RFE: facet reverse sort count
-----------------------------
Key: SOLR-1672
URL: https://issues.apache.org/jira/browse/SOLR-1672
Project: Solr
Issue Type: Improvement
Components: search
Affects Versions: 1.4
Environment: Java, Solrj, http
Reporter: Peter Sturge
Priority: Minor
As suggested by Chris Hosstetter, I have added an optional Comparator to the
BoundedTreeSet<Long> in the UnInvertedField class.
This optional comparator is used when a new (and also optional) field facet
parameter called 'facet.sortorder' is set to the string 'dsc'
(e.g. &f.<facetname>.facet.sortorder=dsc for per field, or &facet.sortorder=dsc
for all facets).
Note that this parameter has no effect if facet.method=enum.
Any value other than 'dsc' (including no value) reverts the BoundedTreeSet to
its default behaviour.
This change affects 2 source files:
> UnInvertedField.java
[line 438] The getCounts() method signature is modified to add the
'facetSortOrder' parameter value to the end of the argument list.
DIFF UnInvertedField.java:
- public NamedList getCounts(SolrIndexSearcher searcher, DocSet baseDocs, int
offset, int limit, Integer mincount, boolean missing, String sort, String
prefix) throws IOException {
+ public NamedList getCounts(SolrIndexSearcher searcher, DocSet baseDocs, int
offset, int limit, Integer mincount, boolean missing, String sort, String
prefix, String facetSortOrder) throws IOException {
[line 556] The getCounts() method is modified to create an overridden
BoundedTreeSet<Long>(int, Comparator) if the 'facetSortOrder' parameter equals
'dsc'.
DIFF UnInvertedField.java:
- final BoundedTreeSet<Long> queue = new BoundedTreeSet<Long>(maxsize);
+ final BoundedTreeSet<Long> queue = (sort.equals("count") ||
sort.equals("true")) ? (facetSortOrder.equals("dsc") ? new
BoundedTreeSet<Long>(maxsize, new Comparator()
{ @Override
public int compare(Object o1, Object o2)
{
if (o1 == null || o2 == null)
return 0;
int result = ((Long) o1).compareTo((Long) o2);
return (result != 0 ? result > 0 ? -1 : 1 : 0); //lowest number first sort
}}) : new BoundedTreeSet<Long>(maxsize)) : null;
> SimpleFacets.java
[line 221] A getFieldParam(field, "facet.sortorder", "asc"); is added to
retrieve the new parameter, if present. 'asc' used as a default value.
DIFF SimpleFacets.java:
+ String facetSortOrder = params.getFieldParam(field, "facet.sortorder", "asc");
[line 253] The call to uif.getCounts() in the getTermCounts() method is
modified to pass the 'facetSortOrder' value string.
DIFF SimpleFacets.java:
- counts = uif.getCounts(searcher, base, offset, limit,
mincount,missing,sort,prefix);
+ counts = uif.getCounts(searcher, base, offset, limit,
mincount,missing,sort,prefix, facetSortOrder);
Implementation Notes:
I have noted in testing that I was not able to retrieve any '0' counts as I had
expected.
I believe this could be because there appear to be some optimizations in
SimpleFacets/count caching such that zero counts are not iterated (at least not
by default)
as a performance enhancement.
I could be wrong about this, and zero counts may appear under some other as yet
untested circumstances. Perhaps an expert familiar with this part of the code
can clarify.
In fact, this is not such a bad thing (at least for my requirements), as a
whole bunch of zero counts is not necessarily useful (for my requirements,
starting at '1' is just right).
There may, however, be instances where someone *will* want zero counts - e.g.
searching for zero product stock counts (e.g. 'what have we run out of'). I was
envisioning the facet.mincount field
being the preferred place to set where the 'lowest value' begins (e.g. 0 or 1
or possibly higher), but because of the caching/optimization, the behaviour is
somewhat different than expected.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
