improve query handling (rewrite) when searching, try and minize the number of rewrites. Also, better highlighting when wrapping in filtered query

Author: kimchy

modules/elasticsearch/src/main/java/org/apache/lucene/search/vectorhighlight/CustomFieldQuery.java

@@ -23,6 +23,7 @@
 import org.apache.lucene.index.Term;
 import org.apache.lucene.search.*;
 import org.apache.lucene.search.spans.SpanTermQuery;
+import org.elasticsearch.util.lucene.search.CustomBoostFactorQuery;
 import org.elasticsearch.util.lucene.search.TermFilter;
 
 import java.io.IOException;
@@ -73,10 +74,9 @@ public CustomFieldQuery(Query query, boolean phraseHighlight, boolean fieldMatch
                 flatQueries.add(termQuery);
             }
         } else if (sourceQuery instanceof ConstantScoreQuery) {
-            Boolean highlight = highlightFilters.get();
-            if (highlight != null && highlight.equals(Boolean.TRUE)) {
-                flatten(((ConstantScoreQuery) sourceQuery).getFilter(), flatQueries);
-            }
+            flatten(((ConstantScoreQuery) sourceQuery).getFilter(), flatQueries);
+        } else if (sourceQuery instanceof CustomBoostFactorQuery) {
+            flatten(((CustomBoostFactorQuery) sourceQuery).getSubQuery(), flatQueries);
         } else if (sourceQuery instanceof MultiTermQuery) {
             MultiTermQuery multiTermQuery = (MultiTermQuery) sourceQuery;
             MultiTermQuery.RewriteMethod rewriteMethod = multiTermQuery.getRewriteMethod();
@@ -87,16 +87,25 @@ public CustomFieldQuery(Query query, boolean phraseHighlight, boolean fieldMatch
                     flatten(multiTermQuery.rewrite(reader.get()), flatQueries);
                 } catch (IOException e) {
                     // ignore
+                } catch (BooleanQuery.TooManyClauses e) {
+                    // ignore
                 } finally {
                     multiTermQuery.setRewriteMethod(rewriteMethod);
                 }
             }
+        } else if (sourceQuery instanceof FilteredQuery) {
+            flatten(((FilteredQuery) sourceQuery).getQuery(), flatQueries);
+            flatten(((FilteredQuery) sourceQuery).getFilter(), flatQueries);
         } else {
             super.flatten(sourceQuery, flatQueries);
         }
     }
 
     void flatten(Filter sourceFilter, Collection<Query> flatQueries) {
+        Boolean highlight = highlightFilters.get();
+        if (highlight == null || highlight.equals(Boolean.FALSE)) {
+            return;
+        }
         if (sourceFilter instanceof TermFilter) {
             flatten(new TermQuery(((TermFilter) sourceFilter).getTerm()), flatQueries);
         } else if (sourceFilter instanceof PublicTermsFilter) {

modules/elasticsearch/src/main/java/org/elasticsearch/search/SearchContextException.java

@@ -37,7 +37,7 @@ public SearchContextException(SearchContext context, String msg, Throwable t) {
     private static String buildMessage(SearchContext context, String msg) {
         StringBuilder sb = new StringBuilder();
         sb.append('[').append(context.shardTarget().index()).append("][").append(context.shardTarget().shardId()).append("]: ");
-        sb.append("query[").append(context.query()).append("],from[").append(context.from()).append("],size[").append(context.size()).append("]");
+        sb.append("query[").append(context.originalQuery()).append("],from[").append(context.from()).append("],size[").append(context.size()).append("]");
         if (context.sort() != null) {
             sb.append(",sort[").append(context.sort()).append("]");
         }

modules/elasticsearch/src/main/java/org/elasticsearch/search/dfs/DfsPhase.java

@@ -42,7 +42,9 @@ public class DfsPhase implements SearchPhase {
 
     public void execute(SearchContext context) {
         try {
-            context.rewriteQuery();
+            if (!context.queryRewritten()) {
+                context.updateRewriteQuery(context.searcher().rewrite(context.query()));
+            }
 
