[core] SortLookupStoreWriter should support empty record (apache#4777)

JingsongLi · Dec 25, 2024 · 49a5bd2 · 49a5bd2
1 parent ffef316
commit 49a5bd2
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Showing 2 changed files with 22 additions and 1 deletion.
diff --git a/paimon-common/src/main/java/org/apache/paimon/lookup/sort/BlockWriter.java b/paimon-common/src/main/java/org/apache/paimon/lookup/sort/BlockWriter.java
@@ -83,8 +83,11 @@ public int memory() {
 
     public MemorySlice finish() throws IOException {
         if (positions.isEmpty()) {
-            throw new IllegalStateException();
+            // Do not use alignment mode, as it is impossible to calculate how many records are
+            // inside when reading
+            aligned = false;
         }
+
         if (aligned) {
             block.writeInt(alignedSize);
         } else {

diff --git a/paimon-common/src/test/java/org/apache/paimon/lookup/sort/SortLookupStoreFactoryTest.java b/paimon-common/src/test/java/org/apache/paimon/lookup/sort/SortLookupStoreFactoryTest.java
@@ -114,6 +114,24 @@ public void testNormal() throws IOException {
         assertThat(cacheManager.indexCache().asMap()).isEmpty();
     }
 
+    @TestTemplate
+    public void testEmpty() throws IOException {
+        CacheManager cacheManager = new CacheManager(MemorySize.ofMebiBytes(1));
+        SortLookupStoreFactory factory =
+                new SortLookupStoreFactory(Comparator.naturalOrder(), cacheManager, 1024, compress);
+
+        SortLookupStoreWriter writer =
+                factory.createWriter(file, createBloomFiler(bloomFilterEnabled));
+        Context context = writer.close();
+
+        SortLookupStoreReader reader = factory.createReader(file, context);
+        byte[] bytes = toBytes(rnd.nextInt(VALUE_COUNT));
+        assertThat(reader.lookup(bytes)).isNull();
+        reader.close();
+        assertThat(cacheManager.dataCache().asMap()).isEmpty();
+        assertThat(cacheManager.indexCache().asMap()).isEmpty();
+    }
+
     @TestTemplate
     public void testIntKey() throws IOException {
         RowCompactedSerializer keySerializer =