improve cache datastruct using keys-queue

This commit is contained in:
terry-xiaoyu 2018-08-26 12:40:23 +08:00
parent a904031979
commit 8cd20744be
4 changed files with 123 additions and 137 deletions

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@ -436,11 +436,12 @@ acl_file = {{ platform_etc_dir }}/acl.conf
## The ACL cache size
## The maximum count of ACL entries allowed for a client.
##
## Value 0 disables ACL cache
##
## Value: Integer
## Default: 100
acl_cache_size = 100
## Default: 32
acl_cache_max_size = 32
## The ACL cache time-to-live.
## The time after which an ACL cache entry will be invalid

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@ -578,8 +578,8 @@ end}.
]}.
%% @doc ACL cache size.
{mapping, "acl_cache_size", "emqx.acl_cache_size", [
{default, 100},
{mapping, "acl_cache_max_size", "emqx.acl_cache_max_size", [
{default, 32},
{datatype, integer}
]}.

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@ -26,11 +26,13 @@
-export([get_acl_cache/2,
put_acl_cache/3,
delete_acl_cache/2,
cleanup_acl_cache/0,
dump_acl_cache/0,
get_cache_size/0,
get_newest_key/0
get_newest_key/0,
get_oldest_key/0,
cache_k/2,
cache_v/1
]).
%% gen_server callbacks
@ -221,158 +223,124 @@ if_existed(_Mod, _Fun) ->
%% ACL cache
%%--------------------------------------------------------------------
%% We'll cleanup the cache before repalcing an expired acl.
-spec(get_acl_cache(PubSub :: publish | subscribe, Topic :: topic())
-> (acl_result() | not_found)).
get_acl_cache(PubSub, Topic) ->
case erlang:get({PubSub, Topic}) of
case erlang:get(cache_k(PubSub, Topic)) of
undefined -> not_found;
{AclResult, CachedAt, _NextK, _PrevK} ->
if_acl_cache_expired(CachedAt,
{AclResult, CachedAt} ->
if_expired(CachedAt,
fun(false) ->
AclResult;
(true) ->
%% this expired entry will get updated in
%% put_acl_cache/3
cleanup_acl_cache(),
not_found
end)
end.
%% If the cache get full, and also the latest one
%% is expired, then delete all the cache entries
-spec(put_acl_cache(PubSub :: publish | subscribe,
Topic :: topic(), AclResult :: acl_result()) -> ok).
put_acl_cache(PubSub, Topic, AclResult) ->
MaxSize = get_cache_max_size(), true = (MaxSize =/= 0),
Size = get_cache_size(),
if
Size =:= 0 ->
create_first(PubSub, Topic, AclResult);
Size < MaxSize ->
append(PubSub, Topic, AclResult);
add_acl_cache(PubSub, Topic, AclResult);
Size =:= MaxSize ->
%% when the cache get full, and also the latest one
%% is expired, we'll perform a cleanup.
NewestK = get_newest_key(),
{_AclResult, CachedAt, OldestK, _PrevK} = erlang:get(NewestK),
if_acl_cache_expired(CachedAt,
{_AclResult, CachedAt} = erlang:get(NewestK),
if_expired(CachedAt,
fun(true) ->
% try to cleanup first
cleanup_acl_cache(OldestK),
add_cache(PubSub, Topic, AclResult);
% all cache expired, cleanup first
empty_acl_cache(),
add_acl_cache(PubSub, Topic, AclResult);
(false) ->
% cache full, perform cache replacement
delete_acl_cache(OldestK),
append(PubSub, Topic, AclResult)
evict_acl_cache(),
add_acl_cache(PubSub, Topic, AclResult)
end)
end.
-spec(delete_acl_cache(PubSub :: publish | subscribe, Topic :: topic()) -> ok).
delete_acl_cache(PubSub, Topic) ->
delete_acl_cache(_K = {PubSub, Topic}).
delete_acl_cache(K) ->
case erlang:get(K) of
undefined -> ok;
{_AclResult, _CachedAt, NextK, PrevK} when NextK =:= PrevK ->
%% there is only one entry in the cache
erlang:erase(K),
decr_cache_size(),
set_newest_key(undefined);
{_AclResult, _CachedAt, NextK, PrevK} ->
update_next(PrevK, NextK),
update_prev(NextK, PrevK),
erlang:erase(K),
empty_acl_cache() ->
map_acl_cache(fun({CacheK, _CacheV}) ->
erlang:erase(CacheK)
end),
set_cache_size(0),
set_keys_queue(queue:new()).
