feat: implement multi stream append.

build.gradle

@@ -64,6 +64,7 @@ dependencies {
     implementation "org.slf4j:slf4j-api:2.0.17"
     implementation "org.bouncycastle:bcprov-jdk18on:1.80"
     implementation "org.bouncycastle:bcpkix-jdk18on:1.80"
+    implementation "org.apache.commons:commons-lang3:3.17.0"
 
     implementation platform("io.opentelemetry:opentelemetry-bom:${openTelemetryVersion}")
     implementation "io.opentelemetry:opentelemetry-api"

src/main/java/io/kurrent/dbclient/v2/AppendStreamFailure.java

@@ -0,0 +1,63 @@
+package io.kurrent.dbclient.v2;
+
+import javax.validation.constraints.NotNull;
+import java.util.Objects;
+
+/**
+ * Represents a failed append to a stream.
+ */
+public class AppendStreamFailure {
+    private final String stream;
+    private final Exception error;
+
+    /**
+     * Initializes a new instance of the AppendStreamFailure class.
+     *
+     * @param stream The stream name.
+     * @param error The error that occurred.
+     */
+    public AppendStreamFailure(@NotNull String stream, Exception error) {
+        this.stream = stream;
+        this.error = error;
+    }
+
+    /**
+     * Gets the stream name.
+     *
+     * @return The stream name.
+     */
+    public String getStream() {
+        return stream;
+    }
+
+    /**
+     * Gets the error that occurred.
+     *
+     * @return The error that occurred.
+     */
+    public Exception getError() {
+        return error;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        AppendStreamFailure that = (AppendStreamFailure) o;
+        return Objects.equals(stream, that.stream) &&
+                Objects.equals(error, that.error);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(stream, error);
+    }
+
+    @Override
+    public String toString() {
+        return "AppendStreamFailure{" +
+                "stream='" + stream + '\'' +
+                ", error=" + error +
+                '}';
+    }
+}

src/main/java/io/kurrent/dbclient/v2/AppendStreamFailures.java

@@ -0,0 +1,26 @@
+package io.kurrent.dbclient.v2;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+/**
+ * Represents a collection of failed appends to streams.
+ */
+public class AppendStreamFailures extends ArrayList<AppendStreamFailure> {
+
+    /**
+     * Initializes a new instance of the AppendStreamFailures class.
+     */
+    public AppendStreamFailures() {
+        super();
+    }
+
+    /**
+     * Initializes a new instance of the AppendStreamFailures class with the specified collection of AppendStreamFailure objects.
+     *
+     * @param input The collection of AppendStreamFailure objects.
+     */
+    public AppendStreamFailures(Collection<AppendStreamFailure> input) {
+        super(input);
+    }
+}

src/main/java/io/kurrent/dbclient/v2/AppendStreamRequest.java

@@ -0,0 +1,80 @@
+package io.kurrent.dbclient.v2;
+
+import io.kurrent.dbclient.StreamState;
+
+import javax.validation.constraints.NotNull;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * Represents a request to append messages to a stream.
+ */
+public class AppendStreamRequest {
+    private final String stream;
+    private final List<Message> messages;
+    private final StreamState expectedState;
+    /**
+     * Initializes a new instance of the AppendStreamRequest class.
+     *
+     * @param stream The stream name.
+     * @param messages The messages to append.
+     * @param expectedState The expected state of the stream.
+     */
+    public AppendStreamRequest(@NotNull String stream, @NotNull List<Message> messages, @NotNull StreamState expectedState) {
+        this.stream = stream;
+        this.messages = messages;
+        this.expectedState = expectedState;
+    }
+
+    /**
+     * Gets the stream name.
+     *
+     * @return The stream name.
+     */
+    public String getStream() {
+        return stream;
+    }
+
+    /**
+     * Gets the messages to append.
+     *
+     * @return The messages to append.
+     */
+    public List<Message> getMessages() {
+        return messages;
+    }
+
+    /**
+     * Gets the expected state of the stream.
+     *
+     * @return The expected state of the stream.
+     */
+    public StreamState getExpectedState() {
+        return expectedState;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        AppendStreamRequest that = (AppendStreamRequest) o;
+        return Objects.equals(stream, that.stream) &&
+                Objects.equals(messages, that.messages) &&
+                Objects.equals(expectedState, that.expectedState);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(stream, messages, expectedState);
+    }
+
+    @Override
+    public String toString() {
+        return "AppendStreamRequest{" +
+                "stream='" + stream + '\'' +
+                ", messages=" + messages +
+                ", expectedState=" + expectedState +
+                '}';
+    }
+}

