fix: persist config hash to disk so hasChanges works correctly across PHP-FPM processes

demo.php

@@ -6,9 +6,10 @@
 use Kevinrob\GuzzleCache\Storage\DoctrineCacheStorage;
 use Monolog\Handler\StreamHandler;
 use Monolog\Logger;
-use Rox\Core\Consts\Environment;
 use Rox\Core\Logging\LoggerFactory;
 use Rox\Core\Logging\MonologLoggerFactory;
+use Rox\Core\Configuration\ConfigurationFetchedArgs;
+use Rox\Core\Configuration\FetcherStatus;
 use Rox\Server\Flags\RoxFlag;
 use Rox\Server\Rox;
 use Rox\Server\RoxOptions;
@@ -33,16 +34,19 @@ public function __construct()
 
 $devModeKey = getenv('ROLLOUT_DEV_MODE_KEY') ?: DEFAULT_DEV_MODE_KEY;
 
+$fetchInfo = ['status' => 'not fired', 'hasChanges' => null];
+
 $roxOptionsBuilder = (new RoxOptionsBuilder())
     ->setDevModeKey($devModeKey)
-    ->setNetworkConfigurationsOptions(new NetworkConfigurationsOptions(
-        'https://api.test.rollout.io/device/get_configuration',
-        'https://rox-conf.test.rollout.io',
-        'https://api.test.rollout.io/device/update_state_store',
-        'https://rox-state.test.rollout.io',
-        'https://analytic.test.rollout.io',
-        'https://notify.bugsnag.com'
-    ));
+    ->setConfigurationFetchedHandler(function (ConfigurationFetchedArgs $args) use (&$fetchInfo) {
+        $statusMap = [
+            FetcherStatus::AppliedFromNetwork       => 'AppliedFromNetwork',
+            FetcherStatus::AppliedFromLocalStorage  => 'AppliedFromLocalStorage',
+            FetcherStatus::ErrorFetchedFailed       => 'ErrorFetchedFailed',
+        ];
+        $fetchInfo['status']     = $statusMap[$args->getFetcherStatus()] ?? $args->getFetcherStatus();
+        $fetchInfo['hasChanges'] = $args->isHasChanges() ? 'true' : 'false';
+    });
 
 echo '<pre>';
 
@@ -86,7 +90,7 @@ public function __construct()
         ->setCacheStorage(new DoctrineCacheStorage(
             new ChainCache([
                 new ArrayCache(),
-                new FilesystemCache('/tmp/rollout/cache'),
+                new FilesystemCache(join(DIRECTORY_SEPARATOR, [sys_get_temp_dir(), 'rollout', 'cache'])),
             ])
         ))
         ->setLogCacheHitsAndMisses(true)
@@ -109,4 +113,10 @@ public function __construct()
     echo "demo.demoFlag: FEATURE IS OFF\n";
 }
 
+echo "\n--- Configuration Fetch Info ---\n";
+echo "Status:     {$fetchInfo['status']}\n";
+echo "hasChanges: {$fetchInfo['hasChanges']}\n";
+echo "--------------------------------\n";
+echo "(Refresh the page - second load should show AppliedFromLocalStorage and hasChanges: false)\n";
+
 echo '</pre>';

src/Rox/Core/Core.php

@@ -140,11 +140,6 @@ final class Core
      */
     private $_errorReporter;
 
-    /**
-     * @var ConfigurationFetchResult $_lastConfigurations
-     */
-    private $_lastConfigurations = null;
-
     /**
      * @var InternalFlagsInterface $_internalFlags
      */
@@ -350,8 +345,7 @@ public function fetch($isSourcePushing = false)
             $this->_targetGroupRepository->setTargetGroups($configuration->getTargetGroups());
             $this->_flagSetter->setExperiments();
 
-            $hasChanges = ($this->_lastConfigurations == null || !$this->_lastConfigurations->equals($result));
-            $this->_lastConfigurations = $result;
+            $hasChanges = !$result->isContentUnchanged();
             $fetcherStatus = $result->isFromCache()
                 ? FetcherStatus::AppliedFromLocalStorage
                 : FetcherStatus::AppliedFromNetwork;

src/Rox/Core/Network/AbstractHttpResponse.php

@@ -13,11 +13,27 @@ final function isSuccessfulStatusCode()
             $this->getStatusCode() <= 299;
     }
 
