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authorGravatar Adam Chlipala <adamc@hcoop.net>2009-03-29 11:37:29 -0400
committerGravatar Adam Chlipala <adamc@hcoop.net>2009-03-29 11:37:29 -0400
commit6217967a353bc9d97ae45c2af495b653a47e2481 (patch)
treebae33dd5ebd8393e6dd1b30f7d1a2b75241c9956 /lib
parent213564f740d896c9a8bd86b5e2221d9434b126d3 (diff)
Redo channels, making them single-client
Diffstat (limited to 'lib')
-rw-r--r--lib/js/urweb.js3
-rw-r--r--lib/ur/basis.urs4
-rw-r--r--lib/ur/top.ur44
-rw-r--r--lib/ur/top.urs18
4 files changed, 69 insertions, 0 deletions
diff --git a/lib/js/urweb.js b/lib/js/urweb.js
index c7cecbbf..4daee66d 100644
--- a/lib/js/urweb.js
+++ b/lib/js/urweb.js
@@ -301,6 +301,9 @@ function listener() {
}
function rv(chn, parse, k) {
+ if (chn == null)
+ return;
+
if (chn < 0)
whine("Out-of-bounds channel receive");
diff --git a/lib/ur/basis.urs b/lib/ur/basis.urs
index 23c3fe57..d6b27852 100644
--- a/lib/ur/basis.urs
+++ b/lib/ur/basis.urs
@@ -115,6 +115,9 @@ val subscribe : t ::: Type -> channel t -> transaction unit
val send : t ::: Type -> channel t -> t -> transaction unit
val recv : t ::: Type -> channel t -> transaction t
+type client
+val self : transaction client
+
(** SQL *)
@@ -207,6 +210,7 @@ val sql_time : sql_injectable_prim time
class sql_injectable_nullable
val sql_channel : t ::: Type -> sql_injectable_nullable (channel t)
+val sql_client : sql_injectable_nullable client
class sql_injectable
val sql_prim : t ::: Type -> sql_injectable_prim t -> sql_injectable t
diff --git a/lib/ur/top.ur b/lib/ur/top.ur
index 713f4311..5465da3d 100644
--- a/lib/ur/top.ur
+++ b/lib/ur/top.ur
@@ -143,6 +143,14 @@ fun foldRX2 K (tf1 :: K -> Type) (tf2 :: K -> Type) (ctx :: {Unit})
<xml>{f [nm] [t] [rest] ! r1 r2}{acc}</xml>)
<xml/>
+fun queryI (tables ::: {{Type}}) (exps ::: {Type})
+ [tables ~ exps] (q : sql_query tables exps)
+ (f : $(exps ++ map (fn fields :: {Type} => $fields) tables)
+ -> transaction unit) =
+ query q
+ (fn fs _ => f fs)
+ ()
+
fun queryX (tables ::: {{Type}}) (exps ::: {Type}) (ctx ::: {Unit})
[tables ~ exps] (q : sql_query tables exps)
(f : $(exps ++ map (fn fields :: {Type} => $fields) tables)
@@ -188,3 +196,39 @@ fun eqNullable' (tables ::: {{Type}}) (agg ::: {{Type}}) (exps ::: {Type})
case e2 of
None => (SQL {e1} IS NULL)
| Some _ => sql_binary sql_eq e1 (sql_inject e2)
+
+
+functor Broadcast(M : sig type t end) = struct
+ sequence s
+ table t : {Id : int, Client : option client, Channel : option (channel M.t)}
+
+ type topic = int
+
+ val inj : sql_injectable topic = _
+
+ val create = nextval s
+
+ val cleanup =
+ dml (DELETE FROM t WHERE Client IS NULL)
+
+ fun subscribe id =
+ cli <- self;
+ cleanup;
+ ro <- oneOrNoRows (SELECT t.Channel FROM t WHERE t.Id = {[id]} AND t.Client = {[Some cli]});
+ case ro of
+ None =>
+ ch <- channel;
+ dml (INSERT INTO t (Id, Client, Channel) VALUES ({[id]}, {[Some cli]}, {[Some ch]}));
+ return ch
+ | Some r =>
+ case r.T.Channel of
+ None => error <xml>Broadcast.subscribe: Got null result</xml>
+ | Some ch => return ch
+
+ fun send id msg =
+ cleanup;
+ queryI (SELECT t.Channel FROM t WHERE t.Id = {[id]})
+ (fn r => case r.T.Channel of
+ None => error <xml>Broadcast.send: Got null result</xml>
+ | Some ch => Basis.send ch msg)
+end
diff --git a/lib/ur/top.urs b/lib/ur/top.urs
index bc0b768e..821aa42a 100644
--- a/lib/ur/top.urs
+++ b/lib/ur/top.urs
@@ -87,6 +87,13 @@ val foldRX2 : K --> tf1 :: (K -> Type) -> tf2 :: (K -> Type) -> ctx :: {Unit}
-> r :: {K} -> folder r
-> $(map tf1 r) -> $(map tf2 r) -> xml ctx [] []
+val queryI : tables ::: {{Type}} -> exps ::: {Type}
+ -> [tables ~ exps] =>
+ sql_query tables exps
+ -> ($(exps ++ map (fn fields :: {Type} => $fields) tables)
+ -> transaction unit)
+ -> transaction unit
+
val queryX : tables ::: {{Type}} -> exps ::: {Type} -> ctx ::: {Unit}
-> [tables ~ exps] =>
sql_query tables exps
@@ -127,3 +134,14 @@ val eqNullable' : tables ::: {{Type}} -> agg ::: {{Type}} -> exps ::: {Type}
-> sql_exp tables agg exps (option t)
-> option t
-> sql_exp tables agg exps bool
+
+
+functor Broadcast(M : sig type t end) : sig
+ type topic
+
+ val inj : sql_injectable topic
+
+ val create : transaction topic
+ val subscribe : topic -> transaction (channel M.t)
+ val send : topic -> M.t -> transaction unit
+end