fix: enforce one partition for single partition mapper (#4427)

fixes: #4209
block · Feb 17, 2025 · fbffe36 · fbffe36
1 parent cf3ed06
commit fbffe36
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diff --git a/...ime/ftl-runtime/common/deployment/src/main/java/xyz/block/ftl/deployment/FTLDotNames.java b/...ime/ftl-runtime/common/deployment/src/main/java/xyz/block/ftl/deployment/FTLDotNames.java
@@ -10,6 +10,7 @@
 import xyz.block.ftl.GeneratedRef;
 import xyz.block.ftl.LeaseClient;
 import xyz.block.ftl.Secret;
+import xyz.block.ftl.SinglePartitionMapper;
 import xyz.block.ftl.Subscription;
 import xyz.block.ftl.Topic;
 import xyz.block.ftl.TypeAlias;
@@ -35,4 +36,5 @@ private FTLDotNames() {
     public static final DotName LEASE_CLIENT = DotName.createSimple(LeaseClient.class);
     public static final DotName GENERATED_REF = DotName.createSimple(GeneratedRef.class);
     public static final DotName TOPIC = DotName.createSimple(Topic.class);
+    public static final DotName SINGLE_PARTITION_MAPPER = DotName.createSimple(SinglePartitionMapper.class);
 }
diff --git a/...ftl-runtime/common/deployment/src/main/java/xyz/block/ftl/deployment/TopicsProcessor.java b/...ftl-runtime/common/deployment/src/main/java/xyz/block/ftl/deployment/TopicsProcessor.java
@@ -75,6 +75,9 @@ TopicsBuildItem handleTopics(CombinedIndexBuildItem index, BuildProducer<Generat
             if (topicDefinition.value("partitions") != null) {
                 partitions = topicDefinition.value("partitions").asInt();
             }
+            if (partitionMapperClass.equals(FTLDotNames.SINGLE_PARTITION_MAPPER) && partitions != 1) {
+                throw new RuntimeException("SinglePartitionMapper can only be used with a single partition");
+            }
 
             String name = topicDefinition.value("name").asString();
             if (names.contains(name)) {