I have tried this with the latest 7.3.1 and also tried to simplify my
client (node.js) code I am still getting errors, not every but most runs.
However now I am getting a stack trace back in the server protocol info
message. This is coming on the event port
I have an event "messenger" defined and then run code
var session1 = new basex.Session("localhost", 1984, "admin", "admin");
var session2 = new basex.Session("localhost", 1984, "admin", "admin");
session2.watch("messenger", watchCallback, this)
// below forced to run after above
session1.execute("XQUERY db:event('messenger', 99)", this);
----------
// called on receipt of event
function watchCallback(name, msg) {
session1.close(this);
session2.close(this);
};
--------- the info message on the event port ---
Improper use? Potential bug? Your feedback is welcome:
Contact: basex-talk@mailman.uni-konstanz.de
Version: BaseX 7.3.1 beta
Java: Sun Microsystems Inc., 1.6.0_26
OS: Linux, i386
Stack Trace:
java.lang.NullPointerException
org.basex.server.ClientListener.notify(ClientListener.java:296)
org.basex.core.Events.notify(Events.java:114)
org.basex.query.func.FNDb.event(FNDb.java:689)
org.basex.query.func.FNDb.item(FNDb.java:100)
org.basex.query.expr.ParseExpr.iter(ParseExpr.java:45)
org.basex.query.func.FNDb.iter(FNDb.java:85)
org.basex.query.QueryContext.iter(QueryContext.java:292)
org.basex.query.QueryContext.iter(QueryContext.java:244)
org.basex.query.QueryProcessor.iter(QueryProcessor.java:76)
org.basex.core.cmd.AQuery.query(AQuery.java:94)
org.basex.core.cmd.XQuery.run(XQuery.java:22)
org.basex.core.Command.run(Command.java:363)
org.basex.core.Command.exec(Command.java:342)
org.basex.core.Command.execute(Command.java:78)
org.basex.server.ClientListener.run(ClientListener.java:150)
-----------------------------------------------------------
Any ideas?
/Andy
On Sun, Jun 3, 2012 at 10:28 PM, Andy Bunce <bunce.a...@gmail.com> wrote:
> I have made some progress on this...
> I think the protocol response to the watch is in fact {port}{id}\0
> Where {port} is a basex server port to connect in order to receive events
> and {id} some identifier.
> The client should connect to the port and send {id}\0. The response is \0.
> After this the connection will receive events in the form {name}{msg}
>
> I have implemented this in node.js. One difficulty is the very
> asynchronous nature of node
> I have tried to recreate something based on the
> c#<https://github.com/BaseXdb/basex-api/blob/master/src/main/c%23/EventExample.cs>example
> in
> node<https://github.com/apb2006/basex-node/blob/master/examples/EventExample.js>allowing
> for this. It runs fine the first time after the server is started,
> in subsequent runs the event is never received.
>
> The log from the 1st run is
>
> 21:19:01.858 [127.0.0.1:38155] LOGIN admin OK
> 21:19:01.861 [127.0.0.1:38156] LOGIN test1 OK
> 21:19:02.003 [127.0.0.1:38155] CREATE EVENT messenger
> 21:19:02.005 [127.0.0.1:38155] OK 143.0 ms
> 21:19:02.027 [127.0.0.1:38156] OK 13.41 ms
> 21:19:02.247 [127.0.0.1:38156] QUERY(0) for $i in 1 to 1000000 where $i=3
> return $i OK 219.51 ms
> 21:19:02.248 [127.0.0.1:38156] QUERY(0) OK 0.5 ms
> 21:19:02.252 [127.0.0.1:38155] QUERY(0) db:event('messenger', 'Hello World!')
