JCBC-1886: Allow to list the number of currently available replicas for a document ID.

Change-Id: I977fa83857f5ecbf87bdfe29250ddecd2690e396 Reviewed-on: http://review.couchbase.org/c/couchbase-java-client/+/164244 Tested-by: Michael Nitschinger <michael.nitschinger@couchbase.com> Reviewed-by: Michael Nitschinger <michael.nitschinger@couchbase.com>

Author: daschl

src/main/java/com/couchbase/client/java/util/NodeLocatorHelper.java

@@ -54,18 +54,17 @@
 @InterfaceAudience.Public
 public class NodeLocatorHelper {
 
- private final ConfigurationProvider configProvider;
  private final AtomicReference<BucketConfig> bucketConfig;
 
  private NodeLocatorHelper(final Bucket bucket) {
- configProvider = bucket
-  .core()
-  .<GetConfigProviderResponse>send(new GetConfigProviderRequest())
-  .toBlocking()
-  .single()
-  .provider();
+ ConfigurationProvider configProvider = bucket
+ .core()
+ .<GetConfigProviderResponse>send(new GetConfigProviderRequest())
+ .toBlocking()
+ .single()
+ .provider();
 
- bucketConfig = new AtomicReference<BucketConfig>(configProvider.config().bucketConfig(bucket.name()));
+ bucketConfig = new AtomicReference<>(configProvider.config().bucketConfig(bucket.name()));
 
  configProvider
  .configs()
@@ -121,7 +120,7 @@ public List<InetAddress> replicaNodesForId(final String id) {
 
  if (config instanceof CouchbaseBucketConfig) {
  CouchbaseBucketConfig cbc = (CouchbaseBucketConfig) config;
- List<InetAddress> replicas = new ArrayList<InetAddress>();
+ List<InetAddress> replicas = new ArrayList<>();
  for (int i = 1; i <= cbc.numberOfReplicas(); i++) {
  replicas.add(replicaNodeForId(id, i));
  }
@@ -131,6 +130,30 @@ public List<InetAddress> replicaNodesForId(final String id) {
  }
  }
 
+ /**
+ * Returns all target replica nodes {@link InetAddress} which are currently available on the bucket.
+ *
+ * @param id the document ID to check.
+ * @return the list of nodes for the given document ID.
+ */
+ public List<InetAddress> availableReplicaNodesForId(final String id) {
+ BucketConfig config = bucketConfig.get();
+
+ if (config instanceof CouchbaseBucketConfig) {
+ CouchbaseBucketConfig cbc = (CouchbaseBucketConfig) config;
+ List<InetAddress> replicas = new ArrayList<>();
+ for (int i = 1; i <= cbc.numberOfReplicas(); i++) {
+ InetAddress foundReplica = replicaNodeForId(id, i, false);
+ if (foundReplica != null) {
+ replicas.add(foundReplica);
+ }
+ }
+ return replicas;
+ } else {
+ throw new UnsupportedOperationException("Bucket type not supported: " + config.getClass().getName());
+ }
+ }
+
  /**
  * Returns the target replica node {@link InetAddress} for a given document ID and replica number on the bucket.
  *
@@ -139,6 +162,19 @@ public List<InetAddress> replicaNodesForId(final String id) {
  * @return the node for the given document id.
  */
  public InetAddress replicaNodeForId(final String id, int replicaNum) {
+ return replicaNodeForId(id, replicaNum, true);
+ }
+
+
+ /**
+ * Returns the target replica node {@link InetAddress} for a given document ID and replica number on the bucket.
+ *
+ * @param id the document id to convert.
+ * @param replicaNum the replica number.
+ * @param throwOnNotAvailable if on -1 and -2 an exception should be thrown.
+ * @return the node for the given document id.
+ */
+ private InetAddress replicaNodeForId(final String id, int replicaNum, boolean throwOnNotAvailable) {
  if (replicaNum < 1 || replicaNum > 3) {
  throw new IllegalArgumentException("Replica number must be between 1 and 3.");
  }
@@ -150,10 +186,18 @@ public InetAddress replicaNodeForId(final String id, int replicaNum) {
  int partitionId = (int) hashId(id) & cbc.numberOfPartitions() - 1;
  int nodeId = cbc.nodeIndexForReplica(partitionId, replicaNum - 1, false);
  if (nodeId == -1) {
- throw new IllegalStateException("No partition assigned to node for Document ID: " + id);
+ if (throwOnNotAvailable) {
+ throw new IllegalStateException("No partition assigned to node for Document ID: " + id);
+ } else {
+ return null;
+ }
  }
  if (nodeId == -2) {
- throw new IllegalStateException("Replica not configured for this bucket.");
+ if (throwOnNotAvailable) {
+ throw new IllegalStateException("Replica not configured for this bucket.");
+ } else {
+ return null;
+ }
  }
  try {
  return InetAddress.getByName(cbc.nodeAtIndex(nodeId).hostname());
@@ -171,7 +215,7 @@ public InetAddress replicaNodeForId(final String id, int replicaNum) {
  * @return all currently known nodes.
  */
  public List<InetAddress> nodes() {
- List<InetAddress> allNodes = new ArrayList<InetAddress>();
+ List<InetAddress> allNodes = new ArrayList<>();
  BucketConfig config = bucketConfig.get();
  for (NodeInfo nodeInfo : config.nodes()) {
  try {