Struct HostBridge 

pub struct HostBridge { /* private fields */ }

Host-side services handed to a function for one invocation.

Constructed on the async side (capturing a runtime [Handle]) and moved into the blocking worker; its HostApi::query blocks on the async database via that handle, which is safe because functions run outside any async context. HostApi::send_email and HostApi::cache work the same way.

Implementations

impl HostBridge

pub fn new( db: Db, handle: Handle, config_json: String, principal_id: String, ) -> Self

pub fn with_services( self, mailer: Option<Mailer>, cache: Option<Cache>, payments: Option<Payments>, ai: Option<Ai>, ) -> Self

Lend the function the app’s email provider, cache, payments and AI assistant.

All four are optional and each stays None when the app configured none, which is what makes send_email, cache, payments and ai fail with “not configured” rather than silently doing nothing.

pub fn with_queue(self, queue: Queue) -> Self

Lend the function the app’s queue, so it can publish.

pub fn streaming(self, chunks: UnboundedSender<String>) -> Self

Stream this invocation: everything the function emits goes to chunks as it is produced, rather than nowhere.

pub fn with_hook(self, hook_json: String) -> Self

Mark this invocation as a resource lifecycle hook and attach its context.

Trait Implementations

impl HostApi for HostBridge

fn query(&self, request: RStr<'_>) -> RResult<RString, RString>

Run a query. request is a JSON object of the form { "sql": "...", "params": [ ... ] } and the reply is a JSON array of row objects (for SELECT) or { "rows_affected": n }.

fn send_email(&self, request: RStr<'_>) -> RResult<RString, RString>

Send an email through whichever provider the app configured.

fn cache(&self, request: RStr<'_>) -> RResult<RString, RString>

Run one cache operation against the app’s Redis, if it configured one.

fn payments(&self, request: RStr<'_>) -> RResult<RString, RString>

Run one payment operation against the app’s provider, if it configured one.

fn ai(&self, request: RStr<'_>) -> RResult<RString, RString>

Ask the app’s AI assistant something, if it configured one.

fn publish(&self, request: RStr<'_>) -> RResult<RString, RString>

Queue a message for whichever functions subscribe to a topic, to be handled after this invocation returns.

fn emit(&self, chunk: RStr<'_>) -> bool

Push a chunk of the response to the caller before this invocation returns.

fn log(&self, level: LogLevel, message: RStr<'_>)

Emit a structured log line through the host’s tracing subscriber.

fn config(&self) -> RString

The function’s resolved configuration as a JSON object (merged defaults + per-deployment overrides from the app’s functions/<name>.toml).

fn principal_id(&self) -> RString

Id of the authenticated principal calling this function, or empty when the endpoint is Visibility::Public and the caller is anonymous.

fn hook(&self) -> RString

Lifecycle-hook context as a JSON object when this invocation is a resource hook, or empty when the function was called over HTTP.