> OK 230.45 ms
> 21:19:02.254 [127.0.0.1:38155] QUERY(0) OK 0.76 ms
> 21:19:02.584 [127.0.0.1:38155] EXEC(0) OK 329.22 ms
> 21:19:02.943 [127.0.0.1:38156] EXEC(0) OK 694.17 ms
> 21:19:02.945 [127.0.0.1:38156] OK 0.34 ms
> 21:19:03.004 [127.0.0.1:38155] DROP EVENT messenger
> 21:19:03.005 [127.0.0.1:38155] OK 2.18 ms
> 21:19:03.006 [127.0.0.1:38155] EXIT
> 21:19:03.011 [127.0.0.1:38155] OK 6.03 ms
> 21:19:03.012 [127.0.0.1:38155] LOGOUT admin OK
> 21:19:03.014 [127.0.0.1:38156] EXIT
> 21:19:03.019 [127.0.0.1:38156] OK 6.57 ms
> 21:19:03.020 [127.0.0.1:38156] LOGOUT test1 OK
> The next run gives
>
> 19:16.106 [127.0.0.1:38158] LOGIN admin OK
> 21:19:16.112 [127.0.0.1:38158] CREATE EVENT messenger
> 21:19:16.115 [127.0.0.1:38158] OK 27.79 ms
> 21:19:16.151 [127.0.0.1:38159] LOGIN test1 OK
> 21:19:16.192 [127.0.0.1:38158] QUERY(0) db:event('messenger', 'Hello World!')
> OK 0.98 ms
> 21:19:16.200 [127.0.0.1:38158] QUERY(0) OK 7.4 ms
> 21:19:16.207 [127.0.0.1:38159] OK 0.65 ms
> 21:19:16.220 [127.0.0.1:38159] QUERY(0) for $i in 1 to 1000000 where $i=3
> return $i OK 7.77 ms
> 21:19:16.231 [127.0.0.1:38159] QUERY(0) OK 4.3 ms
> 21:19:16.253 [127.0.0.1:38158] EXEC(0) Error: null
> 21:19:16.732 [127.0.0.1:38159] EXEC(0) OK 459.42 ms
> 21:19:20.036 [127.0.0.1:38158] LOGOUT admin OK
> 21:19:20.042 [127.0.0.1:38159] LOGOUT test1 OK
>
> The problem seems to EXEC(0) Error: null
> Any ideas what the cause might be or how I can debug this further.
> /Andy
>
>
> On Thu, May 17, 2012 at 12:04 PM, Andreas Weiler <
> andreas.wei...@uni-konstanz.de> wrote:
>
>> Hi Andy,
>>
>> 1) The documentation at http://docs.basex.org/wiki/Server_Protocol shows
>> nothing in the Server Response column. This seems not to be the case. It
>> looks like a standard BaseX protocol type response is to be expected?
>>
>>
>> yes you are right, the server response is a standard basex info message.
>>
>> 2) The example at
>> https://github.com/BaseXdb/basex-examples/blob/master/src/main/java/org/basex/examples/api/EventExample.java
>> shows
>> session2 watching and then executing. Does the server protocol identify
>> "event pushes" in some way. That is when I receive a message how can I tell
>> if is a event or a command response?
>>
>>
>> the event reponse is send over a separate socket connection.
>>
>> -- Andreas
>>
>> Am 17.05.2012 um 12:22 schrieb Andy Bunce:
>>
>> Hi,
>> I am looking at adding WATCH and UNWATCH to my Node.js BaseX interface
>> and I have a couple of questions before I start.
>>
>> 1) The documentation at http://docs.basex.org/wiki/Server_Protocol shows
>> nothing in the Server Response column. This seems not to be the case. It
>> looks like a standard BaseX protocol type response is to be expected?
>>
>> 2) The example at
>> https://github.com/BaseXdb/basex-examples/blob/master/src/main/java/org/basex/examples/api/EventExample.javashows
>> session2 watching and then executing. Does the server protocol
>> identify "event pushes" in some way. That is when I receive a message how
>> can I tell if is a event or a command response?
>>
>> /Andy
>> _______________________________________________
>> BaseX-Talk mailing list
>> BaseX-Talk@mailman.uni-konstanz.de
>> https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk
>>
>>
>>
>
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