src/main/java/io/kurrent/dbclient/v2/AppendStreamResult.java

@@ -0,0 +1,125 @@
+package io.kurrent.dbclient.v2;
+
+import java.util.Objects;
+import java.util.function.Function;
+
+/**
+ * Represents the result of appending to a stream, which can be either a success or a failure.
+ */
+public class AppendStreamResult {
+    private final AppendStreamSuccess success;
+    private final AppendStreamFailure failure;
+
+    private AppendStreamResult(AppendStreamSuccess success, AppendStreamFailure failure) {
+        this.success = success;
+        this.failure = failure;
+    }
+
+    /**
+     * Creates a new AppendStreamResult from a success.
+     *
+     * @param success The success result.
+     * @return A new AppendStreamResult.
+     */
+    public static AppendStreamResult fromSuccess(AppendStreamSuccess success) {
+        if (success == null)
+            throw new IllegalArgumentException("Success cannot be null");
+
+        return new AppendStreamResult(success, null);
+    }
+
+    /**
+     * Creates a new AppendStreamResult from a failure.
+     *
+     * @param failure The failure result.
+     * @return A new AppendStreamResult.
+     */
+    public static AppendStreamResult fromFailure(AppendStreamFailure failure) {
+        if (failure == null)
+            throw new IllegalArgumentException("Failure cannot be null");
+
+        return new AppendStreamResult(null, failure);
+    }
+
+    /**
+     * Checks if this result is a success.
+     *
+     * @return true if this result is a success, false otherwise.
+     */
+    public boolean isSuccess() {
+        return success != null;
+    }
+
+    /**
+     * Checks if this result is a failure.
+     *
+     * @return true if this result is a failure, false otherwise.
+     */
+    public boolean isFailure() {
+        return failure != null;
+    }
+
+    /**
+     * Gets the success result.
+     *
+     * @return The success result.
+     * @throws IllegalStateException if this result is not a success.
+     */
+    public AppendStreamSuccess getSuccess() {
+        if (!isSuccess())
+            throw new IllegalStateException("Result is not a success");
+
+        return success;
+    }
+
+    /**
+     * Gets the failure result.
+     *
+     * @return The failure result.
+     * @throws IllegalStateException if this result is not a failure.
+     */
+    public AppendStreamFailure getFailure() {
+        if (!isFailure())
+            throw new IllegalStateException("Result is not a failure");
+
+        return failure;
+    }
+
+    /**
+     * Folds the result to the appropriate action.
+     *
+     * @param successAction The action to perform if this result is a success.
+     * @param failureAction The action to perform if this result is a failure.
+     * @param <T> The type of the result.
+     * @return The result of the action.
+     */
+    public <T> T fold(Function<AppendStreamSuccess, T> successAction,
+                      Function<AppendStreamFailure, T> failureAction) {
+        if (isSuccess())
+            return successAction.apply(success);
+        else
+            return failureAction.apply(failure);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        AppendStreamResult that = (AppendStreamResult) o;
+        return Objects.equals(success, that.success) &&
+                Objects.equals(failure, that.failure);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(success, failure);
+    }
+
+    @Override
+    public String toString() {
+        if (isSuccess())
+            return "AppendStreamResult{success=" + success + '}';
+        else
+            return "AppendStreamResult{failure=" + failure + '}';
+    }
+}

src/main/java/io/kurrent/dbclient/v2/AppendStreamSuccess.java

@@ -0,0 +1,76 @@
+package io.kurrent.dbclient.v2;
+
+import java.util.Objects;
+
+/**
+ * Represents a successful append to a stream.
+ */
+public class AppendStreamSuccess {
+    private final String stream;
+    private final long position;
+    private final long streamRevision;
+
+    /**
+     * Initializes a new instance of the AppendStreamSuccess class.
+     *
+     * @param stream The stream name.
+     * @param position The position in the log.
+     * @param streamRevision The stream revision.
+     */
+    public AppendStreamSuccess(String stream, long position, long streamRevision) {
+        this.stream = stream != null ? stream : "";
+        this.position = position;
+        this.streamRevision = streamRevision;
+    }
+
+    /**
+     * Gets the stream name.
+     *
+     * @return The stream name.
+     */
+    public String getStream() {
+        return stream;
+    }
+
+    /**
+     * Gets the position in the log.
+     *
+     * @return The position in the log.
+     */
+    public long getPosition() {
+        return position;
+    }
+
+    /**
+     * Gets the stream revision.
+     *
+     * @return The stream revision.
+     */
+    public long getStreamRevision() {
+        return streamRevision;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        AppendStreamSuccess that = (AppendStreamSuccess) o;
+        return position == that.position &&
+                streamRevision == that.streamRevision &&
+                Objects.equals(stream, that.stream);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(stream, position, streamRevision);
+    }
+
+    @Override
+    public String toString() {
+        return "AppendStreamSuccess{" +
+                "stream='" + stream + '\'' +
+                ", position=" + position +
+                ", streamRevision=" + streamRevision +
+                '}';
+    }
+}