feat: add jackson module (#174)

build.gradle.kts

@@ -47,6 +47,7 @@ subprojects {
         dependencies {
             // annotations
             compileOnly("org.jetbrains:annotations:24.1.0")
+            testCompileOnly("org.jetbrains:annotations:24.1.0")
 
             // tests
             testImplementation(platform("org.junit:junit-bom:5.10.1"))

jackson/build.gradle.kts

@@ -0,0 +1,16 @@
+dependencies {
+    api(project(":cache-core"))
+    implementation("com.fasterxml.jackson.core:jackson-databind") {
+        version {
+            require("2.16.0") // imposes a lower bound on acceptable versions
+        }
+    }
+    testImplementation(project(":cache-provider-caffeine"))
+}
+
+publishing.publications.withType<MavenPublication> {
+    pom {
+        name.set("Xanthic - Jackson")
+        description.set("Xanthic Cache Jackson Adapter")
+    }
+}

jackson/src/main/java/io/github/xanthic/jackson/XanthicJacksonCacheAdapter.java

@@ -0,0 +1,80 @@
+package io.github.xanthic.jackson;
+
+import com.fasterxml.jackson.databind.util.LookupCache;
+import io.github.xanthic.cache.api.Cache;
+import io.github.xanthic.cache.core.CacheApi;
+import io.github.xanthic.cache.core.CacheApiSpec;
+import lombok.RequiredArgsConstructor;
+import lombok.Value;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+
+/**
+ * Wraps a Xanthic {@link Cache} for use as a Jackson {@link LookupCache}.
+ * <p>
+ * Most users should utilize {@link XanthicJacksonCacheProvider} rather than directly interact with this class.
+ *
+ * @param <K> The type of keys that form the cache
+ * @param <V> The type of values contained in the cache
+ */
+@Value
+@RequiredArgsConstructor
+public class XanthicJacksonCacheAdapter<K, V> implements LookupCache<K, V> {
+
+	/**
+	 * The Xanthic cache to use as a Jackson {@link LookupCache}.
+	 */
+	Cache<K, V> cache;
+
+	/**
+	 * The specification associated with the constructed cache.
+	 */
+	Consumer<CacheApiSpec<K, V>> spec;
+
+	/**
+	 * Creates a Jackson {@link LookupCache} by wrapping a Xanthic cache with this adapter.
+	 *
+	 * @param spec the cache specification (note: specifying {@link CacheApiSpec#maxSize(Long)} is recommended)
+	 */
+	public XanthicJacksonCacheAdapter(@NotNull Consumer<CacheApiSpec<K, V>> spec) {
+		this(CacheApi.create(spec), spec);
+	}
+
+	@Override
+	public int size() {
+		return (int) cache.size();
+	}
+
+	@Override
+	@SuppressWarnings("unchecked")
+	public V get(Object key) {
+		return cache.get((K) key);
+	}
+
+	@Override
+	public V put(K key, V value) {
+		return cache.put(key, value);
+	}
+
+	@Override
+	public V putIfAbsent(K key, V value) {
+		return cache.putIfAbsent(key, value);
+	}
+
+	@Override
+	public void clear() {
+		cache.clear();
+	}
+
+	@Override
+	public void contents(BiConsumer<K, V> consumer) {
+		cache.forEach(consumer);
+	}
+
+	@Override
+	public XanthicJacksonCacheAdapter<K, V> emptyCopy() {
+		return new XanthicJacksonCacheAdapter<>(spec);
+	}
+}

