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authorAnders Svensson <[email protected]>2017-08-24 20:35:27 +0200
committerAnders Svensson <[email protected]>2017-09-06 15:37:11 +0200
commitfae8ca0c37e54ad109b1612185d17dc5695bebcc (patch)
tree7cfed3bc1e9d6953fa3bfee33f1128af85c28abc /lib
parent257268ba6a2faa38032b2a2a1b6e0276103fca6b (diff)
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Simplify implementation in diameter_reg
Use maps instead of dict for traceability more than performance.
Diffstat (limited to 'lib')
-rw-r--r--lib/diameter/src/base/diameter_reg.erl251
1 files changed, 94 insertions, 157 deletions
diff --git a/lib/diameter/src/base/diameter_reg.erl b/lib/diameter/src/base/diameter_reg.erl
index cabe90ffe8..9ada36acc5 100644
--- a/lib/diameter/src/base/diameter_reg.erl
+++ b/lib/diameter/src/base/diameter_reg.erl
@@ -19,10 +19,11 @@
%%
%%
-%% The module implements a simple term -> pid registry.
+%% A simple term -> pid registry.
%%
-module(diameter_reg).
+
-behaviour(gen_server).
-export([add/1,
@@ -57,18 +58,18 @@
-type key() :: term().
-type from() :: {pid(), term()}.
+-type rcvr() :: [pid() | term()] %% subscribe
+ | from(). %% wait
-type pattern() :: term().
-record(state, {id = diameter_lib:now(),
- receivers = dict:new()
- :: dict:dict(pattern(), [[pid() | term()]%% subscribe
- | from()]), %% wait
+ notify = #{} :: #{pattern() => [rcvr()]},
monitors = sets:new() :: sets:set(pid())}).
%% The ?TABLE bag contains the Key -> Pid mapping, as {Key, Pid}
%% tuples. Each pid is stored in the monitors set to ensure only one
%% monitor for each pid: more are harmless, but unnecessary. A pattern
-%% is added to receivers a result of calls to wait/1 or subscribe/2:
+%% is added to notify a result of calls to wait/1 or subscribe/2:
%% changes to ?TABLE causes processes to be notified as required.
%% ===========================================================================
@@ -156,7 +157,7 @@ wait(Pat) ->
%% # subscribe(Pat, T)
%%
%% Like match/1, but additionally receive messages of the form
-%% {T, add|remove, {term(), pid()} when associations are added
+%% {T, add|remove, {term(), pid()}} when associations are added
%% or removed.
%% ===========================================================================
@@ -186,15 +187,12 @@ uptime() ->
-> [{pid(), [key()]}].
pids() ->
- to_list(fun swap/1).
-
-to_list(Fun) ->
- ets:foldl(fun(T,D) -> append(Fun(T), D) end, orddict:new(), ?TABLE).
-
-append({K,V}, Dict) ->
- orddict:append(K, V, Dict).
+ append(ets:select(?TABLE, [{{'$1','$2'}, [], [{{'$2', '$1'}}]}])).
-id(T) -> T.
+append(Pairs) ->
+ dict:to_list(lists:foldl(fun({K,V}, D) -> dict:append(K, V, D) end,
+ dict:new(),
+ Pairs)).
%% terms/0
@@ -202,9 +200,7 @@ id(T) -> T.
-> [{key(), [pid()]}].
terms() ->
- to_list(fun id/1).
-
-swap({X,Y}) -> {Y,X}.
+ append(ets:tab2list(?TABLE)).
%% subs/0
@@ -212,15 +208,9 @@ swap({X,Y}) -> {Y,X}.
-> [{pattern(), [{pid(), term()}]}].
subs() ->
- #state{receivers = RD} = state(),
- dict:fold(fun sub/3, orddict:new(), RD).
-
-sub(Pat, Ps, Dict) ->
- lists:foldl(fun([P|T], D) -> orddict:append(Pat, {P,T}, D);
- (_, D) -> D
- end,
- Dict,
- Ps).
+ #state{notify = Dict} = state(),
+ [{K, Ts} || {K,Ps} <- maps:to_list(Dict),
+ Ts <- [[{P,T} || [P|T] <- Ps]]].
%% waits/0
@@ -228,15 +218,9 @@ sub(Pat, Ps, Dict) ->
-> [{pattern(), [from()]}].
waits() ->
- #state{receivers = RD} = state(),
- dict:fold(fun wait/3, orddict:new(), RD).
-
-wait(Pat, Ps, Dict) ->
- lists:foldl(fun({_,_} = F, D) -> orddict:append(Pat, F, D);
- (_, D) -> D
- end,
- Dict,
- Ps).
