/// <summary>
/// Main method for console app.
/// </summary>
/// <param name="args">No arguments used.</param>
public static void Main(string[] args)
{
Console.WriteLine("Starting .net consumer.");
var consumerConfig = new ConsumerConfig
{
BootstrapServers = "kafka:9092",
GroupId = "csharp-consumer-prev",
AutoOffsetReset = AutoOffsetReset.Earliest,
PluginLibraryPaths = "monitoring-interceptor",
};
using (var consumer = new ConsumerBuilder <string, string>(consumerConfig)
.SetPartitionsAssignedHandler((c, partitions) =>
{
var timestamp = new Confluent.Kafka.Timestamp(DateTime.Now.AddMinutes(-5));
var timestamps = partitions.Select(tp => new TopicPartitionTimestamp(tp, timestamp));
var offsets = c.OffsetsForTimes(timestamps, TimeSpan.FromMinutes(1));
foreach (var offset in offsets)
{
Console.WriteLine($"Moving partion {offset.Partition.Value} to {offset.Offset.Value}");
}
return(offsets);
})
.Build())
{
consumer.Subscribe(KafkaTopic);
CancellationTokenSource cts = new CancellationTokenSource();
Console.CancelKeyPress += (_, e) =>
{
e.Cancel = true; // prevent the process from terminating.
cts.Cancel();
};
try
{
int recordCount = 0;
while (true)
{
try
{
var cr = consumer.Consume(cts.Token);
Console.WriteLine($"{cr.Key},{cr.Value}");
recordCount++;
if (recordCount >= 100)
{
break;
}
}
catch (ConsumeException e)
{
Console.WriteLine($"Error occured: {e.Error.Reason}");
}
}
}
catch (OperationCanceledException)
{
// Ensure the consumer leaves the group cleanly and final offsets are committed.
Console.WriteLine("Closing consumer.");
consumer.Close();
}
}
}
private ConsumeResult <K, V> ConsumeImpl <K, V>(
int millisecondsTimeout,
IDeserializer <K> keyDeserializer,
IDeserializer <V> valueDeserializer)
{
var msgPtr = kafkaHandle.ConsumerPoll((IntPtr)millisecondsTimeout);
if (msgPtr == IntPtr.Zero)
{
return(null);
}
try
{
var msg = Util.Marshal.PtrToStructure <rd_kafka_message>(msgPtr);
string topic = null;
if (this.enableTopicNameMarshaling)
{
if (msg.rkt != IntPtr.Zero)
{
topic = Util.Marshal.PtrToStringUTF8(Librdkafka.topic_name(msg.rkt));
}
}
if (msg.err == ErrorCode.Local_PartitionEOF)
{
return(new ConsumeResult <K, V>
{
TopicPartitionOffset = new TopicPartitionOffset(topic, msg.partition, msg.offset),
Message = null,
IsPartitionEOF = true
});
}
long timestampUnix = 0;
IntPtr timestampType = (IntPtr)TimestampType.NotAvailable;
if (enableTimestampMarshaling)
{
timestampUnix = Librdkafka.message_timestamp(msgPtr, out timestampType);
}
var timestamp = new Timestamp(timestampUnix, (TimestampType)timestampType);
Headers headers = null;
if (enableHeaderMarshaling)
{
headers = new Headers();
Librdkafka.message_headers(msgPtr, out IntPtr hdrsPtr);
if (hdrsPtr != IntPtr.Zero)
{
for (var i = 0; ; ++i)
{
var err = Librdkafka.header_get_all(hdrsPtr, (IntPtr)i, out IntPtr namep, out IntPtr valuep, out IntPtr sizep);
if (err != ErrorCode.NoError)
{
break;
}
var headerName = Util.Marshal.PtrToStringUTF8(namep);
byte[] headerValue = null;
if (valuep != IntPtr.Zero)
{
headerValue = new byte[(int)sizep];
Marshal.Copy(valuep, headerValue, 0, (int)sizep);
}
headers.Add(headerName, headerValue);
}
}
}
if (msg.err != ErrorCode.NoError)
{
throw new ConsumeException(
new ConsumeResult <byte[], byte[]>
{
TopicPartitionOffset = new TopicPartitionOffset(topic, msg.partition, msg.offset),
Message = new Message <byte[], byte[]>
{
Timestamp = timestamp,
Headers = headers,
Key = KeyAsByteArray(msg),
Value = ValueAsByteArray(msg)
},
IsPartitionEOF = false
},
kafkaHandle.CreatePossiblyFatalError(msg.err, null));
}
K key;
try
{
unsafe
{
key = keyDeserializer.Deserialize(
msg.key == IntPtr.Zero
? ReadOnlySpan <byte> .Empty
: new ReadOnlySpan <byte>(msg.key.ToPointer(), (int)msg.key_len),
msg.key == IntPtr.Zero,
new SerializationContext(MessageComponentType.Key, topic));
}
}
catch (Exception ex)
{
throw new ConsumeException(
new ConsumeResult <byte[], byte[]>
{
TopicPartitionOffset = new TopicPartitionOffset(topic, msg.partition, msg.offset),
Message = new Message <byte[], byte[]>
{
Timestamp = timestamp,
Headers = headers,
Key = KeyAsByteArray(msg),
Value = ValueAsByteArray(msg)
},
IsPartitionEOF = false
},
new Error(ErrorCode.Local_KeyDeserialization),
ex);
}
V val;
try
{
unsafe
{
val = valueDeserializer.Deserialize(
msg.val == IntPtr.Zero
? ReadOnlySpan <byte> .Empty
: new ReadOnlySpan <byte>(msg.val.ToPointer(), (int)msg.len),
msg.val == IntPtr.Zero,
new SerializationContext(MessageComponentType.Value, topic));
}
}
catch (Exception ex)
{
throw new ConsumeException(
new ConsumeResult <byte[], byte[]>
{
TopicPartitionOffset = new TopicPartitionOffset(topic, msg.partition, msg.offset),
Message = new Message <byte[], byte[]>
{
Timestamp = timestamp,
Headers = headers,
Key = KeyAsByteArray(msg),
Value = ValueAsByteArray(msg)
},
IsPartitionEOF = false
},
new Error(ErrorCode.Local_ValueDeserialization),
ex);
}
return(new ConsumeResult <K, V>
{
TopicPartitionOffset = new TopicPartitionOffset(topic, msg.partition, msg.offset),
Message = new Message <K, V>
{
Timestamp = timestamp,
Headers = headers,
Key = key,
Value = val
},
IsPartitionEOF = false
});
}
finally
{
Librdkafka.message_destroy(msgPtr);
}
}
/// <summary>
/// Main method for console app.
