*/
package org.opendaylight.yangtools.util;
+import static com.google.common.base.Preconditions.checkArgument;
+import static java.util.Objects.requireNonNull;
+
import com.google.common.annotations.Beta;
-import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.UnmodifiableIterator;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.List;
import java.util.Map;
import java.util.Set;
-import javax.annotation.Nonnull;
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
/**
* Implementation of the {@link Map} interface which stores a set of immutable mappings using a key-to-offset map and
* a backing array. This is useful for situations where the same key set is shared across a multitude of maps, as this
* class uses a global cache to share the key-to-offset mapping.
*
+ * <p>
+ * In case the set of keys is statically known, you can use {@link ImmutableOffsetMapTemplate} to efficiently create
+ * {@link ImmutableOffsetMap} instances.
+ *
* @param <K> the type of keys maintained by this map
* @param <V> the type of mapped values
*/
static final class Ordered<K, V> extends ImmutableOffsetMap<K, V> {
private static final long serialVersionUID = 1L;
- Ordered(final Map<K, Integer> offsets, final V[] objects) {
+ Ordered(final ImmutableMap<K, Integer> offsets, final V[] objects) {
super(offsets, objects);
}
- @Nonnull
@Override
- public MutableOffsetMap<K, V> toModifiableMap() {
+ public @NonNull MutableOffsetMap<K, V> toModifiableMap() {
return MutableOffsetMap.orderedCopyOf(this);
}
static final class Unordered<K, V> extends ImmutableOffsetMap<K, V> {
private static final long serialVersionUID = 1L;
- Unordered(final Map<K, Integer> offsets, final V[] objects) {
+ Unordered(final ImmutableMap<K, Integer> offsets, final V[] objects) {
super(offsets, objects);
}
- @Nonnull
@Override
- public MutableOffsetMap<K, V> toModifiableMap() {
+ public @NonNull MutableOffsetMap<K, V> toModifiableMap() {
return MutableOffsetMap.unorderedCopyOf(this);
}
private static final long serialVersionUID = 1L;
- private final transient Map<K, Integer> offsets;
- private final transient V[] objects;
+ private final transient @NonNull ImmutableMap<K, Integer> offsets;
+ private final transient @NonNull V[] objects;
private transient int hashCode;
/**
* @param objects Array of value object, may not be null. The array is stored as is, the caller
* is responsible for ensuring its contents remain unmodified.
*/
- ImmutableOffsetMap(@Nonnull final Map<K, Integer> offsets, @Nonnull final V[] objects) {
- this.offsets = Preconditions.checkNotNull(offsets);
- this.objects = Preconditions.checkNotNull(objects);
- Preconditions.checkArgument(offsets.size() == objects.length);
+ ImmutableOffsetMap(final ImmutableMap<K, Integer> offsets, final V[] objects) {
+ this.offsets = requireNonNull(offsets);
+ this.objects = requireNonNull(objects);
+ checkArgument(offsets.size() == objects.length);
}
- @Nonnull
@Override
- public abstract MutableOffsetMap<K, V> toModifiableMap();
+ public abstract @NonNull MutableOffsetMap<K, V> toModifiableMap();
abstract void setFields(List<K> keys, V[] values) throws IOException;
/**
- * Create an {@link ImmutableOffsetMap} as a copy of an existing map. This
- * is actually not completely true, as this method returns an
- * {@link ImmutableMap} for empty and singleton inputs, as those are more
- * memory-efficient. This method also recognizes {@link ImmutableOffsetMap}
- * on input, and returns it back without doing anything else. It also
- * recognizes {@link MutableOffsetMap} (as returned by
- * {@link #toModifiableMap()}) and makes an efficient copy of its contents.
- * All other maps are converted to an {@link ImmutableOffsetMap} with the
- * same iteration order as input.
+ * Create an {@link ImmutableOffsetMap} as a copy of an existing map. This is actually not completely true, as this
+ * method returns an {@link ImmutableMap} for empty and singleton inputs, as those are more memory-efficient. This
+ * method also recognizes {@link ImmutableOffsetMap} and {@link SharedSingletonMap} on input, and returns it back
+ * without doing anything else. It also recognizes {@link MutableOffsetMap} (as returned by
+ * {@link #toModifiableMap()}) and makes an efficient copy of its contents. All other maps are converted to an
+ * {@link ImmutableOffsetMap} with the same iteration order as input.
