quickwit-oss/tantivy · error

buffer should be empty

Error message

buffer should be empty

What it means

Fires at the end of ManagedDirectory::open_write. A fresh BufWriter wrapping the underlying writer must have an empty internal buffer; after into_inner() flushes and returns the raw writer, a Some(buffer) means buffered bytes were still pending — i.e. the flush into the inner writer failed silently or the writer was misused. This generic guard catches that corruption path rather than letting a partially written file proceed.

Source

Thrown at src/directory/managed_directory.rs:293

    }

    fn open_read(&self, path: &Path) -> result::Result<FileSlice, OpenReadError> {
        let file_slice = self.directory.open_read(path)?;
        let (footer, reader) = Footer::extract_footer(file_slice)
            .map_err(|io_error| OpenReadError::wrap_io_error(io_error, path.to_path_buf()))?;
        footer.is_compatible()?;
        Ok(reader)
    }

    fn open_write(&self, path: &Path) -> result::Result<WritePtr, OpenWriteError> {
        self.register_file_as_managed(path)
            .map_err(|io_error| OpenWriteError::wrap_io_error(io_error, path.to_path_buf()))?;
        Ok(io::BufWriter::new(Box::new(FooterProxy::new(
            self.directory
                .open_write(path)?
                .into_inner()
                .map_err(|_| ())
                .expect("buffer should be empty"),
        ))))
    }

    fn atomic_write(&self, path: &Path, data: &[u8]) -> io::Result<()> {
        self.register_file_as_managed(path)?;
        self.directory.atomic_write(path, data)
    }

    fn atomic_read(&self, path: &Path) -> result::Result<Vec<u8>, OpenReadError> {
        self.directory.atomic_read(path)
    }

    fn delete(&self, path: &Path) -> result::Result<(), DeleteError> {
        self.directory.delete(path)
    }

    fn exists(&self, path: &Path) -> Result<bool, OpenReadError> {
        self.directory.exists(path)

View on GitHub (pinned to b5d8deb80c)

Solutions

1. Investigate why BufWriter::into_inner returned Err (typically an IO error during the final flush)
2. Ensure the underlying writer (FooterProxy) does not error on flush for this path
3. Surface the flush IO error to callers instead of discarding it with map_err(|_| ())

When it happens

Trigger: Thrown at src/directory/managed_directory.rs:293 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of quickwit-oss/tantivy@b5d8deb80c (2026-09-05). Data as JSON: /api/errors/f1dd7876aa6dba00. Report an issue: GitHub.