decr_cache_size(),
NewestK = get_newest_key(),
if
K =:= NewestK -> set_newest_key(NextK);
true -> ok
end
evict_acl_cache() ->
{{value, OldestK}, RemKeys} = queue:out(get_keys_queue()),
set_keys_queue(RemKeys),
erlang:erase(OldestK),
decr_cache_size().
add_acl_cache(PubSub, Topic, AclResult) ->
K = cache_k(PubSub, Topic),
V = cache_v(AclResult),
case get(K) of
undefined -> add_new_acl(K, V);
{_AclResult, _CachedAt} ->
update_acl(K, V)
end.
%% evict all the exipired cache entries
add_new_acl(K, V) ->
erlang:put(K, V),
keys_queue_in(K),
incr_cache_size().
update_acl(K, V) ->
erlang:put(K, V),
keys_queue_update(K).
%% cleanup all the exipired cache entries
-spec(cleanup_acl_cache() -> ok).
cleanup_acl_cache() ->
case get_newest_key() of
undefined -> ok;
NewestK ->
{_AclResult, _CachedAt, OldestK, _PrevK} = erlang:get(NewestK),
cleanup_acl_cache(OldestK)
end.
cleanup_acl_cache(FromK) ->
case erlang:get(FromK) of
undefined -> ok;
{_AclResult, CachedAt, NextK, _PrevK} ->
if_acl_cache_expired(CachedAt,
fun(false) ->
ok;
set_keys_queue(
cleanup_acl_cache(get_keys_queue())).
cleanup_acl_cache(KeysQ) ->
case queue:out(KeysQ) of
{{value, OldestK}, RemKeys} ->
{_AclResult, CachedAt} = erlang:get(OldestK),
if_expired(CachedAt,
fun(false) -> KeysQ;
(true) ->
delete_acl_cache(FromK),
cleanup_acl_cache(NextK)
end)
erlang:erase(OldestK),
decr_cache_size(),
cleanup_acl_cache(RemKeys)
end);
{empty, KeysQ} -> KeysQ
end.
get_newest_key() ->
get_key(fun(KeysQ) -> queue:get_r(KeysQ) end).
get_oldest_key() ->
get_key(fun(KeysQ) -> queue:get(KeysQ) end).
get_key(Pick) ->
KeysQ = get_keys_queue(),
case queue:is_empty(KeysQ) of
true -> undefined;
false -> Pick(KeysQ)
end.
%% for test only
dump_acl_cache() ->
[R || R = {{SubPub, _T}, _Acl} <- get(), SubPub =:= publish
map_acl_cache(fun(Cache) -> Cache end).
map_acl_cache(Fun) ->
[Fun(R) || R = {{SubPub, _T}, _Acl} <- get(), SubPub =:= publish
orelse SubPub =:= subscribe].
add_cache(PubSub, Topic, AclResult) ->
Size = get_cache_size(),
MaxSize = get_cache_max_size(), true = (MaxSize =/= 0),
if
Size =:= 0 ->
create_first(PubSub, Topic, AclResult);
Size =:= MaxSize ->
OldestK = get_next_key(get_newest_key()),
delete_acl_cache(OldestK),
case get_cache_size() =:= 0 of
true -> create_first(PubSub, Topic, AclResult);
false -> append(PubSub, Topic, AclResult)
end;
true ->
append(PubSub, Topic, AclResult)
end.
create_first(PubSub, Topic, AclResult) ->
K = cache_k(PubSub, Topic),
V = cache_v(AclResult, _NextK = K, _PrevK = K),
erlang:put(K, V),
set_cache_size(1),
set_newest_key(K).
append(PubSub, Topic, AclResult) ->
%% try to update the existing one:
%% - we delete it and then append it at the tail
delete_acl_cache(PubSub, Topic),
case get_cache_size() =:= 0 of
true -> create_first(PubSub, Topic, AclResult);
false ->
NewestK = get_newest_key(),
OldestK = get_next_key(NewestK),
K = cache_k(PubSub, Topic),
V = cache_v(AclResult, OldestK, NewestK),
erlang:put(K, V),
update_next(NewestK, K),
update_prev(OldestK, K),
incr_cache_size(),
set_newest_key(K)
end.
get_next_key(K) ->
erlang:element(3, erlang:get(K)).
