import org.opendaylight.yangtools.concepts.WritableObjects;
/**
- * Globally-unique identifier of a local history.
+ * Globally-unique identifier of a local history. This identifier is assigned on the frontend and is composed of
+ * - a {@link ClientIdentifier}, which uniquely identifies a single instantiation of a particular frontend
+ * - an unsigned long, which uniquely identifies the history on the backend
+ * - an unsigned long cookie, assigned by the client and meaningless on the backend, which just reflects it back
*
* @author Robert Varga
*/
public final class LocalHistoryIdentifier implements WritableIdentifier {
+ /*
+ * Implementation note: cookie is currently required only for module-based sharding, which is implemented as part
+ * of normal DataBroker interfaces. For DOMDataTreeProducer cookie will always be zero, hence
+ * we may end up not needing cookie at all.
+ *
+ * We use WritableObjects.writeLongs() to output historyId and cookie (in that order). If we
+ * end up not needing the cookie at all, we can switch to writeLong() and use zero flags for
+ * compatibility.
+ */
private static final class Proxy implements Externalizable {
private static final long serialVersionUID = 1L;
private ClientIdentifier clientId;
private long historyId;
+ private long cookie;
public Proxy() {
// For Externalizable
}
- Proxy(final ClientIdentifier frontendId, final long historyId) {
+ Proxy(final ClientIdentifier frontendId, final long historyId, final long cookie) {
this.clientId = Preconditions.checkNotNull(frontendId);
this.historyId = historyId;
+ this.cookie = cookie;
}
@Override
public void writeExternal(final ObjectOutput out) throws IOException {
clientId.writeTo(out);
- WritableObjects.writeLong(out, historyId);
+ WritableObjects.writeLongs(out, historyId, cookie);
}
@Override
public void readExternal(final ObjectInput in) throws IOException, ClassNotFoundException {
clientId = ClientIdentifier.readFrom(in);
- historyId = WritableObjects.readLong(in);
+
+ final byte header = WritableObjects.readLongHeader(in);
+ historyId = WritableObjects.readFirstLong(in, header);
+ cookie = WritableObjects.readSecondLong(in, header);
}
private Object readResolve() {
- return new LocalHistoryIdentifier(clientId, historyId);
+ return new LocalHistoryIdentifier(clientId, historyId, cookie);
}
}
private static final long serialVersionUID = 1L;
private final ClientIdentifier clientId;
private final long historyId;
+ private final long cookie;
public LocalHistoryIdentifier(final ClientIdentifier frontendId, final long historyId) {
+ this(frontendId, historyId, 0);
+ }
+
+ public LocalHistoryIdentifier(final ClientIdentifier frontendId, final long historyId, final long cookie) {
this.clientId = Preconditions.checkNotNull(frontendId);
this.historyId = historyId;
+ this.cookie = cookie;
}
public static LocalHistoryIdentifier readFrom(final DataInput in) throws IOException {
final ClientIdentifier clientId = ClientIdentifier.readFrom(in);
- return new LocalHistoryIdentifier(clientId, WritableObjects.readLong(in));
+
+ final byte header = WritableObjects.readLongHeader(in);
+ return new LocalHistoryIdentifier(clientId, WritableObjects.readFirstLong(in, header),
+ WritableObjects.readSecondLong(in, header));
}
@Override
public void writeTo(final DataOutput out) throws IOException {
clientId.writeTo(out);
- WritableObjects.writeLong(out, historyId);
+ WritableObjects.writeLongs(out, historyId, cookie);
}
public ClientIdentifier getClientId() {
return historyId;
}
+ public long getCookie() {
+ return cookie;
+ }
+
@Override
public int hashCode() {
- return clientId.hashCode() * 31 + Long.hashCode(historyId);
+ int ret = clientId.hashCode();
+ ret = 31 * ret + Long.hashCode(historyId);
+ ret = 31 * ret + Long.hashCode(cookie);
+ return ret;
}
@Override
}
final LocalHistoryIdentifier other = (LocalHistoryIdentifier) o;
- return historyId == other.historyId && clientId.equals(other.clientId);
+ return historyId == other.historyId && cookie == other.cookie && clientId.equals(other.clientId);
}
@Override
public String toString() {
return MoreObjects.toStringHelper(LocalHistoryIdentifier.class).add("client", clientId)
- .add("history", Long.toUnsignedString(historyId)).toString();
+ .add("history", Long.toUnsignedString(historyId, 16))
+ .add("cookie", Long.toUnsignedString(cookie, 16)).toString();
}
private Object writeReplace() {
- return new Proxy(clientId, historyId);
+ return new Proxy(clientId, historyId, cookie);
}
}