fn build()

in core/src/services/hdfs/backend.rs [110:148]

• 31 lines of code
• 5 McCabe index (conditional complexity)

    fn build(&mut self) -> Result<Self::Accessor> {
        debug!("backend build started: {:?}", &self);

        let name_node = match &self.name_node {
            Some(v) => v,
            None => {
                return Err(Error::new(ErrorKind::ConfigInvalid, "name node is empty")
                    .with_context("service", Scheme::Hdfs))
            }
        };

        let root = normalize_root(&self.root.take().unwrap_or_default());
        debug!("backend use root {}", root);

        let mut builder = hdrs::ClientBuilder::new(name_node);
        if let Some(ticket_cache_path) = &self.kerberos_ticket_cache_path {
            builder = builder.with_kerberos_ticket_cache_path(ticket_cache_path.as_str());
        }
        if let Some(user) = &self.user {
            builder = builder.with_user(user.as_str());
        }

        let client = builder.connect().map_err(parse_io_error)?;

        // Create root dir if not exist.
        if let Err(e) = client.metadata(&root) {
            if e.kind() == io::ErrorKind::NotFound {
                debug!("root {} is not exist, creating now", root);

                client.create_dir(&root).map_err(parse_io_error)?
            }
        }

        debug!("backend build finished: {:?}", &self);
        Ok(HdfsBackend {
            root,
            client: Arc::new(client),
        })
    }