Propagate fatal errors

With the Event API we propagate generic client instance-level errors,
such as broker connection failures, authentication issues, etc.

However, fatal errors are also propagated via the Event API. These
indicates that the particular instance of the client (producer/consumer)
becomes non-functional.

Author: scanterog

src/consumer/base_consumer.rs

@@ -225,16 +225,16 @@ where
     fn handle_error_event(&self, event: NativePtr<RDKafkaEvent>) -> Option<KafkaError> {
         let rdkafka_err = unsafe { rdsys::rd_kafka_event_error(event.ptr()) };
         if rdkafka_err.is_error() {
-            let err = match rdkafka_err {
-                rdsys::rd_kafka_resp_err_t::RD_KAFKA_RESP_ERR__PARTITION_EOF => {
-                    let tp_ptr = unsafe { rdsys::rd_kafka_event_topic_partition(event.ptr()) };
-                    let partition = unsafe { (*tp_ptr).partition };
-                    unsafe { rdsys::rd_kafka_topic_partition_destroy(tp_ptr) };
-                    KafkaError::PartitionEOF(partition)
-                }
-                e => KafkaError::MessageConsumption(e.into()),
-            };
-            Some(err)
+            if rdkafka_err == rdsys::rd_kafka_resp_err_t::RD_KAFKA_RESP_ERR__PARTITION_EOF {
+                let tp_ptr = unsafe { rdsys::rd_kafka_event_topic_partition(event.ptr()) };
+                let partition = unsafe { (*tp_ptr).partition };
+                unsafe { rdsys::rd_kafka_topic_partition_destroy(tp_ptr) };
+                Some(KafkaError::PartitionEOF(partition))
+            } else if unsafe { rdsys::rd_kafka_event_error_is_fatal(event.ptr()) } != 0 {
+                Some(KafkaError::MessageConsumptionFatal(rdkafka_err.into()))
+            } else {
+                Some(KafkaError::MessageConsumption(rdkafka_err.into()))
+            }
         } else {
             None
         }

src/error.rs

@@ -157,6 +157,8 @@ pub enum KafkaError {
     GroupListFetch(RDKafkaErrorCode),
     /// Message consumption failed.
     MessageConsumption(RDKafkaErrorCode),
+    /// Message consumption failed with fatal error.
+    MessageConsumptionFatal(RDKafkaErrorCode),
     /// Message production error.
     MessageProduction(RDKafkaErrorCode),
     /// Metadata fetch error.
@@ -217,6 +219,9 @@ impl fmt::Debug for KafkaError {
             KafkaError::MessageConsumption(err) => {
                 write!(f, "KafkaError (Message consumption error: {})", err)
             }
+            KafkaError::MessageConsumptionFatal(err) => {
+                write!(f, "(Fatal) KafkaError (Message consumption error: {})", err)
+            }
             KafkaError::MessageProduction(err) => {
                 write!(f, "KafkaError (Message production error: {})", err)
             }
@@ -265,6 +270,9 @@ impl fmt::Display for KafkaError {
             KafkaError::Global(err) => write!(f, "Global error: {}", err),
             KafkaError::GroupListFetch(err) => write!(f, "Group list fetch error: {}", err),
             KafkaError::MessageConsumption(err) => write!(f, "Message consumption error: {}", err),
+            KafkaError::MessageConsumptionFatal(err) => {
+                write!(f, "(Fatal) Message consumption error: {}", err)
+            }
             KafkaError::MessageProduction(err) => write!(f, "Message production error: {}", err),
             KafkaError::MetadataFetch(err) => write!(f, "Meta data fetch error: {}", err),
             KafkaError::NoMessageReceived => {
@@ -299,6 +307,7 @@ impl Error for KafkaError {
             KafkaError::Global(err) => Some(err),
             KafkaError::GroupListFetch(err) => Some(err),
             KafkaError::MessageConsumption(err) => Some(err),
+            KafkaError::MessageConsumptionFatal(err) => Some(err),
             KafkaError::MessageProduction(err) => Some(err),
             KafkaError::MetadataFetch(err) => Some(err),
             KafkaError::NoMessageReceived => None,
@@ -339,6 +348,7 @@ impl KafkaError {
             KafkaError::Global(err) => Some(*err),
             KafkaError::GroupListFetch(err) => Some(*err),
             KafkaError::MessageConsumption(err) => Some(*err),
+            KafkaError::MessageConsumptionFatal(err) => Some(*err),
             KafkaError::MessageProduction(err) => Some(*err),
             KafkaError::MetadataFetch(err) => Some(*err),
             KafkaError::NoMessageReceived => None,