Add discovery examples

examples/discovery/consumer.php

@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+require dirname(__DIR__).'/../vendor/autoload.php';
+
+use Amp\ByteStream;
+use Amp\Log\ConsoleFormatter;
+use Amp\Log\StreamHandler;
+use Amp\Loop;
+use Monolog\Logger;
+use Monolog\Processor\PsrLogMessageProcessor;
+use Nsq\Config\ClientConfig;
+use Nsq\Config\LookupConfig;
+use Nsq\Lookup;
+use Nsq\Message;
+
+Loop::run(static function () {
+    $handler = new StreamHandler(ByteStream\getStdout());
+    $handler->setFormatter(new ConsoleFormatter());
+    $logger = new Logger('consumer', [$handler], [new PsrLogMessageProcessor()]);
+
+    $callable = static function (Message $message) {
+        yield $message->finish();
+    };
+
+    $clientConfig = new ClientConfig();
+
+    $lookupConfig = new LookupConfig();
+
+    $watcherId = Loop::repeat(5000, function () {
+        yield Amp\Dns\resolver()->reloadConfig();
+    });
+
+    $lookup = Lookup::create(
+        ['http://nsqlookupd0:4161', 'http://nsqlookupd1:4161', 'http://nsqlookupd2:4161'],
+        $lookupConfig,
+        $logger,
+    );
+
+    $lookup->subscribe('local', 'local', $callable, $clientConfig);
+
+    Loop::delay(10000, function () use ($lookup, $watcherId) {
+        $lookup->stop();
+        Loop::cancel($watcherId);
+    });
+});

examples/discovery/producer.php

@@ -0,0 +1,108 @@
+<?php
+
+declare(strict_types=1);
+
+require dirname(__DIR__).'/../vendor/autoload.php';
+
+use Amp\ByteStream;
+use Amp\Log\ConsoleFormatter;
+use Amp\Log\StreamHandler;
+use Amp\Loop;
+use Monolog\Logger;
+use Monolog\Processor\PsrLogMessageProcessor;
+use Nsq\Config\ClientConfig;
+use Nsq\Config\LookupConfig;
+use Nsq\Exception\NsqException;
+use Nsq\Lookup;
+use Nsq\Producer;
+use function Amp\asyncCall;
+use function Amp\delay;
+
+Loop::run(static function () {
+    $handler = new StreamHandler(ByteStream\getStdout());
+    $handler->setFormatter(new ConsoleFormatter());
+    $logger = new Logger('publisher', [$handler], [new PsrLogMessageProcessor()]);
+
+    $clientConfig = new ClientConfig();
+
+    /** @var Producer[] $producers */
+    $producers = [];
+
+    $lookupConfig = new LookupConfig();
+
+    $lookup = Lookup::create(
+        ['http://nsqlookupd0:4161', 'http://nsqlookupd1:4161', 'http://nsqlookupd2:4161'],
+        $lookupConfig,
+        $logger,
+    );
+
+    $isRunning = true;
+
+    asyncCall(static function () use ($lookup, $clientConfig, $logger, &$producers, &$isRunning) {
+        $stopList = [];
+
+        while ($isRunning) {
+            /** @var Lookup\Producer[] $nodes */
+            $nodes = yield $lookup->nodes();
+
+            foreach ($nodes as $node) {
+                $toTcpUri = $node->toTcpUri();
+
+                if (array_key_exists($toTcpUri, $producers) || array_key_exists($toTcpUri, $stopList)) {
+                    continue;
+                }
+
+                $stopList[$node->broadcastAddress] = true;
+
+                $logger->debug('Found new nsqd: '.$toTcpUri);
+
+                asyncCall(function () use ($node, $clientConfig, $logger, &$producers, &$stopList) {
+                    $producer = new Producer(
+                        $node->toTcpUri(),
+                        clientConfig: $clientConfig,
+                        logger: $logger,
+                    );
+
+                    yield $producer->connect();
+
+                    $producers[$node->toTcpUri()] = $producer;
+                    unset($stopList[$node->toTcpUri()]);
+                });
+            }
+
+            yield delay(5000);
+
+            yield Amp\Dns\resolver()->reloadConfig();
+        }
+    });
+
+    Loop::delay(5000, function () use (&$isRunning) {
+        $isRunning = false;
+    });
+
+    $counter = 0;
+    while (true) {
+        if (!$isRunning) {
+            foreach ($producers as $producer) {
+                $producer->close();
+            }
+
+            break;
+        }
+
+        if ([] === $producers) {
+            yield delay(200);
+
+            continue;
+        }
+
+        $index = array_rand($producers);
+        $producer = $producers[$index];
+
+        try {
+            yield $producer->publish('local', 'This is message of count '.$counter++);
+        } catch (NsqException) {
+            unset($producers[$index]);
+        }
+    }
+});