Fix GroupingEffectiveStatementImpl's unknown nodes

Heap analysis has pointed out a linked list, which is both
a correctness problem (it should be immutable) and efficiency
issue, as most of the time this list should be empty.

Use ImmutableList.Builder to build an immutable list of
unknown statements.

Change-Id: I94a42cb75d8fa433bcae304728268b0873d14683
Signed-off-by: Robert Varga <rovarga@cisco.com>
(cherry picked from commit 647eddd0c2c6c2a0e2f68f52f65b7a9b6ee0a53b)

diff --git a/yang/yang-parser-impl/src/main/java/org/opendaylight/yangtools/yang/parser/stmt/rfc6020/effective/GroupingEffectiveStatementImpl.java b/yang/yang-parser-impl/src/main/java/org/opendaylight/yangtools/yang/parser/stmt/rfc6020/effective/GroupingEffectiveStatementImpl.java
index 228e3dd3086e785a486bba1ef197a87997963e1b..8a83eb9d1919bd30ca5c85c0a17549ad3d14baf3 100644 (file)
--- a/yang/yang-parser-impl/src/main/java/org/opendaylight/yangtools/yang/parser/stmt/rfc6020/effective/GroupingEffectiveStatementImpl.java
+++ b/yang/yang-parser-impl/src/main/java/org/opendaylight/yangtools/yang/parser/stmt/rfc6020/effective/GroupingEffectiveStatementImpl.java
@@ -8,8 +8,8 @@
 
 package org.opendaylight.yangtools.yang.parser.stmt.rfc6020.effective;
 
-import java.util.Collection;
-import java.util.LinkedList;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableList.Builder;
 import java.util.List;
 import java.util.Objects;
 import org.opendaylight.yangtools.yang.common.QName;
@@ -43,15 +43,14 @@ public class GroupingEffectiveStatementImpl extends
             addedByUses = false;
         }
 
-        // initSubstatementCollections
-        Collection<? extends EffectiveStatement<?, ?>> effectiveSubstatements = effectiveSubstatements();
-        unknownNodes = new LinkedList<>();
-        for (EffectiveStatement<?, ?> effectiveStatement : effectiveSubstatements) {
+        final Builder<UnknownSchemaNode> b = ImmutableList.builder();
+        for (EffectiveStatement<?, ?> effectiveStatement : effectiveSubstatements()) {
             if (effectiveStatement instanceof UnknownSchemaNode) {
-                UnknownSchemaNode unknownNode = (UnknownSchemaNode) effectiveStatement;
-                unknownNodes.add(unknownNode);
+                b.add((UnknownSchemaNode) effectiveStatement);
             }
         }
+
+        unknownNodes = b.build();
     }
 
     @Override