On 12 April 2017 at 11:53, Andy Seaborne <[email protected]> wrote:
>
>
> On 11/04/17 15:49, Chris Dollin wrote:
>
>> diff --git
>> a/jena-arq/src/main/java/org/apache/jena/sparql/engine/itera
>> tor/QueryIterSort.java
>> b/jena-arq/src/main/java/org/apache/jena/sparql/engine/itera
>> tor/QueryIterSort.java
>> index 173da34..04c2655 100644
>> ---
>> a/jena-arq/src/main/java/org/apache/jena/sparql/engine/itera
>> tor/QueryIterSort.java
>> +++
>> b/jena-arq/src/main/java/org/apache/jena/sparql/engine/itera
>> tor/QueryIterSort.java
>> @@ -92,6 +92,7 @@ public class QueryIterSort extends
>> QueryIterPlainWrapper {
>> // iterator in a try/finally block, and thus will call
>> // close() themselves.
>> catch (QueryCancelledException e) {
>> + QueryIterSort.this.close();
>>
>
> Is this needed? The query is cancelled so QueryIterSort.requestCancel
> happens?
>
Without it, the test fails, but of course that could be an error
in the test.
I ran the failing test in the debugger with a breakpoint
at the QueryIterSort.close() and println()s at the catch above
and in requestCancel -- the former message was printed, the
latter not.
I went back to the close() and looked at the call stack. All
the active methods from the test to the breakpoint were in
code that did not obviously catch exceptions. Interestingly
at line 113/114 of QueryIteratorBase we see
// Handles exceptions
boolean r = hasNextBinding() ;
which will let any QueryCancelledExceptions on upwards
without doing, say, a local cancel or close.
In actual use the code at the top of the query execution
will itself catch any QueryCancelledException and then
close() the entire query, so there's a case for saying the
code is overkill and that the test can be dropped.
Belt and braces or clutter?
Chris
(Same applies to QueryIteratorTopN)
--
"What I don't understand is this ..." Trevor Chaplin, /The Beiderbeck
Affair/
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