Changeset 17136 in josm for trunk/src/org/openstreetmap/josm/data

Timestamp:

2020-10-09T14:19:58+02:00 (4 years ago)

Author:

GerdP

Message:

see #19898: Performance improvements for DatasetMerger
Avoid to avoid to materialise unneeded copies of SubclassFilteredCollection

File:

• trunk/src/org/openstreetmap/josm/data/osm/DataSetMerger.java (modified) (4 diffs)

trunk/src/org/openstreetmap/josm/data/osm/DataSetMerger.java

@@ -425 +425 @@
         }
         targetDataSet.update(() -> {
-            List<? extends OsmPrimitive> candidates = new ArrayList<>(targetDataSet.getNodes());
+            List<? extends OsmPrimitive> candidates = null;
             for (Node node: sourceDataSet.getNodes()) {
+                // lazy initialisation to improve performance, see #19898
+                if (candidates == null) {
+                    candidates = new ArrayList<>(targetDataSet.getNodes());
+                }
                 mergePrimitive(node, candidates);
                 if (progressMonitor != null) {
@@ -432 +436 @@
                 }
             }
-            candidates.clear();
-            candidates = new ArrayList<>(targetDataSet.getWays());
+            candidates = null;
             for (Way way: sourceDataSet.getWays()) {
+                // lazy initialisation to improve performance
+                if (candidates == null) {
+                    candidates = new ArrayList<>(targetDataSet.getWays());
+                }
                 mergePrimitive(way, candidates);
                 if (progressMonitor != null) {
@@ -440 +447 @@
                 }
             }
-            candidates.clear();
-            candidates = new ArrayList<>(targetDataSet.getRelations());
+            candidates = null;
             for (Relation relation: sourceDataSet.getRelations()) {
+                // lazy initialisation to improve performance
+                if (candidates == null) {
+                    candidates = new ArrayList<>(targetDataSet.getRelations());
+                }
                 mergePrimitive(relation, candidates);
                 if (progressMonitor != null) {
@@ -448 +458 @@
                 }
             }
-            candidates.clear();
+            candidates = null;
             fixReferences();