diff options
| author |  Ziv Scully <ziv@mit.edu> | 2015-11-19 18:13:01 -0500 |
|---|---|---|
| committer | Ziv Scully <ziv@mit.edu> | 2015-11-19 18:13:01 -0500 |
| commit | ff19a9c86b380918f50e294848be06f29b2ba1dd (patch) | |
| tree | b085c4af87bc8dbb854754793c6968f3a6b3c395 | |
| parent | 94b1dbce1ae20ded6b2e8cc519f56ac9e3b39b24 (diff) | |
More work on heuristics.
| -rw-r--r-- | src/sqlcache.sml | 41 |
1 files changed, 33 insertions, 8 deletions
diff --git a/src/sqlcache.sml b/src/sqlcache.sml index 312ee217..b2c8504b 100644 --- a/src/sqlcache.sml +++ b/src/sqlcache.sml @@ -93,11 +93,13 @@ val cacheRef = ref LruCache.cache 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 @@ end = struct 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 @@ end = struct 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 |