apr_memcache.c

Apache官方在今天放出产品系列2.2的最新版本2.2.11的源码包 最流行的HTTP服务器软件之一

/* 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 "apr_memcache.h"
#include "apr_poll.h"
#include "apr_version.h"
#include <stdlib.h>

#define BUFFER_SIZE 512
struct apr_memcache_conn_t
{
    char *buffer;
    apr_size_t blen;
    apr_pool_t *p;
    apr_socket_t *sock;
    apr_bucket_alloc_t *balloc;
    apr_bucket_brigade *bb;
    apr_bucket_brigade *tb;
    apr_memcache_server_t *ms;
};                                                          

/* Strings for Client Commands */

#define MC_EOL "\r\n"
#define MC_EOL_LEN (sizeof(MC_EOL)-1)

#define MC_WS " "
#define MC_WS_LEN (sizeof(MC_WS)-1)

#define MC_GET "get "
#define MC_GET_LEN (sizeof(MC_GET)-1)

#define MC_SET "set "
#define MC_SET_LEN (sizeof(MC_SET)-1)

#define MC_ADD "add "
#define MC_ADD_LEN (sizeof(MC_ADD)-1)

#define MC_REPLACE "replace "
#define MC_REPLACE_LEN (sizeof(MC_REPLACE)-1)

#define MC_DELETE "delete "
#define MC_DELETE_LEN (sizeof(MC_DELETE)-1)

#define MC_INCR "incr "
#define MC_INCR_LEN (sizeof(MC_INCR)-1)

#define MC_DECR "decr "
#define MC_DECR_LEN (sizeof(MC_DECR)-1)

#define MC_VERSION "version"
#define MC_VERSION_LEN (sizeof(MC_VERSION)-1)

#define MC_STATS "stats"
#define MC_STATS_LEN (sizeof(MC_STATS)-1)

#define MC_QUIT "quit"
#define MC_QUIT_LEN (sizeof(MC_QUIT)-1)

/* Strings for Server Replies */

#define MS_STORED "STORED"
#define MS_STORED_LEN (sizeof(MS_STORED)-1)

#define MS_NOT_STORED "NOT_STORED"
#define MS_NOT_STORED_LEN (sizeof(MS_NOT_STORED)-1)

#define MS_DELETED "DELETED"
#define MS_DELETED_LEN (sizeof(MS_DELETED)-1)

#define MS_NOT_FOUND "NOT_FOUND"
#define MS_NOT_FOUND_LEN (sizeof(MS_NOT_FOUND)-1)

#define MS_VALUE "VALUE"
#define MS_VALUE_LEN (sizeof(MS_VALUE)-1)

#define MS_ERROR "ERROR"
#define MS_ERROR_LEN (sizeof(MS_ERROR)-1)

#define MS_VERSION "VERSION"
#define MS_VERSION_LEN (sizeof(MS_VERSION)-1)

#define MS_STAT "STAT"
#define MS_STAT_LEN (sizeof(MS_STAT)-1)

#define MS_END "END"
#define MS_END_LEN (sizeof(MS_END)-1)

/** Server and Query Structure for a multiple get */
struct cache_server_query_t {
    apr_memcache_server_t* ms;
    apr_memcache_conn_t* conn;
    struct iovec* query_vec;
    apr_int32_t query_vec_count;
};

#define MULT_GET_TIMEOUT 50000

static apr_status_t make_server_dead(apr_memcache_t *mc, apr_memcache_server_t *ms)
{
#if APR_HAS_THREADS
    apr_thread_mutex_lock(ms->lock);
#endif
    ms->status = APR_MC_SERVER_DEAD;
    ms->btime = apr_time_now();
#if APR_HAS_THREADS
    apr_thread_mutex_unlock(ms->lock);
#endif
    return APR_SUCCESS;
}

static apr_status_t make_server_live(apr_memcache_t *mc, apr_memcache_server_t *ms)
{
    ms->status = APR_MC_SERVER_LIVE; 
    return APR_SUCCESS;
}


