fix: block backlinks

src/segment/block/header.rs

@@ -46,7 +46,7 @@ impl Serializable for Header {
         // Write CRC
         writer.write_u32::<BigEndian>(self.crc)?;
 
-        // Write CRC
+        // Write prev offset
         writer.write_u64::<BigEndian>(self.previous_block_offset)?;
 
         // Write data length
@@ -74,7 +74,7 @@ impl Deserializable for Header {
         // Read CRC
         let crc = reader.read_u32::<BigEndian>()?;
 
-        // Read prev
+        // Read prev offset
         let previous_block_offset = reader.read_u64::<BigEndian>()?;
 
         // Read data length

src/segment/block_index/writer.rs

@@ -21,6 +21,9 @@ fn pipe_file_into_writer<P: AsRef<Path>, W: Write>(src_path: P, sink: &mut W) ->
 pub struct Writer {
     pub index_block_tmp_file_path: PathBuf,
     file_pos: u64,
+
+    prev_pos: (u64, u64),
+
     block_writer: Option<BufWriter<File>>,
     block_size: u32,
     block_counter: u32,
@@ -42,6 +45,7 @@ impl Writer {
         Ok(Self {
             index_block_tmp_file_path,
             file_pos: 0,
+            prev_pos: (0, 0),
             block_writer: Some(block_writer),
             block_counter: 0,
             block_size,
@@ -54,12 +58,12 @@ impl Writer {
         let mut block_writer = self.block_writer.as_mut().expect("should exist");
 
         // Write to file
-        let (header, data) = IndexBlock::to_bytes_compressed(&self.block_handles, self.file_pos)?;
+        let (header, data) = IndexBlock::to_bytes_compressed(&self.block_handles, self.prev_pos.0)?;
 
         header.serialize(&mut block_writer)?;
         block_writer.write_all(&data)?;
 
-        let bytes_written = BlockHeader::serialized_len() + data.len();
+        let bytes_written = (BlockHeader::serialized_len() + data.len()) as u64;
 
         // Expect is fine, because the chunk is not empty
         let last = self
@@ -75,7 +79,10 @@ impl Writer {
         self.tli_pointers.push(index_block_handle);
 
         self.block_counter = 0;
-        self.file_pos += bytes_written as u64;
+        self.file_pos += bytes_written;
+
+        self.prev_pos.0 = self.prev_pos.1;
+        self.prev_pos.1 += bytes_written;
 
         self.block_handles.clear();
 

src/segment/trailer.rs

@@ -16,8 +16,11 @@ pub const TRAILER_SIZE: usize = 256;
 #[derive(Debug)]
 #[allow(clippy::module_name_repetitions)]
 pub struct SegmentFileTrailer {
-    pub(crate) metadata: Metadata,
-    pub(crate) offsets: FileOffsets,
+    #[doc(hidden)]
+    pub metadata: Metadata,
+
+    #[doc(hidden)]
+    pub offsets: FileOffsets,
 }
 
 impl SegmentFileTrailer {
@@ -79,7 +82,11 @@ impl Serializable for SegmentFileTrailer {
 
         v.write_all(TRAILER_MAGIC)?;
 
-        debug_assert_eq!(v.len(), TRAILER_SIZE);
+        assert_eq!(
+            v.len(),
+            TRAILER_SIZE,
+            "segment file trailer has invalid size"
+        );
 
         writer.write_all(&v)?;
 

src/segment/writer.rs

@@ -34,6 +34,8 @@ pub struct Writer {
     pub item_count: usize,
     pub file_pos: u64,
 
+    prev_pos: (u64, u64),
+
     /// Only takes user data into account
     pub uncompressed_size: u64,
 
@@ -68,13 +70,11 @@ pub struct Options {
 
 #[derive(Debug)]
 pub struct FileOffsets {
-    pub(crate) index_block_ptr: u64,
-    pub(crate) tli_ptr: u64,
-    pub(crate) bloom_ptr: u64,
-    pub(crate) range_tombstone_ptr: u64,
-
-    #[allow(unused)]
-    pub(crate) metadata_ptr: u64,
+    pub index_block_ptr: u64,
+    pub tli_ptr: u64,
+    pub bloom_ptr: u64,
+    pub range_tombstone_ptr: u64,
+    pub metadata_ptr: u64,
 }
 
 impl Writer {
@@ -101,6 +101,9 @@ impl Writer {
             block_count: 0,
             item_count: 0,
             file_pos: 0,
+
+            prev_pos: (0, 0),
+
             uncompressed_size: 0,
 
             first_key: None,
@@ -134,7 +137,7 @@ impl Writer {
         self.uncompressed_size += uncompressed_chunk_size;
 
         // Write to file
-        let (header, data) = ValueBlock::to_bytes_compressed(&self.chunk, self.file_pos)?;
+        let (header, data) = ValueBlock::to_bytes_compressed(&self.chunk, self.prev_pos.0)?;
 
         header.serialize(&mut self.block_writer)?;
         self.block_writer.write_all(&data)?;
@@ -152,6 +155,9 @@ impl Writer {
         self.item_count += self.chunk.len();
         self.block_count += 1;
 
+        self.prev_pos.0 = self.prev_pos.1;
+        self.prev_pos.1 += bytes_written;
+
         self.chunk.clear();
 
         Ok(())