Add protocol dto classes #5

- error codes

src/main/java/com/github/nginate/kafka/protocol/ErrorCodes.java

@@ -0,0 +1,78 @@
+package com.github.nginate.kafka.protocol;
+
+import lombok.experimental.UtilityClass;
+
+/**
+ * @see <a href="https://cwiki.apache.org/confluence/display/KAFKA/A+Guide+To+The+Kafka+Protocol#AGuideToTheKafkaProtocol-ErrorCodes">Kafka protocol errors</a>
+ */
+@UtilityClass
+public final class ErrorCodes {
+    /**
+     * No error--it worked!
+     */
+    public static final int NoError = 0;
+    /**
+     * An unexpected server error
+     */
+    public static final int Unknown = -1;
+    /**
+     * The requested offset is outside the range of offsets maintained by the server for the given topic/partition.
+     */
+    public static final int OffsetOutOfRange = 1;
+    /**
+     * This indicates that a message contents does not match its CRC
+     */
+    public static final int InvalidMessage = 2;
+    /**
+     * This request is for a topic or partition that does not exist on this broker.
+     */
+    public static final int UnknownTopicOrPartition = 3;
+    /**
+     * The message has a negative size
+     */
+    public static final int InvalidMessageSize = 4;
+    /**
+     * This error is thrown if we are in the middle of a leadership election and there is currently no leader for this partition and hence it is unavailable for writes.
+     */
+    public static final int LeaderNotAvailable = 5;
+    /**
+     * This error is thrown if the client attempts to send messages to a replica that is not the leader for some partition. It indicates that the clients metadata is out of date.
+     */
+    public static final int NotLeaderForPartition = 6;
+    /**
+     * This error is thrown if the request exceeds the user-specified time limit in the request.
+     */
+    public static final int RequestTimedOut = 7;
+    /**
+     * This is not a client facing error and is used mostly by tools when a broker is not alive.
+     */
+    public static final int BrokerNotAvailable = 8;
+    /**
+     * If replica is expected on a broker, but is not (this can be safely ignored).
+     */
+    public static final int ReplicaNotAvailable = 9;
+    /**
+     * The server has a configurable maximum message size to avoid unbounded memory allocation. This error is thrown if the client attempt to produce a message larger than this maximum.
+     */
+    public static final int MessageSizeTooLarge = 10;
+    /**
+     * Internal error code for broker-to-broker communication.
+     */
+    public static final int StaleControllerEpochCode = 11;
+    /**
+     * If you specify a string larger than configured maximum for offset metadata
+     */
+    public static final int OffsetMetadataTooLargeCode = 12;
+    /**
+     * The broker returns this error code for an offset fetch request if it is still loading offsets (after a leader change for that offsets topic partition).
+     */
+    public static final int OffsetsLoadInProgressCode = 14;
+    /**
+     * The broker returns this error code for consumer metadata requests or offset commit requests if the offsets topic has not yet been created.
+     */
+    public static final int ConsumerCoordinatorNotAvailableCode = 15;
+    /**
+     * The broker returns this error code if it receives an offset fetch or commit request for a consumer group that it is not a coordinator for.
+     */
+    public static final int NotCoordinatorForConsumerCode = 16;
+}