[feat][client] Add Message::hasEventTimestamp

include/pulsar/Message.h

@@ -181,6 +181,17 @@ class PULSAR_PUBLIC Message {
      */
     uint64_t getEventTimestamp() const;
 
+    /**
+     * Check whether the event timestamp was set by the client producer.
+     *
+     * @return true if the event timestamp was set while creating the message
+     *         false if the event timestamp was not set while creating the message
+     *
+     * This is distinct from `getEventTimestamp() != 0`, because a producer may legitimately set an
+     * event timestamp of 0 (the Unix epoch).
+     */
+    bool hasEventTimestamp() const;
+
     /**
      * Get the topic Name from which this message originated from
      */

lib/Message.cc

@@ -232,6 +232,8 @@ uint64_t Message::getPublishTimestamp() const { return impl_ ? impl_->getPublish
 
 uint64_t Message::getEventTimestamp() const { return impl_ ? impl_->getEventTimestamp() : 0ull; }
 
+bool Message::hasEventTimestamp() const { return impl_ ? impl_->hasEventTimestamp() : false; }
+
 const std::string& Message::getProducerName() const noexcept {
     if (!impl_) {
         return emptyString;

lib/MessageImpl.cc

@@ -55,6 +55,8 @@ uint64_t MessageImpl::getEventTimestamp() const {
     }
 }
 
+bool MessageImpl::hasEventTimestamp() const { return metadata.has_event_time(); }
+
 void MessageImpl::setReplicationClusters(const std::vector<std::string>& clusters) {
     google::protobuf::RepeatedPtrField<std::string> r(clusters.begin(), clusters.end());
     r.Swap(metadata.mutable_replicate_to());

lib/MessageImpl.h

@@ -61,6 +61,7 @@ class MessageImpl {
 
     uint64_t getPublishTimestamp() const;
     uint64_t getEventTimestamp() const;
+    bool hasEventTimestamp() const;
 
     /**
      * Get the topic Name from which this message originated from

tests/MessageTest.cc

@@ -63,6 +63,20 @@ bool compareMaps(const Map& lhs, const Map& rhs) {
     return lhs.size() == rhs.size() && std::equal(lhs.begin(), lhs.end(), rhs.begin());
 }
 
+TEST(MessageTest, testHasEventTimestamp) {
+    ASSERT_FALSE(Message().hasEventTimestamp());
+    ASSERT_FALSE(MessageBuilder().setContent("msg").build().hasEventTimestamp());
+
+    // The Unix epoch is a valid event time, so it must not be reported as an unset one.
+    Message msg = MessageBuilder().setContent("msg").setEventTimestamp(0).build();
+    ASSERT_TRUE(msg.hasEventTimestamp());
+    ASSERT_EQ(msg.getEventTimestamp(), 0u);
+
+    msg = MessageBuilder().setContent("msg").setEventTimestamp(1234).build();
+    ASSERT_TRUE(msg.hasEventTimestamp());
+    ASSERT_EQ(msg.getEventTimestamp(), 1234u);
+}
+
 TEST(MessageTest, testProperties) {
     MessageBuilder msgBuilder1;
     msgBuilder1.setProperty("property1", "value1");