+/*
+ * (C) Copyright 2017 Pantheon Technologies, s.r.o. and others.
+ *
+ * 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 org.opendaylight.yangtools.triemap;
+
+import com.google.common.base.Preconditions;
+import com.google.common.base.Verify;
+import java.io.Externalizable;
+import java.io.IOException;
+import java.io.ObjectInput;
+import java.io.ObjectOutput;
+import java.io.ObjectStreamException;
+import java.util.Map.Entry;
+
+/**
+ * External serialization object for use with TrieMap objects. This hides the implementation details, such as object
+ * hierarchy. It also makes handling read-only snapshots more elegant.
+ *
+ * @author Robert Varga
+ */
+final class ExternalForm implements Externalizable {
+ private static final long serialVersionUID = 1L;
+
+ private TrieMap<Object, Object> map;
+ private boolean readOnly;
+
+ public ExternalForm() {
+ // For Externalizable
+ }
+
+ @SuppressWarnings({ "unchecked", "rawtypes" })
+ ExternalForm(final TrieMap<?, ?> map) {
+ this.map = ((TrieMap)map).readOnlySnapshot();
+ this.readOnly = map.isReadOnly();
+ }
+
+ @Override
+ public void writeExternal(final ObjectOutput out) throws IOException {
+ out.writeObject(map.equiv());
+ out.writeInt(map.size());
+ for (Entry<Object, Object> e : map.entrySet()) {
+ out.writeObject(e.getKey());
+ out.writeObject(e.getValue());
+ }
+ out.writeBoolean(readOnly);
+ }
+
+ @Override
+ public void readExternal(final ObjectInput in) throws IOException, ClassNotFoundException {
+ @SuppressWarnings("unchecked")
+ final Equivalence<Object> equiv = (Equivalence<Object>) in.readObject();
+ Preconditions.checkArgument(equiv != null);
+ map = new TrieMap<>(equiv);
+
+ final int size = in.readInt();
+ for (int i = 0; i < size; ++i) {
+ map.add(in.readObject(), in.readObject());
+ }
+
+ readOnly = in.readBoolean();
+ }
+
+ private Object readResolve() throws ObjectStreamException {
+ return Verify.verifyNotNull(readOnly ? map.readOnlySnapshot() : map);
+ }
+}