fix: Support new flag values (#137)

Author: keelerm84

src/LaunchDarkly/Impl/Events/EventFactory.php

@@ -44,6 +44,8 @@ public function newEvalEvent(
             'kind' => 'feature',
             'creationDate' => Util::currentTimeUnixMillis(),
             'key' => $flag->getKey(),
+            'samplingRatio' => $flag->getSamplingRatio(),
+            'excludeFromSummaries' => $flag->getExcludeFromSummaries(),
             'context' => $context,
             'variation' => $detail->getVariationIndex(),
             'value' => $detail->getValue(),
@@ -75,6 +77,8 @@ public function newDefaultEvent(FeatureFlag $flag, LDContext $context, Evaluatio
             'kind' => 'feature',
             'creationDate' => Util::currentTimeUnixMillis(),
             'key' => $flag->getKey(),
+            'samplingRatio' => $flag->getSamplingRatio(),
+            'excludeFromSummaries' => $flag->getExcludeFromSummaries(),
             'context' => $context,
             'value' => $detail->getValue(),
             'default' => $detail->getValue(),
@@ -124,7 +128,7 @@ public function newIdentifyEvent(LDContext $context): array
             'context' => $context
         ];
     }
-    
+
     /**
      * @return mixed[]
      */

src/LaunchDarkly/Impl/Events/EventProcessor.php

@@ -4,6 +4,7 @@
 
 namespace LaunchDarkly\Impl\Events;
 
+use LaunchDarkly\Impl\Util;
 use LaunchDarkly\Integrations\Curl;
 use LaunchDarkly\Subsystems\EventPublisher;
 
@@ -50,6 +51,11 @@ public function enqueue(array $event): bool
             return false;
         }
 
+        $samplingRatio = $event['samplingRatio'] ?? 1;
+        if (is_int($samplingRatio) && !Util::sample($samplingRatio)) {
+            return false;
+        }
+
         $this->_queue[] = $event;
 
         return true;

src/LaunchDarkly/Impl/Events/EventSerializer.php

@@ -50,7 +50,13 @@ private function filterEvent(array $e): array
     {
         $ret = [];
         foreach ($e as $key => $value) {
-            if ($key == 'context') {
+            if ($key == 'samplingRatio' && $value === 1) {
+                // 1 is the default case, so we don't have to include it in the final output.
+                continue;
+            } elseif ($key == 'excludeFromSummaries' && $value === false) {
+                // false is the default case, so we don't have to include it in the final output.
+                continue;
+            } elseif ($key == 'context') {
                 $ret[$key] = $this->serializeContext($value);
             } else {
                 $ret[$key] = $value;

src/LaunchDarkly/Impl/Model/FeatureFlag.php

@@ -34,6 +34,9 @@ class FeatureFlag
     protected bool $_trackEventsFallthrough = false;
     protected ?int $_debugEventsUntilDate = null;
     protected bool $_clientSide = false;
+    protected ?int $_samplingRatio = null;
+    protected bool $_excludeFromSummaries = false;
+    protected ?MigrationSettings $_migrationSettings = null;
 
     // Note, trackEvents and debugEventsUntilDate are not used in EventProcessor, because
     // the PHP client doesn't do summary events. However, we need to capture them in case
@@ -55,7 +58,10 @@ public function __construct(
         bool $trackEvents,
         bool $trackEventsFallthrough,
         ?int $debugEventsUntilDate,
-        bool $clientSide
+        bool $clientSide,
+        ?int $samplingRatio,
+        bool $excludeFromSummaries,
+        ?MigrationSettings $migrationSettings,
     ) {
         $this->_key = $key;
         $this->_version = $version;
@@ -73,6 +79,9 @@ public function __construct(
         $this->_trackEventsFallthrough = $trackEventsFallthrough;
         $this->_debugEventsUntilDate = $debugEventsUntilDate;
         $this->_clientSide = $clientSide;
+        $this->_samplingRatio = $samplingRatio;
+        $this->_excludeFromSummaries = $excludeFromSummaries;
+        $this->_migrationSettings = $migrationSettings;
     }
 
