refactor(IcebergTableOperatorUpsert): use `DeleteWriteBuilder.forTabl…

…e` instead of setting table params manually (#44)

We were setting the parameters "manually" when there is a `forTable`
helper in the iceberg API.

Also, this refactors the `getDeleteFile` to return a `Optional`,
providing more clarity that there can be no delete file for a given
batch

debezium-server-iceberg-sink/src/main/java/io/debezium/server/iceberg/tableoperator/IcebergTableOperatorUpsert.java

@@ -16,6 +16,7 @@
 import java.time.Instant;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Optional;
 import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
@@ -26,7 +27,6 @@
 import javax.inject.Named;
 
 import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.Lists;
 import com.google.common.primitives.Ints;
 import org.apache.iceberg.*;
 import org.apache.iceberg.data.GenericRecord;
@@ -63,11 +63,10 @@ public void initialize() {
     icebergTableAppend.initialize();
   }
 
-  private DeleteFile getDeleteFile(Table icebergTable, ArrayList<Record> icebergRecords) {
+  private Optional<DeleteFile> getDeleteFile(Table icebergTable, ArrayList<Record> icebergRecords) {
 
     final String fileName = "del-" + UUID.randomUUID() + "-" + Instant.now().toEpochMilli() + "." + FileFormat.PARQUET;
     OutputFile out = icebergTable.io().newOutputFile(icebergTable.locationProvider().newDataLocation(fileName));
-    Set<Integer> equalityDeleteFieldIds = icebergTable.schema().identifierFieldIds();
 
     EqualityDeleteWriter<Record> deleteWriter;
 
@@ -82,23 +81,18 @@ private DeleteFile getDeleteFile(Table icebergTable, ArrayList<Record> icebergRe
         ).collect(Collectors.toList());
 
     if (deleteRows.size() == 0) {
-      return null;
+      return Optional.empty();
     }
 
     try {
       LOGGER.debug("Writing data to equality delete file: {}!", out);
-
       deleteWriter = Parquet.writeDeletes(out)
           .createWriterFunc(GenericParquetWriter::buildWriter)
           .overwrite()
-          .rowSchema(icebergTable.sortOrder().schema())
-          .withSpec(icebergTable.spec())
-          .equalityFieldIds(Lists.newArrayList(icebergTable.schema().identifierFieldIds()))
-          .metricsConfig(MetricsConfig.fromProperties(icebergTable.properties()))
+          .forTable(icebergTable)
+          .equalityFieldIds(List.copyOf(icebergTable.schema().identifierFieldIds()))
           .withSortOrder(icebergTable.sortOrder())
-          .setAll(icebergTable.properties())
-          .buildEqualityWriter()
-      ;
+          .buildEqualityWriter();
 
       try (Closeable toClose = deleteWriter) {
         deleteWriter.deleteAll(deleteRows);
@@ -111,15 +105,15 @@ private DeleteFile getDeleteFile(Table icebergTable, ArrayList<Record> icebergRe
     LOGGER.debug("Creating iceberg equality delete file!");
     // Equality delete files identify deleted rows in a collection of data files by one or more column values,
     // and may optionally contain additional columns of the deleted row.
-    return FileMetadata.deleteFileBuilder(icebergTable.spec())
+    return Optional.of(FileMetadata.deleteFileBuilder(icebergTable.spec())
         .ofEqualityDeletes(Ints.toArray(icebergTable.schema().identifierFieldIds()))
         .withFormat(FileFormat.PARQUET)
         .withPath(out.location())
         .withFileSizeInBytes(deleteWriter.length())
         .withFileSizeInBytes(deleteWriter.length())
         .withRecordCount(deleteRows.size())
         .withSortOrder(icebergTable.sortOrder())
-        .build();
+        .build());
   }
 
   private ArrayList<Record> toDeduppedIcebergRecords(Schema schema, ArrayList<ChangeEvent<Object, Object>> events) {
@@ -171,16 +165,12 @@ public void addToTable(Table icebergTable, ArrayList<ChangeEvent<Object, Object>
     // DO UPSERT >>> DELETE + INSERT
     ArrayList<Record> icebergRecords = toDeduppedIcebergRecords(icebergTable.schema(), events);
     DataFile dataFile = getDataFile(icebergTable, icebergRecords);
-    DeleteFile deleteDataFile = getDeleteFile(icebergTable, icebergRecords);
-    LOGGER.debug("Committing new file as Upsert (has deletes:{}) '{}' !", deleteDataFile != null, dataFile.path());
+    Optional<DeleteFile> deleteDataFile = getDeleteFile(icebergTable, icebergRecords);
+    LOGGER.debug("Committing new file as Upsert (has deletes:{}) '{}' !", deleteDataFile.isPresent(), dataFile.path());
     RowDelta c = icebergTable
         .newRowDelta()
         .addRows(dataFile);
-
-    if (deleteDataFile != null) {
-      c.addDeletes(deleteDataFile)
-          .validateDeletedFiles();
-    }
+    deleteDataFile.ifPresent(deleteFile -> c.addDeletes(deleteFile).validateDeletedFiles());
 
     c.commit();
     LOGGER.info("Committed {} events to table! {}", events.size(), icebergTable.location());