Spoole TCP server

learning Swoole4 file
tcp

// establish Server object , monitor  127.0.0.1:9501  port 
$server = new Swoole\Server('127.0.0.1', 9501);

// Listen for connection entry events 
$server->on('Connect', function ($server, $fd) {
    echo "Client: Connect.\n";
});

// Listen for data receiving events 
$server->on('Receive', function ($server, $fd, $from_id, $data) {
    $server->send($fd, "Server: " . $data);
});

// Listen for connection close events 
$server->on('Close', function ($server, $fd) {
    echo "Client: Close.\n";
});

// Start the server 
$server->start(); 

Create a TCP The server , Monitor local 9501 port . Its logic is simple , When the client Socket Send a message over the network hello When the string , The server will reply one Server: hello character string .
Server It's an Asynchronous Server , So the program is written by listening to events . When the corresponding event occurs, the underlying layer will actively call back the specified function . When there is a new TCP When the connection enters, it executes onConnect Event callback , When a connection sends data to the server, it calls back onReceive function .

The server can be connected by thousands of clients at the same time ,$fd Is the unique identifier of the client connection
call $server->send() Method to send data to the client connection , The parameter is $fd Client identifier
call $server->close() Method to force a client connection to close
The client may take the initiative to disconnect , It's going to trigger onClose Event callback
 

The general function of the code is ：

1) When the server finds that the client is connected , Will output text “Client:Connect”

2) Once the message from the client is received , Will send... To the client “Server: The original message ”

3) When the connection is disconnected , Output text “Client:Close”

Detailed explanation of correlation function

1) Constructors

Swoole\Server(string $host = '0.0.0.0', int $port = 0, int $mode = SWOOLE_PROCESS, int $sockType = SWOOLE_SOCK_TCP): \Swoole\Server

$host： Monitoring IP Address , Can support IPV4 It can also support IPV6,0.0.0.0 by IPV4 All the addresses of ,::（ amount to 0:0:0:0:0:0:0:0） by IPV6 All the addresses of .

$port： Listening port , If the port is less than 1024 You need to root jurisdiction .

$mode：SWOOLE_PROCESS（ Default , Multi process mode ）,SWOOLE_BASE（ Basic mode ）.

$socketType：SWOOLE_SOCK_TCP（ Default ,IPV4 TCP）、SWOOLE_SOCK_TCP6、SWOOLE_SOCK_UDP、SWOOLE_SOCK_UDP6

2) function on： Call event

Swoole\Server->on(string $event, mixed $callback): void

$event： Event name , Case insensitive

$callback： Callback function , For the parameter format of the callback function of each event, see the event description . The callback function can be a string of function name , Class static methods , Object method array , Anonymous functions .

3) function start： Start the server , Listen to all specified ports

Swoole\Server->start(): bool

This function has no parameters , But the following things must be understood ：

· After successful startup, it will create worker_num+2 A process .Master process +Manager process +worker_num individual Worker process .
· Startup failure will immediately return false
· After successful startup, it will enter the event cycle , Waiting for client connection request .start The code after the method will not execute
· After the server is shut down ,start The function returns true, And continue down
· Set up task_worker_num The generic value will increase by a corresponding amount Task process
· Method list start The previous method can only be used in start Use before calling , stay start The latter method can only be used in onWorkerStart、onReceive And other event callback functions

4) function send： Send data to client

Swoole\Server->send(int $fd, string $data, int $serverSocket  = -1): bool

$fd： Client file descriptor , Each client is assigned a descriptor , It can be understood as the client's ID.

$data： Data sent ,TCP The maximum agreement shall not exceed 2M, Modifiable buffer_output_size Change the maximum packet length allowed to be sent .

 $serverSocket： towards UnixSocket DGRAM This parameter is required when sending data to the opposite end ,TCP The client does not need to fill .

 5) function getClientInfo： Get connection information

Swoole\Server->getClientInfo(int $fd, int $extraData, bool $ignoreError = false): bool|array

$fd： Client file descriptor , Each client is assigned a descriptor , It can be understood as the client's ID.

$extraData： Extended information , Reserved parameters , There is no effect at present .

$ignoreError： Whether to ignore errors , If set to true, Even if the connection is closed, the connection information will be returned .

Be careful ： When using dispatch_mode = 1（ Round robin mode ） or 3（ Preemption mode ） When the configuration , Consider this packet distribution strategy for stateless Services , When the connection is disconnected, the relevant information will be deleted directly from the memory , therefore Server->getClientInfo Is unable to obtain relevant connection information .