Making message properties accessible while handling/consuming the message

src/main/java/io/appform/dropwizard/actors/actor/ActorConfig.java

@@ -17,24 +17,27 @@
 package io.appform.dropwizard.actors.actor;
 
 import io.appform.dropwizard.actors.TtlConfig;
+import io.appform.dropwizard.actors.actor.metadata.generators.MessageDelayMetaGenerator;
+import io.appform.dropwizard.actors.actor.metadata.generators.MessageExpiredMetaGenerator;
+import io.appform.dropwizard.actors.actor.metadata.generators.MessageReDeliveredMetaGenerator;
 import io.appform.dropwizard.actors.exceptionhandler.config.ExceptionHandlerConfig;
 import io.appform.dropwizard.actors.retry.config.NoRetryConfig;
 import io.appform.dropwizard.actors.retry.config.RetryConfig;
 import io.dropwizard.validation.ValidationMethod;
+import java.util.List;
+import java.util.Objects;
+import javax.validation.Valid;
+import javax.validation.constraints.Max;
+import javax.validation.constraints.Min;
+import javax.validation.constraints.NotEmpty;
+import javax.validation.constraints.NotNull;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
 import lombok.EqualsAndHashCode;
 import lombok.NoArgsConstructor;
 import lombok.ToString;
 
-import javax.validation.Valid;
-import javax.validation.constraints.Max;
-import javax.validation.constraints.Min;
-import javax.validation.constraints.NotEmpty;
-import javax.validation.constraints.NotNull;
-import java.util.Objects;
-
 /**
  * Configuration for an actor
  */
@@ -45,6 +48,13 @@
 @NoArgsConstructor
 @Builder
 public class ActorConfig {
+
+    public static final List<String> DEFAULT_METADATA_GENERATORS = List.of(
+            MessageReDeliveredMetaGenerator.class.getName(),
+            MessageDelayMetaGenerator.class.getName(),
+            MessageExpiredMetaGenerator.class.getName()
+    );
+
     @NotNull
     @NotEmpty
     private String exchange;
@@ -96,6 +106,8 @@ public class ActorConfig {
     @Max(32)
     private Integer shardCount;
 
+    private List<String> messageMetaGeneratorClasses;
+
     public boolean isSharded() {
         return Objects.nonNull(shardCount);
     }

src/main/java/io/appform/dropwizard/actors/actor/MessageMetadata.java

@@ -1,13 +1,35 @@
 package io.appform.dropwizard.actors.actor;
 
+import java.util.Date;
+import java.util.Map;
 import lombok.AllArgsConstructor;
+import lombok.Builder;
 import lombok.Data;
+import lombok.NoArgsConstructor;
 
 @Data
+@Builder
+@NoArgsConstructor
 @AllArgsConstructor
 public final class MessageMetadata {
 
+    private String contentType;
+    private String contentEncoding;
+    private Map<String,Object> headers;
+    private Integer deliveryMode;
+    private Integer priority;
+    private String correlationId;
+    private String replyTo;
+    private String expiration;
+    private String messageId;
+    private Date msgSentTimestamp;
+    private String type;
+    private String userId;
+    private String appId;
+    private String clusterId;
+
+    // custom fields
     private boolean redelivered;
     private long delayInMs;
-
+    private boolean expired;
 }

src/main/java/io/appform/dropwizard/actors/actor/metadata/MessageMetaContext.java

@@ -0,0 +1,30 @@
+package io.appform.dropwizard.actors.actor.metadata;
+
+import java.util.Date;
+import java.util.Map;
+import lombok.Builder;
+import lombok.Data;
+
+/**
+ * Ref : <a href="https://www.rabbitmq.com/amqp-0-9-1-reference.html#class.basic">AMQP properties</a>
+ */
+@Data
+@Builder
+public class MessageMetaContext {
+
+    private boolean redelivered;
+    private String contentType;
+    private String contentEncoding;
+    private Map<String,Object> headers;
+    private Integer deliveryMode;
+    private Integer priority;
+    private String correlationId;
+    private String replyTo;
+    private String expiration;
+    private String messageId;
+    private Date timestamp;
+    private String type;
+    private String userId;
+    private String appId;
+    private String clusterId;
+}

src/main/java/io/appform/dropwizard/actors/actor/metadata/MessageMetadataProvider.java