jackson/src/main/java/io/github/xanthic/jackson/XanthicJacksonCacheProvider.java

@@ -0,0 +1,91 @@
+package io.github.xanthic.jackson;
+
+import com.fasterxml.jackson.databind.DeserializationConfig;
+import com.fasterxml.jackson.databind.JavaType;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializationConfig;
+import com.fasterxml.jackson.databind.cfg.CacheProvider;
+import com.fasterxml.jackson.databind.deser.DeserializerCache;
+import com.fasterxml.jackson.databind.ser.SerializerCache;
+import com.fasterxml.jackson.databind.type.TypeFactory;
+import com.fasterxml.jackson.databind.util.LookupCache;
+import com.fasterxml.jackson.databind.util.TypeKey;
+import io.github.xanthic.cache.core.CacheApiSpec;
+import io.github.xanthic.jackson.util.SerializableConsumer;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import lombok.Value;
+
+/**
+ * Implementation of Jackson's {@link CacheProvider} that yields Xanthic {@link io.github.xanthic.cache.api.Cache} instances,
+ * which are backed by any cache implementation of your choosing.
+ * <p>
+ * Example usage:
+ * {@code ObjectMapper mapper = JsonMapper.builder().cacheProvider(XanthicJacksonCacheProvider.defaultInstance()).build(); }
+ */
+@Value
+@Getter(AccessLevel.PRIVATE)
+@RequiredArgsConstructor
+public class XanthicJacksonCacheProvider implements CacheProvider {
+	private static final long serialVersionUID = 1L;
+	private static final XanthicJacksonCacheProvider DEFAULT_INSTANCE = new XanthicJacksonCacheProvider();
+
+	/**
+	 * Specification for the deserializer cache.
+	 */
+	SerializableConsumer<CacheApiSpec<JavaType, JsonDeserializer<Object>>> deserializationSpec;
+
+	/**
+	 * Specification for the serializer cache.
+	 */
+	SerializableConsumer<CacheApiSpec<TypeKey, JsonSerializer<Object>>> serializationSpec;
+
+	/**
+	 * Specification for the type factory cache.
+	 */
+	SerializableConsumer<CacheApiSpec<Object, JavaType>> typeFactorySpec;
+
+	/**
+	 * Creates a Jackson {@link CacheProvider} backed by Xanthic, using the specified max cache sizes.
+	 *
+	 * @param maxDeserializerCacheSize the maximum size of the deserializer cache
+	 * @param maxSerializerCacheSize   the maximum size of the serializer cache
+	 * @param maxTypeFactoryCacheSize  the maximum size of the type factory cache
+	 */
+	public XanthicJacksonCacheProvider(long maxDeserializerCacheSize, long maxSerializerCacheSize, long maxTypeFactoryCacheSize) {
+		this.deserializationSpec = spec -> spec.maxSize(maxDeserializerCacheSize);
+		this.serializationSpec = spec -> spec.maxSize(maxSerializerCacheSize);
+		this.typeFactorySpec = spec -> spec.maxSize(maxTypeFactoryCacheSize);
+	}
+
+	/**
+	 * Creates a Jackson {@link CacheProvider} backed by Xanthic, using Jackson's recommended default max cache sizes.
+	 */
+	private XanthicJacksonCacheProvider() {
+		this(DeserializerCache.DEFAULT_MAX_CACHE_SIZE, SerializerCache.DEFAULT_MAX_CACHE_SIZE, TypeFactory.DEFAULT_MAX_CACHE_SIZE);
+	}
+
+	@Override
+	public LookupCache<JavaType, JsonDeserializer<Object>> forDeserializerCache(DeserializationConfig config) {
+		return new XanthicJacksonCacheAdapter<>(deserializationSpec);
+	}
+
+	@Override
+	public LookupCache<TypeKey, JsonSerializer<Object>> forSerializerCache(SerializationConfig config) {
+		return new XanthicJacksonCacheAdapter<>(serializationSpec);
+	}
+
+	@Override
+	public LookupCache<Object, JavaType> forTypeFactory() {
+		return new XanthicJacksonCacheAdapter<>(typeFactorySpec);
+	}
+
+	/**
+	 * @return a Jackson {@link CacheProvider} backed by Xanthic, using Jackson's recommended default max cache sizes.
+	 */
+	public static XanthicJacksonCacheProvider defaultInstance() {
+		return DEFAULT_INSTANCE;
+	}
+}

