First step in separation of core ChronicleHash functionality from Map and Set; Start Java 8 adoption; Bug fixes

2021-09-13 01:26:12 +00:00 · 2015-02-12 15:24:24 +07:00
parent 7bfaa87d5d
commit 16f85e4c5e
45 changed files with 2841 additions and 2279 deletions
@@ -0,0 +1,147 @@
+/*
+ * Copyright 2014 Higher Frequency Trading http://www.higherfrequencytrading.com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.openhft.chronicle.map;
+
+import net.openhft.chronicle.hash.impl.hashlookup.EntryConsumer;
+
+import java.util.*;
+
+/**
+ * Very inefficient (esp. if segments are large), but CORRECT implementation
+ */
+abstract class ChronicleMapIterator<K, V, E> implements Iterator<E>, EntryConsumer {
+
+    final AbstractChronicleMap<K, V> map;
+    private final Thread ownerThread = Thread.currentThread();
+    private final Queue<E> entryBuffer = new ArrayDeque<>();
+    private int segmentIndex;
+    VanillaContext<K, ?, ?, V, ?, ?> context;
+    E returned;
+
+    ChronicleMapIterator(AbstractChronicleMap<K, V> map) {
+        this.map = map;
+        segmentIndex = map.actualSegments() - 1;
+    }
+
+    private void checkSingleThreaded() {
+        if (ownerThread != Thread.currentThread()) {
+            throw new IllegalStateException(
+                    "Iterator should be accessed only from a single thread");
+        }
+    }
+
+    private void fillEntryBuffer() {
+        if (!entryBuffer.isEmpty())
+            return;
+        while (true) {
+            if (segmentIndex < 0)
+                return;
+            try (VanillaContext<K, ?, ?, V, ?, ?> c = map.mapContext()) {
+                context = c;
+                c.segmentIndex = segmentIndex;
+                segmentIndex--;
+                if (c.size() == 0)
+                    continue;
+                c.updateLock().lock();
+                c.initSegment();
+                c.hashLookup.forEach(this);
+                return;
+            } finally {
+                context = null;
+            }
+        }
+    }
+
+    @Override
+    public void accept(long hash, long pos) {
+        context.pos = pos;
+        context.initKeyFromPos();
+        try {
+            if (!context.containsKey()) // for replicated map
+                return;
+            entryBuffer.add(read());
+        } finally {
+            context.closeKeySearch();
+        }
+    }
+
+    abstract E read();
+
+    @Override
+    public boolean hasNext() {
+        checkSingleThreaded();
+        fillEntryBuffer();
+        return !entryBuffer.isEmpty();
+    }
+
+    @Override
+    public E next() {
+        checkSingleThreaded();
+        fillEntryBuffer();
+        E e;
+        if ((e = entryBuffer.poll()) == null)
+            throw new NoSuchElementException();
+        return returned = e;
+    }
+
+    @Override
+    public void remove() {
+        checkSingleThreaded();
+        if (returned == null)
+            throw new IllegalStateException();
+        removeReturned();
+        returned = null;
+    }
+
+    abstract void removeReturned();
+
+    static class OfEntries<K, V> extends ChronicleMapIterator<K, V, Map.Entry<K, V>> {
+
+        OfEntries(AbstractChronicleMap<K, V> map) {
+            super(map);
+        }
+
+        @Override
+        Map.Entry<K, V> read() {
+            K key = context.immutableKey();
+            V value = context.getUsing(null);
+            return new WriteThroughEntry<>(map, key, value);
+        }
+
+        @Override
+        void removeReturned() {
+            map.remove(returned.getKey(), returned.getValue());
+        }
+    }
+
+    static class OfKeys<K, V> extends ChronicleMapIterator<K, V, K> {
+
+        OfKeys(AbstractChronicleMap<K, V> map) {
+            super(map);
+        }
+
+        @Override
+        K read() {
+            return context.immutableKey();
+        }
+
+        @Override
+        void removeReturned() {
+            map.remove(returned);
+        }
+    }
+}