@@ -0,0 +1,67 @@
+package io.appform.dropwizard.actors.actor.metadata;
+
+import com.rabbitmq.client.AMQP;
+import com.rabbitmq.client.Envelope;
+import io.appform.dropwizard.actors.actor.MessageMetadata;
+import io.appform.dropwizard.actors.actor.metadata.generators.MessageMetadataGenerator;
+import io.appform.dropwizard.actors.common.RabbitmqActorException;
+import java.lang.reflect.InvocationTargetException;
+import java.util.List;
+import java.util.Objects;
+import lombok.val;
+
+public class MessageMetadataProvider {
+
+    private final List<MessageMetadataGenerator> messageMetadataGenerators;
+
+    public MessageMetadataProvider(List<String> messageMetaGeneratorClasses) {
+        messageMetadataGenerators = configureMessageMetadataGenerators(messageMetaGeneratorClasses);
+    }
+
+    public MessageMetadata createMetadata(final Envelope envelope, final AMQP.BasicProperties properties) {
+        Objects.requireNonNull(envelope, "Envelope should not be null");
+        Objects.requireNonNull(properties, "AMQP.BasicProperties should not be null");
+        val messageMetaContext = MessageMetaContext.builder()
+                .redelivered(envelope.isRedeliver())
+                .contentType(properties.getContentType())
+                .contentEncoding(properties.getContentEncoding())
+                .headers(properties.getHeaders())
+                .deliveryMode(properties.getDeliveryMode())
+                .priority(properties.getPriority())
+                .correlationId(properties.getCorrelationId())
+                .replyTo(properties.getReplyTo())
+                .expiration(properties.getExpiration())
+                .messageId(properties.getMessageId())
+                .timestamp(properties.getTimestamp())
+                .type(properties.getType())
+                .userId(properties.getUserId())
+                .appId(properties.getAppId())
+                .clusterId(properties.getClusterId())
+                .build();
+
+        val messageMetadata = MessageMetadata.builder().build();
+        messageMetadataGenerators.forEach(generator -> generator.generate(messageMetaContext, messageMetadata));
+        return messageMetadata;
+    }
+
+    private List<MessageMetadataGenerator> configureMessageMetadataGenerators(List<String> messageMetaGeneratorClasses) {
+        if (null == messageMetaGeneratorClasses) {
+            return List.of();
+        }
+
+        return messageMetaGeneratorClasses.stream()
+                .distinct()
+                .map(className -> {
+                    try {
+                        return (MessageMetadataGenerator) Class.forName(className)
+                                .getDeclaredConstructor()
+                                .newInstance();
+                    } catch (ClassNotFoundException | NoSuchMethodException | InstantiationException |
+                             IllegalAccessException | InvocationTargetException e) {
+                        throw RabbitmqActorException.propagate("Failed to initialize messageMetadataGenerator "
+                                + className, e);
+                    }
+                })
+                .toList();
+    }
+}

src/main/java/io/appform/dropwizard/actors/actor/metadata/generators/MessageDelayMetaGenerator.java

@@ -0,0 +1,23 @@
+package io.appform.dropwizard.actors.actor.metadata.generators;
+
+import static io.appform.dropwizard.actors.common.Constants.MESSAGE_PUBLISHED_TEXT;
+
+import io.appform.dropwizard.actors.actor.MessageMetadata;
+import io.appform.dropwizard.actors.actor.metadata.MessageMetaContext;
+import io.appform.dropwizard.actors.utils.CommonUtils;
+import java.time.Instant;
+
+public class MessageDelayMetaGenerator implements MessageMetadataGenerator {
+
+    @Override
+    public void generate(final MessageMetaContext messageMetaContext, MessageMetadata messageMetadata) {
+        messageMetadata.setDelayInMs(calculateDelayInMs(messageMetaContext));
+    }
+
+    private long calculateDelayInMs(MessageMetaContext messageMetaContext) {
+        return CommonUtils.extractMessagePropertiesHeader(messageMetaContext.getHeaders(),
+                        MESSAGE_PUBLISHED_TEXT, Long.class)
+                .map(publishedAt -> Math.max(Instant.now().toEpochMilli() - publishedAt, 0))
+                .orElse(0L);
+    }
+}

src/main/java/io/appform/dropwizard/actors/actor/metadata/generators/MessageExpiredMetaGenerator.java

