diff options
Diffstat (limited to 'src/couchdb/couch_work_queue.erl')
| -rw-r--r-- | src/couchdb/couch_work_queue.erl | 61 |
1 files changed, 42 insertions, 19 deletions
diff --git a/src/couchdb/couch_work_queue.erl b/src/couchdb/couch_work_queue.erl index ca9445d3..3581aaf7 100644 --- a/src/couchdb/couch_work_queue.erl +++ b/src/couchdb/couch_work_queue.erl @@ -13,11 +13,11 @@ -module(couch_work_queue). -behaviour(gen_server). --export([new/2,queue/2,dequeue/1,close/1]). +-export([new/2,queue/2,dequeue/1,dequeue/2,close/1]). -export([init/1, terminate/2, handle_call/3, handle_cast/2, code_change/3, handle_info/2]). -record(q, { - buffer=[], + queue=queue:new(), blocked=[], max_size, max_items, @@ -34,7 +34,10 @@ queue(Wq, Item) -> gen_server:call(Wq, {queue, Item}, infinity). dequeue(Wq) -> - try gen_server:call(Wq, dequeue, infinity) + dequeue(Wq, all). + +dequeue(Wq, MaxItems) -> + try gen_server:call(Wq, {dequeue, MaxItems}, infinity) catch _:_ -> closed end. @@ -48,13 +51,13 @@ init({MaxSize,MaxItems}) -> terminate(_Reason, #q{work_waiter=nil}) -> ok; -terminate(_Reason, #q{work_waiter=WW}) -> - gen_server:reply(WW, closed). +terminate(_Reason, #q{work_waiter={WWFrom, _}}) -> + gen_server:reply(WWFrom, closed). handle_call({queue, Item}, From, #q{work_waiter=nil}=Q0) -> Q = Q0#q{size=Q0#q.size + byte_size(term_to_binary(Item)), items=Q0#q.items + 1, - buffer=[Item | Q0#q.buffer]}, + queue=queue:in(Item, Q0#q.queue)}, case (Q#q.size >= Q#q.max_size) orelse (Q#q.items >= Q#q.max_items) of true -> @@ -62,24 +65,44 @@ handle_call({queue, Item}, From, #q{work_waiter=nil}=Q0) -> false -> {reply, ok, Q} end; -handle_call({queue, Item}, _From, #q{work_waiter=WW}=Q) -> - gen_server:reply(WW, {ok, [Item]}), +handle_call({queue, Item}, _From, #q{work_waiter={WWFrom, _Max}}=Q) -> + gen_server:reply(WWFrom, {ok, [Item]}), {reply, ok, Q#q{work_waiter=nil}}; -handle_call(dequeue, _From, #q{work_waiter=WW}) when WW /= nil -> +handle_call({dequeue, _Max}, _From, #q{work_waiter=WW}) when WW /= nil -> exit("Only one caller allowed to wait for work at a time"); -handle_call(dequeue, From, #q{items=0}=Q) -> - {noreply, Q#q{work_waiter=From}}; -handle_call(dequeue, _From, #q{buffer=Buff, max_size=MaxSize, - max_items=MaxItems, close_on_dequeue=Close}=Q) -> - [gen_server:reply(From, ok) || From <- Q#q.blocked], - Q2 = #q{max_size=MaxSize, max_items=MaxItems}, - if Close -> - {stop, normal, {ok, Buff}, Q2}; +handle_call({dequeue, Max}, From, #q{items=0}=Q) -> + {noreply, Q#q{work_waiter={From, Max}}}; +handle_call({dequeue, Max}, _From, #q{queue=Queue, max_size=MaxSize, + max_items=MaxItems, items=Items,close_on_dequeue=Close}=Q) -> + if Max >= Items orelse Max == all -> + [gen_server:reply(From, ok) || From <- Q#q.blocked], + Q2 = #q{max_size=MaxSize, max_items=MaxItems}, + if Close -> + {stop, normal, {ok, queue:to_list(Queue)}, Q2}; + true -> + {reply, {ok, queue:to_list(Queue)}, Q2} + end; true -> - {reply, {ok, Buff}, #q{max_size=MaxSize, max_items=MaxItems}} + {DequeuedItems, Queue2, Blocked2} = + dequeue_items(Max, Queue, Q#q.blocked, []), + {reply, {ok, DequeuedItems}, + Q#q{items=Items-Max,blocked=Blocked2,queue=Queue2}} end. -handle_cast(close, #q{buffer=[]}=Q) -> +dequeue_items(0, Queue, Blocked, DequeuedAcc) -> + {lists:reverse(DequeuedAcc), Queue, Blocked}; +dequeue_items(NumItems, Queue, Blocked, DequeuedAcc) -> + {{value, Item}, Queue2} = queue:out(Queue), + case Blocked of + [] -> + Blocked2 = Blocked; + [From|Blocked2] -> + gen_server:reply(From, ok) + end, + dequeue_items(NumItems-1, Queue2, Blocked2, [Item | DequeuedAcc]). + + +handle_cast(close, #q{items=0}=Q) -> {stop, normal, Q}; handle_cast(close, Q) -> {noreply, Q#q{close_on_dequeue=true}}. |