Rename writeThrowable to writeException

This commit renames writeThrowable to writeException. The situation here
stems from the fact that the StreamOutput method for serializing
Exceptions needs to accept Throwables too as Throwables can be the cause
of serialized Exceptions. Yet, we do not serialize Throwables in the
Error sub-hierarchy in a way that they can be deserialized into their
initial type. This leads to an asymmetry in the StreamOutput method for
serializing Exceptions and the StreamInput method for writing
Excpetions. Namely, the former will accept Throwables but the latter
will only return Exceptions. A goal with the stream methods has always
been symmetry in the method names so that serialization/deserialization
routines appear symmetrical in code. It is this asymmetry on the
input/output types for Exceptions on StreamOutput/StreamInput that
clashes with the desired symmetry of naming. Despite this, we should
favor symmetry in the naming of the methods. This commit renames
StreamOutput#writeThrowable to StreamOutput#writeException which leaves
us with Exception StreamInput#readException and void
StreamOutput#writeException(Throwable).

core/src/main/java/org/elasticsearch/ElasticsearchException.java

@@ -204,7 +204,7 @@ public class ElasticsearchException extends RuntimeException implements ToXConte
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeOptionalString(this.getMessage());
-        out.writeThrowable(this.getCause());
+        out.writeException(this.getCause());
         writeStackTraces(this, out);
         out.writeVInt(headers.size());
         for (Map.Entry<String, List<String>> entry : headers.entrySet()) {
@@ -435,7 +435,7 @@ public class ElasticsearchException extends RuntimeException implements ToXConte
         Throwable[] suppressed = throwable.getSuppressed();
         out.writeVInt(suppressed.length);
         for (Throwable t : suppressed) {
-            out.writeThrowable(t);
+            out.writeException(t);
         }
         return throwable;
     }

core/src/main/java/org/elasticsearch/action/TaskOperationFailure.java

@@ -68,7 +68,7 @@ public final class TaskOperationFailure implements Writeable, ToXContent {
     public void writeTo(StreamOutput out) throws IOException {
         out.writeString(nodeId);
         out.writeLong(taskId);
-        out.writeThrowable(reason);
+        out.writeException(reason);
         RestStatus.writeTo(out, status);
     }
 

core/src/main/java/org/elasticsearch/action/admin/indices/shards/IndicesShardStoresResponse.java

@@ -189,7 +189,7 @@ public class IndicesShardStoresResponse extends ActionResponse implements ToXCon
             allocationStatus.writeTo(out);
             if (storeException != null) {
                 out.writeBoolean(true);
-                out.writeThrowable(storeException);
+                out.writeException(storeException);
             } else {
                 out.writeBoolean(false);
             }

core/src/main/java/org/elasticsearch/action/bulk/BulkItemResponse.java

@@ -115,7 +115,7 @@ public class BulkItemResponse implements Streamable, StatusToXContent {
             out.writeString(getIndex());
             out.writeString(getType());
             out.writeOptionalString(getId());
-            out.writeThrowable(getCause());
+            out.writeException(getCause());
         }
 
 

core/src/main/java/org/elasticsearch/action/get/MultiGetResponse.java

@@ -100,7 +100,7 @@ public class MultiGetResponse extends ActionResponse implements Iterable<MultiGe
             out.writeString(index);
             out.writeOptionalString(type);
             out.writeString(id);
-            out.writeThrowable(exception);
+            out.writeException(exception);
         }
 
         public Exception getFailure() {

core/src/main/java/org/elasticsearch/action/ingest/SimulateDocumentBaseResult.java

@@ -63,7 +63,7 @@ public final class SimulateDocumentBaseResult implements SimulateDocumentResult
             ingestDocument.writeTo(out);
         } else {
             out.writeBoolean(true);
-            out.writeThrowable(failure);
+            out.writeException(failure);
         }
     }
 

core/src/main/java/org/elasticsearch/action/ingest/SimulateProcessorResult.java

@@ -68,7 +68,7 @@ public class SimulateProcessorResult implements Writeable, ToXContent {
             ingestDocument.writeTo(out);
         } else {
             out.writeBoolean(true);
-            out.writeThrowable(failure);
+            out.writeException(failure);
         }
     }
 

core/src/main/java/org/elasticsearch/action/search/MultiSearchResponse.java

@@ -101,7 +101,7 @@ public class MultiSearchResponse extends ActionResponse implements Iterable<Mult
                 response.writeTo(out);
             } else {
                 out.writeBoolean(false);
-                out.writeThrowable(exception);
+                out.writeException(exception);
             }
         }
 

core/src/main/java/org/elasticsearch/action/search/ShardSearchFailure.java

@@ -148,7 +148,7 @@ public class ShardSearchFailure implements ShardOperationFailedException {
         }
         out.writeString(reason);
         RestStatus.writeTo(out, status);
-        out.writeThrowable(cause);
+        out.writeException(cause);
     }
 
