From 66a529ba84c7280142400fd9ca4cfa8d31639978 Mon Sep 17 00:00:00 2001 From: Greg Taylor Date: Mon, 15 Dec 2008 01:10:26 +0000 Subject: [PATCH] The command handler has been completely overhauled and is actually readable now. It -might- be a little faster as well. It's not really that point in development to start micro-optimizing, so I haven't ran any benchmarks. Our command evaluation now mirrors MUX2's. It was kind of weird before now, I'm not really sure how it got so out of order. In any case, I'm no longer ashamed of our command handler code. Hooray. --- src/cmdhandler.py | 254 ++++++++++++++++++++++++++++------------------ src/session.py | 22 +++- 2 files changed, 175 insertions(+), 101 deletions(-) diff --git a/src/cmdhandler.py b/src/cmdhandler.py index 7e1fd61b83..782fbbc914 100755 --- a/src/cmdhandler.py +++ b/src/cmdhandler.py @@ -11,13 +11,17 @@ import defines_global import cmdtable import logger import comsys -from util import functions_general class UnknownCommand(Exception): """ Throw this when a user enters an an invalid command. """ pass +class ExitCommandHandler(Exception): + """ + Thrown when something happens and it's time to exit the command handler. + """ + pass class Command(object): # Reference to the master server object. @@ -32,6 +36,8 @@ class Command(object): command_switches = [] # The un-parsed argument provided. IE: if input is "look dog", this is "dog". command_argument = None + # A reference to the command function looked up in a command table. + command_function = None def parse_command_switches(self): """ @@ -56,6 +62,14 @@ class Command(object): """ (self.command_string, self.command_argument) = self.raw_input.split(' ', 1) self.command_argument = self.command_argument.strip() + self.command_string = self.command_string.strip() + """ + This is a really important behavior to note. If the user enters + anything other than a string with some character in it, the value + of the argument is None, not an empty string. + """ + if self.command_string == '': + self.command_string = None if self.command_argument == '': self.command_argument = None except ValueError: @@ -68,9 +82,13 @@ class Command(object): self.parse_command_switches() def __init__(self, raw_input, server=None, session=None): + """ + Instantiates the Command object and does some preliminary parsing. + """ self.server = server self.raw_input = raw_input self.session = session + # The work starts here. self.parse_command() def arg_has_target(self): @@ -105,14 +123,111 @@ class Command(object): return self.command_argument.split('=', 1)[1] -def match_exits(pobject, searchstr): +def match_idle(command): + """ + Matches against the 'idle' command. It doesn't actually do anything, but it + lets the users get around badly configured NAT timeouts that would cause + them to drop if they don't send or receive something from the connection + for a while. + """ + if not command.command_string == 'idle': + # Anything other than an 'idle' command updates the public-facing idle + # time for the session. + command.session.count_command(silently=False) + else: + # User is hitting IDLE command. Don't update their publicly + # facing idle time, drop out of command handler immediately. + command.session.count_command(silently=True) + raise ExitCommandHandler + +def match_exits(command): """ See if we can find an input match to exits. """ + # If we're not logged in, don't check exits. + pobject = command.session.get_pobject() exits = pobject.get_location().get_contents(filter_type=defines_global.OTYPE_EXIT) - return Object.objects.list_search_object_namestr(exits, - searchstr, + exit_matches = Object.objects.list_search_object_namestr(exits, + command.command_string, match_type="exact") + if exit_matches: + # Only interested in the first match. + targ_exit = exit_matches[0] + # An exit's home is its destination. If the exit has a None home value, + # it's not traversible. + if targ_exit.get_home(): + # SCRIPT: See if the player can traverse the exit + if not targ_exit.scriptlink.default_lock({ + "pobject": pobject + }): + command.session.msg("You can't traverse that exit.") + else: + pobject.move_to(targ_exit.get_home()) + # Force the player to 'look' to see the