--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/LongMap.java Fri May 17 15:53:21 2019 +0200
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/LongMap.java Fri May 17 16:02:27 2019 +0200
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -25,37 +25,232 @@
package jdk.jfr.consumer;
-import java.util.HashMap;
-import java.util.Iterator;
+import java.util.BitSet;
+import java.util.function.Consumer;
+import java.util.function.LongConsumer;
+
+@SuppressWarnings("unchecked")
+final class LongMap<T> {
+ private static final int MAXIMUM_CAPACITY = 1 << 30;
+ private static final long[] EMPTY_KEYS = new long[0];
+ private static final Object[] EMPTY_OBJECTS = new Object[0];
+ private static final int DEFAULT_SIZE = 32;
+ private static final Object NULL_OBJECT = new Object();
+
+ private final int bitCount;
+ private BitSet bitSet;
+ private long[] keys = EMPTY_KEYS;
+ private T[] objects = (T[]) EMPTY_OBJECTS;
+ private int count;
+ private int shift;
+
+ public LongMap() {
+ this.bitCount = 0;
+ }
+
+ public LongMap(int markBits) {
+ this.bitCount = markBits;
+ this.bitSet = new BitSet();
+ }
+
+ // Should be 2^n
+ private void initialize(int capacity) {
+ keys = new long[capacity];
+ objects = (T[]) new Object[capacity];
+ shift = 64 - (31 - Integer.numberOfLeadingZeros(capacity));
+ }
+
+ public void claimBits() {
+ // flip last bit back and forth to make bitset expand to max size
+ int lastBit = bitSetIndex(objects.length - 1, bitCount -1);
+ bitSet.flip(lastBit);
+ bitSet.flip(lastBit);
+ }
-/**
- * Commonly used data structure for looking up objects given an id (long value)
- *
- * TODO: Implement without using Map and Long objects, to minimize allocation
- *
- * @param <T>
- */
-final class LongMap<T> implements Iterable<T> {
- private final HashMap<Long, T> map;
+ public void setId(long id, int bitIndex) {
+ int bitSetIndex = bitSetIndex(tableIndexOf(id), bitIndex);
+ bitSet.set(bitSetIndex, true);
+ }
+
+ public void clearId(long id, int bitIndex) {
+ int bitSetIndex = bitSetIndex(tableIndexOf(id), bitIndex);
+ bitSet.set(bitSetIndex, false);
+ }
+
+ public boolean isSetId(long id, int bitIndex) {
+ int bitSetIndex = bitSetIndex(tableIndexOf(id), bitIndex);
+ return bitSet.get(bitSetIndex);
+ }
+
+ private int bitSetIndex(int tableIndex, int bitIndex) {
+ return bitCount * tableIndex + bitIndex;
+ }
- LongMap() {
- map = new HashMap<>(101);
+ private int tableIndexOf(long id) {
+ int index = index(id);
+ while (true) {
+ if (objects[index] == null) {
+ throw new InternalError("Unknown id");
+ }
+ if (keys[index] == id) {
+ return index;
+ }
+ index++;
+ if (index == keys.length) {
+ index = 0;
+ }
+ }
+ }
+
+ public boolean hasKey(long id) {
+ int index = index(id);
+ while (true) {
+ if (objects[index] == null) {
+ return false;
+ }
+ if (keys[index] == id) {
+ return true;
+ }
+ index++;
+ if (index == keys.length) {
+ index = 0;
+ }
+ }
}
- void put(long id, T object) {
- map.put(id, object);
- }
-
- T get(long id) {
- return map.get(id);
+ public void expand(int size) {
+ int l = 4 * size / 3;
+ if (l <= keys.length) {
+ return;
+ }
+ int n = tableSizeFor(l);
+ LongMap<T> temp = new LongMap<>(bitCount);
+ temp.initialize(n);
+ // Optimization, avoid growing while copying bits
+ if (bitCount > 0 && !bitSet.isEmpty()) {
+ temp.claimBits();
+ claimBits();
+ }
+ for (int tIndex = 0; tIndex < keys.length; tIndex++) {
+ T o = objects[tIndex];
+ if (o != null) {
+ long key = keys[tIndex];
+ temp.put(key, o);
+ if (bitCount != 0) {
+ for (int bIndex = 0; bIndex < bitCount; bIndex++) {
+ boolean bitValue = isSetId(key, bIndex);
+ if (bitValue) {
+ temp.setId(key, bIndex);
+ }
+ }
+ }
+ }
+ }
+ keys = temp.keys;
+ objects = temp.objects;
+ shift = temp.shift;
+ bitSet = temp.bitSet;
}
- @Override
- public Iterator<T> iterator() {
- return map.values().iterator();
+ public void put(long id, T object) {
+ if (keys == EMPTY_KEYS) {
+ // Lazy initialization
+ initialize(DEFAULT_SIZE);
+ }
+ if (count > 3 * keys.length / 4) {
+ expand(2 * keys.length);
+ }
+ if (object == null) {
+ object = (T) NULL_OBJECT;
+ }
+
+ int index = index(id);
+ // probe for empty slot
+ while (true) {
+ if (objects[index] == null) {
+ keys[index] = id;
+ objects[index] = object;
+ count++;
+ return;
+ }
+ // if it already exists, replace
+ if (keys[index] == id) {
+ objects[index] = object;
+ return;
+ }
+ index++;
+ if (index == keys.length) {
+ index = 0;
+ }
+ }
+ }
+ public T getAt(int tableIndex) {
+ T o = objects[tableIndex];
+ return o == NULL_OBJECT ? null : o;
}
- Iterator<Long> keys() {
- return map.keySet().iterator();
+ public T get(long id) {
+ if (keys == EMPTY_KEYS) {
+ return null;
+ }
+ int index = index(id);
+ while (true) {
+ if (objects[index] == null) {
+ return null;
+ }
+ if (keys[index] == id) {
+ return getAt(index);
+ }
+ index++;
+ if (index == keys.length) {
+ index = 0;
+ }
+ }
+ }
+
+ private int index(long id) {
+// int hash = (int) (id ^ (id >>> 32));
+// return hash & (keys.length - 1);
+ return (int) ((id * -7046029254386353131L) >>> shift);
+ }
+
+ // Copied from HashMap::tableSizeFor
+ private static final int tableSizeFor(int cap) {
+ int n = -1 >>> Integer.numberOfLeadingZeros(cap - 1);
+ return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
+ }
+
+ public void forEachKey(LongConsumer keyTraverser) {
+ for (int i = 0; i < keys.length; i++) {
+ if (objects[i] != null) {
+ keyTraverser.accept(keys[i]);
+ }
+ }
+ }
+
+ public void forEach(Consumer<T> consumer) {
+ for (int i = 0; i < keys.length; i++) {
+ T o = objects[i];
+ if (o != null) {
+ consumer.accept(o);
+ }
+ }
+ }
+
+ public int size() {
+ return count;
+ }
+
+ public String toString() {
+ StringBuilder sb = new StringBuilder();
+ for (int i = 0; i < objects.length; i++) {
+ sb.append(i);
+ sb.append(": id=");
+ sb.append(keys[i]);
+ sb.append(" ");
+ sb.append(objects[i]);
+ sb.append("\n");
+ }
+ return sb.toString();
}
}