From 5c012fc865a51363a70ab40c785c3b953a0378c4 Mon Sep 17 00:00:00 2001
From: samandeggs <sam@infused.io>
Date: Mon, 22 Apr 2024 12:24:09 +1200
Subject: [PATCH] FEAT: basic implementation of traces sampling for performance
 monitoring

---
 src/Adaptor/SentryAdaptor.php | 28 ++++++++++++++++++++++++++++
 src/Handler/SentryHandler.php |  5 ++++-
 src/Log/SentryLogger.php      | 26 ++++++++++++++++++++++++--
 3 files changed, 56 insertions(+), 3 deletions(-)

diff --git a/src/Adaptor/SentryAdaptor.php b/src/Adaptor/SentryAdaptor.php
index 067a2db..bc26a2f 100755
--- a/src/Adaptor/SentryAdaptor.php
+++ b/src/Adaptor/SentryAdaptor.php
@@ -19,6 +19,10 @@
 use SilverStripe\Core\Environment as Env;
 use PhpTek\Sentry\Adaptor\SentrySeverity;
 use PhpTek\Sentry\Helper\SentryHelper;
+use Sentry\Tracing\DynamicSamplingContext;
+use Sentry\Tracing\TransactionContext;
+use Sentry\Tracing\TransactionMetadata;
+use Sentry\Tracing\TransactionSource;
 
 /**
  * The SentryAdaptor provides a functionality bridge between the getsentry/sentry
@@ -83,6 +87,7 @@ public function setContext(string $field, $data): SentryAdaptor
                     $scope->setUser($data);
                     $this->context['user'] = $data;
                 });
+
                 break;
             case 'extra':
                 $hub->configureScope(function (Scope $scope) use ($data): void {
@@ -98,6 +103,10 @@ public function setContext(string $field, $data): SentryAdaptor
                     $scope->setLevel(new Severity(SentrySeverity::process_severity($level = $data)));
                 });
                 break;
+            case 'traces_sample_rate':
+                // set's the rate in which traces are sampled 1 is 100%, 0.1 is 10% etc
+                $options->setTracesSampleRate($data);
+                break;
             default:
                 break;
         }
@@ -155,6 +164,10 @@ public static function get_opts(): array
             $opts['release'] = $release;
         }
 
+        if ($traces_sample_rate = Env::getEnv('SENTRY_TRACES_SAMPLE_RATE')) {
+            $opts['traces_sample_rate'] = $traces_sample_rate;
+        }
+
         // Env vars take precedence over YML config in array_merge()
         $optsConfig = Config::inst()->get(static::class, 'opts') ?? [];
 
@@ -176,4 +189,19 @@ public static function get_opts(): array
         return $opts;
     }
 
+    public function startTransaction()
+    {
+        $hub = SentrySdk::getCurrentHub();
+        $options = $hub->getClient()->getOptions();
+        $rate = $options->getTracesSampleRate();
+
+        // create a new transaction and finish it to send the traces to sentry
+        $samplingContext = DynamicSamplingContext::fromOptions($options, $this->getContext());
+        $source = TransactionSource::url();
+        $metadata = new TransactionMetadata($rate, $samplingContext, $source);
+
+        $transaction_context = new TransactionContext('Bong_3', null, $metadata);
+        $Transaction = $hub->startTransaction($transaction_context);
+        $Transaction->finish();
+    }
 }
diff --git a/src/Handler/SentryHandler.php b/src/Handler/SentryHandler.php
index c369e34..2dc44d8 100755
--- a/src/Handler/SentryHandler.php
+++ b/src/Handler/SentryHandler.php
@@ -72,7 +72,10 @@ public function __construct($level = null, bool $bubble = true, array $config =
         $level = Level::fromName($level ?? Level::Debug->getName());
 
         SentrySdk::setCurrentHub(new Hub($client));
-        
+
+        $trace_sample_rate = SentryAdaptor::get_opts()['traces_sample_rate'] ?? null;
+        $config['traces_sample_rate'] = $trace_sample_rate ?: 0.0;
+
         $config['level'] = $level;
 
         $this->logger = SentryLogger::factory($client, $config);
diff --git a/src/Log/SentryLogger.php b/src/Log/SentryLogger.php
index 95f192a..59060ee 100755
--- a/src/Log/SentryLogger.php
+++ b/src/Log/SentryLogger.php
@@ -69,6 +69,8 @@ public static function factory(Client $client, array $config = []): SentryLogger
         $env = $logger->defaultEnv();
         $tags = $logger->defaultTags();
         $extra = $logger->defaultExtra();
+        $traces_sample_rate = $logger->defaultTracesSample();
+
         $user = [];
         $level = Logger::DEBUG;
 
@@ -78,15 +80,25 @@ public static function factory(Client $client, array $config = []): SentryLogger
             $extra = array_merge($extra, $config['extra'] ?? []);
             $user = $config['user'] ?? $user;
             $level = $config['level'] ?? $level;
+            $traces_sample_rate = $config['traces_sample_rate'] ?? $traces_sample_rate;
         }
 
         $adaptor = (new SentryAdaptor($client))
             ->setContext('env', $env)
             ->setContext('tags', $tags)
             ->setContext('extra', $extra)
-            ->setContext('user', $user);
+            ->setContext('user', $user)
+            ->setContext('traces_sample_rate', $traces_sample_rate);
+
+
+        $set_adaptor = $logger->setAdaptor($adaptor);
 
-        return $logger->setAdaptor($adaptor);
+        // trigger the performance tracing if set
+        if ($traces_sample_rate) {
+            $set_adaptor->getAdaptor()->startTransaction();
+        }
+
+        return $set_adaptor;
     }
 
     /**
@@ -161,6 +173,16 @@ public function defaultExtra(): array
         ];
     }
 
+    /**
+     * Returns a default empty array for traces_sample_rate, as this should be blank if not set manually
+     *
+     * @return array
+     */
+    public function defaultTracesSample(): array
+    {
+        return [];
+    }
+
     /**
      * What sort of request is this? (A harder question to answer than you might
      * think: http://stackoverflow.com/questions/6275363/what-is-the-correct-terminology-for-a-non-ajax-request)