*/
package org.opendaylight.yangtools.util;
+import static com.google.common.base.Preconditions.checkState;
+import static java.util.Objects.requireNonNull;
+
import com.google.common.annotations.Beta;
import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.ArrayList;
import java.util.Arrays;
+import java.util.Collections;
import java.util.ConcurrentModificationException;
+import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
/**
* A mutable version of {@link ImmutableOffsetMap}. It inherits the set of mappings from the immutable version and
* </code>
* results in source and result sharing the backing objects.
*
- * This map does not support null keys nor values.
+ * <p>This map does not support null keys nor values.
*
* @param <K> the type of keys maintained by this map
* @param <V> the type of mapped values
*/
@Beta
-public final class MutableOffsetMap<K, V> extends AbstractMap<K, V> implements Cloneable, ModifiableMapPhase<K, V> {
+public abstract class MutableOffsetMap<K, V> extends AbstractMap<K, V> implements Cloneable, ModifiableMapPhase<K, V> {
+ static final class Ordered<K, V> extends MutableOffsetMap<K, V> {
+ Ordered() {
+ }
+
+ Ordered(final Map<K, V> source) {
+ super(OffsetMapCache.orderedOffsets(source.keySet()), source);
+ }
+
+ Ordered(final ImmutableMap<K, Integer> offsets, final V[] objects) {
+ super(offsets, objects);
+ }
+
+ @Override
+ Object removedObject() {
+ return REMOVED;
+ }
+
+ @Override
+ UnmodifiableMapPhase<K, V> modifiedMap(final List<K> keys, final V[] values) {
+ return new ImmutableOffsetMap.Ordered<>(OffsetMapCache.orderedOffsets(keys), values);
+ }
+
+ @Override
+ UnmodifiableMapPhase<K, V> unmodifiedMap(final ImmutableMap<K, Integer> offsetMap, final V[] values) {
+ return new ImmutableOffsetMap.Ordered<>(offsetMap, values);
+ }
+
+ @Override
+ SharedSingletonMap<K, V> singletonMap() {
+ return SharedSingletonMap.orderedCopyOf(this);
+ }
+
+ @Override
+ HashMap<K, V> createNewKeys() {
+ return new LinkedHashMap<>();
+ }
+ }
+
+ static final class Unordered<K, V> extends MutableOffsetMap<K, V> {
+ Unordered() {
+ }
+
+ Unordered(final Map<K, V> source) {
+ super(OffsetMapCache.unorderedOffsets(source.keySet()), source);
+ }
+
+ Unordered(final ImmutableMap<K, Integer> offsets, final V[] objects) {
+ super(offsets, objects);
+ }
+
+ @Override
+ Object removedObject() {
+ return null;
+ }
+
+ @Override
+ UnmodifiableMapPhase<K, V> modifiedMap(final List<K> keys, final V[] values) {
+ final ImmutableMap<K, Integer> offsets = OffsetMapCache.unorderedOffsets(keys);
+ return new ImmutableOffsetMap.Unordered<>(offsets, OffsetMapCache.adjustedArray(offsets, keys, values));
+ }
+
+ @Override
+ UnmodifiableMapPhase<K, V> unmodifiedMap(final ImmutableMap<K, Integer> offsetMap, final V[] values) {
+ return new ImmutableOffsetMap.Unordered<>(offsetMap, values);
+ }
+
+ @Override
+ SharedSingletonMap<K, V> singletonMap() {
+ return SharedSingletonMap.unorderedCopyOf(this);
+ }
+
+ @Override
+ HashMap<K, V> createNewKeys() {
+ return new HashMap<>();
+ }
+ }
+
private static final Object[] EMPTY_ARRAY = new Object[0];
- private final Map<K, Integer> offsets;
- private final Map<K, V> newKeys;
- private V[] objects;
+ private static final Object REMOVED = new Object();
+
+ private final ImmutableMap<K, Integer> offsets;
+ private HashMap<K, V> newKeys;
+ private Object[] objects;
private int removed = 0;
+
+ // Fail-fast iterator guard, see java.util.ArrayList for reference.
