public final class OptionalReferrersProviderImpl
 implements OptionalReferrersProvider
                    

Function-based implementation of external referrer provider.

<p>This implementation uses direct function calls to instantiate external referrer instances that have been registered through the automatic registration system. It completely eliminates reflection for maximum performance and type safety.</p><p><strong>Key Improvements over Previous Implementation:</strong></p> <ul> <li>Eliminated reflection completely - uses direct method references</li> <li>Removed compile-time dependencies on external referrer modules</li> <li>Eliminated manual OptionalFeaturesValidator checks</li> <li>Simplified constructor - no longer requires multiple injected dependencies</li> <li>Compile-time type safety with method references (e.g., {@code HuaweiReferrer::new})</li> </ul><p><strong>Registration Process:</strong></p> <ol> <li>External referrer modules register via {@link BaseReferrerInitProvider}</li> <li>Function references are stored in {@link Referrer#getExternalReferrers()}</li> <li>This provider calls {@code creator.create(prop)} for direct instantiation</li> <li>No reflection, constructor lookup, or runtime type discovery required</li> </ol><p><strong>Performance Characteristics:</strong></p> <ul> <li>Zero reflection overhead - direct method calls only</li> <li>Compile-time optimization - method references can be inlined</li> <li>Error resilience: Individual referrer failures don't affect others</li> <li>Memory impact: Minimal - only function references stored</li> </ul><p><strong>Thread Safety:</strong><br> This class is thread-safe. The underlying referrer registry is thread-safe, and function calls are performed on immutable function references.</p>