Data extractors are modules that are integrated within a scanner. They drive the required information from the scanned blocks and store them in their own database. The observation extractor is designed to fulfill a watcher's main task: observing user payments in source networks. The bridge payment transaction has its own structure, and the observation extractor searches for this pattern occurrence in source chains and stores all needed information for a watcher commitment creation and revealment.
This module is used within the Scanner project. The address scanner is currently used in the Watcher service to drive the valid source chain observations.
This project is written in node-js using Esnext module and typeorm database. Extractors are not standalone projects and should be used as scanner modules. You can easily install it using npm with the command:
npm install @rosen-bridge/observation-extractorAlternatively, you can build and use it manually by cloning the project and running:
npm install
npm run buildIn the first step, you need to create a scanner instance; follow the steps here to create a running instance of the scanner. Then you need to instantiate your address extractor and register it to your scanner:
const ergoObsesrvationExtractor = new ErgoObservationExtractor(
dataSource,
<tokens.json>,
<lock_address>
)
ergoScanner.registerExtractor(ergoObsesrvationExtractor)Where the token.json is a source-target map of token ids that are exchanged in the bridge.
Or similarly for cardano:
const cardanoObsesrvationExtractor = new CardanoObservationExtractor(
dataSource,
<tokens.json>,
<lock_address>
)
cardanoScanner.registerExtractor(cardanoObsesrvationExtractor)TBD
TBD