src/lib/player/dispatch.c

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/*
 *  Empire - A multi-player, client/server Internet based war game.
 *  Copyright (C) 1986-2007, Dave Pare, Jeff Bailey, Thomas Ruschak,
 *                           Ken Stevens, Steve McClure
 *
 *  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
 *
 *  ---
 *
 *  See files README, COPYING and CREDITS in the root of the source
 *  tree for related information and legal notices.  It is expected
 *  that future projects/authors will amend these files as needed.
 *
 *  ---
 *
 *  dispatch.c: Actually execute the command given
 * 
 *  Known contributors to this file:
 *     Dave Pare, 1994
 *     Steve McClure, 1998
 *     Markus Armbruster, 2007
 */

#include <config.h>

#include "com.h"
#include "empio.h"
#include "file.h"
#include "match.h"
#include "misc.h"
#include "nat.h"
#include "optlist.h"
#include "player.h"
#include "proto.h"
#include "prototypes.h"
#include "server.h"

/*
 * Execute command named by player->argp[0].
 * BUF is the raw UTF-8 command line.  It should have been passed to
 * parse() to set up player->argp.
 * If REDIR is not null, it's the command's redirection, in UTF-8.
 * Return -1 if the command is not unique or doesn't exist, else 0.
 */
int
dispatch(char *buf, char *redir)
{
    struct natstr *np;
    struct cmndstr *command;
    int cmd;

    cmd = comtch(player->argp[0], player_coms, player->nstat);
    if (cmd < 0) {
        if (cmd == M_NOTUNIQUE)
            pr("Command \"%s\" is ambiguous -- ", player->argp[0]);
        else if (cmd == M_IGNORE)
            return 0;
        else
            pr("\"%s\" is not a legal command\n", player->argp[0]);
        return -1;
    }
    command = &player_coms[cmd];
    np = getnatp(player->cnum);
    if (np->nat_btu < command->c_cost && command->c_cost > 0) {
        if (player->god || opt_BLITZ)
            np->nat_btu = max_btus;
        else {
            pr("You don't have the BTU's, bozo\n");
            return 0;
        }
    }
    if (command->c_addr == 0) {
        pr("Command not implemented\n");
        return 0;
    }
    /*
     * Rwlocks can hand out read locks while a write lock is wanted.
     * Unfair to writers, but possible.  This lets commands run with
     * !player->aborted, which can then block on input and thus delay
     * the update indefinitely.  We could avoid that by setting
     * player->aborted here, but spinning until the update is done is
     * nicer to players.
     */
    while (play_wrlock_wanted)
        empth_yield();
    player->command = command;
    empth_rwlock_rdlock(play_lock);
    if (redir) {
        prredir(redir);
        uprnf(buf);
        pr("\n");
    }
    switch (command->c_addr()) {
    case RET_OK:
        player->btused += command->c_cost;
        break;
    case RET_FAIL:
        pr("command failed\n");
        player->btused += command->c_cost;
        break;
    case RET_SYN:
        pr("Usage: %s\n", command->c_form);
        break;
    case RET_SYS:
        logerror("System error, command failed: %s", command->c_form);
        break;
    default:
        CANT_REACH();
        break;
    }
    empth_rwlock_unlock(play_lock);
    player->command = NULL;
    return 0;
}

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