rabbitmq消息流轉分析
連接（connection）：消費者或者生產者與消息中間件建立的tcp連接；
頻道（channel）：tcp連接建立之後，必須現在連接上開頻道，才能進行其他操作（原因？）
登錄（logging）：建立頻道之後，要登錄到特定的虛擬機，一組虛擬機持有一組交換機和隊列，其他虛擬機用戶無法訪問當前用戶對應的虛擬機中的交換機和隊列；
交換機（exchange）：在rabbitmq消息中間件啟動時就會創建一個默認的交換機（當然也可以人為創建），與連接無關，負責整個消息中間件中消息的投遞；交換機不會存儲消息，
如果沒有任何隊列與之綁定，那麽交換機會丟棄收到的消息；
隊列（queue）：用來存儲交換機投遞過來的消息，通過路由鍵與交換機綁定，進行消息的持久化存儲；
隊列由消費者或者生產者連上消息中間件後自行創建，人為指定隊列名稱，如果當前創建的隊列rabbitmq上已經存在，rabbitmq不會重復創建；
路由鍵（routingkey）：交換機和隊列進行消息投遞的識別碼，人為指定；
一、生產者發送消息：
conn = amqp_new_connection();//
socket = amqp_tcp_socket_new(conn);
status = amqp_socket_open(socket, hostname, port);
amqp_login(conn, "ois", 0, 131072, 0, AMQP_SASL_METHOD_PLAIN, "ois", "1");
amqp_channel_open(conn, 1);
die_on_amqp_error(amqp_get_rpc_reply(conn), "Opening channel");
amqp_bytes_t queuename;
{
???? amqp_queue_declare_ok_t *r = amqp_queue_declare(conn, 1, amqp_cstring_bytes("myqueue"), 0, 0, 0, 1,
???????? amqp_empty_table);
???? die_on_amqp_error(amqp_get_rpc_reply(conn), "Declaring queue");
???? queuename = amqp_bytes_malloc_dup(r->queue);
???? if (queuename.bytes == NULL) {
???????? fprintf(stderr, "Out of memory while copying queue name");
???????? return 1;
???? }
}//創建名稱為myqueue的隊列
amqp_queue_bind(conn, 1, queuename, amqp_cstring_bytes(exchange), amqp_cstring_bytes(routingkey),
???? amqp_empty_table);
die_on_amqp_error(amqp_get_rpc_reply(conn), "Binding queue");//將隊列myqueue通過路由鍵routingkey綁定到交換機exchange上
?
for (;;)
{
amqp_basic_properties_t props;
props._flags = AMQP_BASIC_CONTENT_TYPE_FLAG | AMQP_BASIC_DELIVERY_MODE_FLAG;
props.content_type = amqp_cstring_bytes("text/plain");
props.delivery_mode = 2; /* persistent delivery mode */
die_on_error(amqp_basic_publish(conn,
1,
amqp_cstring_bytes(exchange),
amqp_cstring_bytes(routingkey),
0,
0,
&props,
amqp_cstring_bytes("test message")),
"Publishing");
????microsleep(1*1000*100);
}//生產者發布消息，發布消息需要指定接收消息的交換機，以及路由鍵，交換機需要根據路由鍵投遞消息到具體的隊列中
二、消費者獲取消息進行處理
static void run(amqp_connection_state_t conn)
{
uint64_t start_time = now_microseconds();
int received = 0;
int previous_received = 0;
uint64_t previous_report_time = start_time;
uint64_t next_summary_time = start_time + SUMMARY_EVERY_US;
?
amqp_frame_t frame;
?
uint64_t now;
?
for (;;) {
amqp_rpc_reply_t ret;
amqp_envelope_t envelope;
?
now = now_microseconds();
if (now > next_summary_time) {
int countOverInterval = received - previous_received;
double intervalRate = countOverInterval / ((now - previous_report_time) / 1000000.0);
printf("%d ms: Received %d - %d since last report (%d Hz)\n",
(int)(now - start_time) / 1000, received, countOverInterval, (int) intervalRate);
?
