Mercurial > urweb
changeset 2300:57f6473b1469
More work on heuristics.
author | Ziv Scully <ziv@mit.edu> |
---|---|
date | Thu, 19 Nov 2015 18:13:01 -0500 (2015-11-19) |
parents | 47d5c94aeeb8 |
children | 8d772fbf59c1 |
files | src/sqlcache.sml |
diffstat | 1 files changed, 33 insertions(+), 8 deletions(-) [+] |
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--- a/src/sqlcache.sml Thu Nov 19 17:29:47 2015 -0500 +++ b/src/sqlcache.sml Thu Nov 19 18:13:01 2015 -0500 @@ -93,11 +93,13 @@ fun setCache c = cacheRef := c fun getCache () = !cacheRef -datatype heuristic = Always | Never | NoPureAll | NoPureOne | NoCombo +datatype heuristic = SmartEq (* | SmartSub *) | Always | Never | NoPureAll | NoPureOne | NoCombo val heuristicRef = ref Always fun setHeuristic h = heuristicRef := (case h of - "always" => Always + "smarteq" => SmartEq + (* | "smartsub" => SmartSub *) + | "always" => Always | "never" => Never | "nopureall" => NoPureAll | "nopureone" => NoPureOne @@ -613,13 +615,13 @@ val union = op@ + fun addToSqlArgsMap ((q, subst), acc) = + IM.foldl (fn (arg, acc) => AM.insert (acc, arg, ())) acc subst + fun sqlArgsMap (qs : t) = let val args = - List.foldl (fn ((q, subst), acc) => - IM.foldl (fn (arg, acc) => AM.insert (acc, arg, ())) acc subst) - AM.empty - qs + List.foldl addToSqlArgsMap AM.empty qs val countRef = ref (~1) fun count () = (countRef := !countRef + 1; !countRef) in @@ -647,8 +649,31 @@ val pureArgs = PS.difference (paths, invalPaths) val shouldCache = case getHeuristic () of - Always => true - | Never => (case qs of [_] => true | _ => false) + SmartEq => + (case (qs, PS.numItems pureArgs) of + ((q::qs), 0) => + let + val m = addToSqlArgsMap (q, AM.empty) + val ms = map (fn q => addToSqlArgsMap (q, AM.empty)) qs + fun test (m, acc) = + acc + <\obind\> + (fn m' => + let + val mm = AM.unionWith #1 (m, m') + in + AM.numItems m = AM.numItems mm + <\oguard\> + (fn _ => SOME mm) + end) + in + case List.foldl test (SOME m) ms of + NONE => false + | SOME _ => true + end + | _ => false) + | Always => true + | Never => (case qs of [_] => PS.numItems pureArgs = 0 | _ => false) | NoPureAll => (case qs of [] => false | _ => true) | NoPureOne => (case qs of [] => false | _ => PS.numItems pureArgs = 0) | NoCombo => PS.numItems pureArgs = 0 orelse AM.numItems argsMap = 0