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|
(*
* Bit Matrix routines
*)
structure RaBitmatrix : RA_BITMATRIX = struct
structure W = Word
structure A = Array
structure UA = Unsafe.Array
datatype bitMatrix =
BM of {table:hashTable,
elems:int ref,
edges:int}
and hashTable =
SMALL of word list Array.array ref * word
| LARGE of bucket Array.array ref * word
(* | BITMATRIX of Word8Array.array *)
and bucket = NIL | B of int * int * bucket
exception Nodes
fun hashFun(i, j, shift, size) =
let val i = W.fromInt i
val j = W.fromInt j
val h = W.+(W.<<(i, shift), W.+(i, j))
val mask = W.-(W.fromInt size, 0w1)
in W.toIntX(W.andb(h, mask)) end
val empty = BM{table=SMALL(ref(A.array(2, [])), 0w0), elems=ref 0, edges=0}
(*
val indices = A.array(1024,0)
fun init(i,j) =
if i < 1024 then
(A.update(indices, i, j); init(i+1, i+j+1))
else ()
val _ = init(0, 0)
*)
fun size (BM{elems, ...}) = !elems
fun edges(BM{table=SMALL(ref table, _), ...}) = A.length table
| edges(BM{table=LARGE(ref table, _), ...}) = A.length table
(*| edges(BM{table=BITMATRIX _, edges, ...}) = edges *)
fun member(BM{table=SMALL(table, shift), ...}) =
(fn (i, j) =>
let val (i,j) = if i < j then (i, j) else (j, i)
val k = W.+(W.<<(W.fromInt i, 0w15), W.fromInt j)
fun find [] = false
| find(k'::b) = k = k' orelse find b
val tab = !table
in find(UA.sub(tab, hashFun(i, j, shift, A.length tab))) end
)
| member(BM{table=LARGE(table, shift), ...}) =
(fn (i, j) =>
let val (i,j) = if i < j then (i, j) else (j, i)
fun find NIL = false
| find(B(i',j',b)) = i = i' andalso j = j' orelse find b
val tab = !table
in find(UA.sub(tab, hashFun(i, j, shift, A.length tab))) end
)
(*
| member(BM{table=BITMATRIX table, ...}) =
(fn (i, j) =>
let val (i,j) = if i > j then (i, j) else (j, i)
val bit = W.fromInt(UA.sub(indices, i) + j)
val index = W.toIntX(W.>>(bit, 0w3))
val mask = W.<<(0w1, W.andb(bit, 0w7))
in W.andb(W.fromInt(W8.toInt(UW8A.sub(table, index))), mask) <> 0w0
end
)
*)
fun add (BM{table=SMALL(table, shift), elems, ...}) =
let fun insert(i, j) =
let val (i,j) = if i < j then (i, j) else (j, i)
val tab = !table
val len = A.length tab
in if !elems < len then
let val index = hashFun(i, j, shift, len)
val k = W.+(W.<<(W.fromInt i, 0w15), W.fromInt j)
fun find [] = false
| find(k'::b) = k = k' orelse find b
val b = UA.sub(tab, index)
in if find b then false
else (UA.update(tab, index, k::b);
elems := !elems + 1; true)
end
else (* grow table *)
let val oldTable = tab
val oldSize = A.length oldTable
val newSize = oldSize + oldSize
val newTable = A.array(newSize,[])
fun enter n =
if n < oldSize then
let fun loop([],a,b) =
(UA.update(newTable, n, a);
UA.update(newTable, n + oldSize, b);
enter(n+1))
| loop(k::l,a,b) =
let val i = W.toIntX(W.>>(k, 0w15))
val j = W.toIntX(W.-(k,W.<<(W.fromInt i, 0w15)))
in if hashFun(i, j, shift, newSize) = n
then loop(l, k::a, b)
else loop(l, a, k::b)
end
in loop(UA.sub(oldTable, n), [], []) end
else ()
in table := newTable;
enter 0;
insert(i, j)
end
end
in insert
end
| add (BM{table=LARGE(table, shift), elems, ...}) =
let fun insert(i, j) =
let val (i,j) = if i < j then (i, j) else (j, i)
val tab = !table
val len = A.length tab
in if !elems < len then
let val index = hashFun(i, j, shift, len)
fun find NIL = false
| find(B(i',j',b)) = i = i' andalso j = j' orelse find b
val b = UA.sub(tab, index)
in if find b then false
else (UA.update(tab, index, B(i,j,b));
elems := !elems + 1; true)
end
else (* grow table *)
let val oldTable = tab
val oldSize = A.length oldTable
val newSize = oldSize + oldSize
val newTable = A.array(newSize,NIL)
fun enter n =
if n < oldSize then
let fun loop(NIL,a,b) =
(UA.update(newTable, n, a);
UA.update(newTable, n + oldSize, b);
enter(n+1))
| loop(B(i,j,l),a,b) =
if hashFun(i, j, shift, newSize) = n
then loop(l, B(i,j,a), b)
else loop(l, a, B(i,j,b))
in loop(UA.sub(oldTable, n), NIL, NIL) end
else ()
in table := newTable;
enter 0;
insert(i, j)
end
end
in insert
end
(*
| add(BM{table=BITMATRIX table, ...}) =
(fn (i, j) =>
let val (i,j) = if i > j then (i, j) else (j, i)
val bit = W.fromInt(UA.sub(indices, i) + j)
val index = W.toIntX(W.>>(bit, 0w3))
val mask = W.<<(0w1, W.andb(bit, 0w7))
val value = W.fromInt(W8.toInt(UW8A.sub(table, index)))
in if W.andb(value, mask) <> 0w0 then false
else (UW8A.update(table, index,
W8.fromInt(W.toIntX(W.orb(value, mask)))); true)
end
)
*)
fun delete (BM{table=SMALL(table, shift), elems, ...}) =
(fn (i,j) =>
let val k = W.+(W.<<(W.fromInt i, 0w15), W.fromInt j)
fun find [] = []
| find(k'::b) =
if k = k' then (elems := !elems - 1; b) else k'::find b
val tab = !table
val index = hashFun(i, j, shift, A.length tab)
val n = !elems
in UA.update(tab, index, find(UA.sub(tab, index)));
!elems <> n
end
)
| delete (BM{table=LARGE(table, shift), elems, ...}) =
(fn (i,j) =>
let fun find NIL = NIL
| find(B(i', j', b)) =
if i = i' andalso j = j' then (elems := !elems - 1; b)
else B(i', j', find b)
val tab = !table
val index = hashFun(i, j, shift, A.length tab)
val n = !elems
in UA.update(tab, index, find(UA.sub(tab, index)));
!elems <> n
end
)
(*
| delete(BM{table=BITMATRIX table, ...}) =
(fn (i, j) =>
let val (i,j) = if i > j then (i, j) else (j, i)
val bit = W.fromInt(UA.sub(indices, i) + j)
val index = W.toIntX(W.>>(bit, 0w3))
val mask = W.-(W.<<(0w1, W.andb(bit, 0w7)), 0w1)
val value = W.fromInt(W8.toInt(UW8A.sub(table, index)))
in if W.andb(value, mask) = 0w0 then false
else (UW8A.update(table, index,
W8.fromInt(W.toIntX(W.andb(value,W.notb mask))));
true)
end
)
*)
end
|
