Merge pull request #211 from ydb-platform/read_without_consumer

Add support for reading without a consumer
ydb-platform · Jan 10, 2024 · 45472d5 · 45472d5
2 parents 9d6758a + ff0a42e
commit 45472d5
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Showing 2 changed files with 29 additions and 4 deletions.
diff --git a/topic/src/main/java/tech/ydb/topic/read/impl/ReaderImpl.java b/topic/src/main/java/tech/ydb/topic/read/impl/ReaderImpl.java
@@ -74,7 +74,11 @@ public ReaderImpl(TopicRpc topicRpc, ReaderSettings settings) {
             }
             message.append("\"").append(topic.getPath()).append("\"");
         }
-        message.append(" and Consumer: \"").append(settings.getConsumerName()).append("\"");
+        if (settings.getConsumerName() != null) {
+            message.append(" and Consumer: \"").append(settings.getConsumerName()).append("\"");
+        } else {
+            message.append(" without a Consumer");
+        }
         logger.info(message.toString());
     }
 
@@ -144,8 +148,10 @@ public void startAndInitialize() {
             start(this::processMessage).whenComplete(this::onSessionClosing);
 
             YdbTopic.StreamReadMessage.InitRequest.Builder initRequestBuilder = YdbTopic.StreamReadMessage.InitRequest
-                    .newBuilder()
-                    .setConsumer(settings.getConsumerName());
+                    .newBuilder();
+            if (settings.getConsumerName() != null) {
+                initRequestBuilder.setConsumer(settings.getConsumerName());
+            }
             settings.getTopics().forEach(topicReadSettings -> {
                 YdbTopic.StreamReadMessage.InitRequest.TopicReadSettings.Builder settingsBuilder =
                         YdbTopic.StreamReadMessage.InitRequest.TopicReadSettings.newBuilder()

diff --git a/topic/src/main/java/tech/ydb/topic/settings/ReaderSettings.java b/topic/src/main/java/tech/ydb/topic/settings/ReaderSettings.java
@@ -78,6 +78,7 @@ public static Builder newBuilder() {
      */
     public static class Builder {
         private String consumerName = null;
+        private boolean readWithoutConsumer = false;
         private String readerName = null;
         private List<TopicReadSettings> topics = new ArrayList<>();
         private long maxMemoryUsageBytes = MAX_MEMORY_USAGE_BYTES_DEFAULT;
@@ -91,6 +92,16 @@ public Builder setConsumerName(String consumerName) {
             return this;
         }
 
+        /**
+         * Experimental feature. Interface may change in future
+         * Explicitly require reading without a consumer. Reading progress will not be saved on server this way.
+         * @return settings builder
+         */
+        public Builder withoutConsumer() {
+            this.readWithoutConsumer = true;
+            return this;
+        }
+
         // Not supported in API yet
         public Builder setReaderName(String readerName) {
             this.readerName = readerName;
@@ -145,7 +156,15 @@ public Builder setDecompressionExecutor(Executor decompressionExecutor) {
 
         public ReaderSettings build() {
             if (consumerName == null) {
-                throw new IllegalArgumentException("Missing consumer name for read settings");
+                if (!readWithoutConsumer) {
+                    throw new IllegalArgumentException("Missing consumer name for read settings. " +
+                            "Use withoutConsumer option explicitly if you want to read without a consumer");
+                }
+            } else {
+                if (readWithoutConsumer) {
+                    throw new IllegalArgumentException("Both mutually exclusive options consumerName and " +
+                            "withoutConsumer are set for read settings");
+                }
             }
             if (topics.isEmpty()) {
                 throw new IllegalArgumentException("Missing topics for read settings. At least one should be set");