+    /**
+     * @return string
+     */
+    function getCacheStatus()
+    {
+        return CacheStatus::MISS;
+    }
+
+    /**
+     * @return bool
+     */
+    final function isFromCache()
+    {
+        return CacheStatus::isFromCache($this->getCacheStatus());
+    }
+
     /**
      * @return bool
      */
-    function isFromCache()
+    final function isContentUnchanged()
     {
-        return false;
+        return CacheStatus::isContentUnchanged($this->getCacheStatus());
     }
 }

src/Rox/Core/Network/CacheStatus.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Rox\Core\Network;
+
+final class CacheStatus
+{
+    const HIT = 'HIT';
+    const MISS = 'MISS';
+    const REVALIDATED = 'REVALIDATED';
+
+    static function isFromCache(string $status): bool
+    {
+        return $status === self::HIT;
+    }
+
+    static function isContentUnchanged(string $status): bool
+    {
+        return $status === self::HIT || $status === self::REVALIDATED;
+    }
+}

src/Rox/Core/Network/ConfigurationFetchResult.php

@@ -16,21 +16,23 @@ class ConfigurationFetchResult
     private $_parsedData;
 
     /**
-     * @var bool $_isFromCache
+     * @var string $_cacheStatus
+     * @see CacheStatus
      */
-    private $_isFromCache;
+    private $_cacheStatus;
 
     /**
      * ConfigurationFetchResult constructor.
      * @param array $parsedData
      * @param int $source
-     * @param bool $isFromCache
+     * @param string $cacheStatus
+     * @see CacheStatus
      */
-    public function __construct($parsedData, $source, $isFromCache = false)
+    public function __construct($parsedData, $source, $cacheStatus = CacheStatus::MISS)
     {
         $this->_source = $source;
         $this->_parsedData = $parsedData;
-        $this->_isFromCache = $isFromCache;
+        $this->_cacheStatus = $cacheStatus;
     }
 
     /**
@@ -54,16 +56,14 @@ public function getParsedData()
      */
     public function isFromCache()
     {
-        return $this->_isFromCache;
+        return CacheStatus::isFromCache($this->_cacheStatus);
     }
 
     /**
-     * @param ConfigurationFetchResult $other
      * @return bool
      */
-    public function equals(ConfigurationFetchResult $other)
+    public function isContentUnchanged()
     {
-        return $this->_parsedData != null && $other->_parsedData != null &&
-            json_encode($this->_parsedData) === json_encode($other->_parsedData);
+        return CacheStatus::isContentUnchanged($this->_cacheStatus);
     }
 }

src/Rox/Core/Network/ConfigurationFetcher.php

@@ -51,7 +51,7 @@ function fetch()
 
             if ($fetchResult->isSuccessfulStatusCode()) {
                 $responseAsString = $fetchResult->getContent()->readAsString();
-                $configurationFetchResult = $this->createConfigurationResult($responseAsString, $source, $fetchResult->isFromCache());
+                $configurationFetchResult = $this->createConfigurationResult($responseAsString, $source, $fetchResult->getCacheStatus());
 
                 if ($configurationFetchResult == null || $configurationFetchResult->getParsedData() == null) {
                     return null;

src/Rox/Core/Network/ConfigurationFetcherBase.php

@@ -4,6 +4,7 @@
 
 use Exception;
 use Psr\Log\LoggerInterface;
+use Rox\Core\Network\CacheStatus;
 use Rox\Core\Client\BUIDInterface;
 use Rox\Core\Client\DevicePropertiesInterface;
 use Rox\Core\Configuration\ConfigurationFetchedInvokerInterface;
@@ -79,11 +80,12 @@ public function __construct(
     /**
      * @param string $data
      * @param int $source
-     * @param bool $isFromCache
+     * @param string $cacheStatus
      * @return ConfigurationFetchResult|null
      * @see ConfigurationSource
+     * @see CacheStatus
      */
-    protected function createConfigurationResult($data, $source, $isFromCache = false)
+    protected function createConfigurationResult($data, $source, $cacheStatus = CacheStatus::MISS)
     {
         if (!$data) {
             $this->_configurationFetchedInvoker->invokeWithError(FetcherError::EmptyJson);
@@ -100,7 +102,7 @@ protected function createConfigurationResult($data, $source, $isFromCache = fals
             return null;
         }
 
-        return new ConfigurationFetchResult($decoded, $source, $isFromCache);
+        return new ConfigurationFetchResult($decoded, $source, $cacheStatus);
     }
 
     /**

src/Rox/Core/Network/GuzzleHttpClient.php

@@ -10,6 +10,7 @@
 use GuzzleHttp\RequestOptions;
 use Psr\Log\LoggerInterface;
 use Rox\Core\Logging\LoggerFactory;
+use Rox\Core\Network\CacheStatus;
 
 class GuzzleHttpClient implements HttpClientInterface
 {
@@ -90,13 +91,17 @@ function sendGet(RequestData $requestData)
                 $cacheState = $response->getHeader("X-Kevinrob-Cache");
                 if (is_array($cacheState) && !empty($cacheState)) {
                     switch ($cacheState[0]) {
-                        case 'HIT':
+                        case CacheStatus::HIT:
                             $this->_log->debug("{$request->getUri()}: HIT");
                             break;
 
