mirror of
https://github.com/berkeleydb/libdb.git
synced 2024-11-17 01:26:25 +00:00
89 lines
2.6 KiB
Erlang
89 lines
2.6 KiB
Erlang
%%% The Registry is a gen_server process that keeps track of the
|
|
%%% currently active set of connection-path processes. The listeners
|
|
%%% add the processes to the list as they're created. The manager
|
|
%%% looks stuff up in order to send commands to the proper place.
|
|
%%%
|
|
%%% For each path we know the two sockets involved, and the
|
|
%%% process(es) reading from them.
|
|
%%%
|
|
%%% A munger looks like either a simple atom (if the rule applies to
|
|
%%% any and all connections paths), or an atom tagged with a path ID
|
|
%%% (like {{6001,6000},page_clog}), which means the rule only applies
|
|
%%% to that path.
|
|
%%%
|
|
%%% Note that "Count" is a count of the number of paths we've *ever*
|
|
%%% registered, not the current length of the list. (Otherwise I
|
|
%%% would have simply called lists:length/1 when needed.)
|
|
|
|
-module(registry).
|
|
-behaviour(gen_server).
|
|
-export([start/0,lookup/1,register/4,unregister/1,all/0]).
|
|
-export([init/1, handle_call/3]).
|
|
-export([code_change/3,handle_cast/2,handle_info/2,terminate/2]).
|
|
|
|
start() ->
|
|
{ok,_Pid} = gen_server:start({local,registry}, registry, [], []),
|
|
ok.
|
|
|
|
init(_) ->
|
|
{ok,{[],0}}.
|
|
|
|
|
|
%%% TODO: see manager.erl - I think we should get rid of sock and fwd
|
|
%%% from here.
|
|
|
|
handle_call({register,Path,Sock,Fwd, Pid}, _From, State) ->
|
|
{Paths,Count} = State,
|
|
{reply, ok, {[{Count,Path,Sock,Fwd,Pid}|Paths],Count+1}};
|
|
|
|
handle_call({lookup,Query}, _, State) ->
|
|
{Paths,_Count} = State,
|
|
Index = if
|
|
is_tuple(Query) ->
|
|
2; % Path desc, like {6001,6000}
|
|
true ->
|
|
1 % unique serial ID number
|
|
end,
|
|
case lists:keysearch(Query, Index, Paths) of
|
|
{value, Tpl} ->
|
|
{reply, {ok,Tpl}, State};
|
|
false ->
|
|
{reply, notfound, State}
|
|
end;
|
|
|
|
handle_call({unregister,Path}, _, State) ->
|
|
{Paths,Count} = State,
|
|
{reply, ok, {lists:keydelete(Path, 2, Paths),Count}};
|
|
|
|
handle_call(all, _, State) ->
|
|
{Paths,_Count} = State,
|
|
{reply, Paths, State}.
|
|
|
|
lookup(Query) ->
|
|
gen_server:call(registry, {lookup, Query}).
|
|
|
|
register(Path, Sock, Fwd, Pid) ->
|
|
gen_server:call(registry, {register, Path, Sock, Fwd, Pid}).
|
|
|
|
unregister(Path) ->
|
|
gen_server:call(registry, {unregister, Path}).
|
|
|
|
all() ->
|
|
gen_server:call(registry, all).
|
|
|
|
%%%
|
|
%%% The following functions defined in the gen_server behavior are not
|
|
%%% used. But we include them in order to avoid distracting
|
|
%%% compilation warnings.
|
|
%%%
|
|
code_change(_,_,_) ->
|
|
ok.
|
|
|
|
handle_cast(_,_) ->
|
|
ok.
|
|
|
|
handle_info(_,_) ->
|
|
ok.
|
|
|
|
terminate(_,_) ->
|
|
ok.
|