Refactor multi stream append to use v2 protocol

build.gradle

@@ -60,6 +60,7 @@ dependencies {
     implementation "io.grpc:grpc-netty-shaded:${grpcVersion}"
     implementation "io.grpc:grpc-stub:${grpcVersion}"
     implementation "io.grpc:grpc-protobuf:${grpcVersion}"
+    implementation "com.google.api.grpc:grpc-google-common-protos:2.61.3"
     implementation "com.fasterxml.jackson.core:jackson-databind:${jacksonVersion}"
     implementation "org.slf4j:slf4j-api:2.0.17"
     implementation "org.bouncycastle:bcprov-jdk18on:1.80"

docs/api/appending-events.md

@@ -255,23 +255,12 @@ This feature is only available in KurrentDB 25.1 and later.
 
 You can append events to multiple streams in a single atomic operation. Either all streams are updated, or the entire operation fails.
 
-The `multiStreamAppend` method accepts a collection of `AppendStreamRequest` objects and returns a `MultiAppendWriteResult`. Each `AppendStreamRequest` contains:
-
-- **streamName** - The name of the stream
-- **expectedState** - The expected state of the stream for optimistic concurrency control
-- **events** - A collection of `EventData` objects to append
-
-The operation returns a `MultiAppendWriteResult` that contains either:
-- A list of `AppendStreamSuccess` objects if all streams were successfully updated
-- A list of `AppendStreamFailure` objects if any streams failed to update
-
 ::: warning
-Event metadata in `EventData` must be valid JSON objects. This requirement will
-be removed in a future major release.
+Currently, metadata must be valid JSON. Binary metadata will not be supported in
+this version. This limitation ensures compatibility with KurrentDB's metadata
+handling and will be removed in the next major release.
 :::
 
-Here's a basic example of appending events to multiple streams:
-
 ```java
 JsonMapper mapper = new JsonMapper();
 
@@ -306,87 +295,5 @@ List<AppendStreamRequest> requests = Arrays.asList(
 );
 
 MultiAppendWriteResult result = client.multiStreamAppend(requests.iterator()).get();
-
-if (result.getSuccesses().isPresent())
-    result.getSuccesses().get().forEach(success -> {
-        System.out.println(success.getStreamName() + " updated at " + success.getPosition());
-    });
 ```
 
-If the operation doesn't succeed, you can handle the failures as follows:
-
-```java
-if (result.getFailures().isPresent()) {
-    MultiAppendErrorVisitor visitor = new MultiAppendErrorVisitor();
-    result.getFailures().get().forEach(failure -> {
-        failure.visit(visitor);
-
-        if (visitor.wasWrongExpectedRevisionVisited()) {
-            System.out.println("Wrong revision for stream: " + failure.getStreamName());
-        } else if (visitor.wasStreamDeletedVisited()) {
-            System.out.println("Stream deleted: " + failure.getStreamName());
-        } else if (visitor.wasAccessDenied()) {
-            System.out.println("Access denied: " + failure.getStreamName());
-        } else if (visitor.wasTransactionMaxSizeExceeded()) {
-            System.out.println("Transaction too large: " + failure.getStreamName());
-        } else {
-            System.out.println("Unknown error: " + failure.getStreamName());
-        }
-    });
-}
-```
-
-::: details Click here to see the implementaton of `MultiAppendErrorVisitor`
-
-```java
-class MultiAppendErrorVisitor implements MultiAppendStreamErrorVisitor {
-    private boolean wrongExpectedRevisionVisited = false;
-    private boolean streamDeletedVisited = false;
-    private boolean transactionMaxSizeExceeded = false;
-    private boolean accessDenied = false;
-    private long actualRevision = -1;
-
-    @Override
-    public void onAccessDenied(ErrorDetails.AccessDenied detail) {
-        this.accessDenied = true;
-    }
-
-    @Override
-    public void onWrongExpectedRevision(long streamRevision) {
-        this.wrongExpectedRevisionVisited = true;
-        this.actualRevision = streamRevision;
-    }
-
-    @Override
-    public void onStreamDeleted() {
-        this.streamDeletedVisited = true;
-    }
-
-    @Override
-    public void onTransactionMaxSizeExceeded(int maxSize) {
-        this.transactionMaxSizeExceeded = true;
-    }
-
-    public boolean wasWrongExpectedRevisionVisited() {
-        return wrongExpectedRevisionVisited;
-    }
-
-    public boolean wasStreamDeletedVisited() {
-        return streamDeletedVisited;
-    }
-
-    public boolean wasAccessDenied() {
-        return accessDenied;
-    }
-
-    public boolean wasTransactionMaxSizeExceeded() {
-        return transactionMaxSizeExceeded;
-    }
-
-    public long getActualRevision() {
-        return actualRevision;
-    }
-}
-```
-
-:::

