Mercurial > urweb
changeset 1212:fc33072c4d33
Replaced Select predicate with special-case handling for one-or-no-rows queries
| author | Adam Chlipala <adamc@hcoop.net> |
|---|---|
| date | Tue, 06 Apr 2010 15:17:28 -0400 |
| parents | 1d4d65245dd3 |
| children | e791d93d4616 |
| files | src/iflow.sml |
| diffstat | 1 files changed, 167 insertions(+), 106 deletions(-) [+] |
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--- a/src/iflow.sml Tue Apr 06 13:59:16 2010 -0400 +++ b/src/iflow.sml Tue Apr 06 15:17:28 2010 -0400 @@ -82,7 +82,7 @@ | And of prop * prop | Or of prop * prop | Reln of reln * exp list - | Select of int * lvar * lvar * prop * exp + | Cond of exp * prop local open Print @@ -162,14 +162,13 @@ p_prop p2, string ")"] | Reln (r, es) => p_reln r es - | Select (n1, n2, n3, p, e) => box [string ("select(x" ^ Int.toString n1 - ^ ",X" ^ Int.toString n2 - ^ ",X" ^ Int.toString n3 - ^ "){"), - p_prop p, - string "}{", - p_exp e, - string "}"] + | Cond (e, p) => box [string "(", + p_exp e, + space, + string "==", + space, + p_prop p, + string ")"] end @@ -185,36 +184,6 @@ end end -fun subExp (v, lv) = - let - fun sub e = - case e of - Const _ => e - | Var v' => if v' = v then Lvar lv else e - | Lvar _ => e - | Func (f, es) => Func (f, map sub es) - | Recd xes => Recd (map (fn (x, e) => (x, sub e)) xes) - | Proj (e, s) => Proj (sub e, s) - | Finish => Finish - in - sub - end - -fun subProp (v, lv) = - let - fun sub p = - case p of - True => p - | False => p - | Unknown => p - | And (p1, p2) => And (sub p1, sub p2) - | Or (p1, p2) => Or (sub p1, sub p2) - | Reln (r, es) => Reln (r, map (subExp (v, lv)) es) - | Select (v1, lv1, lv2, p, e) => Select (v1, lv1, lv2, sub p, subExp (v, lv) e) - in - sub - end - fun isKnown e = case e of Const _ => true @@ -280,6 +249,15 @@ Proj (e', s)) | Finish => Finish +datatype atom = + AReln of reln * exp list + | ACond of exp * prop + +fun p_atom a = + p_prop (case a of + AReln x => Reln x + | ACond x => Cond x) + fun decomp fals or = let fun decomp p k = @@ -293,8 +271,8 @@ k (ps1 @ ps2))) | Or (p1, p2) => or (decomp p1 k, fn () => decomp p2 k) - | Reln x => k [x] - | Select _ => k [] + | Reln x => k [AReln x] + | Cond x => k [ACond x] in decomp end @@ -314,6 +292,51 @@ lvi end +fun lvarInP lv = + let + fun lvi p = + case p of + True => false + | False => false + | Unknown => true + | And (p1, p2) => lvi p1 orelse lvi p2 + | Or (p1, p2) => lvi p1 orelse lvi p2 + | Reln (_, es) => List.exists (lvarIn lv) es + | Cond (e, p) => lvarIn lv e orelse lvi p + in + lvi + end + +fun varIn lv = + let + fun lvi e = + case e of + Const _ => false + | Lvar _ => false + | Var lv' => lv' = lv + | Func (_, es) => List.exists lvi es + | Recd xes => List.exists (lvi o #2) xes + | Proj (e, _) => lvi e + | Finish => false + in + lvi + end + +fun varInP lv = + let + fun lvi p = + case p of + True => false + | False => false + | Unknown => false + | And (p1, p2) => lvi p1 orelse lvi p2 + | Or (p1, p2) => lvi p1 orelse lvi p2 + | Reln (_, es) => List.exists (varIn lv) es + | Cond (e, p) => varIn lv e orelse lvi p + in + lvi + end + fun eq' (e1, e2) = case (e1, e2) of (Const p1, Const p2) => Prim.equal (p1, p2) @@ -399,32 +422,6 @@ NONE => e | SOME (_, e2) => lookup (t, e2) -fun assert (t, e1, e2) = - let - val r1 = lookup (t, e1) - val r2 = lookup (t, e2) - in - if eq (r1, r2) then - t - else - (r1, r2) :: t - end - -open Print - -fun query (t, e1, e2) = - (if !debug then - prefaces "CC query" [("e1", p_exp (simplify e1)), - ("e2", p_exp (simplify e2)), - ("t", p_list (fn (e1, e2) => box [p_exp (simplify e1), - space, - PD.string "->", - space, - p_exp (simplify e2)]) t)] - else - (); - eq (lookup (t, e1), lookup (t, e2))) - fun allPeers (t, e) = let val r = lookup (t, e) @@ -440,6 +437,49 @@ end) t end +fun assert (t, e1, e2) = + let + val r1 = lookup (t, e1) + val r2 = lookup (t, e2) + + fun doUn (t', e1, e2) = + case e2 of + Func (f, [e]) => + if String.isPrefix "un" f then + let + val f' = String.extract (f, 2, NONE) + in + foldl (fn (e', t') => + case e' of + Func (f'', [e'']) => + if f'' = f' then + (lookup (t', e1), e'') :: t' + else + t' + | _ => t') t' (allPeers (t, e)) + end + else + t' + | _ => t' + in + if eq (r1, r2) then + t + else + doUn (doUn ((r1, r2) :: t, e1, e2), e2, e1) + end + +open Print + +fun query (t, e1, e2) = + ((*prefaces "CC query" [("e1", p_exp (simplify e1)), + ("e2", p_exp (simplify e2)), + ("t", p_list (fn (e1, e2) => box [p_exp (simplify e1), + space, + PD.string "->", + space, + p_exp (simplify e2)]) t)];*) + eq (lookup (t, e1), lookup (t, e2))) + end fun rimp cc ((r1, es1), (r2, es2)) = @@ -504,13 +544,14 @@ let val cc = foldl (fn (p, cc) => case p of - (Eq, [e1, e2]) => Cc.assert (cc, e1, e2) + AReln (Eq, [e1, e2]) => Cc.assert (cc, e1, e2) | _ => cc) Cc.empty hyps fun gls goals onFail = case goals of [] => true - | g :: goals => + | ACond _ :: _ => false + | AReln g :: goals => case (doKnown, g) of (false, (Known, _)) => gls goals onFail | _ => @@ -518,7 +559,8 @@ fun hps hyps = case hyps of [] => onFail () - | h :: hyps => + | ACond _ :: hyps => hps hyps + | AReln h :: hyps => let val saved = save () in @@ -540,8 +582,8 @@ orelse hps hyps end in - if List.exists (fn (DtCon c1, [e]) => - List.exists (fn (DtCon c2, [e']) => + if List.exists (fn AReln (DtCon c1, [e]) => + List.exists (fn AReln (DtCon c2, [e']) => c1 <> c2 andalso Cc.query (cc, e, e') | _ => false) hyps @@ -553,9 +595,9 @@ orelse gls goals (fn () => false) then true else - (Print.prefaces "Can't prove" - [("hyps", Print.p_list (fn x => p_prop (Reln x)) hyps), - ("goals", Print.p_list (fn x => p_prop (Reln x)) goals)]; + ((*Print.prefaces "Can't prove" + [("hyps", Print.p_list p_atom hyps), + ("goals", Print.p_list p_atom goals)];*) false) end)) in @@ -569,8 +611,6 @@ PConVar n => "C" ^ Int.toString n | PConFfi {mod = m, datatyp = d, con = c, ...} => m ^ "." ^ d ^ "." ^ c - - datatype chunk = String of string | Exp of Mono.exp @@ -871,6 +911,10 @@ x :: ls end +datatype queryMode = + SomeCol of exp + | AllCols of exp + fun queryProp env rv oe e = case parse query e of NONE => (print ("Warning: Information flow checker can't parse SQL query at " @@ -899,7 +943,7 @@ Reln (Sql t, [Recd (foldl (fn ((v', f), fs) => if v' = v then - (f, Proj (Proj (Lvar rv, v), f)) :: fs + (f, Proj (Proj (rv, v), f)) :: fs else fs) [] allUsed)]))) True (#From r) @@ -907,7 +951,7 @@ fun expIn e = case e of SqConst p => inl (Const p) - | Field (v, f) => inl (Proj (Proj (Lvar rv, v), f)) + | Field (v, f) => inl (Proj (Proj (rv, v), f)) | Binop (bo, e1, e2) => inr (case (bo, expIn e1, expIn e2) of (Exps f, inl e1, inl e2) => f (e1, e2) @@ -931,7 +975,7 @@ inl (case expIn e of inl e => Func (f, [e]) | _ => raise