jackson/src/main/java/io/github/xanthic/jackson/util/SerializableConsumer.java

@@ -0,0 +1,13 @@
+package io.github.xanthic.jackson.util;
+
+import java.io.Serializable;
+import java.util.function.Consumer;
+
+/**
+ * A serializable {@link Consumer} since {@link com.fasterxml.jackson.databind.cfg.CacheProvider}
+ * must be {@link Serializable}, as it is stored in {@link com.fasterxml.jackson.databind.ObjectMapper}.
+ *
+ * @param <T> the type of the input for the consumer
+ */
+@FunctionalInterface
+public interface SerializableConsumer<T> extends Consumer<T>, Serializable {}

jackson/src/test/java/io/github/xanthic/jackson/XanthicJacksonCacheProviderTest.java

@@ -0,0 +1,132 @@
+package io.github.xanthic.jackson;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JavaType;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.cfg.CacheProvider;
+import com.fasterxml.jackson.databind.deser.DeserializerCache;
+import com.fasterxml.jackson.databind.json.JsonMapper;
+import com.fasterxml.jackson.databind.ser.SerializerCache;
+import com.fasterxml.jackson.databind.type.TypeFactory;
+import io.github.xanthic.jackson.util.TrackedCacheProvider;
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class XanthicJacksonCacheProviderTest {
+
+	@Test
+	void defaults() throws JsonProcessingException {
+		ObjectMapper mapper = JsonMapper.builder()
+			.cacheProvider(XanthicJacksonCacheProvider.defaultInstance())
+			.build();
+		assertNotNull(mapper.readValue("{\"bar\":\"baz\"}", Foo.class));
+		assertNotNull(mapper.writeValueAsString(new Foo("baz")));
+		assertNotNull(mapper.getTypeFactory().constructParametricType(List.class, Integer.class));
+	}
+
+	@Test
+	void deserialize() throws JsonProcessingException {
+		TrackedCacheProvider provider = new TrackedCacheProvider();
+		ObjectMapper mapper = JsonMapper.builder()
+			.cacheProvider(createCacheProvider(provider))
+			.build();
+		assertFalse(provider.getConstructedCaches().stream().anyMatch(c -> c.size() > 0));
+		Foo foo = mapper.readValue("{\"bar\":\"baz\"}", Foo.class);
+		assertNotNull(foo);
+		assertEquals("baz", foo.getBar());
+		assertTrue(provider.getConstructedCaches().stream().anyMatch(c -> c.size() > 0));
+	}
+
+	@Test
+	void serialize() throws JsonProcessingException {
+		TrackedCacheProvider provider = new TrackedCacheProvider();
+		ObjectMapper mapper = JsonMapper.builder()
+			.cacheProvider(createCacheProvider(provider))
+			.build();
+		assertFalse(provider.getConstructedCaches().stream().anyMatch(c -> c.size() > 0));
+		String json = mapper.writeValueAsString(new Foo("baz"));
+		assertEquals("{\"bar\":\"baz\"}", json);
+		assertTrue(provider.getConstructedCaches().stream().anyMatch(c -> c.size() > 0));
+	}
+
+	@Test
+	void constructType() {
+		TrackedCacheProvider provider = new TrackedCacheProvider();
+		ObjectMapper mapper = JsonMapper.builder()
+			.cacheProvider(createCacheProvider(provider))
+			.build();
+		assertFalse(provider.getConstructedCaches().stream().anyMatch(c -> c.size() > 0));
+		JavaType type = mapper.getTypeFactory().constructParametricType(List.class, Integer.class);
+		assertNotNull(type);
+		assertTrue(provider.getConstructedCaches().stream().anyMatch(c -> c.size() > 0));
+	}
+
+	@Test
+	void constructMultiple() throws JsonProcessingException {
+		TrackedCacheProvider provider = new TrackedCacheProvider();
+		assertEquals(0, provider.getConstructedCaches().size());
+
+		ObjectMapper m1 = JsonMapper.builder().cacheProvider(createCacheProvider(provider)).build();
+		m1.readValue("{\"bar\":\"baz\"}", Foo.class);
+		m1.writeValueAsString(new Foo("baz"));
+		m1.getTypeFactory().constructParametricType(List.class, Integer.class);
+		assertEquals(3, provider.getConstructedCaches().size());
+		assertTrue(provider.getConstructedCaches().stream().allMatch(c -> c.size() > 0));
+
+		ObjectMapper m2 = JsonMapper.builder().cacheProvider(createCacheProvider(provider)).build();
+		m2.readValue("{\"bar\":\"baz\"}", Foo.class);
+		m2.writeValueAsString(new Foo("baz"));
+		m2.getTypeFactory().constructParametricType(List.class, Integer.class);
+		assertEquals(6, provider.getConstructedCaches().size());
+		assertTrue(provider.getConstructedCaches().stream().allMatch(c -> c.size() > 0));
+	}
+
+	@Test
+	void serializable() throws IOException, ClassNotFoundException {
+		ByteArrayOutputStream baos = new ByteArrayOutputStream();
+		try (ObjectOutputStream oos = new ObjectOutputStream(baos)) {
+			oos.writeObject(XanthicJacksonCacheProvider.defaultInstance());
+		}
+
+		XanthicJacksonCacheProvider provider;
+		try (ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(baos.toByteArray()))) {
+			provider = (XanthicJacksonCacheProvider) ois.readObject();
+		}
+
+		assertNotNull(provider);
+		assertNotNull(provider.forTypeFactory());
+	}
+
+	private static CacheProvider createCacheProvider(TrackedCacheProvider trackedProvider) {
+		return new XanthicJacksonCacheProvider(
+			spec -> spec.provider(trackedProvider).maxSize((long) DeserializerCache.DEFAULT_MAX_CACHE_SIZE),
+			spec -> spec.provider(trackedProvider).maxSize((long) SerializerCache.DEFAULT_MAX_CACHE_SIZE),
+			spec -> spec.provider(trackedProvider).maxSize((long) TypeFactory.DEFAULT_MAX_CACHE_SIZE)
+		);
+	}
+
+	@Data
+	@Setter(AccessLevel.PRIVATE)
+	@NoArgsConstructor
+	@AllArgsConstructor
+	static class Foo {
+		private String bar;
+	}
+
+}

