From 2432fb4e038012e03ca0f52e3ee664aa2e5b18ec Mon Sep 17 00:00:00 2001 From: Francesco Mazzoli Date: Wed, 11 Apr 2012 14:58:28 +0100 Subject: Specialised set difference function for dtree. --- src/dtree.erl | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'src') diff --git a/src/dtree.erl b/src/dtree.erl index 8eff0644..0e0785bf 100644 --- a/src/dtree.erl +++ b/src/dtree.erl @@ -91,8 +91,7 @@ take(PKs, SK, {P, S}) -> none -> {[], {P, S}}; {value, PKS} -> TakenPKS = gb_sets:from_list(PKs), PKSInter = gb_sets:intersection(PKS, TakenPKS), - PKSDiff = - rabbit_misc:gb_sets_difference(PKS, TakenPKS), + PKSDiff = gb_sets_difference_unsafe(PKS, TakenPKS), {KVs, P1} = take2(PKSInter, SK, P), {KVs, {P1, case gb_sets:is_empty(PKSDiff) of true -> gb_trees:delete(SK, S); @@ -153,9 +152,14 @@ take_all2(PKS, P) -> prune(SKS, PKS, S) -> gb_sets:fold(fun (SK0, S0) -> PKS1 = gb_trees:get(SK0, S0), - PKS2 = rabbit_misc:gb_sets_difference(PKS1, PKS), + PKS2 = gb_sets_difference_unsafe(PKS1, PKS), case gb_sets:is_empty(PKS2) of true -> gb_trees:delete(SK0, S0); false -> gb_trees:update(SK0, PKS2, S0) end end, S, SKS). + +%% This function assumes that all the elements we're deleting from the +%% first set are present. +gb_sets_difference_unsafe(S1, S2) -> + lists:foldl(fun gb_sets:delete/2, S1, gb_sets:to_list(S2)). -- cgit v1.2.1