Fail ("Iflow: non-expresion passed to function " ^ f)) - | Count => inl (Func ("COUNT", [])) + | Count => inl (Proj (rv, "$COUNT")) val p = case #Where r of NONE => p @@ -940,13 +984,12 @@ inr p' => And (p, p') | _ => p in - (case oe of - NONE => p - | SOME oe => - And (p, foldl (fn (si, p) => + (And (p, case oe of + SomeCol oe => + foldl (fn (si, p) => let val p' = case si of - SqField (v, f) => Reln (Eq, [oe, Proj (Proj (Lvar rv, v), f)]) + SqField (v, f) => Reln (Eq, [oe, Proj (Proj (rv, v), f)]) | SqExp (e, f) => case expIn e of inr _ => Unknown @@ -954,11 +997,25 @@ in Or (p, p') end) - False (#Select r)), + False (#Select r) + | AllCols oe => + foldl (fn (si, p) => + let + val p' = case si of + SqField (v, f) => Reln (Eq, [Proj (Proj (oe, v), f), + Proj (Proj (rv, v), f)]) + | SqExp (e, f) => + case expIn e of + inr p => Cond (Proj (oe, f), p) + | inl e => Reln (Eq, [Proj (oe, f), e]) + in + And (p, p') + end) + True (#Select r)), case #Where r of NONE => [] - | SOME e => map (fn (v, f) => Proj (Proj (Lvar rv, v), f)) (usedFields e)) + | SOME e => map (fn (v, f) => Proj (Proj (rv, v), f)) (usedFields e)) end fun evalPat env e (pt, _) = @@ -996,9 +1053,7 @@ | (And (x1, y1), And (x2, y2)) => peq (x1, x2) andalso peq (y1, y2) | (Or (x1, y1), Or (x2, y2)) => peq (x1, x2) andalso peq (y1, y2) | (Reln (r1, es1), Reln (r2, es2)) => r1 = r2 andalso ListPair.allEq eeq (es1, es2) - | (Select (n1, n2, n3, p1, e1), Select (n1', n2', n3', p2, e2)) => - n1 = n1' andalso n2 = n2' andalso n3 = n3' - andalso peq (p1, p2) andalso eeq (e1, e2) + | (Cond (e1, p1), Cond (e2, p2)) => eeq (e1, e2) andalso peq (p1, p2) | _ => false fun removeRedundant p1 = @@ -1010,7 +1065,6 @@ case p2 of And (x, y) => And (rr x, rr y) | Or (x, y) => Or (rr x, rr y) - | Select (n1, n2, n3, p, e) => Select (n1, n2, n3, rr p, e) | _ => p2 in rr @@ -1164,28 +1218,35 @@ val (i, st) = evalExp env (i, st) val r = #1 st - val acc = #1 st + 1 - val st' = (#1 st + 2, #2 st, #3 st) + val rv = #1 st + 1 + val acc = #1 st + 2 + val st' = (#1 st + 3, #2 st, #3 st) val (b, st') = evalExp (Var acc :: Var r :: env) (b, st') - val r' = newLvar () - val acc' = newLvar () - val (qp, used) = queryProp env r' NONE q + val (qp, used) = queryProp env (Var rv) (AllCols (Var r)) q - val doSubExp = subExp (r, r') o subExp (acc, acc') - val doSubProp = subProp (r, r') o subProp (acc, acc') + val p' = And (qp, #2 st') - val p = doSubProp (#2 st') - val p' = And (p, qp) - val p = Select (r, r', acc', p', doSubExp b) + val (nvs, p, res) = if varInP acc (#2 st') then + (#1 st + 1, #2 st, Var r) + else + let + val out = #1 st' - val sent = map (fn (loc, e, p) => (loc, - doSubExp e, - And (qp, doSubProp p))) (#3 st') + val p = Or (Reln (Eq, [Var out, i]), + And (Reln (Eq, [Var out, b]), + And (Reln (Gt, [Proj (Var rv, "$COUNT"), + Const (Prim.Int 0)]), + p'))) + in + (out + 1, p, Var out) + end + + val sent = map (fn (loc, e, p) => (loc, e, And (qp, p))) (#3 st') val sent = map (fn e => (loc, e, p')) used @ sent in - (Var r, (#1 st + 1, And (#2 st, p), sent)) + (res, (nvs, p, sent)) end | EDml _ => default () | ENextval _ => default () @@ -1231,7 +1292,7 @@ (sent @ vals, pols) end - | DPolicy (PolQuery e) => (vals, #1 (queryProp [] 0 (SOME (Var 0)) e) :: pols) + | DPolicy (PolQuery e) => (vals, #1 (queryProp [] (Lvar 0) (SomeCol (Var 0)) e) :: pols) | _ => (vals, pols)