     /**
@@ -82,8 +91,14 @@ public function __construct(
      */
     public static function getDecoder(): \Closure
     {
-        return fn ($v) =>
-            new FeatureFlag(
+        return function ($v) {
+            $migrationSettings = null;
+
+            if (is_array($v['migration'] ?? null)) {
+                $migrationSettings = call_user_func(MigrationSettings::getDecoder(), $v['migration']);
+            }
+
+            return new FeatureFlag(
                 $v['key'],
                 $v['version'],
                 $v['on'],
@@ -99,8 +114,12 @@ public static function getDecoder(): \Closure
                 !!($v['trackEvents'] ?? false),
                 !!($v['trackEventsFallthrough'] ?? false),
                 $v['debugEventsUntilDate'] ?? null,
-                !!($v['clientSide'] ?? false)
+                !!($v['clientSide'] ?? false),
+                $v['samplingRatio'] ?? null,
+                !!($v['excludeFromSummaries'] ?? false),
+                $migrationSettings,
             );
+        };
     }
 
     public static function decode(array $v): self
@@ -192,4 +211,19 @@ public function getVersion(): int
     {
         return $this->_version;
     }
+
+    public function getSamplingRatio(): int
+    {
+        return $this->_samplingRatio ?? 1;
+    }
+
+    public function getExcludeFromSummaries(): bool
+    {
+        return $this->_excludeFromSummaries;
+    }
+
+    public function getMigrationSettings(): ?MigrationSettings
+    {
+        return $this->_migrationSettings;
+    }
 }

src/LaunchDarkly/Impl/Model/MigrationSettings.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LaunchDarkly\Impl\Model;
+
+/**
+ * Internal data model class that describes a feature flag's migration settings.
+ *
+ * Application code should never need to reference the data model directly.
+ *
+ * @ignore
+ * @internal
+ */
+class MigrationSettings
+{
+    public function __construct(private readonly ?int $checkRatio = null)
+    {
+    }
+
+    public function getCheckRatio(): int
+    {
+        return $this->checkRatio ?? 1;
+    }
+
+    public static function getDecoder(): \Closure
+    {
+        return fn (array $v) => new MigrationSettings($v['checkRatio'] ?? null);
+    }
+}

src/LaunchDarkly/Impl/Util.php

@@ -21,6 +21,21 @@
  */
 class Util
 {
+    public static function sample(int $ratio): bool
+    {
+        if ($ratio === 0) {
+            return false;
+        }
+
+        if ($ratio === 1) {
+            return true;
+        }
+
+        $rand = mt_rand() / mt_getrandmax();
+
+        return $rand < (1 / $ratio);
+    }
+
     public static function adjustBaseUri(string $uri): string
     {
         if (substr($uri, strlen($uri) - 1, 1) == '/') {

src/LaunchDarkly/Integrations/TestData/FlagBuilder.php

@@ -23,6 +23,9 @@ class FlagBuilder
     protected array $_variations;
     protected ?int $_offVariation;
     protected ?int $_fallthroughVariation;
+    protected ?MigrationSettingsBuilder $_migrationSettingsBuilder;
+    protected ?int $_samplingRatio;
+    protected bool $_excludeFromSummaries;
 
     // In _targets, each key is a context kind, and the value is another associative array where the key is a
     // variation index and the value is an array of context keys.
@@ -39,6 +42,9 @@ public function __construct(string $key)
         $this->_fallthroughVariation = null;
         $this->_targets = [];
         $this->_rules = [];
+        $this->_samplingRatio = null;
+        $this->_excludeFromSummaries = false;
+        $this->_migrationSettingsBuilder = null;
     }
 
     /**
@@ -71,6 +77,9 @@ public function copy(): FlagBuilder
             $to->_targets[$k] = $v;
         }
         $to->_rules = $this->_rules;
+        $to->_samplingRatio = $this->_samplingRatio;
+        $to->_excludeFromSummaries = $this->_excludeFromSummaries;
+        $to->_migrationSettingsBuilder = $this->_migrationSettingsBuilder;
 
         return $to;
     }
@@ -138,6 +147,30 @@ public function fallthroughVariation(bool|int $variation): FlagBuilder
         return $this;
     }
 
