diff --git a/marginalia_nu/src/main/java/nu/marginalia/wmsa/edge/index/conversion/SearchIndexPreconverter.java b/marginalia_nu/src/main/java/nu/marginalia/wmsa/edge/index/conversion/SearchIndexPreconverter.java
index 37560b61..57d63825 100644
--- a/marginalia_nu/src/main/java/nu/marginalia/wmsa/edge/index/conversion/SearchIndexPreconverter.java
+++ b/marginalia_nu/src/main/java/nu/marginalia/wmsa/edge/index/conversion/SearchIndexPreconverter.java
@@ -23,18 +23,6 @@ public class SearchIndexPreconverter {
 
     public record Shard(int bucket, int block) {}
 
-    private record ShardOutput(Shard shard, RandomAccessFile raf, FileChannel fc) {
-        public static ShardOutput fromFile(Shard s, File f) {
-            try {
-                var v = new RandomAccessFile(f, "rw");
-                v.seek(SearchIndexJournalReader.FILE_HEADER_SIZE_BYTES);
-                return new ShardOutput(s, v, v.getChannel());
-            } catch (IOException e) {
-                throw new RuntimeException(e);
-            }
-        }
-    };
-
     @SneakyThrows
     @Inject
     public SearchIndexPreconverter(File inputFile,
@@ -57,7 +45,9 @@ public class SearchIndexPreconverter {
 
         logger.info("{}", indexJournalReader.fileHeader);
 
-        ShardOutput[] outputs = outputFiles.entrySet().stream().map(entry -> ShardOutput.fromFile(entry.getKey(), entry.getValue())).toArray(ShardOutput[]::new);
+        ShardOutput[] outputs = outputFiles.entrySet().stream()
+                .map(entry -> ShardOutput.fromFile(entry.getKey(), entry.getValue()))
+                .toArray(ShardOutput[]::new);
 
         var lock = partitioner.getReadLock();
         try {
@@ -69,18 +59,14 @@ public class SearchIndexPreconverter {
                     continue;
                 }
 
-                int domainId = entry.domainId();
                 buffer.clear();
                 entry.copyToBuffer(buffer);
 
-                for (int i = 0; i < outputs.length; i++) {
-                    if (outputs[i].shard.block == entry.header.block().id
-                        && partitioner.filterUnsafe(domainId, outputs[i].shard.bucket))
-                    {
+                for (ShardOutput output : outputs) {
+                    if (output.shouldWrite(partitioner, entry)) {
                         buffer.flip();
 
-                        while (buffer.position() < buffer.limit())
-                            outputs[i].fc.write(buffer);
+                        output.write(buffer);
                     }
                 }
             }
@@ -90,16 +76,42 @@ public class SearchIndexPreconverter {
         }
         logger.info("Finalizing preconversion");
 
-        for (int i = 0; i < outputs.length; i++) {
-            long pos = outputs[i].raf.getFilePointer();
-            outputs[i].raf.seek(0);
-            outputs[i].raf.writeLong(pos);
-            outputs[i].raf.writeLong(wordCountOriginal);
-            outputs[i].fc.force(true);
-            outputs[i].fc.close();
-            outputs[i].raf.close();
+        for (ShardOutput output : outputs) {
+            output.finish(wordCountOriginal);
         }
     }
 
+    private record ShardOutput(Shard shard, RandomAccessFile raf, FileChannel fc) {
+        public static ShardOutput fromFile(Shard s, File f) {
+            try {
+                var v = new RandomAccessFile(f, "rw");
+                v.seek(SearchIndexJournalReader.FILE_HEADER_SIZE_BYTES);
+                return new ShardOutput(s, v, v.getChannel());
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        }
+
+        public boolean shouldWrite(SearchIndexPartitioner partitioner, SearchIndexJournalReader.JournalEntry entry) {
+            return shard.block == entry.header.block().id
+                    && partitioner.filterUnsafe(entry.domainId(), shard.bucket);
+        }
+
+        public void finish(long wordCountOriginal) throws IOException {
+            long pos = raf.getFilePointer();
+            raf.seek(0);
+            raf.writeLong(pos);
+            raf.writeLong(wordCountOriginal);
+            fc.force(true);
+            fc.close();
+            raf.close();
+        }
+
+        public void write(ByteBuffer buffer) throws IOException {
+            while (buffer.position() < buffer.limit())
+                fc.write(buffer);
+        }
+    };
+
 }