Feature/no websocket (#15)

* PythNetworkHTTPClient can use Pyth Network data without a websocket

* export PythNetworkHTTPClient

* new test for PythNetworkHTTPClient

* PythHttpClient refactoring

* New PythHttpClientResult to getData

* productPriceArray renamed to prices

* Removed not used imports

* Direct call to handlePriceAccount

* PythHttpClient refactoring for thread safe procedure

* Property shorthand suggested by lint

* Indentation from 4 to 2 spaces

Author: Admdebian

src/PythHttpClient.ts

@@ -0,0 +1,95 @@
+import { Commitment, Connection, PublicKey } from "@solana/web3.js";
+import { Product, PriceData, parseProductData, parsePriceData, parseBaseData, AccountType } from ".";
+
+export interface PythHttpClientResult {
+  assetTypes: string[];
+  symbols: string[];
+  products: Product[];
+  productFromSymbol: Map<string, Product>;
+  productPrice: Map<string, PriceData>;
+  prices: PriceData[];
+}
+
+/**
+ * Reads Pyth price data from a solana web3 connection. This class uses a single HTTP call.
+ * Use the method getData() to get updated prices values.
+ */
+export class PythHttpClient {
+  connection: Connection;
+  pythProgramKey: PublicKey;
+  commitment: Commitment;
+
+  constructor(connection: Connection, pythProgramKey: PublicKey, commitment: Commitment = 'finalized') {
+    this.connection = connection;
+    this.pythProgramKey = pythProgramKey;
+    this.commitment = commitment;
+  }
+
+  /*
+  * Get Pyth Network account information and return actual price state.
+  * The result contains lists of asset types, product symbols and their prices.
+  */
+  public async getData(): Promise<PythHttpClientResult> {
+    const assetTypes = new Set<string>();
+    const productSymbols = new Set<string>();
+    const products = new Set<Product>()
+    const productFromSymbol = new Map<string, Product>()
+    const productPrice = new Map<string, PriceData>()
+    const prices = new Array<PriceData>();
+
+    // Retrieve data from blockchain
+    const accountList = await this.connection.getProgramAccounts(this.pythProgramKey, this.commitment);
+
+    // Popolate producs and prices
+    const priceDataQueue = new Array<PriceData>();
+    const productAccountKeyToProduct = new Map<string, Product>();
+
+    accountList.forEach(singleAccount => {
+      const base = parseBaseData(singleAccount.account.data);
+      if (base) {
+        switch (AccountType[base.type]) {
+          case 'Mapping':
+            // We can skip these because we're going to get every account owned by this program anyway.
+            break;
+          case 'Product':
+            const productData = parseProductData(singleAccount.account.data)
+
+            productAccountKeyToProduct.set(singleAccount.pubkey.toBase58(), productData.product)
+            assetTypes.add(productData.product.asset_type);
+            productSymbols.add(productData.product.symbol);
+            products.add(productData.product);
+            productFromSymbol.set(productData.product.symbol, productData.product);
+            break;
+          case 'Price':
+            const priceData = parsePriceData(singleAccount.account.data)
+            priceDataQueue.push(priceData)
+            break;
+          case 'Test':
+            break;
+          default:
+            throw new Error(`Unknown account type: ${base.type}. Try upgrading pyth-client.`)
+        }
+      }
+    });
+
+    priceDataQueue.forEach(priceData => {
+      const product = productAccountKeyToProduct.get(priceData.productAccountKey.toBase58())
+
+      if (product) {
+        productPrice.set(product.symbol, priceData);
+        prices.push(priceData);
+      }
+    });
+
+    const result: PythHttpClientResult = {
+      assetTypes: Array.from(assetTypes),
+      symbols: Array.from(productSymbols),
+      products: Array.from(products),
+      productFromSymbol,
+      productPrice,
+      prices
+    };
+
+    return result;
+  }
+}

src/__tests__/PythNetworkRestClient-test.ts

@@ -0,0 +1,38 @@
+import { clusterApiUrl, Connection } from "@solana/web3.js";
+import { getPythProgramKeyForCluster, PythHttpClient } from "..";
+
+test('PythHttpClientCall', done => {
+  jest.setTimeout(20000)
+  try {
+    const programKey = getPythProgramKeyForCluster('testnet');
+    const currentConnection = new Connection(clusterApiUrl('testnet'));
+    const pyth_client = new PythHttpClient(currentConnection, programKey);
+    pyth_client.getData().then(
+      result => {
+        try {
+          console.log("products number: ", result.products.length)
+          console.log("asset types: ", result.assetTypes);
+          console.log("product symbols: ", result.symbols);
+
+          // Find a product with symbol "SOL/USD"
+          const products = result.products.filter(p => p.symbol === "SOL/USD");
+          expect(products.length).toBeGreaterThan(0);
+
+          // Find product prices
+          const price = result.productPrice.get(products[0].symbol);
+          expect(price).toBeDefined();
+
+          console.log("products", products)
+          console.log("price", price)
+
+          done()
+        } catch (cerr) {
+          done(cerr)
+        }
+      },
+      err => done(err)
+    )
+  } catch (err_catch) {
+    done(err_catch);
+  }
+});

src/index.ts

@@ -336,5 +336,6 @@ export const parsePriceData = (data: Buffer): PriceData => {
   }
 }
 
-export { PythConnection } from './PythConnection'
-export { getPythProgramKeyForCluster } from './cluster'
+export { PythConnection } from './PythConnection';
+export { PythHttpClient } from './PythHttpClient';
+export { getPythProgramKeyForCluster } from './cluster';