+ @SuppressFBWarnings("VO_VOLATILE_INCREMENT")
private transient volatile int modCount;
private boolean needClone = true;
- public MutableOffsetMap() {
- this(ImmutableList.<K>of());
+ MutableOffsetMap(final ImmutableMap<K, Integer> offsets, final Object[] objects) {
+ this.offsets = requireNonNull(offsets);
+ this.objects = requireNonNull(objects);
}
- @VisibleForTesting
- @SuppressWarnings("unchecked")
- MutableOffsetMap(final List<K> keySet) {
- if (!keySet.isEmpty()) {
- removed = keySet.size();
- offsets = OffsetMapCache.orderedOffsets(keySet);
- objects = (V[])new Object[removed];
- } else {
- offsets = ImmutableMap.of();
- objects = (V[])EMPTY_ARRAY;
+ MutableOffsetMap() {
+ this(ImmutableMap.of(), EMPTY_ARRAY);
+ }
+
+ MutableOffsetMap(final ImmutableMap<K, Integer> offsets, final Map<K, V> source) {
+ this(offsets, new Object[offsets.size()]);
+
+ for (Entry<K, V> e : source.entrySet()) {
+ objects[offsets.get(e.getKey())] = requireNonNull(e.getValue());
}
- this.newKeys = new LinkedHashMap<>();
+ this.needClone = false;
}
- protected MutableOffsetMap(final MutableOffsetMap<K, V> m) {
- this.offsets = m.offsets;
- this.objects = m.objects;
- this.newKeys = new LinkedHashMap<>(m.newKeys);
- this.removed = m.removed;
- }
+ /**
+ * Create a {@link MutableOffsetMap} of the specified map, retaining its iteration order.
+ *
+ * @param map input map
+ * @return MutableOffsetMap with the same iteration order
+ * @throws NullPointerException if {@code map} is null
+ */
+ public static <K, V> @NonNull MutableOffsetMap<K, V> orderedCopyOf(final Map<K, V> map) {
+ if (map instanceof Ordered) {
+ return ((Ordered<K, V>) map).clone();
+ }
+ if (map instanceof ImmutableOffsetMap) {
+ final ImmutableOffsetMap<K, V> om = (ImmutableOffsetMap<K, V>) map;
+ return new Ordered<>(om.offsets(), om.objects());
+ }
- private MutableOffsetMap(final Map<K, Integer> offsets, final V[] objects) {
- this.offsets = Preconditions.checkNotNull(offsets);
- this.objects = Preconditions.checkNotNull(objects);
- this.newKeys = new LinkedHashMap<>();
+ return new Ordered<>(map);
}
- public static <K, V> MutableOffsetMap<K, V> copyOf(final Map<K, V> m) {
- if (m instanceof MutableOffsetMap) {
- return ((MutableOffsetMap<K, V>) m).clone();
+ /**
+ * Create a {@link MutableOffsetMap} of the specified map, potentially with a different iteration order.
+ *
+ * @param map input map
+ * @return MutableOffsetMap with undefined iteration order
+ * @throws NullPointerException if {@code map} is null
+ */
+ public static <K, V> @NonNull MutableOffsetMap<K, V> unorderedCopyOf(final Map<K, V> map) {
+ if (map instanceof Unordered) {
+ return ((Unordered<K, V>) map).clone();
}
- if (m instanceof ImmutableOffsetMap) {
- final ImmutableOffsetMap<K, V> map = (ImmutableOffsetMap<K, V>) m;
- return new MutableOffsetMap<>(map.offsets(), map.objects());
+ if (map instanceof ImmutableOffsetMap) {
+ final ImmutableOffsetMap<K, V> om = (ImmutableOffsetMap<K, V>) map;
+ return new Unordered<>(om.offsets(), om.objects());
}
- @SuppressWarnings("unchecked")
- final V[] values = (V[])m.values().toArray();
- return new MutableOffsetMap<>(OffsetMapCache.orderedOffsets(m.keySet()), values);
+ return new Unordered<>(map);
}
- public static <K, V> MutableOffsetMap<K, V> forOffsets(final Map<K, Integer> offsets) {
- @SuppressWarnings("unchecked")
- final V[] objects = (V[]) new Object[offsets.size()];
- return new MutableOffsetMap<>(offsets, objects);
+ /**
+ * Create an empty {@link MutableOffsetMap} which has an iteration order matching the insertion order.
