perf tweaks

onthegomap · Jan 11, 2024 · 87be13b · 87be13b
1 parent c079ed0
commit 87be13b
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Showing 2 changed files with 33 additions and 24 deletions.
diff --git a/...ler-benchmarks/src/main/java/com/onthegomap/planetiler/collection/BenchmarkKWayMerge.java b/...ler-benchmarks/src/main/java/com/onthegomap/planetiler/collection/BenchmarkKWayMerge.java
@@ -15,7 +15,7 @@ public class BenchmarkKWayMerge {
   public static void main(String[] args) {
     for (int i = 0; i < 4; i++) {
       System.err.println();
-      testMinHeap("quaternary", n -> LongMinHeap.newArrayHeap(n, (a, b) -> 0));
+      testMinHeap("quaternary", n -> LongMinHeap.newArrayHeap(n, Integer::compare));
       System.err.println(String.join("\t",
         "priorityqueue",
         Long.toString(testPriorityQueue(10).toMillis()),

diff --git a/planetiler-core/src/main/java/com/onthegomap/planetiler/collection/ArrayLongMinHeap.java b/planetiler-core/src/main/java/com/onthegomap/planetiler/collection/ArrayLongMinHeap.java
@@ -105,21 +105,18 @@ public boolean contains(int id) {
   @Override
   public void update(int id, long value) {
     checkIdInRange(id);
-    int index = idToPos[id];
-    if (index < 0) {
+    int pos = idToPos[id];
+    if (pos < 0) {
       throw new IllegalStateException(
         "The heap does not contain: " + id + ". Use the contains method to check this before calling update");
     }
-    long prev = posToValue[index];
-    posToValue[index] = value;
-    int cmp = Long.compare(value, prev);
-    if (cmp == 0 && value != Long.MIN_VALUE) {
-      cmp = tieBreaker.applyAsInt(id, posToId[index]);
-    }
+    long prev = posToValue[pos];
+    posToValue[pos] = value;
+    int cmp = compareIdPos(value, prev, id, pos);
     if (cmp > 0) {
-      percolateDown(index);
+      percolateDown(pos);
     } else if (cmp < 0) {
-      percolateUp(index);
+      percolateUp(pos);
     }
   }
 
@@ -169,8 +166,7 @@ private void percolateUp(int pos) {
     // the finish condition (index==0) is covered here automatically because we set vals[0]=-inf
     int parent;
     long parentValue;
-    while (val < (parentValue = posToValue[parent = parent(pos)]) ||
-      (val == parentValue && val != Long.MIN_VALUE && tieBreaker.applyAsInt(id, posToId[parent]) < 0)) {
+    while (compareIdPos(val, parentValue = posToValue[parent = parent(pos)], id, parent) < 0) {
       posToValue[pos] = parentValue;
       idToPos[posToId[pos] = posToId[parent]] = pos;
       pos = parent;
@@ -201,29 +197,23 @@ private void percolateDown(int pos) {
       int minChild = child;
       long minValue = posToValue[child], childValue;
       if (++child <= size) {
-        if ((childValue = posToValue[child]) < minValue ||
-          (childValue == minValue && childValue != Long.MIN_VALUE &&
-            tieBreaker.applyAsInt(posToId[child], posToId[minChild]) < 0)) {
+        if (comparePosPos(childValue = posToValue[child], minValue, child, minChild) < 0) {
           minChild = child;
           minValue = childValue;
         }
         if (++child <= size) {
-          if ((childValue = posToValue[child]) < minValue ||
-            (childValue == minValue && childValue != Long.MIN_VALUE &&
-              tieBreaker.applyAsInt(posToId[child], posToId[minChild]) < 0)) {
+          if (comparePosPos(childValue = posToValue[child], minValue, child, minChild) < 0) {
             minChild = child;
             minValue = childValue;
           }
-          if (++child <= size && ((childValue = posToValue[child]) < minValue ||
-            (childValue == minValue && childValue != Long.MIN_VALUE &&
-              tieBreaker.applyAsInt(posToId[child], posToId[minChild]) < 0))) {
+          if (++child <= size &&
+            comparePosPos(childValue = posToValue[child], minValue, child, minChild) < 0) {
             minChild = child;
             minValue = childValue;
           }
         }
       }
-      if (minValue > value ||
-        (minValue == value && minValue != Long.MIN_VALUE && tieBreaker.applyAsInt(posToId[minChild], id) >= 0)) {
+      if (comparePosPos(value, minValue, pos, minChild) <= 0) {
         break;
       }
       posToValue[pos] = minValue;
@@ -234,4 +224,23 @@ private void percolateDown(int pos) {
     posToValue[pos] = value;
     idToPos[id] = pos;
   }
+
+  private int comparePosPos(long val1, long val2, int pos1, int pos2) {
+    if (val1 < val2) {
+      return -1;
+    } else if (val1 == val2 && val1 != Long.MIN_VALUE) {
+      return tieBreaker.applyAsInt(posToId[pos1], posToId[pos2]);
+    }
+    return 1;
+  }
+
+  private int compareIdPos(long val1, long val2, int id1, int pos2) {
+    if (val1 < val2) {
+      return -1;
+    } else if (val1 == val2 && val1 != Long.MIN_VALUE) {
+      return tieBreaker.applyAsInt(id1, posToId[pos2]);
+    }
+    return 1;
+  }
+
 }