@@ -0,0 +1,24 @@
+package io.appform.dropwizard.actors.actor.metadata.generators;
+
+import static io.appform.dropwizard.actors.common.Constants.MESSAGE_EXPIRY_TEXT;
+
+import io.appform.dropwizard.actors.actor.MessageMetadata;
+import io.appform.dropwizard.actors.actor.metadata.MessageMetaContext;
+import io.appform.dropwizard.actors.utils.CommonUtils;
+import java.time.Instant;
+
+public class MessageExpiredMetaGenerator implements MessageMetadataGenerator {
+
+    @Override
+    public void generate(MessageMetaContext messageMetaContext, MessageMetadata messageMetadata) {
+        messageMetadata.setExpired(isExpired(messageMetaContext));
+    }
+
+    private boolean isExpired(MessageMetaContext messageMetaContext) {
+        return CommonUtils.extractMessagePropertiesHeader(messageMetaContext.getHeaders(),
+                MESSAGE_EXPIRY_TEXT, Long.class)
+                .filter(expiry -> Instant.now().toEpochMilli() >= expiry)
+                .isPresent();
+    }
+
+}

src/main/java/io/appform/dropwizard/actors/actor/metadata/generators/MessageHeadersMetaGenerator.java

@@ -0,0 +1,13 @@
+package io.appform.dropwizard.actors.actor.metadata.generators;
+
+import io.appform.dropwizard.actors.actor.MessageMetadata;
+import io.appform.dropwizard.actors.actor.metadata.MessageMetaContext;
+
+public class MessageHeadersMetaGenerator implements MessageMetadataGenerator {
+
+    @Override
+    public void generate(final MessageMetaContext messageMetaContext, MessageMetadata messageMetadata) {
+        messageMetadata.setHeaders(messageMetaContext.getHeaders());
+    }
+
+}

src/main/java/io/appform/dropwizard/actors/actor/metadata/generators/MessageMetaInfoGenerator.java

@@ -0,0 +1,25 @@
+package io.appform.dropwizard.actors.actor.metadata.generators;
+
+import io.appform.dropwizard.actors.actor.MessageMetadata;
+import io.appform.dropwizard.actors.actor.metadata.MessageMetaContext;
+
+public class MessageMetaInfoGenerator implements MessageMetadataGenerator {
+
+    @Override
+    public void generate(final MessageMetaContext messageMetaContext, MessageMetadata messageMetadata) {
+        messageMetadata.setContentType(messageMetaContext.getContentType());
+        messageMetadata.setContentEncoding(messageMetaContext.getContentEncoding());
+        messageMetadata.setDeliveryMode(messageMetaContext.getDeliveryMode());
+        messageMetadata.setPriority(messageMetaContext.getPriority());
+        messageMetadata.setCorrelationId(messageMetaContext.getCorrelationId());
+        messageMetadata.setReplyTo(messageMetaContext.getReplyTo());
+        messageMetadata.setExpiration(messageMetaContext.getExpiration());
+        messageMetadata.setMessageId(messageMetaContext.getMessageId());
+        messageMetadata.setMsgSentTimestamp(messageMetaContext.getTimestamp());
+        messageMetadata.setType(messageMetaContext.getType());
+        messageMetadata.setUserId(messageMetaContext.getUserId());
+        messageMetadata.setAppId(messageMetaContext.getAppId());
+        messageMetadata.setClusterId(messageMetaContext.getClusterId());
+    }
+
+}

src/main/java/io/appform/dropwizard/actors/actor/metadata/generators/MessageMetadataGenerator.java

@@ -0,0 +1,11 @@
+package io.appform.dropwizard.actors.actor.metadata.generators;
+
+import io.appform.dropwizard.actors.actor.MessageMetadata;
+import io.appform.dropwizard.actors.actor.metadata.MessageMetaContext;
+
+@FunctionalInterface
+public interface MessageMetadataGenerator {
+
+    void generate(final MessageMetaContext messageMetaContext, final MessageMetadata messageMetadata);
+
+}

src/main/java/io/appform/dropwizard/actors/actor/metadata/generators/MessageReDeliveredMetaGenerator.java

@@ -0,0 +1,13 @@
+package io.appform.dropwizard.actors.actor.metadata.generators;
+
+import io.appform.dropwizard.actors.actor.MessageMetadata;
+import io.appform.dropwizard.actors.actor.metadata.MessageMetaContext;
+
+public class MessageReDeliveredMetaGenerator implements MessageMetadataGenerator {
+
+    @Override
+    public void generate(final MessageMetaContext messageMetaContext, MessageMetadata messageMetadata) {
+        messageMetadata.setRedelivered(messageMetaContext.isRedelivered());
+    }
+
+}