int main(int argc, char **argv)
{
Client::Configuration configuration;
configuration.auto_connect = true;
configuration.client_id = "libkafka_asio_example";
configuration.socket_timeout = 10000;
configuration.AddBrokerFromString("192.168.15.137:49162");
boost::asio::io_service ios;
Client client(ios, configuration);
// Create a 'Fetch' request and try to get data for partition 0 of topic
// 'mytopic', starting with offset 1
FetchRequest request;
request.FetchTopic("mytopic", 0, 1);
// Helper to interpret the received bytes as string
auto BytesToString = [](const libkafka_asio::Bytes& bytes) -> std::string
{
if (!bytes || bytes->empty())
{
return "";
}
return std::string((const char*) &(*bytes)[0], bytes->size());
};
// Send the prepared fetch request.
// The client will attempt to automatically connect to the broker, specified
// in the configuration.
client.AsyncRequest(
request,
[&](const Client::ErrorCodeType& err,
const FetchResponse::OptionalType& response)
{
if (err)
{
std::cerr
<< "Error: " << boost::system::system_error(err).what()
<< std::endl;
return;
}
// Loop through the received messages.
// A range based for loop might also work.
std::for_each(response->begin(), response->end(),
[&](const MessageAndOffset& message)
{
std::cout << BytesToString(message.value()) << std::endl;
});
});
// Let's go!
ios.run();
return 0;
}
TEST_F(RequestWriteTest, RequestMessageWireSize)
{
MessageAndOffset test_message;
test_message.mutable_key().reset(new Bytes::element_type(1024));
test_message.mutable_value().reset(new Bytes::element_type(2048));
// See test above
size_t expected_message_size = MessageWireSize(test_message);
{ // Metadata Request
MetadataRequest req;
req.AddTopicName("foo");
req.AddTopicName("bar!");
size_t expected_size =
4 + // Array size
(2 + 3) + // 'foo'
(2 + 4); // 'bar'
ASSERT_EQ(expected_size, RequestMessageWireSize(req));
}
{ // Produce Request
ProduceRequest req;
req.AddMessage(test_message, "bar!");
size_t expected_size =
2 + // RequiredAcks
4 + // Timeout
4 + // Topic Array Size
(2 + 4) + // 'bar!'
4 + // Partition Array Size
4 + // Partition
4 + // MessageSetSize
(8 + 4 + expected_message_size); // MessageSet
ASSERT_EQ(expected_size, RequestMessageWireSize(req));
}
{ // Fetch Request
FetchRequest req;
req.FetchTopic("foo", 0);
size_t expected_size =
4 + // ReplicaId
4 + // MaxWaitTime
4 + // MinBytes
4 + // Topic Array Size
(2 + 3) + // 'foo'
4 + // Partition Array Size
4 + // Partition
8 + // Fetch Offset
4; // MaxBytes
ASSERT_EQ(expected_size, RequestMessageWireSize(req));
}
{ // Offset Request
OffsetRequest req;
req.FetchTopicOffset("foo", 0, 2500);
size_t expected_size =
4 + // ReplicaId
4 + // Topic Array Size
(2 + 3) + // 'foo'
4 + // Partition Array Size
4 + // Partition
8 + // Time
4; // MaxNumberOfOffsets
ASSERT_EQ(expected_size, RequestMessageWireSize(req));
}
}