/// </summary>
/// <param name="args">No arguments used.</param>
public static void Main(string[] args)
{
Console.WriteLine("Starting .net consumer.");
// Configure the group id, location of the bootstrap server, default deserializers,
// Confluent interceptors
var consumerConfig = new ConsumerConfig
{
BootstrapServers = "kafka:9092",
GroupId = "csharp-consumer-prev",
AutoOffsetReset = AutoOffsetReset.Earliest,
PluginLibraryPaths = "monitoring-interceptor",
};
using (var consumer = new ConsumerBuilder <string, string>(consumerConfig)
.SetPartitionsAssignedHandler((c, partitions) =>
{
// Calculate the time 5 minutes ago
var timestamp = new Confluent.Kafka.Timestamp(DateTime.Now.AddMinutes(-5));
// Build a list of TopicPartitionTimestamp
var timestamps = partitions.Select(tp => new TopicPartitionTimestamp(tp, timestamp));
// TODO: Request the offsets for the start timestamp
var offsets = c.OffsetsForTimes(timestamps, TimeSpan.FromMinutes(1));
foreach (var offset in offsets)
{
// TODO: Print the new offset for each partition
Console.WriteLine($"Moving partion {offset.Partition.Value} to {offset.Offset.Value}");
}
// Return the new partition offsets
return(offsets);
})
.Build())
{
// Subscribe to our topic
consumer.Subscribe(KafkaTopic);
CancellationTokenSource cts = new CancellationTokenSource();
Console.CancelKeyPress += (_, e) =>
{
e.Cancel = true; // prevent the process from terminating.
cts.Cancel();
};
try
{
int recordCount = 0;
while (true)
{
try
{
// Poll for available records
var cr = consumer.Consume(cts.Token);
Console.WriteLine($"{cr.Message.Key},{cr.Message.Value}");
recordCount++;
// Exit processing after 100 records
if (recordCount >= 100)
{
break;
}
}
catch (ConsumeException e)
{
Console.WriteLine($"Error occured: {e.Error.Reason}");
}
}
}
catch (OperationCanceledException)
{
// Clean up when the application exits
Console.WriteLine("Closing consumer.");
consumer.Close();
}
}
}
private void ProduceImpl(
string topic,
byte[] val, int valOffset, int valLength,
byte[] key, int keyOffset, int keyLength,
Timestamp timestamp,
Partition partition,
IEnumerable <IHeader> headers,
IDeliveryHandler deliveryHandler)
{
if (timestamp.Type != TimestampType.CreateTime)
{
if (timestamp != Timestamp.Default)
{
throw new ArgumentException("Timestamp must be either Timestamp.Default, or Timestamp.CreateTime.");
}
}
ErrorCode err;
if (this.enableDeliveryReports && deliveryHandler != null)
{
// Passes the TaskCompletionSource to the delivery report callback via the msg_opaque pointer
// Note: There is a level of indirection between the GCHandle and
// physical memory address. GCHandle.ToIntPtr doesn't get the
// physical address, it gets an id that refers to the object via
// a handle-table.
var gch = GCHandle.Alloc(deliveryHandler);
var ptr = GCHandle.ToIntPtr(gch);
err = KafkaHandle.Produce(
topic,
val, valOffset, valLength,
key, keyOffset, keyLength,
partition.Value,
timestamp.UnixTimestampMs,
headers,
ptr);
if (err != ErrorCode.NoError)
{
// note: freed in the delivery handler callback otherwise.
gch.Free();
}
}
else
{
err = KafkaHandle.Produce(
topic,
val, valOffset, valLength,
key, keyOffset, keyLength,
partition.Value,
timestamp.UnixTimestampMs,
headers,
IntPtr.Zero);
}
if (err != ErrorCode.NoError)
{
throw new KafkaException(KafkaHandle.CreatePossiblyFatalError(err, null));
}
}