APU_DECLARE(apr_status_t) apr_memcache_add_server(apr_memcache_t *mc, apr_memcache_server_t *ms)
{
    apr_status_t rv = APR_SUCCESS;

    if(mc->ntotal >= mc->nalloc) {
        return APR_ENOMEM;
    }

    mc->live_servers[mc->ntotal] = ms;
    mc->ntotal++;
    make_server_live(mc, ms);
    return rv;
}

static apr_status_t mc_version_ping(apr_memcache_server_t *ms);

APU_DECLARE(apr_memcache_server_t *) 
apr_memcache_find_server_hash(apr_memcache_t *mc, const apr_uint32_t hash)
{
    if (mc->server_func) {
        return mc->server_func(mc->server_baton, mc, hash);
    }
    else {
        return apr_memcache_find_server_hash_default(NULL, mc, hash);
    }
}   

APU_DECLARE(apr_memcache_server_t *) 
apr_memcache_find_server_hash_default(void *baton, apr_memcache_t *mc,
                                      const apr_uint32_t hash)
{
    apr_memcache_server_t *ms = NULL;
    apr_uint32_t h = hash ? hash : 1;
    apr_uint32_t i = 0;
    apr_time_t curtime = 0;
   
    if(mc->ntotal == 0) {
        return NULL;
    }

    do {
        ms = mc->live_servers[h % mc->ntotal];
        if(ms->status == APR_MC_SERVER_LIVE) {
            break;
        }
        else {
            if (curtime == 0) {
                curtime = apr_time_now();
            }
#if APR_HAS_THREADS
            apr_thread_mutex_lock(ms->lock);
#endif
            /* Try the the dead server, every 5 seconds */
            if (curtime - ms->btime >  apr_time_from_sec(5)) {
                if (mc_version_ping(ms) == APR_SUCCESS) {
                    ms->btime = curtime;
                    make_server_live(mc, ms);
#if APR_HAS_THREADS
                    apr_thread_mutex_unlock(ms->lock);
#endif
                    break;
                }
            }
#if APR_HAS_THREADS
            apr_thread_mutex_unlock(ms->lock);
#endif
        }
        h++;
        i++;
    } while(i < mc->ntotal);

    if (i == mc->ntotal) {
        ms = NULL;
    }

    return ms;
}

APU_DECLARE(apr_memcache_server_t *) apr_memcache_find_server(apr_memcache_t *mc, const char *host, apr_port_t port)
{
    int i;

    for (i = 0; i < mc->ntotal; i++) {
        if (strcmp(mc->live_servers[i]->host, host) == 0
            && mc->live_servers[i]->port == port) {

            return mc->live_servers[i];
        }
    }

    return NULL;
}

static apr_status_t ms_find_conn(apr_memcache_server_t *ms, apr_memcache_conn_t **conn) 
{
#if APR_HAS_THREADS
    return apr_reslist_acquire(ms->conns, (void **)conn);
#else
    *conn = ms->conn;
    return APR_SUCCESS;
#endif
}

static apr_status_t ms_bad_conn(apr_memcache_server_t *ms, apr_memcache_conn_t *conn) 
{
#if APR_HAS_THREADS
    return apr_reslist_invalidate(ms->conns, conn);
#else
    return APR_SUCCESS;
#endif
}

static apr_status_t ms_release_conn(apr_memcache_server_t *ms, apr_memcache_conn_t *conn) 
{
#if APR_HAS_THREADS
    return apr_reslist_release(ms->conns, conn);
#else
    return APR_SUCCESS;
#endif
}

APU_DECLARE(apr_status_t) apr_memcache_enable_server(apr_memcache_t *mc, apr_memcache_server_t *ms)
{
    apr_status_t rv = APR_SUCCESS;

    if (ms->status == APR_MC_SERVER_LIVE) {
        return rv;
    }

    rv = make_server_live(mc, ms);
    return rv;
}

APU_DECLARE(apr_status_t) apr_memcache_disable_server(apr_memcache_t *mc, apr_memcache_server_t *ms)
{
    return make_server_dead(mc, ms);
}

static apr_status_t conn_connect(apr_memcache_conn_t *conn)
{
    apr_status_t rv = APR_SUCCESS;
    apr_sockaddr_t *sa;

    rv = apr_sockaddr_info_get(&sa, conn->ms->host, APR_INET, conn->ms->port, 0, conn->p);
    if (rv != APR_SUCCESS) {
        return rv;
    }

    rv = apr_socket_timeout_set(conn->sock, 1 * APR_USEC_PER_SEC);
    if (rv != APR_SUCCESS) {
        return rv;
    }

    rv = apr_socket_connect(conn->sock, sa);
    if (rv != APR_SUCCESS) {
        return rv;
    }

    rv = apr_socket_timeout_set(conn->sock, -1);
    if (rv != APR_SUCCESS) {
        return rv;
    }

    return rv;
}

static apr_status_t conn_clean(void *data)
{
    apr_memcache_conn_t *conn = data;
    struct iovec vec[2];
    apr_size_t written;