     @Override

core/src/main/java/org/elasticsearch/action/support/DefaultShardOperationFailedException.java

@@ -111,7 +111,7 @@ public class DefaultShardOperationFailedException implements ShardOperationFaile
             out.writeString(index);
         }
         out.writeVInt(shardId);
-        out.writeThrowable(reason);
+        out.writeException(reason);
         RestStatus.writeTo(out, status);
     }
 

core/src/main/java/org/elasticsearch/action/support/replication/ReplicationResponse.java

@@ -260,7 +260,7 @@ public class ReplicationResponse extends ActionResponse {
             public void writeTo(StreamOutput out) throws IOException {
                 shardId.writeTo(out);
                 out.writeOptionalString(nodeId);
-                out.writeThrowable(cause);
+                out.writeException(cause);
                 RestStatus.writeTo(out, status);
                 out.writeBoolean(primary);
             }

core/src/main/java/org/elasticsearch/action/termvectors/MultiTermVectorsResponse.java

@@ -100,7 +100,7 @@ public class MultiTermVectorsResponse extends ActionResponse implements Iterable
             out.writeString(index);
             out.writeOptionalString(type);
             out.writeString(id);
-            out.writeThrowable(cause);
+            out.writeException(cause);
         }
     }
 

core/src/main/java/org/elasticsearch/cluster/action/shard/ShardStateAction.java

@@ -437,7 +437,7 @@ public class ShardStateAction extends AbstractComponent {
             shardRouting.writeTo(out);
             sourceShardRouting.writeTo(out);
             out.writeString(message);
-            out.writeThrowable(failure);
+            out.writeException(failure);
         }
 
         @Override

core/src/main/java/org/elasticsearch/cluster/routing/UnassignedInfo.java

@@ -167,7 +167,7 @@ public final class UnassignedInfo implements ToXContent, Writeable {
         // Do not serialize unassignedTimeNanos as System.nanoTime() cannot be compared across different JVMs
         out.writeBoolean(delayed);
         out.writeOptionalString(message);
-        out.writeThrowable(failure);
+        out.writeException(failure);
         out.writeVInt(failedAllocations);
     }
 

core/src/main/java/org/elasticsearch/common/io/stream/NotSerializableExceptionWrapper.java

@@ -27,7 +27,7 @@ import java.io.IOException;
 
 /**
  * This exception can be used to wrap a given, not serializable exception
- * to serialize via {@link StreamOutput#writeThrowable(Throwable)}.
+ * to serialize via {@link StreamOutput#writeException(Throwable)}.
  * This class will preserve the stacktrace as well as the suppressed exceptions of
  * the throwable it was created with instead of it's own. The stacktrace has no indication
  * of where this exception was created.

core/src/main/java/org/elasticsearch/common/io/stream/StreamOutput.java

@@ -631,7 +631,7 @@ public abstract class StreamOutput extends OutputStream {
         }
     }
 
-    public void writeThrowable(Throwable throwable) throws IOException {
+    public void writeException(Throwable throwable) throws IOException {
         if (throwable == null) {
             writeBoolean(false);
         } else {
@@ -739,7 +739,7 @@ public abstract class StreamOutput extends OutputStream {
                 writeOptionalString(throwable.getMessage());
             }
             if (writeCause) {
-                writeThrowable(throwable.getCause());
+                writeException(throwable.getCause());
             }
             ElasticsearchException.writeStackTraces(throwable, this);
         }

core/src/main/java/org/elasticsearch/gateway/TransportNodesListGatewayStartedShards.java

@@ -298,7 +298,7 @@ public class TransportNodesListGatewayStartedShards extends
             out.writeBoolean(primary);
             if (storeException != null) {
                 out.writeBoolean(true);
-                out.writeThrowable(storeException);
+                out.writeException(storeException);
             } else {
                 out.writeBoolean(false);
             }

core/src/main/java/org/elasticsearch/index/store/Store.java

@@ -1337,7 +1337,7 @@ public class Store extends AbstractIndexShardComponent implements Closeable, Ref
             try (IndexOutput output = this.directory().createOutput(uuid, IOContext.DEFAULT)) {
                 CodecUtil.writeHeader(output, CODEC, VERSION);
                 BytesStreamOutput out = new BytesStreamOutput();
-                out.writeThrowable(exception);
+                out.writeException(exception);
                 BytesReference bytes = out.bytes();
                 output.writeVInt(bytes.length());
                 BytesRef ref = bytes.toBytesRef();

