t get_hits;
/** Number of items that have been requested and not found */
apr_uint32_t get_misses;
/** Number of items removed from cache because they passed their
expiration time */
apr_uint64_t evictions;
/** Total number of bytes read by this server */
apr_uint64_t bytes_read;
/** Total number of bytes sent by this server */
apr_uint64_t bytes_written;
/** Number of bytes this server is allowed to use for storage. */
apr_uint32_t limit_maxbytes;
/** Number of threads the server is running (if built with threading) */
apr_uint32_t threads;
} apr_memcache_stats_t;
/**
* Query a server for statistics
* @param ms server to query
* @param p Pool to allocate answer from
* @param stats location of the new statistics structure
*/
APU_DECLARE(apr_status_t) apr_memcache_stats(apr_memcache_server_t *ms,
apr_pool_t *p,
apr_memcache_stats_t **stats);
/** @} */
#ifdef __cplusplus
}
#endif
#endif /* APR_MEMCACHE_H */