update_next(K, NextK) ->
NoNext = erlang:delete_element(3, erlang:get(K)),
erlang:put(K, erlang:insert_element(3, NoNext, NextK)).
update_prev(K, PrevK) ->
NoPrev = erlang:delete_element(4, erlang:get(K)),
erlang:put(K, erlang:insert_element(4, NoPrev, PrevK)).
cache_k(PubSub, Topic)-> {PubSub, Topic}.
cache_v(AclResult, NextK, PrevK)-> {AclResult, time_now(), NextK, PrevK}.
cache_v(AclResult)-> {AclResult, time_now()}.
get_cache_max_size() ->
application:get_env(emqx, acl_cache_size, 100).
application:get_env(emqx, acl_cache_max_size, 0).
get_cache_size() ->
case erlang:get(acl_cache_size) of
@ -386,15 +354,31 @@ decr_cache_size() ->
set_cache_size(N) ->
erlang:put(acl_cache_size, N), ok.
get_newest_key() ->
erlang:get(acl_cache_newest_key).
keys_queue_in(Key) ->
%% delete the key first if exists
KeysQ = get_keys_queue(),
set_keys_queue(queue:in(Key, KeysQ)).
set_newest_key(Key) ->
erlang:put(acl_cache_newest_key, Key), ok.
keys_queue_update(Key) ->
NewKeysQ = remove_key(Key, get_keys_queue()),
set_keys_queue(queue:in(Key, NewKeysQ)).
remove_key(Key, KeysQ) ->
queue:filter(fun
(K) when K =:= Key -> false; (_) -> true
end, KeysQ).
set_keys_queue(KeysQ) ->
erlang:put(acl_keys_q, KeysQ), ok.
get_keys_queue() ->
case erlang:get(acl_keys_q) of
undefined -> queue:new();
KeysQ -> KeysQ
end.
time_now() -> erlang:system_time(millisecond).
if_acl_cache_expired(CachedAt, Fun) ->
if_expired(CachedAt, Fun) ->
TTL = application:get_env(emqx, acl_cache_ttl, 60000),
Now = time_now(),
if (CachedAt + TTL) =< Now ->

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@ -22,6 +22,7 @@
-include("emqx.hrl").
-include_lib("common_test/include/ct.hrl").
-include_lib("eunit/include/eunit.hrl").
-define(AC, emqx_access_control).
@ -71,10 +72,10 @@ init_per_group(_Group, Config) ->
prepare_config(Group = access_control) ->
set_acl_config_file(Group),
application:set_env(emqx, acl_cache_size, 0);
application:set_env(emqx, acl_cache_max_size, 0);
prepare_config(Group = access_control_cache_mode) ->
set_acl_config_file(Group),
application:set_env(emqx, acl_cache_size, 100).
application:set_env(emqx, acl_cache_max_size, 100).
set_acl_config_file(_Group) ->
Rules = [{allow, {ipaddr, "127.0.0.1"}, subscribe, ["$SYS/#", "#"]},
@ -170,7 +171,7 @@ acl_cache_expiry(_) ->
ok.
acl_cache_full(_) ->
application:set_env(emqx, acl_cache_size, 1),
application:set_env(emqx, acl_cache_max_size, 1),
SelfUser = #client{id = <<"client1">>, username = <<"testuser">>},
allow = ?AC:check_acl(SelfUser, subscribe, <<"users/testuser/1">>),
@ -185,7 +186,7 @@ acl_cache_cleanup(_) ->
%% The acl cache will try to evict memory, if the size is full and the newest
%% cache entry is expired
application:set_env(emqx, acl_cache_ttl, 1000),
application:set_env(emqx, acl_cache_size, 2),
application:set_env(emqx, acl_cache_max_size, 2),
SelfUser = #client{id = <<"client1">>, username = <<"testuser">>},
allow = ?AC:check_acl(SelfUser, subscribe, <<"users/testuser/1">>),
@ -206,7 +207,7 @@ acl_cache_cleanup(_) ->
put_get_del_cache(_) ->
application:set_env(emqx, acl_cache_ttl, 300000),
application:set_env(emqx, acl_cache_size, 30),
application:set_env(emqx, acl_cache_max_size, 30),
not_found = ?AC:get_acl_cache(publish, <<"a">>),
ok = ?AC:put_acl_cache(publish, <<"a">>, allow),
@ -217,11 +218,11 @@ put_get_del_cache(_) ->
deny = ?AC:get_acl_cache(subscribe, <<"b">>),
2 = ?AC:get_cache_size(),
{subscribe, <<"b">>} = ?AC:get_newest_key().
