1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
structure Sqlcache :> SQLCACHE = struct
open Sql
open Mono
structure IS = IntBinarySet
structure IM = IntBinaryMap
structure StringKey = struct type ord_key = string val compare = String.compare end
structure SS = BinarySetFn (StringKey)
structure SM = BinaryMapFn (StringKey)
structure SIMM = MultimapFn (structure KeyMap = SM structure ValSet = IS)
val ffiIndices : int list ref = ref []
(* Expression construction utilities. *)
fun intExp (n, loc) = (EPrim (Prim.Int (Int64.fromInt n)), loc)
fun intTyp loc = (TFfi ("Basis", "int"), loc)
fun boolPat (b, loc) = (PCon (Enum,
PConFfi {mod = "Basis", datatyp = "bool", arg = NONE,
con = if b then "True" else "False"},
NONE),
loc)
fun boolTyp loc = (TFfi ("Basis", "int"), loc)
fun ffiAppExp (module, func, index, loc) =
(EFfiApp (module, func ^ Int.toString index, []), loc)
fun sequence ((exp :: exps), loc) =
List.foldl (fn (exp, seq) => (ESeq (seq, exp), loc)) exp exps
fun antiguardUnit (cond, exp, loc) =
(ECase (cond,
[(boolPat (false, loc), exp),
(boolPat (true, loc), (ERecord [], loc))],
{disc = boolTyp loc, result = (TRecord [], loc)}),
loc)
fun underAbs f (exp as (exp', loc)) =
case exp' of
EAbs (x, y, z, body) => (EAbs (x, y, z, underAbs f body), loc)
| _ => f exp
(* Program analysis and augmentation. *)
val rec tablesRead =
fn Query1 {From=tablePairs, ...} => SS.fromList (map #1 tablePairs)
| Union (q1,q2) => SS.union (tablesRead q1, tablesRead q2)
val tableWritten =
fn Insert (tab, _) => tab
| Delete (tab, _) => tab
| Update (tab, _, _) => tab
fun tablesInExp' exp' =
let
val nothing = {read = SS.empty, written = SS.empty}
in
case exp' of
EQuery {query=e, ...} =>
(case parse query e of
SOME q => {read = tablesRead q, written = SS.empty}
| NONE => nothing)
| EDml (e, _) =>
(case parse dml e of
SOME q => {read = SS.empty, written = SS.singleton (tableWritten q)}
| NONE => nothing)
| _ => nothing
end
val tablesInExp =
let
fun addTables (exp', {read, written}) =
let val {read = r, written = w} = tablesInExp' exp'
in {read = SS.union (r, read), written = SS.union (w, written)} end
in
MonoUtil.Exp.fold {typ = #2, exp = addTables}
{read = SS.empty, written = SS.empty}
end
fun addCacheCheck (index, exp) =
let
fun f (body as (_, loc)) =
let
val check = ffiAppExp ("Cache", "check", index, loc)
val store = ffiAppExp ("Cache", "store", index, loc)
in
antiguardUnit (check, sequence ([body, store], loc), loc)
end
in
underAbs f exp
end
fun addCacheFlush (exp, tablesToIndices) =
let
fun addIndices (table, indices) = IS.union (indices, SIMM.find (tablesToIndices, table))
fun f (body as (_, loc)) =
let
fun mapFfi func = List.map (fn i => ffiAppExp ("Cache", func, i, loc))
val flushes =
IS.listItems (SS.foldr addIndices IS.empty (#written (tablesInExp body)))
in
sequence (mapFfi "flush" flushes @ [body] @ mapFfi "ready" flushes, loc)
end
in
underAbs f exp
end
val handlerIndices =
let
val isUnit =
fn (TRecord [], _) => true
| _ => false
fun maybeAdd (d, soFar as {readers, writers}) =
case d of
DExport (Link ReadOnly, _, name, typs, typ, _) =>
if List.all isUnit (typ::typs)
then {readers = IS.add (readers, name), writers = writers}
else soFar
| DExport (_, _, name, _, _, _) => (* Not read only. *)
{readers = readers, writers = IS.add (writers, name)}
| _ => soFar
in
MonoUtil.File.fold {typ = #2, exp = #2, decl = maybeAdd}
{readers = IS.empty, writers = IS.empty}
end
fun fileFoldMapiSelected f init (file, indices) =
let
fun doExp (original as ((a, index, b, exp, c), state)) =
if IS.member (indices, index)
then let val (newExp, newState) = f (index, exp, state)
in ((a, index, b, newExp, c), newState) end
else original
fun doDecl decl state =
let
val result =
case decl of
DVal x =>
let val (y, newState) = doExp (x, state)
in (DVal y, newState) end
| DValRec xs =>
let val (ys, newState) = ListUtil.foldlMap doExp state xs
in (DValRec ys, newState) end
| _ => (decl, state)
in
Search.Continue result
end
fun nada x y = Search.Continue (x, y)
in
case MonoUtil.File.mapfold {typ = nada, exp = nada, decl = doDecl} file init of
Search.Continue x => x
| _ => (file, init) (* Should never happen. *)
end
fun fileMapSelected f = #1 o fileFoldMapiSelected (fn (_, x, _) => (f x, ())) ()
val addCacheChecking =
let
fun f (index, exp, tablesToIndices) =
(addCacheCheck (index, exp),
SS.foldr (fn (table, tsToIs) => SIMM.insert (tsToIs, table, index))
tablesToIndices
(#read (tablesInExp exp)))
in
fileFoldMapiSelected f (SM.empty)
end
fun addCacheFlushing (file, tablesToIndices, writers) =
fileMapSelected (fn exp => addCacheFlush (exp, tablesToIndices)) (file, writers)
fun go file =
let
val {readers, writers} = handlerIndices file
val (fileWithChecks, tablesToIndices) = addCacheChecking (file, readers)
in
ffiIndices := IS.listItems readers;
addCacheFlushing (fileWithChecks, tablesToIndices, writers)
end
end
|
