Documentation

SelectiveTransportExecutor
in package
implements ExecutorInterface

Send DNS queries over a UDP or TCP/IP stream transport.

This class will automatically choose the correct transport protocol to send a DNS query to your DNS server. It will always try to send it over the more efficient UDP transport first. If this query yields a size related issue (truncated messages), it will retry over a streaming TCP/IP transport.

For more advanced usages one can utilize this class directly. The following example looks up the IPv6 address for reactphp.org.

$executor = new SelectiveTransportExecutor($udpExecutor, $tcpExecutor);

$executor->query(
    new Query($name, Message::TYPE_AAAA, Message::CLASS_IN)
)->then(function (Message $message) {
    foreach ($message->answers as $answer) {
        echo 'IPv6: ' . $answer->data . PHP_EOL;
    }
}, 'printf');

Note that this executor only implements the logic to select the correct transport for the given DNS query. Implementing the correct transport logic, implementing timeouts and any retry logic is left up to the given executors, see also UdpTransportExecutor and TcpTransportExecutor for more details.

Note that this executor is entirely async and as such allows you to execute any number of queries concurrently. You should probably limit the number of concurrent queries in your application or you're very likely going to face rate limitations and bans on the resolver end. For many common applications, you may want to avoid sending the same query multiple times when the first one is still pending, so you will likely want to use this in combination with a CoopExecutor like this:

$executor = new CoopExecutor(
    new SelectiveTransportExecutor(
        $datagramExecutor,
        $streamExecutor
    )
);

Table of Contents

Interfaces

ExecutorInterface

Properties

$datagramExecutor  : mixed
$streamExecutor  : mixed

Methods

__construct()  : mixed
query()  : PromiseInterface<string|int, Message>
Executes a query and will return a response message

Properties

Methods

query()

Executes a query and will return a response message

public query(Query $query) : PromiseInterface<string|int, Message>

It returns a Promise which either fulfills with a response React\Dns\Model\Message on success or rejects with an Exception if the query is not successful. A response message may indicate an error condition in its rcode, but this is considered a valid response message.

$executor->query($query)->then(
    function (React\Dns\Model\Message $response) {
        // response message successfully received
        var_dump($response->rcode, $response->answers);
    },
    function (Exception $error) {
        // failed to query due to $error
    }
);

The returned Promise MUST be implemented in such a way that it can be cancelled when it is still pending. Cancelling a pending promise MUST reject its value with an Exception. It SHOULD clean up any underlying resources and references as applicable.

$promise = $executor->query($query);

$promise->cancel();
Parameters
$query : Query
Return values
PromiseInterface<string|int, Message> 

        

        
    




    

    

                                

                

                                
    

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