pool.h

/* TDSPool - Connection pooling for TDS based databases
 * Copyright (C) 2001 Brian Bruns
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */
 
#ifndef _tdsguard_clBmMDiJ1W6vO4Q4ftyzgV_
#define _tdsguard_clBmMDiJ1W6vO4Q4ftyzgV_
 
#include <assert.h>
 
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
 
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
 
/* 
 * POSIX says fd_set type may be defined in either sys/select.h or sys/time.h. 
 */
#if HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
 
#include <freetds/tds.h>
#include <freetds/utils/dlist.h>
#include <freetds/replacements.h>
 
/* defines */
#define PGSIZ 2048
#define BLOCKSIZ 512
#define MAX_POOL_USERS 1024
 
/* enums and typedefs */
typedef enum
{
    TDS_SRV_WAIT,       /* if no members are free wait */
    TDS_SRV_QUERY,
} TDS_USER_STATE;
 
/* forward declaration */
typedef struct tds_pool_event TDS_POOL_EVENT;
typedef struct tds_pool_socket TDS_POOL_SOCKET;
typedef struct tds_pool_member TDS_POOL_MEMBER;
typedef struct tds_pool_user TDS_POOL_USER;
typedef struct tds_pool TDS_POOL;
typedef void (*TDS_POOL_EXECUTE)(TDS_POOL_EVENT *event);
 
struct tds_pool_event
{
    TDS_POOL_EVENT *next;
    TDS_POOL_EXECUTE execute;
};
 
struct tds_pool_socket
{
    TDSSOCKET *tds;
    uint32_t poll_index;
    bool poll_recv;
    bool poll_send;
};
 
struct tds_pool_user
{
    TDS_POOL_SOCKET sock;
    DLIST_FIELDS(dlist_user_item);
    TDSLOGIN *login;
    TDS_USER_STATE user_state;
    TDS_POOL_MEMBER *assigned_member;
};
 
struct tds_pool_member
{
    TDS_POOL_SOCKET sock;
    DLIST_FIELDS(dlist_member_item);
    bool doing_async;
    time_t last_used_tm;
    TDS_POOL_USER *current_user;
};
 
#define DLIST_PREFIX dlist_member
#define DLIST_LIST_TYPE dlist_members
#define DLIST_ITEM_TYPE TDS_POOL_MEMBER
#include <freetds/utils/dlist.tmpl.h>
 
#define DLIST_PREFIX dlist_user
#define DLIST_LIST_TYPE dlist_users
#define DLIST_ITEM_TYPE TDS_POOL_USER
#include <freetds/utils/dlist.tmpl.h>
 
struct tds_pool
{
    char *name;
    char *user;
    char *password;
    char *server;
    char *database;
    char *server_user;
    char *server_password;
    int port;
    int max_member_age; /* in seconds */
    int min_open_conn;
    int max_open_conn;
    tds_mutex events_mtx;
    TDS_SYS_SOCKET listen_fd;
    TDS_SYS_SOCKET wakeup_fd;
    TDS_SYS_SOCKET event_fd;
    TDS_POOL_EVENT *events;
 
    int num_active_members;
    dlist_members active_members;
    dlist_members idle_members;

    dlist_users waiters;
    int num_users;
    dlist_users users;
    TDSCONTEXT *ctx;
 
    unsigned long user_logins;
    unsigned long member_logins;
};
 
/* prototypes */
 
/* member.c */
int pool_process_members(TDS_POOL * pool, struct pollfd *fds, unsigned num_fds);
TDS_POOL_MEMBER *pool_assign_idle_member(TDS_POOL * pool, TDS_POOL_USER *user);
void pool_mbr_init(TDS_POOL * pool);
void pool_mbr_destroy(TDS_POOL * pool);
void pool_free_member(TDS_POOL *pool, TDS_POOL_MEMBER * pmbr);
void pool_assign_member(TDS_POOL *pool, TDS_POOL_MEMBER * pmbr, TDS_POOL_USER *puser);
void pool_deassign_member(TDS_POOL *pool, TDS_POOL_MEMBER * pmbr);
void pool_reset_member(TDS_POOL *pool, TDS_POOL_MEMBER * pmbr);
bool pool_packet_read(TDSSOCKET * tds);
#if ENABLE_EXTRA_CHECKS
void pool_mbr_check(TDS_POOL *pool);
#else
static inline void pool_mbr_check(TDS_POOL *pool TDS_UNUSED)
{
}
#endif
 
 
/* user.c */
void pool_process_users(TDS_POOL * pool, struct pollfd *fds, unsigned num_fds);
void pool_user_init(TDS_POOL * pool);
void pool_user_destroy(TDS_POOL * pool);
TDS_POOL_USER *pool_user_create(TDS_POOL * pool, TDS_SYS_SOCKET s);
void pool_free_user(TDS_POOL * pool, TDS_POOL_USER * puser);
void pool_user_query(TDS_POOL * pool, TDS_POOL_USER * puser);
bool pool_user_send_login_ack(TDS_POOL * pool, TDS_POOL_USER * puser);
void pool_user_finish_login(TDS_POOL * pool, TDS_POOL_USER * puser);
 
/* util.c */
void dump_login(TDSLOGIN * login);
void pool_event_add(TDS_POOL *pool, TDS_POOL_EVENT *ev, TDS_POOL_EXECUTE execute);
int pool_write(TDS_SYS_SOCKET sock, const void *buf, size_t len);
bool pool_write_data(TDS_POOL_SOCKET *from, TDS_POOL_SOCKET *to);
 
/* config.c */
bool pool_read_conf_files(const tds_dir_char *path, const char *poolname, TDS_POOL * pool, char **err);
 
 
#endif