Fix code review

Author: shibd

include/pulsar/ConsumerConfiguration.h

@@ -400,8 +400,30 @@ class PULSAR_PUBLIC ConsumerConfiguration {
     const BatchReceivePolicy& getBatchReceivePolicy() const;
 
     /**
-     * Set dead letter policy.
-     *
+     * Set dead letter policy for consumer
+     *
+     * By default some message will redelivery so many times possible, even to the extent that it can be never
+     * stop. By using dead letter mechanism messages will has the max redelivery count, when message exceeding
+     * the maximum number of redeliveries, message will send to the Dead Letter Topic and acknowledged
+     * automatic.
+     *
+     * You can enable the dead letter mechanism by setting dead letter policy.
+     * example:
+     *
+     * <pre>
+     * * DeadLetterPolicy dlqPolicy = DeadLetterPolicyBuilder()
+     *                       .maxRedeliverCount(10)
+     *                       .build();
+     * </pre>
+     * Default dead letter topic name is {TopicName}-{Subscription}-DLQ.
+     * To setting a custom dead letter topic name
+     * <pre>
+     * DeadLetterPolicy dlqPolicy = DeadLetterPolicyBuilder()
+     *                       .deadLetterTopic("dlq-topic")
+     *                       .maxRedeliverCount(10)
+     *                       .initialSubscriptionName("init-sub-name")
+     *                       .build();
+     * </pre>
      * @param deadLetterPolicy thd default is empty
      */
     void setDeadLetterPolicy(const DeadLetterPolicy& deadLetterPolicy);

include/pulsar/DeadLetterPolicyBuilder.h

@@ -46,7 +46,10 @@ class PULSAR_PUBLIC DeadLetterPolicyBuilder {
     DeadLetterPolicyBuilder();
 
     /**
-     * Set dead letter topic
+     * Set dead letter topic.
+     *
+     * @param deadLetterTopic Name of the dead topic where the failing messages will be sent.
+     * The default value is: sourceTopicName + "-" + subscriptionName + "-DLQ"
      *
      * @return
      */
@@ -55,13 +58,23 @@ class PULSAR_PUBLIC DeadLetterPolicyBuilder {
     /**
      * Set max redeliver count
      *
+     * @param maxRedeliverCount Maximum number of times that a message will be redelivered before being sent
+     * to the dead letter queue.
+     * - The maxRedeliverCount must be greater than 0.
+     * - The default value is {INT_MAX} (DLQ is not enabled)
+     *
      * @return
      */
     DeadLetterPolicyBuilder& maxRedeliverCount(int maxRedeliverCount);
 
     /**
      * Set initial subscription name
      *
+     * @param initialSubscriptionName  Name of the initial subscription name of the dead letter topic.
+     * If this field is not set, the initial subscription for the dead letter topic will not be created.
+     * If this field is set but the broker's `allowAutoSubscriptionCreation` is disabled, the DLQ producer
+     * will fail to be created.
+     *
      * @return
      */
     DeadLetterPolicyBuilder& initialSubscriptionName(const std::string& initialSubscriptionName);

lib/DeadLetterPolicyImpl.h

@@ -18,8 +18,8 @@
  */
 #pragma once
 
-#include "climits"
-#include "string"
+#include <climits>
+#include <string>
 
 namespace pulsar {
 

tests/ConsumerConfigurationTest.cc

@@ -26,9 +26,10 @@
 
 DECLARE_LOG_OBJECT()
 
+#include <pulsar/DeadLetterPolicyBuilder.h>
+
 #include "../lib/Future.h"
 #include "../lib/Utils.h"
-#include "pulsar/DeadLetterPolicyBuilder.h"
 
 using namespace pulsar;
 

tests/DeadLetterQueueTest.cc

@@ -18,6 +18,7 @@
  */
 #include <gtest/gtest.h>
 #include <pulsar/Client.h>
+#include <pulsar/DeadLetterPolicyBuilder.h>
 
 #include "HttpHelper.h"
 #include "PulsarFriend.h"
@@ -26,7 +27,6 @@
 #include "lib/MessageIdUtil.h"
 #include "lib/UnAckedMessageTrackerEnabled.h"
 #include "lib/Utils.h"
-#include "pulsar/DeadLetterPolicyBuilder.h"
 
 static const std::string lookupUrl = "pulsar://localhost:6650";
 static const std::string adminUrl = "http://localhost:8080/";