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Fix predictable strategy

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In the case where a merge results in an output
file that fits in the current level, we will
normally just leave it here; but with if said
level already has a C-file, then we will not
see enough merge steps to actually finish merging
in time.
This commit is contained in:
Kresten Krab Thorup 2012-07-31 15:24:58 +02:00
parent e59c3d7add
commit 166a127a43
1 changed files with 13 additions and 12 deletions
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25
src/hanoidb_level.erl
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@ -546,7 +546,8 @@ main_loop(State = #state{ next=Next }) ->
main_loop(State2#state{ a = AFile, c = undefined, merge_pid=undefined })
end;
?CAST(_From,{merge_done, Count, OutFileName}) when Count =< ?BTREE_SIZE(State#state.level) ->
?CAST(_From,{merge_done, Count, OutFileName})
when Count =< ?BTREE_SIZE(State#state.level), State#state.c =:= undefined ->
?log("merge_done, out:~w~n -> self", [Count]),
@ -666,17 +667,17 @@ do_step(StepFrom, PreviousWork, StepSize, State) ->
%% heuristic doesn't work when there are aggressive deletes (expiry or delete).
%% https://github.com/basho/hanoidb/issues/7
WorkToDoHere =
min(WorkLeftHere, WorkUnitsLeft),
%% case hanoidb:get_opt( merge_strategy, State#state.opts, fast) of
%% fast ->
%% min(WorkLeftHere, WorkUnitsLeft);
%% predictable ->
%% if (WorkLeftHere < Depth * WorkUnit) ->
%% min(WorkLeftHere, WorkUnit);
%% true ->
%% min(WorkLeftHere, WorkUnitsLeft)
%% end
%% end,
%% min(WorkLeftHere, WorkUnitsLeft),
case hanoidb:get_opt( merge_strategy, State#state.opts, fast) of
fast ->
min(WorkLeftHere, WorkUnitsLeft);
predictable ->
if (WorkLeftHere < Depth * WorkUnit) ->
min(WorkLeftHere, WorkUnit);
true ->
min(WorkLeftHere, WorkUnitsLeft)
end
end,
WorkIncludingHere = PreviousWork + WorkToDoHere,
?log("do_step prev:~p, do:~p of ~p ~n", [PreviousWork, WorkToDoHere, WorkLeftHere]),