Create simple_promise_wrapper.php

examples/simple_promise_wrapper.php

@@ -0,0 +1,164 @@
+<?php
+
+require_once 'vendor/autoload.php';
+
+$loop = \React\EventLoop\Factory::create();
+
+$cache = new CacheRedis($loop, [
+    'connectionString' => 'tcp://127.0.0.1:6379',
+]);
+$cache->set('mykey', 'myvalue', 1)->then(function(){
+    print 'Set key successfull for 1 seconds lifetime' . PHP_EOL;
+}, function($reason){
+    print 'Set key failed (' . $reason . ')' . PHP_EOL;
+})->then(function() use($cache){
+    return $cache->get('mykey');
+})->then(function($response){
+    print 'Got key value: ' . $response . PHP_EOL;
+}, function($reason){
+    print 'Cannot get key value: ' . $reason . PHP_EOL;
+})->then(function() use($loop, $cache){
+    print "Trying to get value after 2 seconds" . PHP_EOL;
+    $loop->addTimer(2, function() use($cache){
+        $cache->get('mykey')->then(function($response){
+            print "Got value from redis after 2 seconds: " . $response . '(isnull: ' . ((int)is_null($response)) . ')' . PHP_EOL;
+        }, function($reason){
+            print 'Cannot get key value after 2 seconds: ' . $reason . PHP_EOL;
+        });
+    });
+});
+
+$loop->run();
+
+class CacheRedis{
+    /**
+     * @var array connection options
+     */
+    public $options;
+
+    /**
+     * @var \React\EventLoop\LoopInterface $loop
+     */
+    public $loop;
+
+    /**
+     * @var \Predis\Async\Client $handle
+     */
+    public $client;
+
+    /**
+     * @var \React\Promise\Deferred
+     */
+    public $deferredConnect;
+
+    /**
+     * CacheRedis constructor.
+     * @param \React\EventLoop\LoopInterface $loop
+     * @param array $options [connectionString => ...]
+     * @throws Exception
+     */
+    public function __construct(\React\EventLoop\LoopInterface $loop, $options)
+    {
+
+        if(!isset($options['connectionString'])){
+            throw new Exception('Cannot create CacheRedis without connectionString');
+        }
+
+        $this->loop = $loop;
+        $this->options = $options;
+
+        $clientOptions = new \Predis\Async\Configuration\Options([
+            'eventloop' => $this->loop,
+        ]);
+        /** @noinspection PhpUndefinedFieldInspection */
+        $clientOptions->on_error = function(){
+            if(!is_null($this->deferredConnect)){
+                $this->deferredConnect->reject('Cannot connect to Redis servers');
+                $this->deferredConnect = null;
+                return;
+            }
+            throw new Exception('Got unknown error when working with redis');
+        };
+
+        $this->client = new \Predis\Async\Client($this->options['connectionString'], $clientOptions);
+    }
+
+    /**
+     * Connect to server if not connected
+     * @return \React\Promise\Promise
+     */
+    public function getConnection(){
+        if($this->client->isConnected()){
+            return \React\Promise\resolve($this->client);
+        }
+        if(!is_null($this->deferredConnect)){
+            return $this->deferredConnect->promise();
+        }
+        $this->deferredConnect = new \React\Promise\Deferred();
+        $this->client->connect(function(){
+            $this->deferredConnect->resolve($this->client);
+            $this->deferredConnect = null;
+        });
+        return $this->deferredConnect->promise();
+    }
+
+    /**
+     * Set key to value with lifetime in seconds
+     * @param string $key key to set
+     * @param string $value value to set
+     * @param int $lifetime lifetime in seconds
+     * @return \React\Promise\Promise
+     */
+    public function set($key, $value, $lifetime)
+    {
+        $command = new \React\Promise\Deferred();
+        $this->getConnection()->then(function() use($key, $value, $lifetime, $command){
+            /** @noinspection PhpUndefinedMethodInspection */
+            $this->client->setex($key, $lifetime, $value, function($status) use($command){
+                switch(true){
+                    case ($status instanceof \Predis\Response\Error):
+                        $command->reject($status->getMessage());
+                        break;
+                    case ($status instanceof \Predis\Response\Status):
+                        if($status->getPayload() == 'OK'){
+                            $command->resolve();
+                        }
+                        else{
+                            $command->reject('Got unknown response status from redis: ' . $status->getPayload());
+                        }
+                        break;
+                    default:
+                        $command->reject('Got unknown status from redis');
+                        break;
+                }
+            });
+        }, function() use($command){
+            $command->reject('Cannot execute set command, no connection to server');
+        });
+        return $command->promise();
+    }
+
+    /**
+     * Get key value from Redis
+     * @param string $key
+     * @return \React\Promise\Promise
+     */
+    public function get($key)
+    {
+        $command = new \React\Promise\Deferred();
+        $this->getConnection()->then(function() use($command, $key){
+            /** @noinspection PhpUndefinedMethodInspection */
+            $this->client->get($key, function($response) use($command){
+                if(is_null($response) || is_string($response)){
+                    $command->resolve($response);
+                }
+                else{
+                    $command->reject('Cannot execute get command, got unexpected response');
+                }
+            });
+        }, function() use($command){
+            $command->reject('Cannot execute get command, no connection to server');
+        });
+        return $command->promise();
+    }
+}