SOLR-14552: Add BMW support to ReRank queries (#1559)

solr/CHANGES.txt

@@ -163,6 +163,8 @@ Optimizations
 * SOLR-14472: Autoscaling "cores" preference now retrieves the core count more efficiently, and counts all cores.
   (David Smiley)
 
+* SOLR-14552: Add BlockMax-WAND support to ReRank queries (Tomás Fernández Löbbe)
+
 Bug Fixes
 ---------------------
 * SOLR-13264: IndexSizeTrigger aboveOp / belowOp properties not in valid properties.

solr/core/src/java/org/apache/solr/search/ReRankCollector.java

@@ -45,8 +45,7 @@ import org.apache.solr.request.SolrRequestInfo;
 @SuppressWarnings({"rawtypes"})
 public class ReRankCollector extends TopDocsCollector {
 
-  @SuppressWarnings({"rawtypes"})
+  final private TopDocsCollector<?> mainCollector;
-  final private TopDocsCollector  mainCollector;
   final private IndexSearcher searcher;
   final private int reRankDocs;
   final private int length;
@@ -71,11 +70,11 @@ public class ReRankCollector extends TopDocsCollector {
     Sort sort = cmd.getSort();
     if(sort == null) {
       this.sort = null;
-      this.mainCollector = TopScoreDocCollector.create(Math.max(this.reRankDocs, length), Integer.MAX_VALUE);
+      this.mainCollector = TopScoreDocCollector.create(Math.max(this.reRankDocs, length), cmd.getMinExactCount());
     } else {
       this.sort = sort = sort.rewrite(searcher);
       //scores are needed for Rescorer (regardless of whether sort needs it)
-      this.mainCollector = TopFieldCollector.create(sort, Math.max(this.reRankDocs, length), Integer.MAX_VALUE);
+      this.mainCollector = TopFieldCollector.create(sort, Math.max(this.reRankDocs, length), cmd.getMinExactCount());
     }
     this.searcher = searcher;
     this.reRankQueryRescorer = reRankQueryRescorer;
@@ -92,7 +91,7 @@ public class ReRankCollector extends TopDocsCollector {
 
   @Override
   public ScoreMode scoreMode() {
-    return sort == null || sort.needsScores() ? ScoreMode.COMPLETE : ScoreMode.COMPLETE_NO_SCORES;
+    return this.mainCollector.scoreMode();
   }
 
   @SuppressWarnings({"unchecked"})

solr/core/src/test/org/apache/solr/search/TestReRankQParserPlugin.java

@@ -17,9 +17,12 @@
 package org.apache.solr.search;
 
 import java.util.Map;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
 
 import org.apache.solr.SolrTestCaseJ4;
 import org.apache.solr.common.SolrException;
+import org.apache.solr.common.params.CommonParams;
 import org.apache.solr.common.params.ModifiableSolrParams;
 import org.apache.solr.metrics.MetricsMap;
 import org.apache.solr.metrics.SolrMetricManager;
@@ -598,10 +601,12 @@ public class TestReRankQParserPlugin extends SolrTestCaseJ4 {
     params.add("start", "0");
     params.add("rows", "2");
 
+    ignoreException("reRankQuery parameter is mandatory");
     SolrException se = expectThrows(SolrException.class, "A syntax error should be thrown when "+ReRankQParserPlugin.RERANK_QUERY+" parameter is not specified",
         () -> h.query(req(params))
     );
     assertTrue(se.code() == SolrException.ErrorCode.BAD_REQUEST.code);
+    unIgnoreException("reRankQuery parameter is mandatory");
 
   }
 
@@ -646,4 +651,94 @@ public class TestReRankQParserPlugin extends SolrTestCaseJ4 {
     }
   }
   