description. + command.session.execute_cmd("look") + else: + command.session.msg("That exit leads to nowhere.") + # We found a match, kill the command handler. + raise ExitCommandHandler + +def match_alias(command): + """ + Checks to see if the entered command matches an alias. If so, replaces + the command_string with the correct command. + + We do a dictionary lookup. If the key (the player's command_string) doesn't + exist on the dict, just keep the command_string the same. If the key exists, + its value replaces the command_string. For example, sa -> say. + """ + command.command_string = command.server.cmd_alias_list.get( + command.command_string, + command.command_string) + +def match_channel(command): + """ + Match against a comsys channel or comsys command. If the player is talking + over a channel, replace command_string with @cemit. If they're entering + a channel manipulation command, perform the operation and kill the things + immediately with a True value sent back to the command handler. + """ + if comsys.plr_has_channel(command.session, command.command_string, + alias_search=True, return_muted=True): + + calias = command.command_string + cname = comsys.plr_cname_from_alias(command.session, calias) + + if command.command_argument == "who": + comsys.msg_cwho(command.session, cname) + raise ExitCommandHandler + elif command.command_argument == "on": + comsys.plr_chan_on(command.session, calias) + raise ExitCommandHandler + elif command.command_argument == "off": + comsys.plr_chan_off(command.session, calias) + raise ExitCommandHandler + elif command.command_argument == "last": + comsys.msg_chan_hist(command.session, cname) + ExitCommandHandler + + second_arg = "%s=%s" % (cname, command.command_argument) + command.command_string = "@cemit" + command.command_switches = ["sendername", "quiet"] + +def command_table_lookup(command, command_table, eval_perms=True): + """ + Performs a command table lookup on the specified command table. Also + evaluates the permissions tuple. + """ + # Get the command's function reference (Or False) + cmdtuple = command_table.get_command_tuple(command.command_string) + if cmdtuple: + # If there is a permissions element to the entry, check perms. + if eval_perms and cmdtuple[1]: + if not command.session.get_pobject().user_has_perm_list(cmdtuple[1]): + command.session.msg(defines_global.NOPERMS_MSG) + raise ExitCommandHandler + # If flow reaches this point, user has perms and command is ready. + command.command_function = cmdtuple[0] def handle(command): """ @@ -128,113 +243,58 @@ def handle(command): try: # TODO: Protect against non-standard characters. - if command.raw_input == '': + if not command.command_string: # Nothing sent in of value, ignore it. - return - - # Now we'll see if the user is using an alias. We do a dictionary lookup, - # if the key (the player's command_string) doesn't exist on the dict, - # just keep the command_string the same. If the key exists, its value - # replaces the command_string. For example, sa -> say. - command.command_string = server.cmd_alias_list.get( - command.command_string, - command.command_string) - - # This will hold the reference to the command's function. - cmd = None + raise ExitCommandHandler if session.logged_in: - # Store the timestamp of the user's last command. - session.cmd_last = time.time() - - # Lets the users get around badly configured NAT timeouts. - if command.command_string == 'idle': - return - - # Increment our user's command counter. - session.cmd_total += 1 - # Player-visible idle time, not used in idle timeout calcs. - session.cmd_last_visible = time.time() - - # Just in case. Prevents some really funky-case crashes. - if len(command.command_string) == 0: - raise UnknownCommand - - if comsys.plr_has_channel(session, command.command_string, - alias_search=True, return_muted=True): - - calias = command.command_string - cname = comsys.plr_cname_from_alias(session, calias) - - if command.command_argument == "who": - comsys.msg_cwho(session, cname) - return - elif command.command_argument == "on": - comsys.plr_chan_on(session, calias) - return - elif command.command_argument == "off": - comsys.plr_chan_off(session, calias) - return - elif command.command_argument == "last": - comsys.msg_chan_hist(session, cname) - return - - second_arg = "%s=%s" % (cname, command.command_argument) - command.command_string = "@cemit" - command.command_switches = ["sendername", "quiet"] - - # Get the command's function reference (Or False) - cmdtuple = cmdtable.GLOBAL_CMD_TABLE.get_command_tuple(command.command_string) - if cmdtuple: - # If there is a permissions element to the entry, check perms. - if cmdtuple[1]: - if not session.get_pobject().user_has_perm_list(cmdtuple[1]): - session.msg(defines_global.NOPERMS_MSG) - return - # If flow reaches this point, user has perms and command is ready. - cmd = cmdtuple[0] - + # Match against the 'idle' command. + match_idle(command) + # See if this is an aliased command. + match_alias(command) + # Check if the user is using a channel command. + match_channel(command) + # See if the user is trying to traverse an exit. + match_exits(command) + # Retrieve the appropriate (if any) command function. + command_table_lookup(command, cmdtable.GLOBAL_CMD_TABLE) else: # Not logged in, look through the unlogged-in command table. - cmdtuple = cmdtable.GLOBAL_UNCON_CMD_TABLE.get_command_tuple(command.command_string) - if cmdtuple: - cmd = cmdtuple[0] - - # Debugging stuff. - #session.msg("ROOT : %s" % (parsed_input['root_cmd'],)) - #session.msg("SPLIT: %s" % (parsed_input['splitted'],)) + command_table_lookup(command, cmdtable.GLOBAL_UNCON_CMD_TABLE, + eval_perms=False) - if callable(cmd): + """ + By this point, we assume that the user has entered a command and not + something like a channel or exit. Make sure that the command's + function reference is value and try to run it. + """ + if callable(command.command_function): try: - cmd(command) + # Move to the command function, passing the command object. + command.command_function(command) except: - session.msg("Untrapped error, please file a bug report:\n%s" % (format_exc(),)) + """ + This is a crude way of trapping command-related exceptions + and showing them to the user and server log. Once the + codebase stabilizes, we will probably want something more + useful or give them the option to hide exception values. + """ + session.msg("Untrapped error, please file a bug report:\n%s" % + (format_exc(),)) logger.log_errmsg("Untrapped error, evoker %s: %s" % (session, format_exc())) - return - - if session.logged_in: - # If we're not logged in, don't check exits. - pobject = session.get_pobject() - exit_matches = match_exits(pobject, command.command_string) - if exit_matches: - targ_exit = exit_matches[0] - if targ_exit.get_home(): - # SCRIPT: See if the player can traverse the exit - if not targ_exit.scriptlink.default_lock({ - "pobject": pobject - }): - session.msg("You can't traverse that exit.") - else: - pobject.move_to(targ_exit.get_home()) - session.execute_cmd("look") - else: - session.msg("That exit leads to nowhere.") - return + finally: + # Prevent things from falling through to UnknownCommand. + raise ExitCommandHandler # If we reach this point, we haven't matched anything. raise UnknownCommand + except ExitCommandHandler: + # When this is thrown, just get out and do nothing. It doesn't mean + # something bad has happened. + pass except UnknownCommand: + # Default fall-through. No valid command match. session.msg("Huh? (Type \"help\" for help.)") diff --git a/src/session.py b/src/session.py index 90b1395fd1..7220546048 100755 --- a/src/session.py +++ b/src/session.py @@ -90,10 +90,24 @@ class SessionProtocol(StatefulTelnetProtocol): cmdhandler.handle(command) def execute_cmd(self, cmdstr): - """ - Executes a command as this session. - """ - self.lineReceived(data=cmdstr) + """ + Executes a command as this session. + """ + self.lineReceived(data=cmdstr) + + def count_command(self, silently=False): + """ + Hit this when the user enters a command in order to update idle timers + and command counters. If silently is True, the public-facing idle time + is not updated. + """ + # Store the timestamp of the user's last command. + self.cmd_last = time.time() + # Increment the user's command counter. + self.cmd_total += 1 + if not silently: + # Player-visible idle time, not used in idle timeout calcs. + self.cmd_last_visible = time.time() def handle_close(self): """