60 lines
1.7 KiB
TypeScript
60 lines
1.7 KiB
TypeScript
/**
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* Pricecaster Service.
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*
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* Fetcher backend component.
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*
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* (c) 2021 Randlabs, Inc.
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*/
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import { IPriceFetcher } from './IPriceFetcher'
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import { IStrategy } from '../strategy/strategy'
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import { getPythProgramKeyForCluster, PriceData, Product, PythConnection } from '@pythnetwork/client'
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import { Cluster, clusterApiUrl, Connection } from '@solana/web3.js'
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import { PriceTicker } from '../common/priceTicker'
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export class PythPriceFetcher implements IPriceFetcher {
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private strategy: IStrategy
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private symbol: string
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private pythConnection: PythConnection
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constructor (symbol: string, strategy: IStrategy, solanaClusterName: string) {
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const SOLANA_CLUSTER_NAME: Cluster = solanaClusterName as Cluster
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const connection = new Connection(clusterApiUrl(SOLANA_CLUSTER_NAME))
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const pythPublicKey = getPythProgramKeyForCluster(SOLANA_CLUSTER_NAME)
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this.pythConnection = new PythConnection(connection, pythPublicKey)
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this.strategy = strategy
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this.symbol = symbol
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}
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async start () {
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await this.pythConnection.start()
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this.pythConnection.onPriceChange((product: Product, price: PriceData) => {
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if (product.symbol === this.symbol) {
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this.onPriceChange(price)
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}
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})
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}
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stop (): void {
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this.pythConnection.stop()
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}
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setStrategy (s: IStrategy) {
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this.strategy = s
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}
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hasData (): boolean {
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return this.strategy.bufferCount() > 0
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}
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queryTicker (): PriceTicker | undefined {
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return this.strategy.getPrice()
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}
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private onPriceChange (price: PriceData) {
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const pt: PriceTicker = new PriceTicker(price.priceComponent,
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price.confidenceComponent, price.exponent, price.publishSlot)
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this.strategy.put(pt)
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}
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}
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