previous_received = received;
previous_report_time = now;
next_summary_time += SUMMARY_EVERY_US;
}
?
amqp_maybe_release_buffers(conn);
ret = amqp_consume_message(conn, &envelope, NULL, 0);//定時獲取隊列中的消息
?
if (AMQP_RESPONSE_NORMAL != ret.reply_type) {
if (AMQP_RESPONSE_LIBRARY_EXCEPTION == ret.reply_type &&
AMQP_STATUS_UNEXPECTED_STATE == ret.library_error) {
if (AMQP_STATUS_OK != amqp_simple_wait_frame(conn, &frame)) {
return;
}
?
if (AMQP_FRAME_METHOD == frame.frame_type) {
switch (frame.payload.method.id) {
case AMQP_BASIC_ACK_METHOD:
/* if we‘ve turned publisher confirms on, and we‘ve published a message
* here is a message being confirmed
*/
?
break;
case AMQP_BASIC_RETURN_METHOD:
/* if a published message couldn‘t be routed and the mandatory flag was set
* this is what would be returned. The message then needs to be read.
*/
{
amqp_message_t message;
ret = amqp_read_message(conn, frame.channel, &message, 0);
if (AMQP_RESPONSE_NORMAL != ret.reply_type) {
return;
}
?
amqp_destroy_message(&message);
}
?
break;
?
case AMQP_CHANNEL_CLOSE_METHOD:
/* a channel.close method happens when a channel exception occurs, this
* can happen by publishing to an exchange that doesn‘t exist for example
*
* In this case you would need to open another channel redeclare any queues
* that were declared auto-delete, and restart any consumers that were attached
* to the previous channel
*/
return;
?
case AMQP_CONNECTION_CLOSE_METHOD:
/* a connection.close method happens when a connection exception occurs,
* this can happen by trying to use a channel that isn‘t open for example.
*
* In this case the whole connection must be restarted.
*/
return;
?
default:
fprintf(stderr ,"An unexpected method was received %u\n", frame.payload.method.id);
return;
}
}
}
?
} else {
amqp_destroy_envelope(&envelope);
}
?
received++;
}
}
?
int main(int argc, char const *const *argv)
{
conn = amqp_new_connection();
socket = amqp_tcp_socket_new(conn);
status = amqp_socket_open(socket, hostname, port);
die_on_amqp_error(amqp_login(conn, "ot", 0, 131072, 0, AMQP_SASL_METHOD_PLAIN, "guest", "guest"),
"Logging in");
amqp_channel_open(conn, 1);
die_on_amqp_error(amqp_get_rpc_reply(conn), "Opening channel");
{
amqp_queue_declare_ok_t *r = amqp_queue_declare(conn, 1, amqp_empty_bytes, 0, 0, 0, 1,
amqp_empty_table);
die_on_amqp_error(amqp_get_rpc_reply(conn), "Declaring queue");
queuename = amqp_bytes_malloc_dup(r->queue);
if (queuename.bytes == NULL) {
fprintf(stderr, "Out of memory while copying queue name");
return 1;
}
}
?
amqp_queue_bind(conn, 1, queuename, amqp_cstring_bytes(exchange), amqp_cstring_bytes(bindingkey),
amqp_empty_table);//綁定消息隊列
die_on_amqp_error(amqp_get_rpc_reply(conn), "Binding queue");
?
amqp_basic_consume(conn, 1, queuename, amqp_empty_bytes, 0, 1, 0, amqp_empty_table);
die_on_amqp_error(amqp_get_rpc_reply(conn), "Consuming");//指定這是一個消費者
?
run(conn);
?
die_on_amqp_error(amqp_channel_close(conn, 1, AMQP_REPLY_SUCCESS), "Closing channel");
die_on_amqp_error(amqp_connection_close(conn, AMQP_REPLY_SUCCESS), "Closing connection");
die_on_error(amqp_destroy_connection(conn), "Ending connection");
?
return 0;
}
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rabbitmq消息流轉分析