fn build()

in core/src/services/b2/backend.rs [143:258]
88 lines of code
5 McCabe index (conditional complexity)

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

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

        // Handle bucket.
        if self.config.bucket.is_empty() {
            return Err(Error::new(ErrorKind::ConfigInvalid, "bucket is empty")
                .with_operation("Builder::build")
                .with_context("service", Scheme::B2));
        }

        debug!("backend use bucket {}", &self.config.bucket);

        // Handle bucket_id.
        if self.config.bucket_id.is_empty() {
            return Err(Error::new(ErrorKind::ConfigInvalid, "bucket_id is empty")
                .with_operation("Builder::build")
                .with_context("service", Scheme::B2));
        }

        debug!("backend bucket_id {}", &self.config.bucket_id);

        let application_key_id = match &self.config.application_key_id {
            Some(application_key_id) => Ok(application_key_id.clone()),
            None => Err(
                Error::new(ErrorKind::ConfigInvalid, "application_key_id is empty")
                    .with_operation("Builder::build")
                    .with_context("service", Scheme::B2),
            ),
        }?;

        let application_key = match &self.config.application_key {
            Some(key_id) => Ok(key_id.clone()),
            None => Err(
                Error::new(ErrorKind::ConfigInvalid, "application_key is empty")
                    .with_operation("Builder::build")
                    .with_context("service", Scheme::B2),
            ),
        }?;

        let signer = B2Signer {
            application_key_id,
            application_key,
            ..Default::default()
        };

        Ok(B2Backend {
            core: Arc::new(B2Core {
                info: {
                    let am = AccessorInfo::default();
                    am.set_scheme(Scheme::B2)
                        .set_root(&root)
                        .set_native_capability(Capability {
                            stat: true,
                            stat_has_content_length: true,
                            stat_has_content_md5: true,
                            stat_has_content_type: true,

                            read: true,

                            write: true,
                            write_can_empty: true,
                            write_can_multi: true,
                            write_with_content_type: true,
                            // The min multipart size of b2 is 5 MiB.
                            //
                            // ref: <https://www.backblaze.com/docs/cloud-storage-large-files>
                            write_multi_min_size: Some(5 * 1024 * 1024),
                            // The max multipart size of b2 is 5 Gb.
                            //
                            // ref: <https://www.backblaze.com/docs/cloud-storage-large-files>
                            write_multi_max_size: if cfg!(target_pointer_width = "64") {
                                Some(5 * 1024 * 1024 * 1024)
                            } else {
                                Some(usize::MAX)
                            },

                            delete: true,
                            copy: true,

                            list: true,
                            list_with_limit: true,
                            list_with_start_after: true,
                            list_with_recursive: true,
                            list_has_content_length: true,
                            list_has_content_md5: true,
                            list_has_content_type: true,

                            presign: true,
                            presign_read: true,
                            presign_write: true,
                            presign_stat: true,

                            shared: true,

                            ..Default::default()
                        });

                    // allow deprecated api here for compatibility
                    #[allow(deprecated)]
                    if let Some(client) = self.http_client {
                        am.update_http_client(|_| client);
                    }

                    am.into()
                },
                signer: Arc::new(RwLock::new(signer)),
                root,

                bucket: self.config.bucket.clone(),
                bucket_id: self.config.bucket_id.clone(),
            }),
        })
    }