diff options
author | Pierre-Marie Pédrot <pierre-marie.pedrot@inria.fr> | 2016-08-22 17:13:14 +0200 |
---|---|---|
committer | Pierre-Marie Pédrot <pierre-marie.pedrot@inria.fr> | 2016-08-22 18:33:41 +0200 |
commit | fb9dfa53f2f71ed501be27213600143ee0b7554d (patch) | |
tree | bfa08ea579cbd794dffad281221298c336c6fdd3 /lib | |
parent | c38f0ff80f28624b3cbf4df1e317f133caa94d1d (diff) |
Fast path for set operations.
We consider an approximation of the size of sets before choosing the most
appropriate algorithm. This drastically affects some universe-polymorphic
code which was doing a lot of set operations on disimilar sizes.
Diffstat (limited to 'lib')
-rw-r--r-- | lib/cMap.ml | 6 | ||||
-rw-r--r-- | lib/cMap.mli | 3 | ||||
-rw-r--r-- | lib/hMap.ml | 101 |
3 files changed, 89 insertions, 21 deletions
diff --git a/lib/cMap.ml b/lib/cMap.ml index 4b058380c..ba0873ffa 100644 --- a/lib/cMap.ml +++ b/lib/cMap.ml @@ -34,6 +34,7 @@ sig val fold_right : (key -> 'a -> 'b -> 'b) -> 'a t -> 'b -> 'b val smartmap : ('a -> 'a) -> 'a t -> 'a t val smartmapi : (key -> 'a -> 'a) -> 'a t -> 'a t + val height : 'a t -> int module Unsafe : sig val map : (key -> 'a -> key * 'b) -> 'a t -> 'b t @@ -57,6 +58,7 @@ sig val fold_right : (M.t -> 'a -> 'b -> 'b) -> 'a map -> 'b -> 'b val smartmap : ('a -> 'a) -> 'a map -> 'a map val smartmapi : (M.t -> 'a -> 'a) -> 'a map -> 'a map + val height : 'a map -> int module Unsafe : sig val map : (M.t -> 'a -> M.t * 'b) -> 'a map -> 'b map @@ -168,6 +170,10 @@ struct if l == l' && r == r' && v == v' then s else map_inj (MNode (l', k, v', r', h)) + let height s = match map_prj s with + | MEmpty -> 0 + | MNode (_, _, _, _, h) -> h + module Unsafe = struct diff --git a/lib/cMap.mli b/lib/cMap.mli index 3ef7fa2c8..2838b374e 100644 --- a/lib/cMap.mli +++ b/lib/cMap.mli @@ -61,6 +61,9 @@ sig val smartmapi : (key -> 'a -> 'a) -> 'a t -> 'a t (** As [mapi] but tries to preserve sharing. *) + val height : 'a t -> int + (** An indication of the logarithmic size of a map *) + module Unsafe : sig val map : (key -> 'a -> key * 'b) -> 'a t -> 'b t diff --git a/lib/hMap.ml b/lib/hMap.ml index 778c366fd..ea76e7427 100644 --- a/lib/hMap.ml +++ b/lib/hMap.ml @@ -68,34 +68,91 @@ struct Int.Map.update h m s with Not_found -> s + let height s = Int.Map.height s + + let is_smaller s1 s2 = height s1 <= height s2 + 3 + + (** Assumes s1 << s2 *) + let fast_union s1 s2 = + let fold h s accu = + try Int.Map.modify h (fun _ s' -> Set.fold Set.add s s') accu + with Not_found -> Int.Map.add h s accu + in + Int.Map.fold fold s1 s2 + let union s1 s2 = - let fu _ m1 m2 = match m1, m2 with - | None, None -> None - | (Some _ as m), None | None, (Some _ as m) -> m - | Some m1, Some m2 -> Some (Set.union m1 m2) + if is_smaller s1 s2 then fast_union s1 s2 + else if is_smaller s2 s1 then fast_union s2 s1 + else + let fu _ m1 m2 = match m1, m2 with + | None, None -> None + | (Some _ as m), None | None, (Some _ as m) -> m + | Some m1, Some m2 -> Some (Set.union m1 m2) + in + Int.Map.merge fu s1 s2 + + (** Assumes s1 << s2 *) + let fast_inter s1 s2 = + let fold h s accu = + try + let s' = Int.Map.find h s2 in + let si = Set.filter (fun e -> Set.mem e s') s in + if Set.is_empty si then accu + else Int.Map.add h si accu + with Not_found -> accu in - Int.Map.merge fu s1 s2 + Int.Map.fold fold s1 Int.Map.empty let inter s1 s2 = - let fu _ m1 m2 = match m1, m2 with - | None, None -> None - | Some _, None | None, Some _ -> None - | Some m1, Some m2 -> - let m = Set.inter m1 m2 in - if Set.is_empty m then None else Some m + if is_smaller s1 s2 then fast_inter s1 s2 + else if is_smaller s2 s1 then fast_inter s2 s1 + else + let fu _ m1 m2 = match m1, m2 with + | None, None -> None + | Some _, None | None, Some _ -> None + | Some m1, Some m2 -> + let m = Set.inter m1 m2 in + if Set.is_empty m then None else Some m + in + Int.Map.merge fu s1 s2 + + (** Assumes s1 << s2 *) + let fast_diff_l s1 s2 = + let fold h s accu = + try + let s' = Int.Map.find h s2 in + let si = Set.filter (fun e -> not (Set.mem e s')) s in + if Set.is_empty si then accu + else Int.Map.add h si accu + with Not_found -> Int.Map.add h s accu + in + Int.Map.fold fold s1 Int.Map.empty + + (** Assumes s2 << s1 *) + let fast_diff_r s1 s2 = + let fold h s accu = + try + let s' = Int.Map.find h accu in + let si = Set.filter (fun e -> not (Set.mem e s)) s' in + if Set.is_empty si then Int.Map.remove h accu + else Int.Map.update h si accu + with Not_found -> accu in - Int.Map.merge fu s1 s2 + Int.Map.fold fold s2 s1 let diff s1 s2 = - let fu _ m1 m2 = match m1, m2 with - | None, None -> None - | (Some _ as m), None -> m - | None, Some _ -> None - | Some m1, Some m2 -> - let m = Set.diff m1 m2 in - if Set.is_empty m then None else Some m - in - Int.Map.merge fu s1 s2 + if is_smaller s1 s2 then fast_diff_l s1 s2 + else if is_smaller s2 s2 then fast_diff_r s1 s2 + else + let fu _ m1 m2 = match m1, m2 with + | None, None -> None + | (Some _ as m), None -> m + | None, Some _ -> None + | Some m1, Some m2 -> + let m = Set.diff m1 m2 in + if Set.is_empty m then None else Some m + in + Int.Map.merge fu s1 s2 let compare s1 s2 = Int.Map.compare Set.compare s1 s2 @@ -324,6 +381,8 @@ struct let fs m = Map.smartmapi f m in Int.Map.smartmap fs s + let height s = Int.Map.height s + module Unsafe = struct let map f s = |