Struct AtomicHttpBackend 

pub struct AtomicHttpBackend { /* private fields */ }

HTTP backend that promises CAS — only constructible when the operator confirmed the upstream server honors RFC 7232 preconditions (If-Match / If-None-Match).

Wrapping HttpBackend rather than mutating it keeps the snapshot- transport surface (download/upload/delete) callable on servers that don’t support CAS, while still preventing LeaseStore from binding to a non-CAS HTTP server (the type system rejects it at compile).

Implementations

impl AtomicHttpBackend

pub fn try_new(config: HttpBackendConfig) -> Result<Self, BackendError>

Build a CAS-capable HTTP backend. Returns BackendError::Config when config.conditional_writes is false — operators must explicitly opt in via RED_HTTP_CONDITIONAL_WRITES=true after confirming their server supports preconditions.

pub fn inner(&self) -> &HttpBackend

Trait Implementations

impl AtomicRemoteBackend for AtomicHttpBackend

fn object_version( &self, remote_key: &str, ) -> Result<Option<BackendObjectVersion>, BackendError>

Return the current opaque version token for an object. Ok(None) means the object does not exist.

fn upload_conditional( &self, local_path: &Path, remote_key: &str, condition: ConditionalPut, ) -> Result<BackendObjectVersion, BackendError>

Upload a local file only if the backend-side condition still holds. Returns the new version token on success; BackendError::PreconditionFailed on contention.

fn delete_conditional( &self, remote_key: &str, condition: ConditionalDelete, ) -> Result<(), BackendError>

Delete a remote object only if the backend-side condition still holds. BackendError::PreconditionFailed on contention.

impl RemoteBackend for AtomicHttpBackend

fn name(&self) -> &str

Human-readable name of this backend (e.g., “s3”, “r2”, “turso”, “d1”).

fn download( &self, remote_key: &str, local_path: &Path, ) -> Result<bool, BackendError>

Download a remote object to a local file path. Returns Ok(true) if downloaded, Ok(false) if remote object doesn’t exist.

fn upload( &self, local_path: &Path, remote_key: &str, ) -> Result<(), BackendError>

Upload a local file to remote storage.

fn exists(&self, remote_key: &str) -> Result<bool, BackendError>

Check if a remote object exists.

fn delete(&self, remote_key: &str) -> Result<(), BackendError>

Delete a remote object. Returns Ok(()) even if it didn’t exist.

fn list(&self, prefix: &str) -> Result<Vec<String>, BackendError>

List remote objects matching a prefix.