+    public function migrationSettings(MigrationSettingsBuilder $builder): FlagBuilder
+    {
+        $this->_migrationSettingsBuilder = $builder;
+        return $this;
+    }
+
+    /**
+     * Control the rate at which events from this flag will be sampled.
+     */
+    public function samplingRatio(int $samplingRatio): FlagBuilder
+    {
+        $this->_samplingRatio = $samplingRatio;
+        return $this;
+    }
+
+    /**
+     * Control whether or not this flag should should be included in flag summary counts.
+     */
+    public function excludeFromSummaries(bool $excludeFromSummaries): FlagBuilder
+    {
+        $this->_excludeFromSummaries = $excludeFromSummaries;
+        return $this;
+    }
+
     /**
      * Specifies the off variation for a boolean flag or index of variation.
      * This is the variation that is returned whenever targeting is off.
@@ -484,6 +517,11 @@ public function build(int $version): array
             $baseFlagObject['rules'][] = $rule->build($idx);
         }
 
+        $migrationSettings = $this->_migrationSettingsBuilder?->build() ?? [];
+        if (!empty($migrationSettings)) {
+            $baseFlagObject['migration'] = $migrationSettings;
+        }
+
         $baseFlagObject['deleted'] = false;
 
         return $baseFlagObject;

src/LaunchDarkly/Integrations/TestData/MigrationSettingsBuilder.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LaunchDarkly\Integrations\TestData;
+
+class MigrationSettingsBuilder
+{
+    protected ?int $checkRatio = null;
+
+    public function setCheckRatio(int $checkRatio): MigrationSettingsBuilder
+    {
+        $this->checkRatio = $checkRatio;
+        return $this;
+    }
+
+    /**
+     * Creates an associative array representation of the migration settings
+     *
+     * @return array the array representation of the migration settings
+     */
+    public function build(): array
+    {
+        return [
+            "checkRatio" => $this->checkRatio,
+        ];
+    }
+}

src/LaunchDarkly/Migrations/Migrator.php

@@ -5,6 +5,7 @@
 namespace LaunchDarkly\Migrations;
 
 use LaunchDarkly\Impl\Migrations\Executor;
+use LaunchDarkly\Impl\Util;
 use LaunchDarkly\LDClient;
 use LaunchDarkly\LDContext;
 
@@ -94,8 +95,7 @@ public function write(
 
     private function readBoth(Executor $authoritative, Executor $nonauthoritative, OpTracker $tracker): OperationResult
     {
-        // TODO(sc-219378): Add sampling to limit to 50% chance
-        if ($this->executionOrder == ExecutionOrder::RANDOM) {
+        if ($this->executionOrder == ExecutionOrder::RANDOM && Util::sample(2)) {
             $nonauthoritativeResult = $nonauthoritative->run();
             $authoritativeResult = $authoritative->run();
         } else {

src/LaunchDarkly/Migrations/OpTracker.php

@@ -38,7 +38,7 @@ public function __construct(
         private EvaluationDetail $detail,
         private Stage $default_stage
     ) {
-        $this->consistentRatio = 1; # TODO(sc-219378): This needs to get set from the flag once we support those fields
+        $this->consistentRatio = $flag?->getMigrationSettings()?->getCheckRatio() ?? 1;
     }
 
 
@@ -77,7 +77,10 @@ public function invoked(Origin $origin): OpTracker
     */
     public function consistent(callable $isConsistent): OpTracker
     {
-        # TODO(sc-219378): Add sampling support
+        if (!Util::sample($this->consistentRatio)) {
+            return $this;
+        }
+
         try {
             $this->consistent = boolval($isConsistent());
         } catch (Exception $e) {
@@ -136,14 +139,15 @@ public function build(): array|string
 
         $event = [
             'kind' => 'migration_op',
+            'samplingRatio' => 1,
             'creationDate' => Util::currentTimeUnixMillis(),
             'contextKeys' => $this->context->getKeys(),
             'operation' => $this->operation->value,
             'evaluation' => [
                 'key' => $this->key,
                 'value' => $this->detail->getValue(),
                 'default' => $this->default_stage->value,
-                'reason' => $this->detail->getReason(),
+                'reason' => $this->detail->getReason()->jsonSerialize(),
             ],
 
             'measurements' => [
@@ -156,6 +160,7 @@ public function build(): array|string
 
         if ($this->flag) {
             $event['evaluation']['version'] = $this->flag->getVersion();
+            $event['samplingRatio'] = $this->flag->getSamplingRatio();
         }
 
         if ($this->detail->getVariationIndex() !== null) {