jackson/src/test/java/io/github/xanthic/jackson/util/TrackedCacheProvider.java

@@ -0,0 +1,23 @@
+package io.github.xanthic.jackson.util;
+
+import io.github.xanthic.cache.api.Cache;
+import io.github.xanthic.cache.api.CacheProvider;
+import io.github.xanthic.cache.api.ICacheSpec;
+import io.github.xanthic.cache.core.CacheApiSettings;
+import lombok.Value;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Value
+public class TrackedCacheProvider implements CacheProvider {
+	CacheProvider underlyingProvider = CacheApiSettings.getInstance().getDefaultCacheProvider();
+	List<Cache<?, ?>> constructedCaches = new ArrayList<>();
+
+	@Override
+	public <K, V> Cache<K, V> build(ICacheSpec<K, V> spec) {
+		Cache<K, V> cache = underlyingProvider.build(spec);
+		constructedCaches.add(cache);
+		return cache;
+	}
+}

settings.gradle.kts

@@ -5,6 +5,7 @@ include(
     ":api",
     ":core",
     ":kotlin",
+    ":jackson",
     ":spring",
     ":spring-java17",
     ":provider-androidx",
@@ -22,6 +23,7 @@ project(":bom").name = "cache-bom"
 project(":api").name = "cache-api"
 project(":core").name = "cache-core"
 project(":kotlin").name = "cache-kotlin"
+project(":jackson").name = "cache-jackson"
 project(":spring").name = "cache-spring"
 project(":spring-java17").name = "cache-spring-java17"
 project(":provider-androidx").name = "cache-provider-androidx"