feat: optional hardcoded rates

BoltzExchange · Jan 20, 2019 · 9b3388b · 9b3388b
1 parent a816011
commit 9b3388b
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Showing 4 changed files with 31 additions and 8 deletions.
diff --git a/lib/consts/Database.ts b/lib/consts/Database.ts
@@ -17,6 +17,7 @@ export type SequelizeAttributes<T extends { [key: string]: any }> = {
 export type PairFactory = {
   base: string;
   quote: string;
+  rate?: number;
 };
 
 export type PairAttributes = PairFactory & {

diff --git a/lib/db/models/Pair.ts b/lib/db/models/Pair.ts
@@ -7,6 +7,7 @@ export default (sequelize: Sequelize.Sequelize, dataTypes: Sequelize.DataTypes)
     id: { type: dataTypes.STRING, primaryKey: true },
     base: { type: dataTypes.STRING, allowNull: false },
     quote: { type: dataTypes.STRING, allowNull: false },
+    rate: { type: dataTypes.FLOAT, allowNull: true },
   };
 
   const options: Sequelize.DefineOptions<db.PairInstance> = {

diff --git a/lib/rates/RateProvider.ts b/lib/rates/RateProvider.ts
@@ -23,6 +23,14 @@ class RateProvider {
    */
   public init = async (pairs: PairInstance[]) => {
     pairs.forEach((pair) => {
+      // If a pair has a hardcoded rate the CryptoCompare rate doesn't have to be queried
+      if (pair.rate) {
+        this.logger.debug(`Setting hardcoded rate for pair ${pair.id}: ${pair.rate}`);
+
+        this.rates.set(pair.id, pair.rate);
+        return;
+      }
+
       const baseAssets = this.baseAssetsMap.get(pair.quote);
 
       if (baseAssets) {

diff --git a/lib/service/Service.ts b/lib/service/Service.ts
@@ -13,6 +13,9 @@ import { splitPairId, stringify, generateId, mapToObject } from '../Utils';
 type PairConfig = {
   base: string;
   quote: string;
+
+  // If there is a hardcoded rate the CryptoCompare API will not be queried
+  rate?: number;
 };
 
 type Pair = {
@@ -61,13 +64,23 @@ class Service extends EventEmitter {
 
     type PairArray = PairConfig[] | PairInstance[];
 
+    const isUndefinedOrNull = (value: any) => value === undefined || value === null;
+
     const comparePairArrays = (array: PairArray, compare: PairArray, callback: Function) => {
       array.forEach((pair) => {
         let inCompare = false;
 
-        compare.forEach((comaprePair) => {
-          if (pair.base === comaprePair.base && pair.quote === comaprePair.quote) {
-            inCompare = true;
+        compare.forEach((comparePair) => {
+          if (pair.base === comparePair.base &&
+            pair.quote === comparePair.quote) {
+
+            // If the rate is equal in config and database or not defined in the config
+            // and null in the database the database entry doesn't have to be updated
+            if (pair.rate === comparePair.rate ||
+              (isUndefinedOrNull(pair.rate)) && isUndefinedOrNull(comparePair.rate)) {
+
+              inCompare = true;
+            }
           }
         });
 
@@ -79,16 +92,16 @@ class Service extends EventEmitter {
 
     const promises: Promise<any>[] = [];
 
-    comparePairArrays(pairs, dbPairs, (pair: PairFactory) => {
-      promises.push(this.pairRepository.addPair(pair));
-      this.logger.debug(`Adding pair to database: ${stringify(pair)}`);
-    });
-
     comparePairArrays(dbPairs, pairs, (pair: PairFactory) => {
       promises.push(this.pairRepository.removePair(pair));
       this.logger.debug(`Removing pair from database: ${stringify(pair)}`);
     });
 
+    comparePairArrays(pairs, dbPairs, (pair: PairFactory) => {
+      promises.push(this.pairRepository.addPair(pair));
+      this.logger.debug(`Adding pair to database: ${stringify(pair)}`);
+    });
+
     await Promise.all(promises);
 
     if (promises.length !== 0) {