Method read

src/models/wal.rs:265–381

(&self)

    }

    pub fn read(&self) -> Result<Option<VectorOp>, BufIoError> {
        let guard = self.read_lock.lock();

        let cursor_pos = self.bufman.cursor_position(self.cursor)?;
        let file_size = self.bufman.file_size();

        if cursor_pos >= file_size {
            return Ok(None);
        }

        let len_with_tag = self.bufman.read_u32_with_cursor(self.cursor)?;
        let (len, is_delete) = if len_with_tag & (1u32 << 31) != 0 {
            (0x7FFFFFFF & len_with_tag, true)
        } else {
            (len_with_tag, false)
        };
        self.bufman
            .seek_with_cursor(self.cursor, len as u64 + 4 + cursor_pos)?;

        drop(guard);

        let cursor = self.bufman.open_cursor()?;
        self.bufman.seek_with_cursor(cursor, cursor_pos + 4)?;
        let op = if is_delete {
            let id = read_string(&self.bufman, cursor)?;
            VectorOp::Delete(VectorId::from(id))
        } else {
            let len = read_len(&self.bufman, cursor)? as usize;
            let mut vectors = Vec::with_capacity(len);

            for _ in 0..len {
                let id = VectorId::from(read_string(&self.bufman, cursor)?);
                let document_id = read_opt_string(&self.bufman, cursor)?.map(DocumentId::from);
                let dense_values_len = read_len(&self.bufman, cursor)? as usize;
                let dense_values = if dense_values_len == 0 {
                    None
                } else {
                    let mut values = Vec::with_capacity(dense_values_len);
                    for _ in 0..dense_values_len {
                        values.push(self.bufman.read_f32_with_cursor(cursor)?);
                    }
                    Some(values)
                };
                let metadata_len = read_len(&self.bufman, cursor)? as usize;
                let metadata = if metadata_len == 0 {
                    None
                } else {
                    let mut metadata = HashMap::with_capacity(metadata_len);

                    for _ in 0..metadata_len {
                        let field = read_string(&self.bufman, cursor)?;
                        let val = {
                            let variant = self.bufman.read_u8_with_cursor(cursor)?;
                            match variant {
                                0 => FieldValue::Int(self.bufman.read_i32_with_cursor(cursor)?),
                                1 => FieldValue::String(read_string(&self.bufman, cursor)?),
                                other => {
                                    return Err(BufIoError::Io(io::Error::new(