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mirror of https://github.com/danog/dns.git synced 2024-11-27 04:24:48 +01:00
dns/lib/functions.php
2017-01-10 23:49:38 -06:00

80 lines
2.7 KiB
PHP

<?php
namespace Amp\Dns;
use AsyncInterop\{ Loop, Promise };
const LOOP_STATE_IDENTIFIER = Resolver::class;
/**
* Retrieve the application-wide dns resolver instance
*
* @param \Amp\Dns\Resolver $resolver Optionally specify a new default dns resolver instance
* @return \Amp\Dns\Resolver Returns the application-wide dns resolver instance
*/
function resolver(Resolver $resolver = null): Resolver {
if ($resolver === null) {
$resolver = Loop::getState(LOOP_STATE_IDENTIFIER);
if ($resolver) {
return $resolver;
}
$resolver = driver();
}
Loop::setState(LOOP_STATE_IDENTIFIER, $resolver);
return $resolver;
}
/**
* Create a new dns resolver best-suited for the current environment
*
* @return \Amp\Dns\Resolver
*/
function driver(): Resolver {
return new DefaultResolver;
}
/**
* Resolve a hostname name to an IP address
* [hostname as defined by RFC 3986]
*
* Upon success the returned promise resolves to an indexed array of the form:
*
* [string $recordValue, int $type, int $ttl]
*
* A null $ttl value indicates the DNS name was resolved from the cache or the
* local hosts file.
* $type being one constant from Amp\Dns\Record
*
* Options:
*
* - "server" | string Custom DNS server address in ip or ip:port format (Default: 8.8.8.8:53)
* - "timeout" | int DNS server query timeout (Default: 3000ms)
* - "hosts" | bool Use the hosts file (Default: true)
* - "reload_hosts" | bool Reload the hosts file (Default: false), only active when no_hosts not true
* - "cache" | bool Use local DNS cache when querying (Default: true)
* - "types" | array Default: [Record::A, Record::AAAA] (only for resolve())
* - "recurse" | bool Check for DNAME and CNAME records (always active for resolve(), Default: false for query())
*
* If the custom per-request "server" option is not present the resolver will
* use the first nameserver in /etc/resolv.conf or default to Google's public
* DNS servers on Windows or if /etc/resolv.conf is not found.
*
* @param string $name The hostname to resolve
* @param array $options
* @return \AsyncInterop\Promise
* @TODO add boolean "clear_cache" option flag
*/
function resolve(string $name, array $options = []): Promise {
return resolver()->resolve($name, $options);
}
/**
* Query specific DNS records.
*
* @param string $name Unlike resolve(), query() allows for requesting _any_ name (as DNS RFC allows for arbitrary strings)
* @param int|int[] $type Use constants of Amp\Dns\Record
* @param array $options @see resolve documentation
* @return \AsyncInterop\Promise
*/
function query(string $name, $type, array $options = []): Promise {
return resolver()->query($name, $type, $options);
}