Implementing Resilience

.gitignore

@@ -11,3 +11,4 @@
 *.log
 build/
 out/
+/absmarly.db

build.gradle

@@ -13,14 +13,16 @@ plugins {
 
 
 ext {
-	VERSION = "1.5.3"
+	VERSION = "1.6.0"
 	GROUP_ID = "com.absmartly.sdk"
 
 	slf4jVersion = "1.7.30"
 
 	jacksonVersion = "2.13.4.2"
 	jacksonDataTypeVersion = "2.13.4"
 
+	sqliteVersion = "3.40.1.0"
+
 	junitVersion = "5.7.0"
 	mockitoVersion = "3.6.28"
 }
@@ -63,6 +65,7 @@ configure(subprojects.findAll {
 		from javadoc.destinationDir
 	}
 
+	//Config for local maven publish
 	afterEvaluate {
 		publishing {
 			publications {

core-api/build.gradle

@@ -8,6 +8,14 @@ description = """ABSmartly Java SDK"""
 
 def httpClientVersion = "5.1.3"
 
+jar {
+	from {
+		configurations.runtimeClasspath.collect {
+			it.getName().contains("simpleCircuitBreaker") ? zipTree(it) : null
+		}
+	}
+}
+
 dependencies {
 	implementation group: "org.slf4j", name: "slf4j-api", version: slf4jVersion
 
@@ -21,6 +29,9 @@ dependencies {
 
 	implementation group: "com.fasterxml.jackson.core", name: "jackson-databind", version: jacksonVersion
 	implementation group: "com.fasterxml.jackson.datatype", name: "jackson-datatype-jsr310", version: jacksonDataTypeVersion
+	implementation group: 'org.xerial', name: 'sqlite-jdbc', version: sqliteVersion
+
+	implementation files('../libs/simpleCircuitBreaker-2.0.5.jar')
 
 	testImplementation group: "org.junit.jupiter", name: "junit-jupiter-api", version: junitVersion
 	testImplementation group: "org.junit.jupiter", name: "junit-jupiter-params", version: junitVersion

core-api/src/main/java/com/absmartly/sdk/ABSmartly.java

@@ -25,18 +25,35 @@ private ABSmartly(@Nonnull ABSmartlyConfig config) {
 		audienceDeserializer_ = config.getAudienceDeserializer();
 		scheduler_ = config.getScheduler();
 
+		if (config.getResilienceConfig() != null
+				&& config.getResilienceConfig().getLocalCache() == null) {
+			throw new IllegalArgumentException("Missing LocalCache instance");
+		}
+
 		if ((contextDataProvider_ == null) || (contextEventHandler_ == null)) {
 			client_ = config.getClient();
 			if (client_ == null) {
 				throw new IllegalArgumentException("Missing Client instance");
 			}
 
 			if (contextDataProvider_ == null) {
-				contextDataProvider_ = new DefaultContextDataProvider(client_);
+				if (config.getResilienceConfig() != null) {
+					contextDataProvider_ = new ResilientContextDataProvider(client_,
+							config.getResilienceConfig().getLocalCache());
+				} else {
+					contextDataProvider_ = new DefaultContextDataProvider(client_);
+				}
 			}
 
 			if (contextEventHandler_ == null) {
-				contextEventHandler_ = new DefaultContextEventHandler(client_);
+				if (config.getResilienceConfig() != null) {
+					contextEventHandler_ = new ResilientContextEventHandler(
+							client_,
+							config.getResilienceConfig());
+				} else {
+					contextEventHandler_ = new DefaultContextEventHandler(client_);
+				}
+
 			}
 		}
 

core-api/src/main/java/com/absmartly/sdk/ABSmartlyConfig.java

@@ -38,6 +38,15 @@ public ABSmartlyConfig setVariableParser(@Nonnull final VariableParser variableP
 		return this;
 	}
 
