Struct Response

pub struct Response { /* private fields */ }

Response builder. Use Response::new() to start a Response, then build it, then call Response::send() on it to fire.

Implementations

impl Response

pub fn new() -> Self

Start building a new Response. Attempting to send this Response will not succeed until its body has been set with [Response::body() or Response::try_body().

pub fn inherit(self, inherit: bool) -> Self

Set whether this Response will “inherit” the blob of the crate::Request that this process most recently received. Unlike with crate::Requests, the inherit field of a Response only deals with blob attachment, since Responses don’t themselves have to consider Responses or contexts.

Note that if the blob is set for this Response, this flag will not override it.

pub fn body<T>(self, body: T) -> Self

where T: Into<Vec<u8>>,

Set the IPC body (Inter-Process Communication) value for this message. This field is mandatory. An IPC body is simply a vector of bytes. Process developers are responsible for architecting the serialization/derserialization strategy for these bytes, but the simplest and most common strategy is just to use a JSON spec that gets stored in bytes as a UTF-8 string.

If the serialization strategy is complex, it’s best to define it as an impl of TryInto on your IPC body type, then use Response::try_body() instead of this.

pub fn try_body<T, E>(self, body: T) -> Result<Self, E>

where T: TryInto<Vec<u8>, Error = E>, E: Error,

Set the IPC body (Inter-Process Communication) value for this message, using a type that’s got an implementation of TryInto for Vec<u8>. It’s best to define an IPC body type within your app, then implement TryFrom/TryInto for all IPC body serialization/deserialization.

pub fn metadata(self, metadata: &str) -> Self

Set the metadata field for this response. Metadata is simply a String. Metadata should usually be used for middleware and other message-passing situations that require the original IPC body and blob to be preserved. As such, metadata should not always be expected to reach the final destination of this response unless the full chain of behavior is known / controlled by the developer.

pub fn blob(self, blob: LazyLoadBlob) -> Self

Set the blob of this response. A LazyLoadBlob holds bytes and an optional MIME type.

The purpose of having a blob field distinct from the IPC body field is to enable performance optimizations in all sorts of situations. LazyLoadBlobs are only brought across the runtime<>Wasm boundary if the process calls get_blob(), and this saves lots of work in data-intensive pipelines.

LazyLoadBlobs also provide a place for less-structured data, such that an IPC body type can be quickly locked in and upgraded within an app-protocol without breaking changes, while still allowing freedom to adjust the contents and shape of a blob. IPC body formats should be rigorously defined.

pub fn blob_mime(self, mime: &str) -> Self

Set the LazyLoadBlobs MIME type. If a blob has not been set, it will be set here as an empty vector of bytes. If it has been set, the MIME type will be replaced or created.

pub fn blob_bytes<T>(self, bytes: T) -> Self

where T: Into<Vec<u8>>,

Set the LazyLoadBlobs bytes. If a blob has not been set, it will be set here with no MIME type. If it has been set, the bytes will be replaced with these bytes.

pub fn try_blob_bytes<T, E>(self, bytes: T) -> Result<Self, E>

where T: TryInto<Vec<u8>, Error = E>, E: Error,

Set the LazyLoadBlobs bytes with a type that implements TryInto<Vec<u8>> and may or may not successfully be set.

pub fn capabilities(self, capabilities: Vec<Capability>) -> Self

Attach capabilities to this next Response.

pub fn attach_all(self, target: &Address) -> Self

Attach all capabilities we have that were issued by target to the next message.

pub fn send(self) -> Result<(), BuildError>

Attempt to send the Response. This will only fail if the IPC body field of the Response has not yet been set using body() or try_body().

Trait Implementations

impl Default for Response

fn default() -> Self

Returns the “default value” for a type.