             THashSet<Term> termsSet = new THashSet<Term>();
             context.query().extractTerms(termsSet);

modules/elasticsearch/src/main/java/org/elasticsearch/search/highlight/HighlighterParseElement.java

@@ -106,9 +106,9 @@ public class HighlighterParseElement implements SearchParseElement {
                 if ("highlight_filter".equals(topLevelFieldName) || "highlightFilter".equals(topLevelFieldName)) {
                     highlightFilter = jp.getIntValue() != 0;
                 }
-            } else if (token == JsonToken.VALUE_FALSE) {
+            } else if (token == JsonToken.VALUE_FALSE || token == JsonToken.VALUE_TRUE) {
                 if ("highlight_filter".equals(topLevelFieldName) || "highlightFilter".equals(topLevelFieldName)) {
-                    highlightFilter = false;
+                    highlightFilter = token == JsonToken.VALUE_TRUE;
                 }
             } else if (token == JsonToken.START_OBJECT) {
                 if ("fields".equals(topLevelFieldName)) {

modules/elasticsearch/src/main/java/org/elasticsearch/search/internal/ContextIndexSearcher.java

@@ -28,7 +28,7 @@
 import java.io.IOException;
 
 /**
- * @author kimchy (Shay Banon)
+ * @author kimchy (shay.banon)
  */
 public class ContextIndexSearcher extends IndexSearcher {
 
@@ -57,6 +57,20 @@ public OpenBitSet docIdSet() {
         return docIdSet;
     }
 
+    @Override public Query rewrite(Query original) throws IOException {
+        if (original == searchContext.query() || original == searchContext.originalQuery()) {
+            // optimize in case its the top level search query and we already rewrote it...
+            if (searchContext.queryRewritten()) {
+                return searchContext.query();
+            }
+            Query rewriteQuery = super.rewrite(original);
+            searchContext.updateRewriteQuery(rewriteQuery);
+            return rewriteQuery;
+        } else {
+            return super.rewrite(original);
+        }
+    }
+
     @Override protected Weight createWeight(Query query) throws IOException {
         if (dfSource == null) {
             return super.createWeight(query);

modules/elasticsearch/src/main/java/org/elasticsearch/search/internal/SearchContext.java

@@ -86,6 +86,8 @@ public class SearchContext implements Releasable {
 
     private String queryParserName;
 
+    private Query originalQuery;
+
     private Query query;
 
     private int[] docIdsToLoad;
@@ -238,19 +240,42 @@ public SearchContext queryParserName(String queryParserName) {
     }
 
     public SearchContext query(Query query) {
-        if (query == null) {
-            this.query = query;
-            return this;
-        }
         queryRewritten = false;
+        this.originalQuery = query;
         this.query = query;
         return this;
     }
 
+    /**
+     * The original query to execute, unmodified.
+     */
+    public Query originalQuery() {
+        return this.originalQuery;
+    }
+
+    /**
+     * The query to execute, might be rewritten.
+     */
     public Query query() {
         return this.query;
     }
 
+    /**
+     * Has the query been rewritten already?
+     */
+    public boolean queryRewritten() {
+        return queryRewritten;
+    }
+
+    /**
+     * Rewrites the query and updates it. Only happens once.
+     */
+    public SearchContext updateRewriteQuery(Query rewriteQuery) {
+        query = rewriteQuery;
+        queryRewritten = true;
+        return this;
+    }
+
     public int from() {
         return from;
     }
@@ -286,15 +311,6 @@ public void explain(boolean explain) {
         this.explain = explain;
     }
 
-    public SearchContext rewriteQuery() throws IOException {
-        if (queryRewritten) {
-            return this;
-        }
-        query = query.rewrite(searcher.getIndexReader());
-        queryRewritten = true;
-        return this;
-    }
-
     public int[] docIdsToLoad() {
         return docIdsToLoad;
     }