Support regexp in file operator if Lucene indexing is enabled

Change-Id: Id68206412e1aa88a42adfdd34b63faaffd77ee40
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneChangeIndex.java

@@ -34,6 +34,7 @@ import com.google.gerrit.server.index.FieldDef;
 import com.google.gerrit.server.index.FieldDef.FillArgs;
 import com.google.gerrit.server.index.FieldType;
 import com.google.gerrit.server.index.IndexPredicate;
+import com.google.gerrit.server.index.RegexPredicate;
 import com.google.gerrit.server.index.TimestampRangePredicate;
 import com.google.gerrit.server.query.AndPredicate;
 import com.google.gerrit.server.query.NotPredicate;
@@ -61,6 +62,7 @@ import org.apache.lucene.search.BooleanQuery;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.NumericRangeQuery;
 import org.apache.lucene.search.Query;
+import org.apache.lucene.search.RegexpQuery;
 import org.apache.lucene.search.ScoreDoc;
 import org.apache.lucene.search.SearcherManager;
 import org.apache.lucene.search.Sort;
@@ -307,8 +309,24 @@ public class LuceneChangeIndex implements ChangeIndex, LifecycleListener {
   }
 
   private Query exactQuery(IndexPredicate<ChangeData> p) {
+    if (p instanceof RegexPredicate<?>) {
+      return regexQuery(p);
+    } else {
       return new TermQuery(new Term(p.getOperator(), p.getValue()));
     }
+  }
+
+  private Query regexQuery(IndexPredicate<ChangeData> p) {
+    String re = p.getValue();
+    if (re.startsWith("^")) {
+      re = re.substring(1);
+    }
+    if (re.endsWith("$") && !re.endsWith("\\$")) {
+      re = re.substring(0, re.length() - 1);
+    }
+
+    return new RegexpQuery(new Term(p.getOperator(), re));
+  }
 
   private class QuerySource implements ChangeDataSource {
     // TODO(dborowitz): Push limit down from predicate tree.

gerrit-server/src/main/java/com/google/gerrit/server/index/RegexPredicate.java

@@ -0,0 +1,21 @@
+// Copyright (C) 2013 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.index;
+
+public abstract class RegexPredicate<I> extends IndexPredicate<I> {
+  protected RegexPredicate(FieldDef<I, ?> def, String value) {
+    super(def, value);
+  }
+}

gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java

@@ -305,16 +305,13 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
 
   @Operator
   public Predicate<ChangeData> file(String file) throws QueryParseException {
-    if (allowFileRegex) {
     if (file.startsWith("^")) {
+      if (allowFileRegex || args.index != ChangeIndex.DISABLED) {
         return new RegexFilePredicate(args.dbProvider, args.patchListCache, file);
       } else {
-        throw new IllegalArgumentException();
+        throw error("secondary index must be enabled for file:" + file);
       }
     } else {
-      if (file.startsWith("^")) {
-        throw error("regular expression not permitted here: file:" + file);
-      }
       if (args.index == ChangeIndex.DISABLED) {
         throw error("secondary index must be enabled for file:" + file);
       }

gerrit-server/src/main/java/com/google/gerrit/server/query/change/RegexFilePredicate.java

@@ -15,8 +15,9 @@
 package com.google.gerrit.server.query.change;
 
 import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.index.ChangeField;
+import com.google.gerrit.server.index.RegexPredicate;
 import com.google.gerrit.server.patch.PatchListCache;
-import com.google.gerrit.server.query.OperatorPredicate;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Provider;
 
@@ -27,7 +28,7 @@ import dk.brics.automaton.RunAutomaton;
 import java.util.Collections;
 import java.util.List;
 
-class RegexFilePredicate extends OperatorPredicate<ChangeData> {
+class RegexFilePredicate extends RegexPredicate<ChangeData> {
   private final Provider<ReviewDb> db;
   private final PatchListCache cache;
   private final RunAutomaton pattern;
@@ -38,7 +39,7 @@ class RegexFilePredicate extends OperatorPredicate<ChangeData> {
   private final boolean prefixOnly;
 
   RegexFilePredicate(Provider<ReviewDb> db, PatchListCache plc, String re) {
-    super(ChangeQueryBuilder.FIELD_FILE, re);
+    super(ChangeField.FILE, re);
     this.db = db;
     this.cache = plc;