?assertEqual(?AC:cache_k(subscribe, <<"b">>), ?AC:get_newest_key()).
cache_expiry(_) ->
application:set_env(emqx, acl_cache_ttl, 1000),
application:set_env(emqx, acl_cache_size, 30),
application:set_env(emqx, acl_cache_max_size, 30),
ok = ?AC:put_acl_cache(subscribe, <<"a">>, allow),
allow = ?AC:get_acl_cache(subscribe, <<"a">>),
@ -236,25 +237,25 @@ cache_expiry(_) ->
cache_update(_) ->
application:set_env(emqx, acl_cache_ttl, 300000),
application:set_env(emqx, acl_cache_size, 30),
application:set_env(emqx, acl_cache_max_size, 30),
[] = ?AC:dump_acl_cache(),
ok = ?AC:put_acl_cache(subscribe, <<"a">>, allow),
ok = ?AC:put_acl_cache(publish, <<"b">>, allow),
ok = ?AC:put_acl_cache(publish, <<"c">>, allow),
3 = ?AC:get_cache_size(),
{publish, <<"c">>} = ?AC:get_newest_key(),
?assertEqual(?AC:cache_k(publish, <<"c">>), ?AC:get_newest_key()),
%% update the 2nd one
ok = ?AC:put_acl_cache(publish, <<"b">>, allow),
%ct:pal("dump acl cache: ~p~n", [?AC:dump_acl_cache()]),
3 = ?AC:get_cache_size(),
{publish, <<"b">>} = ?AC:get_newest_key().
?assertEqual(?AC:cache_k(publish, <<"b">>), ?AC:get_newest_key()).
cache_full_replacement(_) ->
application:set_env(emqx, acl_cache_ttl, 300000),
application:set_env(emqx, acl_cache_size, 3),
application:set_env(emqx, acl_cache_max_size, 3),
ok = ?AC:put_acl_cache(subscribe, <<"a">>, allow),
ok = ?AC:put_acl_cache(publish, <<"b">>, allow),
ok = ?AC:put_acl_cache(publish, <<"c">>, allow),
@ -262,15 +263,15 @@ cache_full_replacement(_) ->
allow = ?AC:get_acl_cache(publish, <<"b">>),
allow = ?AC:get_acl_cache(publish, <<"c">>),
3 = ?AC:get_cache_size(),
{publish, <<"c">>} = ?AC:get_newest_key(),
?assertEqual(?AC:cache_k(publish, <<"c">>), ?AC:get_newest_key()),
ok = ?AC:put_acl_cache(publish, <<"d">>, deny),
3 = ?AC:get_cache_size(),
{publish, <<"d">>} = ?AC:get_newest_key(),
?assertEqual(?AC:cache_k(publish, <<"d">>), ?AC:get_newest_key()),
ok = ?AC:put_acl_cache(publish, <<"e">>, deny),
3 = ?AC:get_cache_size(),
{publish, <<"e">>} = ?AC:get_newest_key(),
?assertEqual(?AC:cache_k(publish, <<"e">>), ?AC:get_newest_key()),
not_found = ?AC:get_acl_cache(subscribe, <<"a">>),
not_found = ?AC:get_acl_cache(publish, <<"b">>),
@ -278,7 +279,7 @@ cache_full_replacement(_) ->
cache_cleanup(_) ->
application:set_env(emqx, acl_cache_ttl, 1000),
application:set_env(emqx, acl_cache_size, 30),
application:set_env(emqx, acl_cache_max_size, 30),
ok = ?AC:put_acl_cache(subscribe, <<"a">>, allow),
ok = ?AC:put_acl_cache(publish, <<"b">>, allow),
ok = ?AC:put_acl_cache(publish, <<"c">>, allow),
@ -290,7 +291,7 @@ cache_cleanup(_) ->
cache_full_cleanup(_) ->
application:set_env(emqx, acl_cache_ttl, 1000),
application:set_env(emqx, acl_cache_size, 3),
application:set_env(emqx, acl_cache_max_size, 3),
ok = ?AC:put_acl_cache(subscribe, <<"a">>, allow),
ok = ?AC:put_acl_cache(publish, <<"b">>, allow),
ok = ?AC:put_acl_cache(publish, <<"c">>, allow),