+	public ResilienceConfig getResilienceConfig() {
+		return this.resilienceConfig;
+	}
+
+	public ABSmartlyConfig setResilienceConfig(@Nonnull final ResilienceConfig resilienceConfig) {
+		this.resilienceConfig = resilienceConfig;
+		return this;
+	}
+
 	public ScheduledExecutorService getScheduler() {
 		return scheduler_;
 	}
@@ -83,4 +92,5 @@ public ABSmartlyConfig setClient(Client client) {
 	private AudienceDeserializer audienceDeserializer_;
 	private ScheduledExecutorService scheduler_;
 	private Client client_;
+	private ResilienceConfig resilienceConfig;
 }

core-api/src/main/java/com/absmartly/sdk/Client.java

@@ -53,7 +53,7 @@ static public Client create(@Nonnull final ClientConfig config, @Nonnull final H
 		executor_ = config.getExecutor();
 
 		if (deserializer_ == null) {
-			deserializer_ = new DefaultContextDataDeserializer();
+			deserializer_ = new DefaultContextDataSerializer();
 		}
 
 		if (serializer_ == null) {
@@ -154,6 +154,6 @@ public void close() throws IOException {
 	private final Map<String, String> headers_;
 	private final HTTPClient httpClient_;
 	private final Executor executor_;
-	private ContextDataDeserializer deserializer_;
+	private ContextDataSerializer deserializer_;
 	private ContextEventSerializer serializer_;
 }

core-api/src/main/java/com/absmartly/sdk/ClientConfig.java

@@ -60,11 +60,11 @@ public ClientConfig setApplication(@Nonnull final String application) {
 		return this;
 	}
 
-	public ContextDataDeserializer getContextDataDeserializer() {
+	public ContextDataSerializer getContextDataDeserializer() {
 		return deserializer_;
 	}
 
-	public ClientConfig setContextDataDeserializer(@Nonnull final ContextDataDeserializer deserializer) {
+	public ClientConfig setContextDataDeserializer(@Nonnull final ContextDataSerializer deserializer) {
 		deserializer_ = deserializer;
 		return this;
 	}
@@ -91,7 +91,7 @@ public ClientConfig setExecutor(@Nonnull final Executor executor) {
 	private String apiKey_;
 	private String environment_;
 	private String application_;
-	private ContextDataDeserializer deserializer_;
+	private ContextDataSerializer deserializer_;
 	private ContextEventSerializer serializer_;
 	private Executor executor_;
 }

core-api/src/main/java/com/absmartly/sdk/Context.java

@@ -11,6 +11,7 @@
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java8.util.concurrent.CompletableFuture;
 import java8.util.concurrent.CompletionException;
+import java8.util.function.BiConsumer;
 import java8.util.function.Consumer;
 import java8.util.function.Function;
 
@@ -71,6 +72,13 @@ private Context(Clock clock, ContextConfig config, ScheduledExecutorService sche
 		cassignments_ = (cassignments != null) ? new HashMap<String, Integer>(cassignments)
 				: new HashMap<String, Integer>();
 
+		dataFuture.whenComplete(new BiConsumer<ContextData, Throwable>() {
+			@Override
+			public void accept(ContextData unused, Throwable throwable) {
+				eventHandler_.onContextReady();
+			}
+		});
+
 		if (dataFuture.isDone()) {
 			dataFuture.thenAccept(new Consumer<ContextData>() {
 				@Override
@@ -602,7 +610,6 @@ public void run() {
 						@Override
 						public Void apply(Throwable throwable) {
 							Context.this.logError(throwable);
-
 							result.completeExceptionally(throwable);
 							return null;
 						}
@@ -920,7 +927,7 @@ private void setData(final ContextData data) {
 								new Comparator<ExperimentVariables>() {
 									@Override
 									public int compare(ExperimentVariables a, ExperimentVariables b) {
-										return Integer.valueOf(a.data.id).compareTo(b.data.id);
+										return Integer.compare(Integer.valueOf(a.data.id), b.data.id);
 									}
 								});
 

core-api/src/main/java/com/absmartly/sdk/ContextDataDeserializer.java → core-api/src/main/java/com/absmartly/sdk/ContextDataSerializer.java

@@ -4,6 +4,9 @@
 
 import com.absmartly.sdk.json.ContextData;
 
-interface ContextDataDeserializer {
+public interface ContextDataSerializer {
+
+	byte[] serialize(@Nonnull final ContextData contextData);
+
 	ContextData deserialize(@Nonnull final byte[] bytes, final int offset, final int length);
 }

core-api/src/main/java/com/absmartly/sdk/ContextEventHandler.java

@@ -7,5 +7,6 @@
 import com.absmartly.sdk.json.PublishEvent;
 
 public interface ContextEventHandler {
-	CompletableFuture<Void> publish(@Nonnull final Context context, @Nonnull final PublishEvent event);
+	CompletableFuture<Void> publish(final Context context, @Nonnull final PublishEvent event);
+	void onContextReady();
 }

core-api/src/main/java/com/absmartly/sdk/ContextEventSerializer.java

@@ -6,4 +6,6 @@
 
 public interface ContextEventSerializer {
 	byte[] serialize(@Nonnull final PublishEvent publishEvent);
+
+	PublishEvent deserialize(@Nonnull final byte[] bytes, final int offset, final int length);
 }

core-api/src/main/java/com/absmartly/sdk/DefaultContextDataDeserializer.java → core-api/src/main/java/com/absmartly/sdk/DefaultContextDataSerializer.java

