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8247605: Avoid array allocation when concatenating with empty string
Reviewed-by: redestad, plevart
This commit is contained in:
parent
8e687450d6
commit
55e381b32f
5 changed files with 304 additions and 238 deletions
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@ -39,11 +39,13 @@ import java.util.Arrays;
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import java.util.Collections;
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import java.util.Comparator;
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import java.util.Map;
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import java.util.NavigableMap;
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import java.util.Random;
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import java.util.TreeMap;
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import java.util.concurrent.TimeUnit;
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import java.util.function.Function;
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import java.util.function.Supplier;
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import java.util.function.UnaryOperator;
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import java.util.stream.Collectors;
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import java.util.stream.IntStream;
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@ -54,6 +56,9 @@ import java.util.stream.IntStream;
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@Fork(3)
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@State(Scope.Thread)
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public class TreeMapUpdate {
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@Param({"TreeMap", "descendingMap", "tailMap"})
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public String mode;
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@Param({"10", "1000", "100000"})
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public int size;
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@ -68,10 +73,25 @@ public class TreeMapUpdate {
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private Supplier<TreeMap<Integer, Integer>> supplier;
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private UnaryOperator<NavigableMap<Integer, Integer>> transformer;
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private Integer[] keys;
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@Setup
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public void setUp() {
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switch(mode) {
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case "TreeMap":
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transformer = map -> map;
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break;
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case "descendingMap":
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transformer = map -> map.descendingMap();
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break;
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case "tailMap":
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transformer = map -> map.tailMap(0, true);
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break;
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default:
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throw new IllegalStateException(mode);
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}
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supplier = comparator ? () -> new TreeMap<>(Comparator.reverseOrder()) : TreeMap::new;
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keys = IntStream.range(0, size).boxed().toArray(Integer[]::new);
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Random rnd = seed == 0 ? new Random() : new Random(seed);
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@ -86,12 +106,12 @@ public class TreeMapUpdate {
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@Benchmark
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public Map<Integer, Integer> baseline() {
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// Just create map (empty or pre-filled)
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return supplier.get();
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return transformer.apply(supplier.get());
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}
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@Benchmark
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public Map<Integer, Integer> put(Blackhole bh) {
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Map<Integer, Integer> map = supplier.get();
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Map<Integer, Integer> map = transformer.apply(supplier.get());
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Integer[] keys = this.keys;
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for (Integer key : keys) {
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bh.consume(map.put(key, key));
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@ -101,7 +121,7 @@ public class TreeMapUpdate {
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@Benchmark
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public Map<Integer, Integer> putIfAbsent(Blackhole bh) {
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Map<Integer, Integer> map = supplier.get();
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Map<Integer, Integer> map = transformer.apply(supplier.get());
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Integer[] keys = this.keys;
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for (Integer key : keys) {
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bh.consume(map.putIfAbsent(key, key));
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@ -111,7 +131,7 @@ public class TreeMapUpdate {
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@Benchmark
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public Map<Integer, Integer> computeIfAbsent(Blackhole bh) {
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Map<Integer, Integer> map = supplier.get();
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Map<Integer, Integer> map = transformer.apply(supplier.get());
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Integer[] keys = this.keys;
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for (Integer key : keys) {
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bh.consume(map.computeIfAbsent(key, k -> k));
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@ -121,7 +141,7 @@ public class TreeMapUpdate {
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@Benchmark
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public Map<Integer, Integer> compute(Blackhole bh) {
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Map<Integer, Integer> map = supplier.get();
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Map<Integer, Integer> map = transformer.apply(supplier.get());
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Integer[] keys = this.keys;
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for (Integer key : keys) {
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bh.consume(map.compute(key, (k, old) -> k));
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@ -131,7 +151,7 @@ public class TreeMapUpdate {
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@Benchmark
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public Map<Integer, Integer> computeIfPresent(Blackhole bh) {
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Map<Integer, Integer> map = supplier.get();
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Map<Integer, Integer> map = transformer.apply(supplier.get());
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Integer[] keys = this.keys;
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for (Integer key : keys) {
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bh.consume(map.computeIfPresent(key, (k, old) -> k));
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@ -141,7 +161,7 @@ public class TreeMapUpdate {
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@Benchmark
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public Map<Integer, Integer> merge(Blackhole bh) {
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Map<Integer, Integer> map = supplier.get();
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Map<Integer, Integer> map = transformer.apply(supplier.get());
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Integer[] keys = this.keys;
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for (Integer key : keys) {
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bh.consume(map.merge(key, key, (k1, k2) -> k1));
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