HSTP Daemon

The HSTP Daemon (hstp.d) is the core runtime for a spatial web node. It handles UDG queries and updates, and depends on hsml.d for data storage and validation.

The name 'HSTP.d' stands for "Hyper Space Transaction Protocol Daemon." It follows the naming convention of Unix-like systems, where daemons (background processes) often have names ending in '.d'.

High level overview of hstp.d

hstp.d is a very early implementation of a spatial web node that focuses on allowing early and rapid prototyping of spatial web nodes.

The current implementation of hstp.d provides only a simple binding to HTTP. Specifically: synchronous/blocking request/response calls where the client provides a HSTPOperationRequest and hstp.d responds, in a synchronous/blocking fashion, with a HSTPOperationResponse.

This will soon evolve to support many more call patterns (e.g. MQTT, Kafka) as we clarify the HSTP bindings in the Implementation Specification, but for now this is an implicit limitation in this implementation. Most of these patterns will rely on some form of handshake (likely through HTTP) and delegate (to multiple other protocols/mime types, etc).

There is some early support for using Channels in the context of an Activity execution, using websockets to provide a very simple pubsub providing an example of this "handshake and delegate" pattern but it is still nascent and yet to be documented in gitbook.