-                        case 'MISS':
+                        case CacheStatus::MISS:
                             $this->_log->debug("{$request->getUri()}: MISS");
                             break;
+
+                        case CacheStatus::REVALIDATED:
+                            $this->_log->debug("{$request->getUri()}: REVALIDATED");
+                            break;
                     }
                 }
             }

src/Rox/Core/Network/HttpResponseInterface.php

@@ -19,9 +19,10 @@ function getStatusCode();
     function isSuccessfulStatusCode();
 
     /**
-     * @return bool
+     * Returns the Guzzle cache state: 'HIT', 'MISS', or 'REVALIDATED'.
+     * @return string
      */
-    function isFromCache();
+    function getCacheStatus();
 
     /**
      * @return HttpResponseContentInterface

src/Rox/Core/Network/Psr7ResponseWrapper.php

@@ -3,6 +3,7 @@
 namespace Rox\Core\Network;
 
 use Psr\Http\Message\ResponseInterface;
+use Rox\Core\Network\CacheStatus;
 
 class Psr7ResponseWrapper extends AbstractHttpResponse
 {
@@ -26,12 +27,15 @@ function getStatusCode()
     }
 
     /**
-     * @return bool
+     * @return string
      */
-    function isFromCache()
+    function getCacheStatus()
     {
         $header = $this->_response->getHeader('X-Kevinrob-Cache');
-        return !empty($header) && $header[0] === 'HIT';
+        $value = !empty($header) ? $header[0] : CacheStatus::MISS;
+        return in_array($value, [CacheStatus::HIT, CacheStatus::REVALIDATED], true)
+            ? $value
+            : CacheStatus::MISS;
     }
 
     /**

tests/Rox/Core/Network/ConfigurationFetcherTests.php

@@ -318,7 +318,7 @@ public function testWillReturnIsFromCacheTrueWhenCDNResponseIsFromCache()
     {
         $confFetchInvoker = new ConfigurationFetchedInvoker(Mockery::mock(UserspaceUnhandledErrorInvokerInterface::class));
 
-        $response = new TestHttpResponse(200, "{\"a\": \"cached\"}", true);
+        $response = new TestHttpResponse(200, "{\"a\": \"cached\"}", CacheStatus::HIT);
 
         $request = Mockery::mock(HttpClientInterface::class)
             ->shouldReceive('sendGet')
@@ -352,6 +352,28 @@ public function testWillReturnIsFromCacheFalseWhenCDNResponseIsFromNetwork()
         $this->assertFalse($result->isFromCache());
     }
 
+    public function testRevalidatedResponseIsNotFromCacheButContentIsUnchanged()
+    {
+        // REVALIDATED = server returned 304 Not Modified; content is identical to cached copy.
+        // isFromCache() must be false (we hit the network), but isContentUnchanged() must be
+        // true (no changes to apply) so hasChanges is correctly reported as false.
+        $confFetchInvoker = new ConfigurationFetchedInvoker(Mockery::mock(UserspaceUnhandledErrorInvokerInterface::class));
+
+        $response = new TestHttpResponse(200, "{\"a\": \"same\"}", CacheStatus::REVALIDATED);
+
+        $request = Mockery::mock(HttpClientInterface::class)
+            ->shouldReceive('sendGet')
+            ->andReturn($response)
+            ->getMock();
+
+        $confFetcher = new ConfigurationFetcher($request, $this->_bu, $this->_dp, $confFetchInvoker, $this->_errorReporter, $this->_environment);
+        $result = $confFetcher->fetch();
+
+        $this->assertNotNull($result);
+        $this->assertFalse($result->isFromCache());
+        $this->assertTrue($result->isContentUnchanged());
+    }
+
     public function testWillReturnNullDataWhenBothNotFound()
     {
         $confFetchInvoker = new ConfigurationFetchedInvoker(Mockery::mock(UserspaceUnhandledErrorInvokerInterface::class));

tests/Rox/Core/Network/TestHttpResponse.php

@@ -15,21 +15,22 @@ class TestHttpResponse extends AbstractHttpResponse
     private $_content;
 
     /**
-     * @var bool $_isFromCache
+     * @var string $_cacheStatus
      */
-    private $_isFromCache;
+    private $_cacheStatus;
 
     /**
      * TestHttpResponse constructor.
      * @param int $status
      * @param string $content
-     * @param bool $isFromCache
+     * @param string $cacheStatus
+     * @see CacheStatus
      */
-    public function __construct($status, $content = "", $isFromCache = false)
+    public function __construct($status, $content = "", $cacheStatus = CacheStatus::MISS)
     {
         $this->_status = $status;
         $this->_content = $content;
-        $this->_isFromCache = $isFromCache;
+        $this->_cacheStatus = $cacheStatus;
     }
 
     /**
@@ -41,11 +42,11 @@ function getStatusCode()
     }
 
     /**
-     * @return bool
+     * @return string
      */
-    function isFromCache()
+    function getCacheStatus()
     {
-        return $this->_isFromCache;
+        return $this->_cacheStatus;
     }
 
     /**