+ *
+ * @return MutableOffsetMap which preserves insertion order
+ */
+ public static <K, V> @NonNull MutableOffsetMap<K, V> ordered() {
+ return new MutableOffsetMap.Ordered<>();
+ }
+
+ /**
+ * Create an empty {@link MutableOffsetMap} which has unspecified iteration order.
+ *
+ * @return An MutableOffsetMap
+ */
+ public static <K, V> @NonNull MutableOffsetMap<K, V> unordered() {
+ return new MutableOffsetMap.Unordered<>();
}
+ abstract Object removedObject();
+
+ abstract UnmodifiableMapPhase<K, V> modifiedMap(List<K> keys, V[] values);
+
+ abstract UnmodifiableMapPhase<K, V> unmodifiedMap(ImmutableMap<K, Integer> offsetMap, V[] values);
+
+ abstract SharedSingletonMap<K, V> singletonMap();
+
@Override
- public int size() {
- return offsets.size() + newKeys.size() - removed;
+ public final int size() {
+ return offsets.size() - removed + (newKeys == null ? 0 : newKeys.size());
}
@Override
- public boolean isEmpty() {
+ public final boolean isEmpty() {
return size() == 0;
}
@Override
- public boolean containsKey(final Object key) {
+ public final boolean containsKey(final Object key) {
final Integer offset = offsets.get(key);
- return offset == null ? newKeys.containsKey(key) : objects[offset] != null;
+ if (offset != null) {
+ final Object obj = objects[offset];
+ if (!REMOVED.equals(obj)) {
+ return obj != null;
+ }
+ }
+
+ return newKeys != null && newKeys.containsKey(key);
}
@Override
- public V get(final Object key) {
+ public final V get(final Object key) {
final Integer offset = offsets.get(key);
- return offset == null ? newKeys.get(key) : objects[offset];
+ if (offset != null) {
+ final Object obj = objects[offset];
+
+ /*
+ * This is a bit tricky: Ordered will put REMOVED to removed objects to retain strict insertion order.
+ * Unordered will add null, indicating that the slot may be reused in future. Hence if we see a REMOVED
+ * marker, we need to fall back to checking with new keys.
+ */
+ if (!REMOVED.equals(obj)) {
+ @SuppressWarnings("unchecked")
+ final V ret = (V)obj;
+ return ret;
+ }
+ }
+
+ return newKeys == null ? null : newKeys.get(key);
}
private void cloneArray() {
if (needClone) {
needClone = false;
- if (!EMPTY_ARRAY.equals(objects)) {
+ if (objects.length != 0) {
objects = objects.clone();
}
}
}
@Override
- public V put(final K key, final V value) {
- Preconditions.checkNotNull(value);
- final Integer offset = offsets.get(Preconditions.checkNotNull(key));
- if (offset == null) {
- final V ret = newKeys.put(key, value);
- if (ret == null) {
- modCount++;
+ public final V put(final K key, final V value) {
+ requireNonNull(value);
+ final Integer offset = offsets.get(requireNonNull(key));
+ if (offset != null) {
+ final Object obj = objects[offset];
+
+ /*
+ * Put which can potentially replace something in objects. Replacing an object does not cause iterators
+ * to be invalidated and does follow insertion order (since it is not a fresh insert). If the object has
+ * been removed, we fall back to newKeys.
