You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: mod.rs
    path of file: ./repos/zoxide/src/db
    
    the code of the file until where you have to start completion: mod dir;
mod stream;

use std::path::{Path, PathBuf};
use std::{fs
    
    pub fn open_dir(data_dir: impl AsRef<Path>) -> Result<Self> {
        let data_dir = data_dir.as_ref();
        let path = data_dir.join("db.zo");

        match fs::read(&path) {
            Ok(bytes) => Self::try_new(path, bytes, |bytes| Self::deserialize(bytes), false),
            Err(e) if e.kind() == io::ErrorKind::NotFound => {
                // Create data directory, but don't create any file yet. The file will be
                // created later by [`Database::save`] if any data is modified.
                fs::create_dir_all(data_dir).with_context(|| {
                    format!("unable to create data directory: {}", data_dir.display())
                })?;
                Ok(Self::new(path, Vec::new(), |_| Vec::new(), false))
            }
            Err(e) => {
                Err(e).with_context(|| format!("could not read from database: {}", path.display()))
            }
        }
    }