+ #state{notify = Dict} = state(),
+ [{K, Ts} || {K,Ps} <- maps:to_list(Dict),
+ Ts <- [[T || {_,_} = T <- Ps]]].
%% ----------------------------------------------------------
%% # init/1
@@ -250,33 +234,28 @@ init(_) ->
%% # handle_call/3
%% ----------------------------------------------------------
-handle_call({add, Uniq, Key}, {Pid, _}, S0) ->
+handle_call({add, Uniq, Key}, {Pid, _}, S) ->
Rec = {Key, Pid},
- S1 = flush(Uniq, Rec, S0),
+ NS = flush(Uniq, Rec, S), %% before insert
{Res, New} = insert(Uniq, Rec),
- {Recvs, S} = add(New, Rec, S1),
- notify(Recvs, Rec),
- {reply, Res, S};
+ {reply, Res, notify(add, New andalso Rec, NS)};
handle_call({remove, Key}, {Pid, _}, S) ->
Rec = {Key, Pid},
- Recvs = delete([Rec], S),
ets:delete_object(?TABLE, Rec),
- notify(Recvs, remove),
- {reply, true, S};
+ {reply, true, notify(remove, Rec, S)};
-handle_call({wait, Pat}, {Pid, _} = From, #state{receivers = RD} = S) ->
+handle_call({wait, Pat}, {Pid, _} = From, S) ->
NS = add_monitor(Pid, S),
case match(Pat) of
- [_|_] = L ->
- {reply, L, NS};
+ [_|_] = Recs ->
+ {reply, Recs, NS};
[] ->
- {noreply, NS#state{receivers = dict:append(Pat, From, RD)}}
+ {noreply, queue(Pat, From, NS)}
end;
-handle_call({subscribe, Pat, T}, {Pid, _}, #state{receivers = RD} = S) ->
- NS = add_monitor(Pid, S),
- {reply, match(Pat), NS#state{receivers = dict:append(Pat, [Pid | T], RD)}};
+handle_call({subscribe, Pat, T}, {Pid, _}, S) ->
+ {reply, match(Pat), queue(Pat, [Pid | T], add_monitor(Pid, S))};
handle_call(state, _, S) ->
{reply, S, S};
@@ -332,106 +311,62 @@ insert(true, Rec) ->
B = ets:insert_new(?TABLE, Rec), %% entry inserted?
{B, B}.
-%% add/3
-
+%% add_monitor/2
+%%
%% Only add a single monitor for any given process, since there's no
%% use to more.
-add(true, {_Key, Pid} = Rec, S) ->
- NS = add_monitor(Pid, S),
- {Recvs, RD} = add(Rec, NS),
- {Recvs, NS#state{receivers = RD}};
-
-add(false = No, _, S) ->
- {No, S}.
-
-%% add/2
-
-%% Notify processes whose patterns match the inserted key.
-add({_Key, Pid} = Rec, #state{receivers = RD}) ->
- dict:fold(fun(Pt, Ps, A) ->
- add(lists:member(Rec, match(Pt, Pid)), Pt, Ps, Rec, A)
- end,
- {sets:new(), RD},
- RD).
-
-%% add/5
-add(true, Pat, Recvs, {_,_} = Rec, {Set, Dict}) ->
- {lists:foldl(fun sets:add_element/2, Set, Recvs),
- remove(fun erlang:is_list/1, Pat, Recvs, Dict)};
-
-add(false, _, _, _, Acc) ->
+add_monitor(Pid, #state{monitors = Ps} = S) ->
+ case sets:is_element(Pid, Ps) of
+ false ->
+ monitor(process, Pid),
+ S#state{monitors = sets:add_element(Pid, Ps)};
+ true ->
+ S
+ end.
+
+%% notify/3
+
+notify(_, false, S) ->
+ S;
+
+notify(Op, {_,_} = Rec, #state{notify = Dict} = S) ->
+ S#state{notify = maps:fold(fun(P,Rs,D) -> notify(Op, Rec, P, Rs, D) end,
+ Dict,
+ Dict)}.
+
+%% notify/5
+
+notify(Op, {_, Pid} = Rec, Pat, Rcvrs, Dict) ->
+ case lists:member(Rec, match(Pat, Pid)) of
+ true ->
+ reset(Pat, Dict, lists:foldr(fun(P,A) -> send(P, Op, Rec, A) end,
+ [],
+ Rcvrs));
+ false ->
+ Dict
+ end.