+ */
+ if (!REMOVED.equals(obj)) {
+ @SuppressWarnings("unchecked")
+ final V ret = (V)obj;
+
+ cloneArray();
+ objects[offset] = value;
+ if (ret == null) {
+ modCount++;
+ removed--;
+ }
+
+ return ret;
}
- return ret;
}
- cloneArray();
- final V ret = objects[offset];
- objects[offset] = value;
+ if (newKeys == null) {
+ newKeys = createNewKeys();
+ }
+ final V ret = newKeys.put(key, value);
if (ret == null) {
modCount++;
- removed--;
}
-
return ret;
}
@Override
- public V remove(final Object key) {
+ public final V remove(final Object key) {
final Integer offset = offsets.get(key);
- if (offset == null) {
- final V ret = newKeys.remove(key);
- if (ret != null) {
- modCount++;
+ if (offset != null) {
+ final Object obj = objects[offset];
+
+ /*
+ * A previous remove() may have indicated that the objects slot cannot be reused. In that case we need
+ * to fall back to checking with newKeys.
+ */
+ if (!REMOVED.equals(obj)) {
+ cloneArray();
+
+ @SuppressWarnings("unchecked")
+ final V ret = (V)obj;
+ objects[offset] = removedObject();
+ if (ret != null) {
+ modCount++;
+ removed++;
+ }
+ return ret;
}
- return ret;
}
- cloneArray();
- final V ret = objects[offset];
- objects[offset] = null;
+ if (newKeys == null) {
+ return null;
+ }
+ final V ret = newKeys.remove(key);
if (ret != null) {
modCount++;
- removed++;
}
return ret;
}
@Override
- public void clear() {
+ public final void clear() {
if (size() != 0) {
- newKeys.clear();
+ if (newKeys != null) {
+ newKeys.clear();
+ }
cloneArray();
- Arrays.fill(objects, null);
+ Arrays.fill(objects, removedObject());
removed = objects.length;
modCount++;
}
}
@Override
- public Set<Entry<K, V>> entrySet() {
+ public final @NonNull Set<Entry<K, V>> entrySet() {
return new EntrySet();
}
@Override
- public Map<K, V> toUnmodifiableMap() {
- if (newKeys.isEmpty() && removed == 0) {
+ public @NonNull Map<K, V> toUnmodifiableMap() {
+ if (removed == 0 && noNewKeys()) {
// Make sure next modification clones the array, as we leak it to the map we return.
needClone = true;
+
+ // We have ended up with no removed objects, hence this cast is safe
+ @SuppressWarnings("unchecked")
+ final V[] values = (V[])objects;
+
/*
* TODO: we could track the ImmutableOffsetMap from which this one was instantiated and if we do not
* perform any modifications, just return the original instance. The trade-off is increased complexity
* and an additional field in this class.
*/
- return new ImmutableOffsetMap<>(offsets, objects);
+ return unmodifiedMap(offsets, values);
}
final int s = size();
return ImmutableMap.of();
}
if (s == 1) {
- return ImmutableMap.copyOf(this);
+ return singletonMap();
}
// Construct the set of keys
if (removed != 0) {
if (removed != offsets.size()) {
for (Entry<K, Integer> e : offsets.entrySet()) {
- if (objects[e.getValue()] != null) {
+ final Object o = objects[e.getValue()];
+ if (o != null && !REMOVED.equals(o)) {
keyset.add(e.getKey());
}
}
} else {
keyset.addAll(offsets.keySet());
}
- keyset.addAll(newKeys.keySet());
+ if (newKeys != null) {
+ keyset.addAll(newKeys.keySet());
+ }
// Construct the values
@SuppressWarnings("unchecked")
final V[] values = (V[])new Object[keyset.size()];
- int i = 0;
+ int offset = 0;
if (removed != 0) {
if (removed != offsets.size()) {
for (Entry<K, Integer> e : offsets.entrySet()) {
