Changeset 18502 in josm for trunk/src/org/openstreetmap

Timestamp:

2022-06-27T18:29:34+02:00 (2 years ago)

Author:

taylor.smock

Message:

Fix #22139: Significantly reduce allocations in NodeElement

This significantly reduces the cost for painting nodes.
In testing (Mesa County, Colorado, downloaded via overpass),
this reduces the cost for painting nodes (no paintstyle) by
66% (memory allocations) and ~17% (CPU allocations).

This comes out to about 7% of CPU cycles during map paint and
~20% of memory allocations during map paint.

File:

• trunk/src/org/openstreetmap/josm/gui/mappaint/styleelement/NodeElement.java (modified) (2 diffs)

trunk/src/org/openstreetmap/josm/gui/mappaint/styleelement/NodeElement.java

@@ -8 +8 @@
 import java.util.Objects;
 import java.util.Optional;
-import java.util.stream.IntStream;
 
 import org.openstreetmap.josm.data.osm.INode;
@@ -351 +350 @@
     }
 
-    private static int max(int... elements) {
-        return IntStream.of(elements).max().orElseThrow(IllegalStateException::new);
+    private static int max(int a, int b, int c, int d) {
+        // Profile before switching to a stream/int[] array
+        // This was 66% give or take for painting nodes in terms of memory allocations
+        // and was ~17% of the CPU allocations. By not using a vararg method call, we avoid
+        // the creation of an array. By avoiding both streams and arrays, the cost for this method is negligible.
+        // This means that this saves about 7% of the CPU cycles during map paint, and about 20%
+        // of the memory allocations during map paint.
+        return Math.max(a, Math.max(b, Math.max(c, d)));
     }