rabbitmq-tutorials/cpp/rpc_client.cpp

90 lines
2.5 KiB
C++

#include <string.h>
#include <iostream>
#include <amqp.h>
#include <amqp_tcp_socket.h>
class FibonacciRpcClient
{
public:
FibonacciRpcClient()
{
m_conn = amqp_new_connection();
amqp_socket_t *socket = amqp_tcp_socket_new(m_conn);
amqp_socket_open(socket, "localhost", AMQP_PROTOCOL_PORT);
amqp_login(m_conn, "/", 0, AMQP_DEFAULT_FRAME_SIZE, 0, AMQP_SASL_METHOD_PLAIN, "guest", "guest");
amqp_channel_open(m_conn, KChannel);
amqp_queue_declare_ok_t *r = amqp_queue_declare(m_conn, KChannel, amqp_empty_bytes, false, false, false, /*auto delete*/true, amqp_empty_table);
m_callbackQueue = amqp_bytes_malloc_dup(r->queue);
}
int call(int n)
{
m_corr_id = std::to_string(++m_requestCount);
amqp_basic_properties_t props;
props._flags = AMQP_BASIC_CORRELATION_ID_FLAG | AMQP_BASIC_REPLY_TO_FLAG;
props.correlation_id = amqp_cstring_bytes(m_corr_id.c_str());
props.reply_to = m_callbackQueue;
amqp_bytes_t n_;
n_.bytes = &n;
n_.len = sizeof(n);
amqp_basic_publish(m_conn, KChannel, amqp_empty_bytes, /* routing key*/ amqp_cstring_bytes("rpc_queue"), false, false, &props, n_);
amqp_basic_consume(m_conn, KChannel, m_callbackQueue, amqp_empty_bytes, false, /* auto ack*/ true, false, amqp_empty_table);
int response = 0;
bool keepProcessing = true;
while (keepProcessing)
{
amqp_maybe_release_buffers(m_conn);
amqp_envelope_t envelope;
amqp_consume_message(m_conn, &envelope, nullptr, 0);
std::string correlation_id((char *)envelope.message.properties.correlation_id.bytes, (int)envelope.message.properties.correlation_id.len);
if (correlation_id == m_corr_id)
{
response = *(int *)envelope.message.body.bytes;
keepProcessing = false;
}
amqp_destroy_envelope(&envelope);
}
return response;
}
~FibonacciRpcClient()
{
amqp_bytes_free(m_callbackQueue);
amqp_channel_close(m_conn, KChannel, AMQP_REPLY_SUCCESS);
amqp_connection_close(m_conn, AMQP_REPLY_SUCCESS);
amqp_destroy_connection(m_conn);
}
private:
amqp_connection_state_t m_conn;
const amqp_channel_t KChannel = 1;
amqp_bytes_t m_callbackQueue;
std::string m_corr_id;
int m_requestCount = 0;
};
int main(int argc, char const *const *argv)
{
int n = 30;
if (argc > 1)
{
n = std::stoi(argv[1]);
}
FibonacciRpcClient fibonacciRpcClient;
std::cout << " [x] Requesting fib(" << n << ")" << std::endl;
int response = fibonacciRpcClient.call(n);
std::cout << " [.] Got " << response << std::endl;
return 0;
}