Refactoring improvements housekeeping

src/Agent.php

@@ -5,6 +5,8 @@
 namespace Scoutapm;
 
 use Closure;
+use DateTimeImmutable;
+use DateTimeZone;
 use Exception;
 use Psr\Log\LoggerInterface;
 use Psr\Log\NullLogger;
@@ -13,6 +15,8 @@
 use Scoutapm\Connector\SocketConnector;
 use Scoutapm\CoreAgent\AutomaticDownloadAndLaunchManager;
 use Scoutapm\CoreAgent\Downloader;
+use Scoutapm\Events\Metadata;
+use Scoutapm\Events\RegisterMessage;
 use Scoutapm\Events\Request\Request;
 use Scoutapm\Events\Request\RequestId;
 use Scoutapm\Events\Span\Span;
@@ -63,12 +67,7 @@ public function __construct(Config $configuration, Connector $connector, LoggerI
 
     private static function createConnectorFromConfig(Config $config) : SocketConnector
     {
-        return new SocketConnector(
-            $config->get('socket_path'),
-            (string) $config->get('name'),
-            (string) $config->get('key'),
-            $config->get('api_version')
-        );
+        return new SocketConnector($config->get('socket_path'));
     }
 
     /**
@@ -237,8 +236,21 @@ public function send() : bool
             return false;
         }
 
-        // Send this request off to the CoreAgent
-        return $this->connector->sendRequest($this->request);
+        if (!$this->connector->sendMessage(new RegisterMessage(
+            (string) $this->config->get('name'),
+            (string) $this->config->get('key'),
+            $this->config->get('api_version')
+        ))) {
+            return false;
+        }
+
+        if (!$this->connector->sendMessage(new Metadata(
+            new DateTimeImmutable('now', new DateTimeZone('UTC'))
+        ))) {
+            return false;
+        }
+
+        return $this->connector->sendMessage($this->request);
     }
 
     /**

src/Config.php

@@ -48,6 +48,18 @@ public function __construct()
         ];
     }
 
+    /** @param mixed[]|array<string, mixed> $config */
+    public static function fromArray(array $config = []) : self
+    {
+        $instance = new self();
+
+        foreach ($config as $key => $value) {
+            $instance->set($key, $value);
+        }
+
+        return $instance;
+    }
+
     /**
      * Looks through all available sources for the first that can handle this
      * key, then returns the value from that source.

src/Connector/Connector.php

@@ -4,15 +4,18 @@
 
 namespace Scoutapm\Connector;
 
-use Scoutapm\Events\Request\Request;
+use Scoutapm\Connector\Exception\FailedToConnect;
+use Scoutapm\Connector\Exception\NotConnected;
 
 interface Connector
 {
+    /** @throws FailedToConnect */
     public function connect() : void;
 
     public function connected() : bool;
 
-    public function sendRequest(Request $request) : bool;
+    /** @throws NotConnected */
+    public function sendMessage(SerializableMessage $message) : bool;
 
     public function shutdown() : void;
 }

src/Connector/Exception/FailedToConnect.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Scoutapm\Connector\Exception;
+
+use RuntimeException;
+
+final class FailedToConnect extends RuntimeException
+{
+    public static function fromSocketPathAndPrevious(string $socketPath, \Throwable $previous) : self
+    {
+        return new self(sprintf(
+            'Failed to connect to socket on path "%s", previous message: %s',
+            $socketPath,
+            $previous->getMessage()
+        ));
+    }
+}

src/Connector/Exception/NotConnected.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Scoutapm\Connector\Exception;
+
+use RuntimeException;
+
+final class NotConnected extends RuntimeException
+{
+    public static function fromSocketPath(string $socketPath) : self
+    {
+        return new self(sprintf(
+            'Connector has not been connected to socket path "%s"',
+            $socketPath
+        ));
+    }
+}

src/Connector/SerializableMessage.php

@@ -0,0 +1,11 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Scoutapm\Connector;
+
+use JsonSerializable;
+
+interface SerializableMessage extends JsonSerializable
+{
+}

src/Connector/SocketConnector.php

@@ -4,11 +4,8 @@
 
 namespace Scoutapm\Connector;
 
-use DateTimeImmutable;
-use DateTimeZone;
-use Exception;
-use Scoutapm\Events\Metadata;
-use Scoutapm\Events\Request\Request;
+use Scoutapm\Connector\Exception\FailedToConnect;
+use Scoutapm\Connector\Exception\NotConnected;
 use Throwable;
 use const AF_UNIX;
 use const SOCK_STREAM;
@@ -37,33 +34,32 @@ final class SocketConnector implements Connector
     /** @var string */
     private $socketPath;
 
-    /** @var string */
-    private $appName;
-
-    /** @var string */
-    private $appKey;
-
-    /** @var string */
-    private $apiVersion;
-
-    public function __construct(string $socketPath, string $appName, string $appKey, string $apiVersion)
+    public function __construct(string $socketPath)
     {
         $this->socketPath = $socketPath;
-        $this->appName    = $appName;
-        $this->appKey     = $appKey;
-        $this->apiVersion = $apiVersion;
 