+
+%% send/4
+
+send([Pid | T] = Rcvr, Op, Rec, Acc) ->
+ Pid ! {T, Op, Rec},
+ [Rcvr | Acc];
+
+%% No processes wait on remove: they receive notification immediately
+%% or at add, by construction.
+send({_,_} = From, add, Rec, Acc) ->
+ gen_server:reply(From, [Rec]),
Acc.
-%% add_monitor/2
-
-add_monitor(Pid, #state{monitors = MS} = S) ->
- add_monitor(sets:is_element(Pid, MS), Pid, S).
-
-%% add_monitor/3
-
-add_monitor(false, Pid, #state{monitors = MS} = S) ->
- monitor(process, Pid),
- S#state{monitors = sets:add_element(Pid, MS)};
-
-add_monitor(true, _, S) ->
- S.
-
-%% delete/2
-
-delete(Recs, #state{receivers = RD}) ->
- lists:foldl(fun(R,S) -> delete(R, RD, S) end, sets:new(), Recs).
-
-%% delete/3
-
-delete({_Key, Pid} = Rec, RD, Set) ->
- dict:fold(fun(Pt, Ps, S) ->
- delete(lists:member(Rec, match(Pt, Pid)), Rec, Ps, S)
- end,
- Set,
- RD).
-
-%% delete/4
-
-%% Entry matches a pattern ...
-delete(true, Rec, Recvs, Set) ->
- lists:foldl(fun(R,S) -> sets:add_element({R, Rec}, S) end,
- Set,
- Recvs);
-
-%% ... or not.
-delete(false, _, _, Set) ->
- Set.
-
-%% notify/2
-
-notify(false = No, _) ->
- No;
-
-notify(Recvs, remove = Op) ->
- sets:fold(fun({P,R}, N) -> send(P, R, Op), N+1 end, 0, Recvs);
-
-notify(Recvs, {_,_} = Rec) ->
- sets:fold(fun(P,N) -> send(P, Rec, add), N+1 end, 0, Recvs).
-
-%% send/3
-
-%% No processes waiting on remove, by construction: they've either
-%% received notification at add or aren't waiting.
-send([Pid | T], Rec, Op) ->
- Pid ! {T, Op, Rec};
-
-send({_,_} = From, Rec, add) ->
- gen_server:reply(From, [Rec]).
-
%% down/2
-down(Pid, #state{monitors = MS} = S) ->
- NS = flush(Pid, S),
- Recvs = delete(match('_', Pid), NS),
+down(Pid, #state{monitors = Ps} = S) ->
+ Recs = match('_', Pid),
ets:match_delete(?TABLE, {'_', Pid}),
- notify(Recvs, remove),
- NS#state{monitors = sets:del_element(Pid, MS)}.
+ lists:foldl(fun(R,NS) -> notify(remove, R, NS) end,
+ flush(Pid, S#state{monitors = sets:del_element(Pid, Ps)}),
+ Recs).
%% flush/3
@@ -452,16 +387,15 @@ flush(false, _, S) ->
%% flush/2
%% Process has died and should no longer receive messages/replies.
-flush(Pid, #state{receivers = RD} = S)
- when is_pid(Pid) ->
- S#state{receivers = dict:fold(fun(Pt,Ps,D) -> flush(Pid, Pt, Ps, D) end,
- RD,
- RD)}.
+flush(Pid, #state{notify = Dict} = S) ->
+ S#state{notify = maps:fold(fun(P,Rs,D) -> flush(Pid, P, Rs, D) end,
+ Dict,
+ Dict)}.
%% flush/4
-flush(Pid, Pat, Recvs, Dict) ->
- remove(fun(T) -> Pid /= head(T) end, Pat, Recvs, Dict).
+flush(Pid, Pat, Rcvrs, Dict) ->
+ reset(Pat, Dict, [T || T <- Rcvrs, Pid /= head(T)]).
%% head/1
@@ -471,15 +405,18 @@ head([P|_]) ->
head({P,_}) ->
P.
-%% remove/4
+%% reset/3
+
+reset(Key, Map, []) ->
+ maps:remove(Key, Map);
+
+reset(Key, Map, List) ->
+ maps:put(Key, List, Map).
+
+%% queue/3
-remove(Pred, Key, Values, Dict) ->
- case lists:filter(Pred, Values) of
- [] ->
- dict:erase(Key, Dict);
- Rest ->
- dict:store(Key, Rest, Dict)
- end.
+queue(Pat, Rcvr, #state{notify = Dict} = S) ->
+ S#state{notify = maps:put(Pat, [Rcvr | maps:get(Pat, Dict, [])], Dict)}.
%% call/1