SOLR-5057 - queryResultCache should match out-of-order fq clauses

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1516299 13f79535-47bb-0310-9956-ffa450edef68

solr/CHANGES.txt

@@ -155,6 +155,8 @@ Optimizations
 * SOLR-5134: Have HdfsIndexOutput extend BufferedIndexOutput. 
   (Mark Miller, Uwe Schindler)
 
+ * SOLR-5057: QueryResultCache should not related with the order of fq's list (Feihong Huang via Erick Erickson)
+
 Other Changes
 ----------------------
 

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

@@ -90,9 +90,36 @@ public final class QueryResultKey {
   }
 
 
-  private static boolean isEqual(Object o1, Object o2) {
-    if (o1==o2) return true;  // takes care of identity and null cases
-    if (o1==null || o2==null) return false;
-    return o1.equals(o2);
+  // Do fast version, expecting that filters are ordered and only
+  // fall back to unordered compare on the first non-equal elements.
+  // This will only be called if the hash code of the entire key already
+  // matched, so the slower unorderedCompare should pretty much never
+  // be called if filter lists are generally ordered.
+  private static boolean isEqual(List<Query> fqList1, List<Query> fqList2) {
+    if (fqList1 == fqList2) return true;  // takes care of identity and null cases
+    if (fqList1 == null || fqList2 == null) return false;
+    int sz = fqList1.size();
+    if (sz != fqList2.size()) return false;
+    for (int i = 0; i < sz; i++) {
+      if (!fqList1.get(i).equals(fqList2.get(i))) {
+        return unorderedCompare(fqList1, fqList2, i);
+      }
+    }
+    return true;
   }
+
+  private static boolean unorderedCompare(List<Query> fqList1, List<Query> fqList2, int start) {
+    int sz = fqList1.size();
+    outer:
+    for (int i = start; i < sz; i++) {
+      Query q1 = fqList1.get(i);
+      for (int j = start; j < sz; j++) {
+        if (q1.equals(fqList2.get(j)))
+          continue outer;
+      }
+      return false;
+    }
+    return true;
+  }
+
 }

solr/core/src/test/org/apache/solr/core/QueryResultKeyTest.java

@@ -56,4 +56,24 @@ public class QueryResultKeyTest extends SolrTestCaseJ4 {
     assertEquals(qrk1.hashCode(), qrk2.hashCode());
   }
 
+  @Test
+  public void testQueryResultKeySortedFilters() {
+    Query fq1 = new TermQuery(new Term("test1", "field1"));
+    Query fq2 = new TermQuery(new Term("test2", "field2"));
+
+    Query query = new TermQuery(new Term("test3", "field3"));
+    List<Query> filters = new ArrayList<Query>();
+    filters.add(fq1);
+    filters.add(fq2);
+
+    QueryResultKey key = new QueryResultKey(query, filters, null, 0);
+
+    List<Query> newFilters = new ArrayList<Query>();
+    newFilters.add(fq2);
+    newFilters.add(fq1);
+    QueryResultKey newKey = new QueryResultKey(query, newFilters, null, 0);
+
+    assertEquals(key, newKey);
+  }
+
 }