+  @Test
+  public void testMinExactCount() throws Exception {
+
+    assertU(delQ("*:*"));
+    assertU(commit());
+    
+    int numDocs = 200;
+    
+    for (int i = 0 ; i < numDocs ; i ++) {
+      assertU(adoc(
+          "id", String.valueOf(i),
+          "id_p_i", String.valueOf(i),
+          "field_t", IntStream.range(0, numDocs).mapToObj(val -> Integer.toString(val)).collect(Collectors.joining(" "))));
+    }
+    assertU(commit());
+    
+    ModifiableSolrParams params = new ModifiableSolrParams();
+    params.add("q", "field_t:0");
+    params.add("start", "0");
+    params.add("rows", "10");
+    params.add("fl", "id");
+    assertQ(req(params),
+        "*[count(//doc)=10]",
+        "//result[@numFound='" + numDocs + "']",
+        "//result[@numFoundExact='true']",
+        "//result/doc[1]/str[@name='id'][.='0']",
+        "//result/doc[2]/str[@name='id'][.='1']",
+        "//result/doc[3]/str[@name='id'][.='2']",
+        "//result/doc[4]/str[@name='id'][.='3']",
+        "//result/doc[5]/str[@name='id'][.='4']",
+        "//result/doc[6]/str[@name='id'][.='5']",
+        "//result/doc[7]/str[@name='id'][.='6']",
+        "//result/doc[8]/str[@name='id'][.='7']",
+        "//result/doc[9]/str[@name='id'][.='8']",
+        "//result/doc[10]/str[@name='id'][.='9']"
+        );
+    
+    params.add("rq", "{!"+ReRankQParserPlugin.NAME+" "+ReRankQParserPlugin.RERANK_QUERY+"=$rrq "+ReRankQParserPlugin.RERANK_DOCS+"=20}");
+    params.add("rrq", "id:10");
+    assertQ(req(params),
+        "*[count(//doc)=10]",
+        "//result[@numFound='" + numDocs + "']",
+        "//result[@numFoundExact='true']",
+        "//result/doc[1]/str[@name='id'][.='10']",
+        "//result/doc[2]/str[@name='id'][.='0']",
+        "//result/doc[3]/str[@name='id'][.='1']",
+        "//result/doc[4]/str[@name='id'][.='2']",
+        "//result/doc[5]/str[@name='id'][.='3']",
+        "//result/doc[6]/str[@name='id'][.='4']",
+        "//result/doc[7]/str[@name='id'][.='5']",
+        "//result/doc[8]/str[@name='id'][.='6']",
+        "//result/doc[9]/str[@name='id'][.='7']",
+        "//result/doc[10]/str[@name='id'][.='8']"
+        );
+    
+    params.add(CommonParams.MIN_EXACT_COUNT, "2");
+    assertQ(req(params),
+        "*[count(//doc)=10]",
+        "//result[@numFound<='" + numDocs + "']",
+        "//result[@numFoundExact='false']",
+        "//result/doc[1]/str[@name='id'][.='10']",
+        "//result/doc[2]/str[@name='id'][.='0']",
+        "//result/doc[3]/str[@name='id'][.='1']",
+        "//result/doc[4]/str[@name='id'][.='2']",
+        "//result/doc[5]/str[@name='id'][.='3']",
+        "//result/doc[6]/str[@name='id'][.='4']",
+        "//result/doc[7]/str[@name='id'][.='5']",
+        "//result/doc[8]/str[@name='id'][.='6']",
+        "//result/doc[9]/str[@name='id'][.='7']",
+        "//result/doc[10]/str[@name='id'][.='8']"
+        );
+    
+    params.add("sort", "score desc, id_p_i asc");
+    assertQ(req(params),
+        "*[count(//doc)=10]",
+        "//result[@numFound<='" + numDocs + "']",
+        "//result[@numFoundExact='false']",
+        "//result/doc[1]/str[@name='id'][.='10']",
+        "//result/doc[2]/str[@name='id'][.='0']",
+        "//result/doc[3]/str[@name='id'][.='1']",
+        "//result/doc[4]/str[@name='id'][.='2']",
+        "//result/doc[5]/str[@name='id'][.='3']",
+        "//result/doc[6]/str[@name='id'][.='4']",
+        "//result/doc[7]/str[@name='id'][.='5']",
+        "//result/doc[8]/str[@name='id'][.='6']",
+        "//result/doc[9]/str[@name='id'][.='7']",
+        "//result/doc[10]/str[@name='id'][.='8']"
+        );
+  }
+
 }