*
- * @param map
- * Input map, may not be null.
+ * @param map Input map, may not be null.
* @return An isolated, immutable copy of the input map
+ * @throws NullPointerException if {@code map} or any of its elements is null.
*/
- @Nonnull public static <K, V> Map<K, V> orderedCopyOf(@Nonnull final Map<K, V> map) {
- // Prevent a copy. Note that ImmutableMap is not listed here because of its potentially larger keySet overhead.
- if (map instanceof ImmutableOffsetMap || map instanceof SharedSingletonMap) {
- return map;
- }
-
- // Familiar and efficient to copy
- if (map instanceof MutableOffsetMap) {
- return ((MutableOffsetMap<K, V>) map).toUnmodifiableMap();
+ public static <K, V> @NonNull Map<K, V> orderedCopyOf(final @NonNull Map<K, V> map) {
+ final Map<K, V> common = commonCopy(map);
+ if (common != null) {
+ return common;
}
final int size = map.size();
- if (size == 0) {
- // Shares a single object
- return ImmutableMap.of();
- }
if (size == 1) {
// Efficient single-entry implementation
final Entry<K, V> e = map.entrySet().iterator().next();
return SharedSingletonMap.orderedOf(e.getKey(), e.getValue());
}
- final Map<K, Integer> offsets = OffsetMapCache.orderedOffsets(map.keySet());
+ final ImmutableMap<K, Integer> offsets = OffsetMapCache.orderedOffsets(map.keySet());
@SuppressWarnings("unchecked")
final V[] array = (V[]) new Object[offsets.size()];
for (Entry<K, V> e : map.entrySet()) {
}
/**
- * Create an {@link ImmutableOffsetMap} as a copy of an existing map. This
- * is actually not completely true, as this method returns an
- * {@link ImmutableMap} for empty and singleton inputs, as those are more
- * memory-efficient. This method also recognizes {@link ImmutableOffsetMap}
- * on input, and returns it back without doing anything else. It also
- * recognizes {@link MutableOffsetMap} (as returned by
- * {@link #toModifiableMap()}) and makes an efficient copy of its contents.
- * All other maps are converted to an {@link ImmutableOffsetMap}. Iterator
- * order is not guaranteed to be retained.
+ * Create an {@link ImmutableOffsetMap} as a copy of an existing map. This is actually not completely true, as this
+ * method returns an {@link ImmutableMap} for empty and singleton inputs, as those are more memory-efficient. This
+ * method also recognizes {@link ImmutableOffsetMap} and {@link SharedSingletonMap} on input, and returns it back
+ * without doing anything else. It also recognizes {@link MutableOffsetMap} (as returned by
+ * {@link #toModifiableMap()}) and makes an efficient copy of its contents. All other maps are converted to an
+ * {@link ImmutableOffsetMap}. Iterator order is not guaranteed to be retained.
*
- * @param map
- * Input map, may not be null.
+ * @param map Input map, may not be null.
* @return An isolated, immutable copy of the input map
+ * @throws NullPointerException if {@code map} or any of its elements is null.
*/
- @Nonnull public static <K, V> Map<K, V> unorderedCopyOf(@Nonnull final Map<K, V> map) {
- // Prevent a copy. Note that ImmutableMap is not listed here because of its potentially larger keySet overhead.
- if (map instanceof ImmutableOffsetMap || map instanceof SharedSingletonMap) {
- return map;
+ public static <K, V> @NonNull Map<K, V> unorderedCopyOf(final @NonNull Map<K, V> map) {
+ final Map<K, V> common = commonCopy(map);
+ if (common != null) {
+ return common;
}
- // Familiar and efficient to copy
- if (map instanceof MutableOffsetMap) {
- return ((MutableOffsetMap<K, V>) map).toUnmodifiableMap();
- }
-
- final int size = map.size();
- if (size == 0) {
- // Shares a single object
- return ImmutableMap.of();
- }
- if (size == 1) {
+ if (map.size() == 1) {
// Efficient single-entry implementation
final Entry<K, V> e = map.entrySet().iterator().next();
return SharedSingletonMap.unorderedOf(e.getKey(), e.getValue());
}
- final Map<K, Integer> offsets = OffsetMapCache.unorderedOffsets(map.keySet());
+ final ImmutableMap<K, Integer> offsets = OffsetMapCache.unorderedOffsets(map.keySet());
@SuppressWarnings("unchecked")
final V[] array = (V[]) new Object[offsets.size()];
for (Entry<K, V> e : map.entrySet()) {
return new Unordered<>(offsets, array);
}
+ private static <K, V> @Nullable Map<K, V> commonCopy(final @NonNull Map<K, V> map) {
+ // Prevent a copy. Note that ImmutableMap is not listed here because of its potentially larger keySet overhead.