@@ -7,21 +7,40 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.MapperFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.ObjectReader;
+import com.fasterxml.jackson.databind.ObjectWriter;
 
 import com.absmartly.sdk.json.ContextData;
 
-public class DefaultContextDataDeserializer implements ContextDataDeserializer {
-	private static final Logger log = LoggerFactory.getLogger(DefaultContextDataDeserializer.class);
+public class DefaultContextDataSerializer implements ContextDataSerializer {
+	private static final Logger log = LoggerFactory.getLogger(DefaultContextDataSerializer.class);
 
-	public DefaultContextDataDeserializer() {
+	public DefaultContextDataSerializer() {
 		final ObjectMapper objectMapper = new ObjectMapper();
 		objectMapper.enable(MapperFeature.USE_STATIC_TYPING);
+
+		this.writer_ = objectMapper.writerFor(ContextData.class);
 		this.reader_ = objectMapper.readerFor(ContextData.class);
 	}
 
+	public DefaultContextDataSerializer(final ObjectWriter writer, final ObjectReader reader) {
+		this.writer_ = writer;
+		this.reader_ = reader;
+	}
+
+	@Override
+	public byte[] serialize(@Nonnull ContextData contextData) {
+		try {
+			return writer_.writeValueAsBytes(contextData);
+		} catch (JsonProcessingException e) {
+			log.error("", e);
+			return null;
+		}
+	}
+
 	public ContextData deserialize(@Nonnull final byte[] bytes, final int offset, final int length) {
 		try {
 			return reader_.readValue(bytes, offset, length);
@@ -31,5 +50,6 @@ public ContextData deserialize(@Nonnull final byte[] bytes, final int offset, fi
 		}
 	}
 
+	final private ObjectWriter writer_;
 	private final ObjectReader reader_;
 }

core-api/src/main/java/com/absmartly/sdk/DefaultContextEventHandler.java

@@ -12,9 +12,13 @@ public DefaultContextEventHandler(@Nonnull final Client client) {
 	}
 
 	@Override
-	public CompletableFuture<Void> publish(@Nonnull final Context context, @Nonnull final PublishEvent event) {
+	public CompletableFuture<Void> publish(final Context context, @Nonnull final PublishEvent event) {
 		return client_.publish(event);
 	}
 
-	private final Client client_;
+	@Override
+	public void onContextReady() {
+	}
+
+	final Client client_;
 }

core-api/src/main/java/com/absmartly/sdk/DefaultContextEventSerializer.java

@@ -1,12 +1,16 @@
 package com.absmartly.sdk;
 
+import java.io.IOException;
+
 import javax.annotation.Nonnull;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.MapperFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectReader;
 import com.fasterxml.jackson.databind.ObjectWriter;
 
 import com.absmartly.sdk.json.PublishEvent;
@@ -17,10 +21,14 @@ public class DefaultContextEventSerializer implements ContextEventSerializer {
 	public DefaultContextEventSerializer() {
 		final ObjectMapper objectMapper = new ObjectMapper();
 		this.writer_ = objectMapper.writerFor(PublishEvent.class);
+
+		objectMapper.enable(MapperFeature.USE_STATIC_TYPING);
+		this.reader_ = objectMapper.readerFor(PublishEvent.class);
 	}
 
-	public DefaultContextEventSerializer(final ObjectWriter writer) {
+	public DefaultContextEventSerializer(final ObjectWriter writer, final ObjectReader reader) {
 		this.writer_ = writer;
+		this.reader_ = reader;
 	}
 
 	@Override
@@ -33,5 +41,17 @@ public byte[] serialize(@Nonnull final PublishEvent event) {
 		}
 	}
 
+	@Override
+	public PublishEvent deserialize(@Nonnull byte[] bytes, int offset, int length) {
+		try {
+			return reader_.readValue(bytes, offset, length);
+		} catch (IOException e) {
+			log.error("", e);
+			return null;
+		}
+	}
+
 	final private ObjectWriter writer_;
+
+	private final ObjectReader reader_;
 }