feat: use ServiceLoader to discover cache providers (#367)

Co-authored-by: iProdigy <[email protected]>

Author: DerSimeon

core/src/main/java/io/github/xanthic/cache/core/AbstractCacheProvider.java

@@ -4,6 +4,7 @@
 import io.github.xanthic.cache.api.domain.ExpiryType;
 import io.github.xanthic.cache.api.domain.MisconfigurationPolicy;
 import io.github.xanthic.cache.api.exception.MisconfiguredCacheException;
+import org.jetbrains.annotations.ApiStatus;
 
 import java.time.Duration;
 import java.util.function.BiConsumer;
@@ -34,5 +35,10 @@ protected void handleExpiration(Duration time, ExpiryType type, BiConsumer<Durat
 	protected ExpiryType preferredType() {
 		return ExpiryType.POST_ACCESS; // LRU
 	}
+	
+	@ApiStatus.Internal
+	public int getDiscoveryOrder() {
+		return 1000;
+	}
 
 }

core/src/main/java/io/github/xanthic/cache/core/CacheApiSettings.java

@@ -12,11 +12,12 @@
 import org.jetbrains.annotations.Nullable;
 
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.IdentityHashMap;
 import java.util.Map;
-import java.util.concurrent.atomic.AtomicInteger;
+import java.util.ServiceLoader;
 import java.util.concurrent.atomic.AtomicReference;
-import java.util.function.Consumer;
+import java.util.stream.StreamSupport;
 
 /**
  * Holds a registry of default settings and cache providers.
@@ -103,31 +104,12 @@ public void registerCacheProvider(@NonNull Class<? extends CacheProvider> cacheP
 	private void populateProviders() {
 		log.debug("Xanthic: Registering canonical cache providers from the classpath...");
 
-		AtomicInteger registered = new AtomicInteger();
-		Consumer<String> loadImpl = (providerClass) -> {
-			try {
-				Class<? extends CacheProvider> clazz = Class.forName(providerClass).asSubclass(CacheProvider.class);
-				registerCacheProvider(clazz, null); // lazy, init if needed
-				registered.incrementAndGet();
-			} catch (ClassNotFoundException cx) {
-				log.trace("Xanthic: Could not find optional cache provider " + providerClass);
-			} catch (Exception e) {
-				log.trace("Xanthic: Could not find optional cache provider " + providerClass, e);
-			}
-		};
-
-		loadImpl.accept("io.github.xanthic.cache.provider.androidx.AndroidLruProvider");
-		loadImpl.accept("io.github.xanthic.cache.provider.caffeine3.Caffeine3Provider");
-		loadImpl.accept("io.github.xanthic.cache.provider.caffeine.CaffeineProvider");
-		loadImpl.accept("io.github.xanthic.cache.provider.cache2k.Cache2kProvider");
-		loadImpl.accept("io.github.xanthic.cache.provider.infinispanjdk17.InfinispanProvider");
-		loadImpl.accept("io.github.xanthic.cache.provider.infinispanjdk11.InfinispanProvider");
-		loadImpl.accept("io.github.xanthic.cache.provider.infinispan.InfinispanProvider");
-		loadImpl.accept("io.github.xanthic.cache.provider.expiringmap.ExpiringMapProvider");
-		loadImpl.accept("io.github.xanthic.cache.provider.guava.GuavaProvider");
-		loadImpl.accept("io.github.xanthic.cache.provider.ehcache.EhcacheProvider");
-
-		log.debug("Xanthic: Loaded {} canonical cache provider(s) on settings construction!", registered.get());
+		ServiceLoader<AbstractCacheProvider> load = ServiceLoader.load(AbstractCacheProvider.class);
+		StreamSupport.stream(load.spliterator(), false)
+			.sorted(Comparator.comparingInt(AbstractCacheProvider::getDiscoveryOrder))
+			.forEach(provider -> registerCacheProvider(provider.getClass(), provider));
+
+		log.debug("Xanthic: Loaded {} canonical cache provider(s) on settings construction!", providers.size());
 	}
 
 	/**

provider-androidx/src/main/java/io/github/xanthic/cache/provider/androidx/AndroidLruProvider.java

@@ -55,4 +55,8 @@ protected void entryRemoved(boolean evicted, @NotNull K key, @NotNull V oldValue
 		};
 	}
 
+	@Override
+	public int getDiscoveryOrder() {
+		return 1;
+	}
 }

provider-androidx/src/main/resources/META-INF/services/io.github.xanthic.cache.core.AbstractCacheProvider

@@ -0,0 +1 @@
+io.github.xanthic.cache.provider.androidx.AndroidLruProvider

provider-cache2k/src/main/java/io/github/xanthic/cache/provider/cache2k/Cache2kProvider.java

@@ -108,4 +108,8 @@ private static <K, V> Collection<CacheEntryOperationListener<K, V>> buildListene
 		);
 	}
 
+	@Override
+	public int getDiscoveryOrder() {
+		return 4;
+	}
 }

provider-cache2k/src/main/resources/META-INF/services/io.github.xanthic.cache.core.AbstractCacheProvider

@@ -0,0 +1 @@
+io.github.xanthic.cache.provider.cache2k.Cache2kProvider

provider-caffeine/src/main/java/io/github/xanthic/cache/provider/caffeine/CaffeineProvider.java

@@ -51,4 +51,9 @@ private static RemovalCause getCause(com.github.benmanes.caffeine.cache.RemovalC
 				return RemovalCause.OTHER;
 		}
 	}
+
+	@Override
+	public int getDiscoveryOrder() {
+		return 3;
+	}
 }

provider-caffeine/src/main/resources/META-INF/services/io.github.xanthic.cache.core.AbstractCacheProvider

@@ -0,0 +1 @@
+io.github.xanthic.cache.provider.caffeine.CaffeineProvider

provider-caffeine3/src/main/java/io/github/xanthic/cache/provider/caffeine3/Caffeine3Provider.java

@@ -49,4 +49,9 @@ private static RemovalCause getCause(com.github.benmanes.caffeine.cache.RemovalC
 				return RemovalCause.OTHER;
 		}
 	}
+
+	@Override
+	public int getDiscoveryOrder() {
+		return 2;
+	}
 }

provider-caffeine3/src/main/resources/META-INF/services/io.github.xanthic.cache.core.AbstractCacheProvider

@@ -0,0 +1 @@
+io.github.xanthic.cache.provider.caffeine3.Caffeine3Provider