src/main/java/io/kurrent/dbclient/AppendResponse.java

@@ -0,0 +1,19 @@
+package io.kurrent.dbclient;
+
+public class AppendResponse {
+    private final String stream;
+    private final long streamRevision;
+
+    public AppendResponse(String stream, long streamRevision) {
+        this.stream = stream;
+        this.streamRevision = streamRevision;
+    }
+
+    public String getStream() {
+        return stream;
+    }
+
+    public long getStreamRevision() {
+        return streamRevision;
+    }
+}

src/main/java/io/kurrent/dbclient/AppendToStream.java

@@ -5,8 +5,6 @@
 import io.kurrent.dbclient.proto.streams.StreamsOuterClass;
 import com.google.protobuf.ByteString;
 import io.grpc.ManagedChannel;
-import io.grpc.Metadata;
-import io.grpc.StatusRuntimeException;
 import io.grpc.stub.StreamObserver;
 
 import java.util.ArrayList;
@@ -112,16 +110,6 @@ private CompletableFuture<WriteResult> append(ManagedChannel channel, List<Event
                         .build());
             }
             requestStream.onCompleted();
-        } catch (StatusRuntimeException e) {
-            String leaderHost = e.getTrailers().get(Metadata.Key.of("leader-endpoint-host", Metadata.ASCII_STRING_MARSHALLER));
-            String leaderPort = e.getTrailers().get(Metadata.Key.of("leader-endpoint-port", Metadata.ASCII_STRING_MARSHALLER));
-
-            if (leaderHost != null && leaderPort != null) {
-                NotLeaderException reason = new NotLeaderException(leaderHost, Integer.valueOf(leaderPort));
-                result.completeExceptionally(reason);
-            } else {
-                result.completeExceptionally(e);
-            }
         } catch (RuntimeException e) {
             result.completeExceptionally(e);
         }

src/main/java/io/kurrent/dbclient/ClientTelemetry.java

@@ -5,8 +5,6 @@
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import io.grpc.ManagedChannel;
 import io.opentelemetry.api.GlobalOpenTelemetry;
-import io.opentelemetry.api.common.AttributeKey;
-import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.trace.*;
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.Scope;
@@ -16,8 +14,6 @@
 import java.util.concurrent.CompletionException;
 import java.util.function.BiFunction;
 
-import static io.kurrentdb.protocol.streams.v2.AppendStreamFailure.*;
-
 class ClientTelemetry {
     private static final ClientTelemetryTags DEFAULT_ATTRIBUTES = new ClientTelemetryTags() {{
         put(ClientTelemetryAttributes.Database.SYSTEM, ClientTelemetryConstants.INSTRUMENTATION_NAME);
@@ -123,8 +119,8 @@ static CompletableFuture<WriteResult> traceAppend(
         }
     }
 