- final V o = objects[e.getValue()];
- if (o != null) {
- values[i++] = o;
+ final Object o = objects[e.getValue()];
+ if (o != null && !REMOVED.equals(o)) {
+ @SuppressWarnings("unchecked")
+ final V v = (V) o;
+ values[offset++] = v;
}
}
}
} else {
System.arraycopy(objects, 0, values, 0, offsets.size());
- i = offsets.size();
+ offset = offsets.size();
}
- for (V v : newKeys.values()) {
- values[i++] = v;
+ if (newKeys != null) {
+ for (V v : newKeys.values()) {
+ values[offset++] = v;
+ }
}
- return new ImmutableOffsetMap<>(OffsetMapCache.orderedOffsets(keyset), values);
+ return modifiedMap(keyset, values);
}
+ @SuppressWarnings("unchecked")
@Override
public MutableOffsetMap<K, V> clone() {
- // FIXME: super.clone()
- return new MutableOffsetMap<K, V>(this);
+ final MutableOffsetMap<K, V> ret;
+
+ try {
+ ret = (MutableOffsetMap<K, V>) super.clone();
+ } catch (CloneNotSupportedException e) {
+ throw new IllegalStateException("Clone is expected to work", e);
+ }
+
+ ret.newKeys = newKeys == null ? null : (HashMap<K, V>) newKeys.clone();
+ ret.needClone = true;
+ return ret;
}
@Override
- public int hashCode() {
+ public final int hashCode() {
int result = 0;
for (Entry<K, Integer> e : offsets.entrySet()) {
}
}
- return result + newKeys.hashCode();
+ return newKeys != null ? result + newKeys.hashCode() : result;
}
@Override
- public boolean equals(final Object o) {
- if (o == this) {
+ public final boolean equals(final Object obj) {
+ if (obj == this) {
return true;
}
- if (o == null) {
+ if (!(obj instanceof Map)) {
return false;
}
- if (o instanceof ImmutableOffsetMap) {
- final ImmutableOffsetMap<?, ?> om = (ImmutableOffsetMap<?, ?>) o;
- if (newKeys.isEmpty() && offsets == om.offsets() && Arrays.deepEquals(objects, om.objects())) {
- return true;
- }
- } else if (o instanceof MutableOffsetMap) {
- final MutableOffsetMap<?, ?> om = (MutableOffsetMap<?, ?>) o;
- if (offsets == om.offsets && Arrays.deepEquals(objects, om.objects) && newKeys.equals(om.newKeys)) {
- return true;
+ if (obj instanceof ImmutableOffsetMap) {
+ final ImmutableOffsetMap<?, ?> om = (ImmutableOffsetMap<?, ?>) obj;
+
+ if (noNewKeys() && offsets.equals(om.offsets())) {
+ return Arrays.deepEquals(objects, om.objects());
}
- } else if (o instanceof Map) {
- final Map<?, ?> om = (Map<?, ?>)o;
+ } else if (obj instanceof MutableOffsetMap) {
+ final MutableOffsetMap<?, ?> om = (MutableOffsetMap<?, ?>) obj;
- // Size and key sets have to match
- if (size() != om.size() || !keySet().equals(om.keySet())) {
- return false;
+ if (offsets.equals(om.offsets)) {
+ return Arrays.deepEquals(objects, om.objects) && equalNewKeys(om);
}
+ }
+
+ // Fall back to brute map compare
+ return mapEquals((Map<?, ?>)obj);
+ }
+
+ private boolean equalNewKeys(final MutableOffsetMap<?, ?> other) {
+ return noNewKeys() ? other.noNewKeys() : newKeys.equals(other.newKeys());
+ }
- try {
- // Ensure all newKeys are present. Note newKeys is guaranteed to
- // not contain null value.
+ private boolean mapEquals(final Map<?, ?> other) {
+ // Size and key sets have to match
+ if (size() != other.size() || !keySet().equals(other.keySet())) {
+ return false;
+ }
+
+ try {
+ if (newKeys != null) {
+ // Ensure all newKeys are present. Note newKeys is guaranteed to not contain a null value.
