Source payload mapping engine for Drasi.

Transforms arbitrary JSON payloads into graph change events (SourceChange) using Handlebars templates. This crate provides a shared mapping mechanism used by sources that receive arbitrary payloads (HTTP webhooks, Kafka messages, etc.).

Overview

The mapping engine takes:

• A SourceMapping configuration defining how to extract graph elements from payloads
• A serde_json::Value context containing the payload and any source-specific metadata
• A source ID string

And produces SourceChange events (Insert, Update, Delete) that can be dispatched to the Drasi query engine.