+ if (map instanceof ImmutableOffsetMap || map instanceof SharedSingletonMap) {
+ return map;
+ }
+
+ // Familiar and efficient to copy
+ if (map instanceof MutableOffsetMap) {
+ return ((MutableOffsetMap<K, V>) map).toUnmodifiableMap();
+ }
+
+ if (map.isEmpty()) {
+ // Shares a single object
+ return ImmutableMap.of();
+ }
+
+ return null;
+ }
+
@Override
public final int size() {
return offsets.size();
@Override
public final V get(final Object key) {
- final Integer offset = offsets.get(key);
- return offset == null ? null : objects[offset];
+ Integer offset;
+ return (offset = offsets.get(key)) == null ? null : objects[offset];
}
@Override
@Override
@SuppressWarnings("checkstyle:parameterName")
- public final void putAll(@Nonnull final Map<? extends K, ? extends V> m) {
+ public final void putAll(final Map<? extends K, ? extends V> m) {
throw new UnsupportedOperationException();
}
return offsets.keySet();
}
- @Nonnull
@Override
- public final Collection<V> values() {
+ public final @NonNull Collection<V> values() {
return new ConstantArrayCollection<>(objects);
}
- @Nonnull
@Override
- public final Set<Entry<K, V>> entrySet() {
+ public final @NonNull Set<Entry<K, V>> entrySet() {
return new EntrySet();
}
final Iterator<K> it = offsets.keySet().iterator();
int offset = 0;
while (it.hasNext()) {
- sb.append(it.next());
- sb.append('=');
- sb.append(objects[offset++]);
+ sb.append(it.next()).append('=').append(objects[offset++]);
if (it.hasNext()) {
sb.append(", ");
return sb.append('}').toString();
}
- final Map<K, Integer> offsets() {
+ final @NonNull ImmutableMap<K, Integer> offsets() {
return offsets;
}
- final V[] objects() {
+ final @NonNull V[] objects() {
return objects;
}
private final class EntrySet extends AbstractSet<Entry<K, V>> {
- @Nonnull
@Override
- public Iterator<Entry<K, V>> iterator() {
+ public @NonNull Iterator<Entry<K, V>> iterator() {
final Iterator<Entry<K, Integer>> it = offsets.entrySet().iterator();
-
- return new UnmodifiableIterator<Entry<K, V>>() {
+ return new UnmodifiableIterator<>() {
@Override
public boolean hasNext() {
return it.hasNext();
private static final Field OFFSETS_FIELD = fieldFor("offsets");
private static final Field ARRAY_FIELD = fieldFor("objects");
- private static Field fieldFor(final String name) {
+ private static @NonNull Field fieldFor(final @NonNull String name) {
final Field f;
try {
f = ImmutableOffsetMap.class.getDeclaredField(name);
return f;
}
- private static void setField(final ImmutableOffsetMap<?, ?> map, final Field field, final Object value)
- throws IOException {
+ @SuppressFBWarnings(value = "UPM_UNCALLED_PRIVATE_METHOD",
+ justification = "https://github.com/spotbugs/spotbugs/issues/811")
+ private static void setField(final @NonNull ImmutableOffsetMap<?, ?> map, final @NonNull Field field,
+ final Object value) throws IOException {
try {
field.set(map, value);
} catch (IllegalArgumentException | IllegalAccessException e) {
}
@SuppressWarnings("unchecked")
- private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException {
+ private void readObject(final @NonNull ObjectInputStream in) throws IOException, ClassNotFoundException {
final int s = in.readInt();
final List<K> keys = new ArrayList<>(s);
Code Review / yangtools.git / blobdiff