for (Entry<K, V> e : newKeys.entrySet()) {
- if (!e.getValue().equals(om.get(e.getKey()))) {
+ if (!e.getValue().equals(other.get(e.getKey()))) {
return false;
}
}
+ }
- // Ensure all objects are present
- for (Entry<K, Integer> e : offsets.entrySet()) {
- final V v = objects[e.getValue()];
- if (v != null && !v.equals(om.get(e.getKey()))) {
- return false;
- }
+ // Ensure all objects are present
+ for (Entry<K, Integer> e : offsets.entrySet()) {
+ final Object val = objects[e.getValue()];
+ if (val != null && !REMOVED.equals(val) && !val.equals(other.get(e.getKey()))) {
+ return false;
}
- } catch (ClassCastException e) {
- // Can be thrown by om.get() and indicate we have incompatible key types
- return false;
}
-
- return true;
+ } catch (ClassCastException e) {
+ // Can be thrown by other.get() and indicate we have incompatible key types
+ return false;
}
- return false;
+ return true;
}
@Override
- public Set<K> keySet() {
+ public final @NonNull Set<K> keySet() {
return new KeySet();
}
@VisibleForTesting
- boolean needClone() {
+ final boolean needClone() {
return needClone;
}
@VisibleForTesting
- Object array() {
+ final Object array() {
return objects;
}
@VisibleForTesting
- Object newKeys() {
- return newKeys;
+ final Object newKeys() {
+ return newKeys != null ? newKeys : ImmutableMap.of();
+ }
+
+ abstract HashMap<K, V> createNewKeys();
+
+ private boolean noNewKeys() {
+ return newKeys == null || newKeys.isEmpty();
}
private final class EntrySet extends AbstractSet<Entry<K, V>> {
@Override
- public Iterator<Entry<K, V>> iterator() {
- return new AbstractSetIterator<Entry<K, V>>() {
+ public @NonNull Iterator<Entry<K, V>> iterator() {
+ return new AbstractSetIterator<>() {
@Override
public Entry<K, V> next() {
final K key = nextKey();
}
@Override
+ @SuppressWarnings("checkstyle:parameterName")
public boolean contains(final Object o) {
if (!(o instanceof Entry)) {
return false;
}
@Override
+ @SuppressWarnings("checkstyle:parameterName")
public boolean add(final Entry<K, V> e) {
- Preconditions.checkNotNull(e.getValue());
- final V p = MutableOffsetMap.this.put(e.getKey(), e.getValue());
- return !e.getValue().equals(p);
+ final V v = requireNonNull(e.getValue());
+ final V p = MutableOffsetMap.this.put(e.getKey(), v);
+ return !v.equals(p);
}
@Override
+ @SuppressWarnings("checkstyle:parameterName")
public boolean remove(final Object o) {
if (!(o instanceof Entry)) {
return false;
private final class KeySet extends AbstractSet<K> {
@Override
- public Iterator<K> iterator() {
- return new AbstractSetIterator<K>() {
+ public @NonNull Iterator<K> iterator() {
+ return new AbstractSetIterator<>() {
@Override
public K next() {
return nextKey();
private abstract class AbstractSetIterator<E> implements Iterator<E> {
private final Iterator<Entry<K, Integer>> oldIterator = offsets.entrySet().iterator();
- private final Iterator<K> newIterator = newKeys.keySet().iterator();
+ private final Iterator<K> newIterator = newKeys == null ? Collections.emptyIterator()
+ : newKeys.keySet().iterator();
private int expectedModCount = modCount;
- private K currentKey, nextKey;
+ private @Nullable K currentKey = null;
+ private @Nullable K nextKey;
AbstractSetIterator() {
updateNextKey();
private void updateNextKey() {
while (oldIterator.hasNext()) {
final Entry<K, Integer> e = oldIterator.next();
- if (objects[e.getValue()] != null) {
+ final Object obj = objects[e.getValue()];
+ if (obj != null && !REMOVED.equals(obj)) {
nextKey = e.getKey();
return;
}
@Override
public final void remove() {
- Preconditions.checkState(currentKey != null);
-
checkModCount();
+ checkState(currentKey != null);
final Integer offset = offsets.get(currentKey);
if (offset != null) {
cloneArray();
- objects[offset] = null;
+ objects[offset] = removedObject();
removed++;
} else {
newIterator.remove();