move the exceptions in HankResponse down into an exceptions union. (f…

…ixed LiveRamp#11)

src/hank.thrift

@@ -1,35 +1,32 @@
 namespace java com.rapleaf.hank.generated
 
-union HankResponse {
-  /** Equivalent to a "null" value */
-  1: bool not_found;
-  /** Single-valued result */
-  2: binary value;
-  /** Multi-valued result for a single key */
-  3: list<binary> values;
-
-  /** Multi-key multi-value result */
-  //4: map<binary, binary> multivalues;
-
-  // error states
-
+union HankExceptions {
   /** The host queried is not assigned the key that was requested */
-  5: bool wrong_host;
+  1: bool wrong_host;
 
   /** The domain_id passed in the request does not correspond to a valid domain */
-  6: bool no_such_domain;
+  2: bool no_such_domain;
 
   /** There were no available replicas for a given partition */
-  7: bool zero_replicas;
+  3: bool zero_replicas;
 
   /** There was some internal error in the server. This is pretty bad. */
-  8: bool internal_error;
+  4: string internal_error;
+}
+
+union HankResponse {
+  /** Equivalent to a "null" value */
+  1: bool not_found;
+
+  /** if found, binary result */
+  2: binary value;
+
+  /** error states */
+  3: HankExceptions xception;
 }
 
 service PartDaemon {
   HankResponse get(1:i32 domain_id, 2:binary key);
-
-  //HankResponse multiget(1:byte domain_id, 2:list<binary> keys);
 }
 
 service SmartClient {

src/java/com/rapleaf/hank/client/HankSmartClient.java

@@ -38,6 +38,7 @@
 import com.rapleaf.hank.coordinator.RingGroupConfig;
 import com.rapleaf.hank.coordinator.RingStateChangeListener;
 import com.rapleaf.hank.exception.DataNotFoundException;
+import com.rapleaf.hank.generated.HankExceptions;
 import com.rapleaf.hank.generated.HankResponse;
 import com.rapleaf.hank.generated.SmartClient.Iface;
 
@@ -133,20 +134,22 @@ public HankResponse get(String domain_name, ByteBuffer key) throws TException {
       DomainConfig domainConfig = domainGroup.getDomainConfig(domainId);
       partition = domainConfig.getPartitioner().partition(key) % domainConfig.getNumParts();
     } catch (DataNotFoundException e) {
-      return HankResponse.no_such_domain(true);
+      return HankResponse.xception(HankExceptions.no_such_domain(true));
     }
 
     Map<Integer, PartDaemonConnectionSet> domainMap = domainPartToHost.get(domainId);
     if (domainMap == null) {
-      LOG.error(String.format("Got a null domain->part map for domain %s (%d)!", domain_name, domainId));
-      return HankResponse.internal_error(true);
+      String errMsg = String.format("Got a null domain->part map for domain %s (%d)!", domain_name, domainId);
+      LOG.error(errMsg);
+      return HankResponse.xception(HankExceptions.internal_error(errMsg));
     }
 
     PartDaemonConnectionSet hpc = domainMap.get(partition);
     if (hpc == null) {
       // this is a problem, since the cache must not have been loaded correctly
-      LOG.error(String.format("Got a null list of hosts for domain %s (%d) when looking for partition %d", domain_name, domainId, partition));
-      return HankResponse.internal_error(true);
+      String errMsg = String.format("Got a null list of hosts for domain %s (%d) when looking for partition %d", domain_name, domainId, partition);
+      LOG.error(errMsg);
+      return HankResponse.xception(HankExceptions.internal_error(errMsg));
     }
 
     return hpc.get(domainId, key);

src/java/com/rapleaf/hank/client/PartDaemonConnectionSet.java

@@ -22,6 +22,7 @@
 
 import org.apache.thrift.TException;
 
+import com.rapleaf.hank.generated.HankExceptions;
 import com.rapleaf.hank.generated.HankResponse;
 
 public class PartDaemonConnectionSet {
@@ -49,6 +50,6 @@ public HankResponse get(int domainId, ByteBuffer key) throws TException {
         clientBundle.unlock();
       }
     }
-    return HankResponse.zero_replicas(true);
+    return HankResponse.xception(HankExceptions.zero_replicas(true));
   }
 }