fn build()

in core/src/services/azblob/backend.rs [376:472]
83 lines of code
4 McCabe index (conditional complexity)

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

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

        // Handle endpoint, region and container name.
        let container = match self.container.is_empty() {
            false => Ok(&self.container),
            true => Err(Error::new(ErrorKind::ConfigInvalid, "container is empty")
                .with_operation("Builder::build")
                .with_context("service", Scheme::Azblob)),
        }?;
        debug!("backend use container {}", &container);

        let endpoint = match &self.endpoint {
            Some(endpoint) => Ok(endpoint.clone()),
            None => Err(Error::new(ErrorKind::ConfigInvalid, "endpoint is empty")
                .with_operation("Builder::build")
                .with_context("service", Scheme::Azblob)),
        }?;
        debug!("backend use endpoint {}", &container);

        let client = if let Some(client) = self.http_client.take() {
            client
        } else {
            HttpClient::new().map_err(|err| {
                err.with_operation("Builder::build")
                    .with_context("service", Scheme::Azblob)
            })?
        };

        let config_loader = AzureStorageConfig {
            account_name: self
                .account_name
                .clone()
                .or_else(|| infer_storage_name_from_endpoint(endpoint.as_str())),
            account_key: self.account_key.clone(),
            sas_token: self.sas_token.clone(),
            ..Default::default()
        };

        let encryption_key =
            match &self.encryption_key {
                None => None,
                Some(v) => Some(build_header_value(v).map_err(|err| {
                    err.with_context("key", "server_side_encryption_customer_key")
                })?),
            };

        let encryption_key_sha256 = match &self.encryption_key_sha256 {
            None => None,
            Some(v) => Some(build_header_value(v).map_err(|err| {
                err.with_context("key", "server_side_encryption_customer_key_sha256")
            })?),
        };

        let encryption_algorithm = match &self.encryption_algorithm {
            None => None,
            Some(v) => {
                if v == "AES256" {
                    Some(build_header_value(v).map_err(|err| {
                        err.with_context("key", "server_side_encryption_customer_algorithm")
                    })?)
                } else {
                    return Err(Error::new(
                        ErrorKind::ConfigInvalid,
                        "encryption_algorithm value must be AES256",
                    ));
                }
            }
        };

        let cred_loader = AzureStorageLoader::new(config_loader);

        let signer = AzureStorageSigner::new();

        let batch_max_operations = self.batch_max_operations.unwrap_or(AZBLOB_BATCH_LIMIT);

        debug!("backend build finished: {:?}", &self);
        Ok(AzblobBackend {
            core: Arc::new(AzblobCore {
                root,
                endpoint,
                encryption_key,
                encryption_key_sha256,
                encryption_algorithm,
                container: self.container.clone(),

                client,
                loader: cred_loader,
                signer,
                batch_max_operations,
            }),
            has_sas_token: self.sas_token.is_some(),
        })
    }