    /* send a quit message to the memcached server to be nice about it. */
    vec[0].iov_base = MC_QUIT;
    vec[0].iov_len = MC_QUIT_LEN;

    vec[1].iov_base = MC_EOL;
    vec[1].iov_len = MC_EOL_LEN;
    
    /* Return values not checked, since we just want to make it go away. */
    apr_socket_sendv(conn->sock, vec, 2, &written);
    apr_socket_close(conn->sock);

    conn->p = NULL; /* so that destructor does not destroy the pool again */

    return APR_SUCCESS;
}

static apr_status_t
mc_conn_construct(void **conn_, void *params, apr_pool_t *pool)
{
    apr_status_t rv = APR_SUCCESS;
    apr_memcache_conn_t *conn;
    apr_bucket *e;
    apr_pool_t *np;
    apr_memcache_server_t *ms = params;

    rv = apr_pool_create(&np, pool);
    if (rv != APR_SUCCESS) {
        return rv;
    }

#if APR_HAS_THREADS
    conn = malloc(sizeof( apr_memcache_conn_t )); /* non-pool space! */
#else
    conn = apr_palloc(np, sizeof( apr_memcache_conn_t ));
#endif

    conn->p = np;

    rv = apr_socket_create(&conn->sock, APR_INET, SOCK_STREAM, 0, np);

    if (rv != APR_SUCCESS) {
        apr_pool_destroy(np);
#if APR_HAS_THREADS
        free(conn);
#endif
        return rv;
    }

    conn->balloc = apr_bucket_alloc_create(conn->p);
    conn->bb = apr_brigade_create(conn->p, conn->balloc);
    conn->tb = apr_brigade_create(conn->p, conn->balloc);
    conn->buffer = apr_palloc(conn->p, BUFFER_SIZE);
    conn->blen = 0;
    conn->ms = ms;

    e = apr_bucket_socket_create(conn->sock, conn->balloc);
    APR_BRIGADE_INSERT_TAIL(conn->bb, e);

    rv = conn_connect(conn);
    if (rv != APR_SUCCESS) {
        apr_pool_destroy(np);
#if APR_HAS_THREADS
        free(conn);
#endif
    }
    else {
        apr_pool_cleanup_register(np, conn, conn_clean, apr_pool_cleanup_null);
        *conn_ = conn;
    }
    
    return rv;
}

#if APR_HAS_THREADS
static apr_status_t
mc_conn_destruct(void *conn_, void *params, apr_pool_t *pool)
{
    apr_memcache_conn_t *conn = (apr_memcache_conn_t*)conn_;
    
    if (conn->p) {
        apr_pool_destroy(conn->p);
    }

    free(conn); /* free non-pool space */
    
    return APR_SUCCESS;
}
#endif

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 **ms)
{
    apr_status_t rv = APR_SUCCESS;
    apr_memcache_server_t *server;
    apr_pool_t *np;

    rv = apr_pool_create(&np, p);

    server = apr_palloc(np, sizeof(apr_memcache_server_t));

    server->p = np;
    server->host = apr_pstrdup(np, host);
    server->port = port;
    server->status = APR_MC_SERVER_DEAD;
#if APR_HAS_THREADS
    rv = apr_thread_mutex_create(&server->lock, APR_THREAD_MUTEX_DEFAULT, np);
    if (rv != APR_SUCCESS) {
        return rv;
    }

    rv = apr_reslist_create(&server->conns, 
                               min,                     /* hard minimum */
                               smax,                    /* soft maximum */
                               max,                     /* hard maximum */
                               ttl,                     /* Time to live */
                               mc_conn_construct,       /* Make a New Connection */