         $this->socket = socket_create(AF_UNIX, SOCK_STREAM, 0);
-        $this->connect();
-        register_shutdown_function([&$this, 'shutdown']);
+
+        // Pre-emptive attempt to connect, strictly speaking `__construct` should not have side-effects, so if this
+        // fails then swallow it. The `Agent` goes on to call connect() anyway, and handles launching of the core agent.
+        try {
+            $this->connect();
+        } catch (FailedToConnect $failedToConnect) {
+        }
     }
 
     public function connect() : void
     {
+        if ($this->connected()) {
+            return;
+        }
+
         try {
             $this->connected = socket_connect($this->socket, $this->socketPath);
+            register_shutdown_function([&$this, 'shutdown']);
         } catch (Throwable $e) {
             $this->connected = false;
+            throw FailedToConnect::fromSocketPathAndPrevious($this->socketPath, $e);
         }
     }
 
@@ -72,11 +68,12 @@ public function connected() : bool
         return $this->connected;
     }
 
-    /**
-     * @param mixed $message
-     */
-    private function sendMessage($message) : void
+    public function sendMessage(SerializableMessage $message) : bool
     {
+        if (!$this->connected()) {
+            throw NotConnected::fromSocketPath($this->socketPath);
+        }
+
         $serializedJsonString = json_encode($message);
 
         $size = strlen($serializedJsonString);
@@ -85,36 +82,15 @@ private function sendMessage($message) : void
 
         // Read the response back and drop it. Needed for socket liveness
         $responseLength = socket_read($this->socket, 4);
+        /** @noinspection UnusedFunctionResultInspection */
         socket_read($this->socket, unpack('N', $responseLength)[1]);
-    }
-
-    /** @throws Exception */
-    public function sendRequest(Request $request) : bool
-    {
-        $this->sendMessage([
-            'Register' => [
-                'app' => $this->appName,
-                'key' => $this->appKey,
-                'language' => 'php',
-                'api_version' => $this->apiVersion,
-            ],
-        ]);
-
-        $this->sendMessage(new Metadata(
-            new DateTimeImmutable('now', new DateTimeZone('UTC'))
-        ));
-
-        // Send the whole Request as a batch command
-        $this->sendMessage([
-            'BatchCommand' => ['commands' => $request],
-        ]);
 
         return socket_last_error($this->socket) === 0;
     }
 
     public function shutdown() : void
     {
-        if ($this->connected !== true) {
+        if (!$this->connected()) {
             return;
         }
 

src/Events/Metadata.php

@@ -5,7 +5,7 @@
 namespace Scoutapm\Events;
 
 use DateTimeImmutable;
-use JsonSerializable;
+use Scoutapm\Connector\SerializableMessage;
 use Scoutapm\Helper\Timer;
 use const PHP_VERSION;
 use function gethostname;
@@ -15,7 +15,7 @@
  *
  * @internal
  */
-final class Metadata implements JsonSerializable
+final class Metadata implements SerializableMessage
 {
     /** @var Timer */
     private $timer;

src/Events/RegisterMessage.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Scoutapm\Events;
+
+use Scoutapm\Connector\SerializableMessage;
+
+final class RegisterMessage implements SerializableMessage
+{
+    /** @var string */
+    private $appName;
+
+    /** @var string */
+    private $appKey;
+
+    /** @var string */
+    private $apiVersion;
+
+    public function __construct(string $appName, string $appKey, string $apiVersion)
+    {
+        $this->appName    = $appName;
+        $this->appKey     = $appKey;
+        $this->apiVersion = $apiVersion;
+    }
+
+    public function jsonSerialize() : array
+    {
+        return [
+            'Register' => [
+                'app' => $this->appName,
+                'key' => $this->appKey,
+                'language' => 'php',
+                'api_version' => $this->apiVersion,
+            ],
+        ];
+    }
+}

src/Events/Request/Request.php

@@ -5,7 +5,7 @@
 namespace Scoutapm\Events\Request;
 
 use Exception;
-use JsonSerializable;
+use Scoutapm\Connector\SerializableMessage;
 use Scoutapm\Events\Exception\SpanHasNotBeenStarted;
 use Scoutapm\Events\Span\Span;
 use Scoutapm\Events\Tag\TagRequest;
@@ -16,7 +16,7 @@
 use function end;
 
 /** @internal */
-class Request implements JsonSerializable
+class Request implements SerializableMessage
 {
     /** @var Timer */
     private $timer;
@@ -110,9 +110,7 @@ public function jsonSerialize() : array
         ];
 
         foreach ($this->events as $event) {
-            $array = $event->jsonSerialize();
-
-            foreach ($array as $value) {
+            foreach ($event->jsonSerialize() as $value) {
                 $commands[] = $value;
             }
         }
@@ -124,7 +122,9 @@ public function jsonSerialize() : array
             ],
         ];
 
-        return $commands;
+        return [
+            'BatchCommand' => ['commands' => $commands],
+        ];
     }
 
     /**

src/Events/Span/Span.php

@@ -5,13 +5,13 @@
 namespace Scoutapm\Events\Span;
 
 use Exception;
-use JsonSerializable;
+use Scoutapm\Connector\SerializableMessage;
 use Scoutapm\Events\Request\RequestId;
 use Scoutapm\Events\Tag\TagSpan;
 use Scoutapm\Helper\Timer;
 
 /** @internal */
-class Span implements JsonSerializable
+class Span implements SerializableMessage
 {
     /** @var SpanId */
     private $id;