-    static CompletableFuture<MultiAppendWriteResult> traceMultiStreamAppend(
-            BiFunction<WorkItemArgs, Iterator<AppendStreamRequest>, CompletableFuture<MultiAppendWriteResult>> multiAppendOperation,
+    static CompletableFuture<MultiStreamAppendResponse> traceMultiStreamAppend(
+            BiFunction<WorkItemArgs, Iterator<AppendStreamRequest>, CompletableFuture<MultiStreamAppendResponse>> multiAppendOperation,
             WorkItemArgs args,
             Iterator<AppendStreamRequest> requests, KurrentDBClientSettings settings) {
 
@@ -164,47 +160,8 @@ static CompletableFuture<MultiAppendWriteResult> traceMultiStreamAppend(
                         span.end();
                         throw new CompletionException(throwable);
                     } else {
-                        if (result.getFailures().isPresent()) {
-                            for (AppendStreamFailure failure : result.getFailures().get()) {
-                                failure.visit(new MultiAppendStreamErrorVisitor() {
-                                    @Override
-                                    public void onWrongExpectedRevision(long streamRevision) {
-                                        span.addEvent("exception", Attributes.of(
-                                                AttributeKey.stringKey("exception.type"), ErrorCase.STREAM_REVISION_CONFLICT.toString(),
-                                                AttributeKey.longKey("exception.revision"), streamRevision
-                                        ));
-                                    }
-
-                                    @Override
-                                    public void onAccessDenied(io.kurrentdb.protocol.streams.v2.ErrorDetails.AccessDenied detail) {
-                                        span.addEvent("exception", Attributes.of(
-                                                AttributeKey.stringKey("exception.type"), ErrorCase.ACCESS_DENIED.toString()
-                                        ));
-                                    }
-
-                                    @Override
-                                    public void onStreamDeleted() {
-                                        span.addEvent("exception", Attributes.of(
-                                                AttributeKey.stringKey("exception.type"), ErrorCase.STREAM_DELETED.toString()
-                                        ));
-                                    }
-
-                                    @Override
-                                    public void onTransactionMaxSizeExceeded(int maxSize) {
-                                        span.addEvent("exception", Attributes.of(
-                                                AttributeKey.stringKey("exception.type"), ErrorCase.TRANSACTION_MAX_SIZE_EXCEEDED.toString(),
-                                                AttributeKey.longKey("exception.maxSize"), (long) maxSize
-                                        ));
-                                    }
-                                });
-                            }
-                            span.setStatus(StatusCode.ERROR);
-                            span.end();
-                        } else if (result.getSuccesses().isPresent()) {
-                            span.setStatus(StatusCode.OK);
-                            span.end();
-                        }
-
+                        span.setStatus(StatusCode.OK);
+                        span.end();
                         return result;
                     }
                 });

src/main/java/io/kurrent/dbclient/ContentTypeMapper.java

@@ -1,20 +1,22 @@
 package io.kurrent.dbclient;
 
+import io.kurrentdb.protocol.v2.streams.SchemaFormat;
+
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
 public class ContentTypeMapper {
-    private static final Map<String, String> CONTENT_TYPE_MAP;
+    private static final Map<String, SchemaFormat> CONTENT_TYPE_MAP;
 
     static {
-        Map<String, String> map = new HashMap<>();
-        map.put("application/json", "Json");
-        map.put("application/octet-stream", "Binary");
+        Map<String, SchemaFormat> map = new HashMap<>();
+        map.put("application/json", SchemaFormat.SCHEMA_FORMAT_JSON);
+        map.put("application/octet-stream", SchemaFormat.SCHEMA_FORMAT_BYTES);
         CONTENT_TYPE_MAP = Collections.unmodifiableMap(map);
     }
 
-    public static String toSchemaDataFormat(String contentType) {
-        return CONTENT_TYPE_MAP.getOrDefault(contentType, contentType);
+    public static SchemaFormat toSchemaDataFormat(String contentType) {
+        return CONTENT_TYPE_MAP.getOrDefault(contentType, SchemaFormat.SCHEMA_FORMAT_UNSPECIFIED);
     }
 }