Hi,
I'm writing in the mailing list, not as comments in the Jira, in order to have a
discussion that may wander around a bit, without "diluting" the Jira.
I can think of several approaches to what the user-facing API might look like,
considering users might be using Java 7 or 8.
One approach would use the try/ finally form:
controlVar = cas.startUimaIndexProtectedBlock();
try {
some code which modifies a FS (or maybe, multiple FSs
} finally {
controlVar.close(); // causes any "removes" to be now re-added to indices
}
A form like the above could use in Java 8 the simpler try-with-resources form:
try (controlVar = cas.startUimaIndexProtectedBlock()) {
some code which modifies a FS (or maybe, multiple FSs
}
This approach has the advantage of allowing arbitrary code in the inner block,
and passing checked exceptions out.
-------------------
Another form could use Java 8 lambdas, or Java 7 anonymous classes. Java 8
lambdas, I think, however, don't support the inner code throwing checked
exceptions.
-------------------
So, I'm leaning toward the "try" form. Other opinions/suggestions welcome :-)
-Marshall
On 12/1/2014 10:13 AM, Marshall Schor (JIRA) wrote:
> Marshall Schor created UIMA-4135:
> ------------------------------------
>
> Summary: support for modifying indexed FSs
> Key: UIMA-4135
> URL: https://issues.apache.org/jira/browse/UIMA-4135
> Project: UIMA
> Issue Type: Improvement
> Components: Core Java Framework
> Reporter: Marshall Schor
> Assignee: Marshall Schor
> Fix For: 2.7.0SDK
>
>
> Both users and the UIMA framework (during deserialization of CASes in XCAS,
> XMI, or various Binary formats) may want to modify a feature in a FS which is
> used as a key in some index specification. If this FS is in the index, then
> indices which use this feature as a key may become corrupted, unless the FS
> is first removed from the indices. After that, the feature may be updated,
> and the FS re-added to the indices.
>
> If allow_multiple_add_to_indices is enabled, a particular FS may be added to
> indices multiple times; the above remove operation would need to remove all
> of these, and the above add operation would need to add-to-indices the same
> number as was removed.
>
> The count of the number of times a FS was in the indices needs to be kept by
> View.
>
> There are several optimizations possible for this operation. Bag indices do
> not need to be disturbed as they have no keys. Set indices only have at most
> one instance of a particular FS. FSs which are subtypes of AnnotationBase
> are only indexed in at most 1 view (the view of their sofa). The remove-all
> kind of operation for Sorted indices can be made efficient in that all the
> identical elements are stored adjacently, and the remove can be done in bulk.
>
> The update operations for one FS may involve multiple key values.
> Design a way to encapsulate the update operation that is efficient, for both
> users and the UIMA framework.
>
>
>
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