core/src/main/java/org/elasticsearch/repositories/VerificationFailure.java

@@ -59,7 +59,7 @@ public class VerificationFailure implements Streamable {
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeOptionalString(nodeId);
-        out.writeThrowable(cause);
+        out.writeException(cause);
     }
 
     public static VerificationFailure readNode(StreamInput in) throws IOException {

core/src/main/java/org/elasticsearch/transport/TcpTransport.java

@@ -940,7 +940,7 @@ public abstract class TcpTransport<Channel> extends AbstractLifecycleComponent i
             stream.setVersion(nodeVersion);
             RemoteTransportException tx = new RemoteTransportException(
                 nodeName(), new InetSocketTransportAddress(getLocalAddress(channel)), action, error);
-            stream.writeThrowable(tx);
+            stream.writeException(tx);
             byte status = 0;
             status = TransportStatus.setResponse(status);
             status = TransportStatus.setError(status);

core/src/main/java/org/elasticsearch/transport/local/LocalTransportChannel.java

@@ -96,7 +96,7 @@ public class LocalTransportChannel implements TransportChannel {
         writeResponseExceptionHeader(stream);
         RemoteTransportException tx = new RemoteTransportException(targetTransport.nodeName(),
                 targetTransport.boundAddress().boundAddresses()[0], action, exception);
-        stream.writeThrowable(tx);
+        stream.writeException(tx);
         sendResponseData(BytesReference.toBytes(stream.bytes()));
         sourceTransportServiceAdapter.onResponseSent(requestId, action, exception);
     }

core/src/test/java/org/elasticsearch/ESExceptionTests.java

@@ -301,7 +301,7 @@ public class ESExceptionTests extends ESTestCase {
     public void testSerializeElasticsearchException() throws IOException {
         BytesStreamOutput out = new BytesStreamOutput();
         ParsingException ex = new ParsingException(1, 2, "foobar", null);
-        out.writeThrowable(ex);
+        out.writeException(ex);
 
         StreamInput in = out.bytes().streamInput();
         ParsingException e = in.readException();
@@ -315,7 +315,7 @@ public class ESExceptionTests extends ESTestCase {
         BytesStreamOutput out = new BytesStreamOutput();
         ParsingException parsingException = new ParsingException(1, 2, "foobar", null);
         final Exception ex = new UnknownException("eggplant", parsingException);
-        out.writeThrowable(ex);
+        out.writeException(ex);
 
         StreamInput in = out.bytes().streamInput();
         Throwable throwable = in.readException();
@@ -354,7 +354,7 @@ public class ESExceptionTests extends ESTestCase {
         for (final Exception cause : causes) {
             BytesStreamOutput out = new BytesStreamOutput();
             ElasticsearchException ex = new ElasticsearchException("topLevel", cause);
-            out.writeThrowable(ex);
+            out.writeException(ex);
             StreamInput in = out.bytes().streamInput();
             ElasticsearchException e = in.readException();
             assertEquals(e.getMessage(), ex.getMessage());

core/src/test/java/org/elasticsearch/ExceptionSerializationTests.java

@@ -222,7 +222,7 @@ public class ExceptionSerializationTests extends ESTestCase {
     private <T extends Exception> T serialize(T exception) throws IOException {
         ElasticsearchAssertions.assertVersionSerializable(VersionUtils.randomVersion(random()), exception);
         BytesStreamOutput out = new BytesStreamOutput();
-        out.writeThrowable(exception);
+        out.writeException(exception);
         StreamInput in = out.bytes().streamInput();
         return in.readException();
     }

modules/lang-mustache/src/main/java/org/elasticsearch/action/search/template/MultiSearchTemplateResponse.java

@@ -96,7 +96,7 @@ public class MultiSearchTemplateResponse extends ActionResponse implements Itera
                 response.writeTo(out);
             } else {
                 out.writeBoolean(false);
-                out.writeThrowable(exception);
+                out.writeException(exception);
             }
         }
 

modules/percolator/src/main/java/org/elasticsearch/percolator/MultiPercolateResponse.java

@@ -172,7 +172,7 @@ public class MultiPercolateResponse extends ActionResponse implements Iterable<M
                 response.writeTo(out);
             } else {
                 out.writeBoolean(false);
-                out.writeThrowable(exception);
+                out.writeException(exception);
             }
         }
     }

test/framework/src/main/java/org/elasticsearch/test/hamcrest/ElasticsearchAssertions.java

@@ -682,7 +682,7 @@ public class ElasticsearchAssertions {
 
         @Override
         public void writeTo(StreamOutput out) throws IOException {
-            out.writeThrowable(exception);
+            out.writeException(exception);
         }
 
     }