fix: partitioned filter if no items were written

Author: marvin-j97

src/table/writer/filter/full.rs

@@ -50,7 +50,7 @@ impl<W: std::io::Write + std::io::Seek> FilterWriter<W> for FullFilterWriter {
         file_writer: &mut sfa::Writer<ChecksummedWriter<BufWriter<File>>>,
     ) -> crate::Result<usize> {
         if self.bloom_hash_buffer.is_empty() {
-            log::trace!("Filter write has no buffered hashes - not building filter");
+            log::trace!("Filter writer has no buffered hashes - not building filter");
         } else {
             file_writer.start("filter")?;
 

src/table/writer/filter/partitioned.rs

@@ -170,21 +170,24 @@ impl<W: std::io::Write + std::io::Seek> FilterWriter<W> for PartitionedFilterWri
         mut self: Box<Self>,
         file_writer: &mut sfa::Writer<ChecksummedWriter<BufWriter<File>>>,
     ) -> crate::Result<usize> {
-        if !self.bloom_hash_buffer.is_empty() {
+        if self.bloom_hash_buffer.is_empty() {
+            log::trace!("Filter writer has no buffered hashes - not building filter");
+            Ok(0)
+        } else {
             let last_key = self.last_key.take().expect("last key should exist");
             self.spill_filter_partition(&last_key)?;
-        }
 
-        let index_base_offset = BlockOffset(file_writer.get_mut().stream_position()?);
+            let index_base_offset = BlockOffset(file_writer.get_mut().stream_position()?);
 
-        file_writer.start("filter")?;
-        file_writer.write_all(&self.final_filter_buffer)?;
-        log::trace!("Concatted filter partitions onto blocks file");
+            file_writer.start("filter")?;
+            file_writer.write_all(&self.final_filter_buffer)?;
+            log::trace!("Concatted filter partitions onto blocks file");
 
-        let block_count = self.tli_handles.len();
+            let block_count = self.tli_handles.len();
 
-        self.write_top_level_index(file_writer, index_base_offset)?;
+            self.write_top_level_index(file_writer, index_base_offset)?;
 
-        Ok(block_count)
+            Ok(block_count)
+        }
     }
 }

src/table/writer/mod.rs

@@ -359,9 +359,11 @@ impl Writer {
         }
 
         // Write index
+        log::trace!("Finishing index writer");
         let index_block_count = self.index_writer.finish(&mut self.file_writer)?;
 
         // Write filter
+        log::trace!("Finishing filter writer");
         let filter_block_count = self.filter_writer.finish(&mut self.file_writer)?;
 
         if !self.linked_blob_files.is_empty() {