如何使用c通过rabbitmq发送和接收protobuf数据

Question

我是rabbitmq和protobuf的新手，有没有一些代码示例可以通过rabbitmq用c语言发送和接收protobuf数据？谢谢

Answer 1

操作定义如下：

syntax = "proto2";

message Operation {
    required string operation = 1;
    optional int32 tracking_id = 2;
    optional double x = 3;
    optional double y = 4;
}

发送代码：

Operation msg = OPERATION__INIT;
uint8_t *buf;
size_t len;
msg.operation = "d";
msg.tracking_id = 1;
msg.x = 0.5566;
msg.y = 0.2666;
msg.has_tracking_id = 1;
msg.has_x = 1;
msg.has_y = 1;
len = operation__get_packed_size(&msg);
buf = malloc(len);
operation__pack(&msg, buf);
amqp_bytes_t body;
body.len = len;
body.bytes = buf;
amqp_basic_publish(conn, 1, amqp_cstring_bytes(exchange),amqp_cstring_bytes(routingkey), 0, 0, &props, body);
free(buf);

接收代码：

amqp_rpc_reply_t res;
amqp_envelope_t envelope;

amqp_maybe_release_buffers(conn);

res = amqp_consume_message(conn, &envelope, NULL, 0);

if (AMQP_RESPONSE_NORMAL != res.reply_type)
{
   break;
}
fprintf(stderr, "%s\n", envelope.message.body.bytes);
fprintf(stderr, "%zu\n", envelope.message.body.len);
Operation *msg = operation__unpack(NULL, envelope.message.body.len, (const uint8_t *)envelope.message.body.bytes);
printf("operation:%s\n", msg->operation);
if (msg->has_tracking_id)
    printf("%d\n", msg->tracking_id);
if (msg->has_x)
    printf("%f\n", msg->x);
if (msg->has_y)
    printf("%f\n", msg->y);

amqp_destroy_envelope(&envelope);