emqx/src/emqx_batch.erl

92 lines
2.8 KiB
Erlang

%%--------------------------------------------------------------------
%% Copyright (c) 2018-2022 EMQ Technologies Co., Ltd. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%--------------------------------------------------------------------
-module(emqx_batch).
%% APIs
-export([ init/1
, push/2
, commit/1
, size/1
, items/1
]).
-export_type([options/0, batch/0]).
-record(batch, {
batch_size :: non_neg_integer(),
batch_q :: list(any()),
linger_ms :: pos_integer(),
linger_timer :: reference() | undefined,
commit_fun :: function()
}).
-type(options() :: #{
batch_size => non_neg_integer(),
linger_ms => pos_integer(),
commit_fun := function()
}).
-opaque(batch() :: #batch{}).
%%--------------------------------------------------------------------
%% APIs
%%--------------------------------------------------------------------
-spec(init(options()) -> batch()).
init(Opts) when is_map(Opts) ->
#batch{batch_size = maps:get(batch_size, Opts, 1000),
batch_q = [],
linger_ms = maps:get(linger_ms, Opts, 1000),
commit_fun = maps:get(commit_fun, Opts)}.
-spec(push(any(), batch()) -> batch()).
push(El, Batch = #batch{batch_q = Q,
linger_ms = Ms,
linger_timer = undefined})
when length(Q) == 0 ->
TRef = erlang:send_after(Ms, self(), batch_linger_expired),
Batch#batch{batch_q = [El], linger_timer = TRef};
%% no limit.
push(El, Batch = #batch{batch_size = 0, batch_q = Q}) ->
Batch#batch{batch_q = [El|Q]};
push(El, Batch = #batch{batch_size = MaxSize, batch_q = Q})
when length(Q) >= MaxSize ->
commit(Batch#batch{batch_q = [El|Q]});
push(El, Batch = #batch{batch_q = Q}) ->
Batch#batch{batch_q = [El|Q]}.
-spec(commit(batch()) -> batch()).
commit(Batch = #batch{batch_q = Q, commit_fun = Commit}) ->
_ = Commit(lists:reverse(Q)),
reset(Batch).
reset(Batch = #batch{linger_timer = TRef}) ->
_ = emqx_misc:cancel_timer(TRef),
Batch#batch{batch_q = [], linger_timer = undefined}.
-spec(size(batch()) -> non_neg_integer()).
size(#batch{batch_q = Q}) ->
length(Q).
-spec(items(batch()) -> list(any())).
items(#batch{batch_q = Q}) ->
lists:reverse(Q).