/*-
 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef __NSCD_QUERY_H__
#define __NSCD_QUERY_H__

#include "cachelib.h"
#include "config.h"
#include "protocol.h"

struct query_state;
struct configuration;
struct configuration_entry;

typedef int (*query_process_func)(struct query_state *);
typedef void (*query_destroy_func)(struct query_state *);
typedef ssize_t (*query_read_func)(struct query_state *, void *, size_t);
typedef ssize_t (*query_write_func)(struct query_state *, const void *, size_t);

/*
 * The query state structure contains the information to process all types of
 * requests and to send all types of responses.
 */
struct query_state {
        struct timeval creation_time;
        struct timeval timeout;

        struct comm_element request;
        struct comm_element response;
        struct configuration_entry *config_entry;
        void    *mdata;

        query_process_func process_func;        /* called on each event */
        query_destroy_func destroy_func;        /* called on destroy */

        /*
         * By substituting these functions we can opaquely send and received
         * very large buffers
         */
        query_write_func write_func;            /* data write function */
        query_read_func read_func;              /* data read function */

        char    *eid_str;       /* the user-identifying string (euid_egid_) */
        size_t  eid_str_length;

        uid_t   euid;   /* euid of the caller, received via getpeereid */
        uid_t   uid;    /* uid of the caller, received via credentials */
        gid_t   egid;   /* egid of the caller, received via getpeereid */
        gid_t   gid;    /* gid of the caller received via credentials */

        size_t  io_buffer_size;
        size_t  io_buffer_watermark;
        size_t  kevent_watermark;       /* bytes to be sent/received */
        int     sockfd;                 /* the unix socket to read/write */
        int     kevent_filter;  /* EVFILT_READ or EVFILT_WRITE */
        int socket_failed; /* set to 1 if the socket doesn't work correctly */

        /*
         * These fields are used to opaquely proceed sending/receiving of
         * the large buffers
         */
        char    *io_buffer;
        char    *io_buffer_p;
        int     io_buffer_filter;
        int     use_alternate_io;
};

int check_query_eids(struct query_state *);

ssize_t query_io_buffer_read(struct query_state *, void *, size_t);
ssize_t query_io_buffer_write(struct query_state *, const void *, size_t);

ssize_t query_socket_read(struct query_state *, void *, size_t);
ssize_t query_socket_write(struct query_state *, const void *, size_t);

struct query_state *init_query_state(int, size_t, uid_t, gid_t);
void destroy_query_state(struct query_state *);

#endif