Merge pull request #118 from EdgeApp/paul/fixMapSync

Run setupCurrencyCodeMapsSync at startup

Author: paullinator

src/exchangeRateRouter.ts

@@ -1,4 +1,4 @@
-import { mul } from 'biggystring'
+import { div, eq, mul } from 'biggystring'
 import { asArray, asMaybe, asObject, asOptional, asString } from 'cleaners'
 import express from 'express'
 import nano from 'nano'
@@ -7,7 +7,7 @@ import promisify from 'promisify-node'
 
 import { config } from './config'
 import { REDIS_COINRANK_KEY_PREFIX } from './constants'
-import { asReturnGetRate, getExchangeRates } from './rates'
+import { asReturnGetRate, getExchangeRates, PRECISION } from './rates'
 import {
   asCoinrankAssetReq,
   asCoinrankReq,
@@ -293,13 +293,46 @@ const queryExchangeRates: express.RequestHandler = async (
     return next()
   }
 
+  const flippedAssets: { [key: string]: true } = {}
+
+  // To prevent redudant rate requests and storage, sort the assets in alphabetical order
+  // ie. iso:USD_BTC -> BTC_iso:USD. Mark any flipped assets with the flippedAssets flag true
+  // so we can flip them back later.
+  const normalizedRequestedRates = exReq.requestedRates.data.map(req => {
+    const [assetA, assetB] = req.currency_pair.split('_')
+    if (assetA > assetB) {
+      const flippedPair = `${assetB}_${assetA}`
+      flippedAssets[`${flippedPair}_${req.date}`] = true
+      return { ...req, currency_pair: flippedPair }
+    }
+    return req
+  })
+
   try {
     const queriedRates = await getExchangeRates(
-      exReq.requestedRates.data,
+      normalizedRequestedRates,
       dbRates
     )
+    const unflippedRates = queriedRates.data.map(rate => {
+      const key = `${rate.currency_pair}_${rate.date}`
+      if (flippedAssets[key] === true) {
+        delete flippedAssets[key]
+        const [assetA, assetB] = rate.currency_pair.split('_')
+        const unflippedPair = `${assetB}_${assetA}`
+        if (rate.exchangeRate != null) {
+          if (eq(rate.exchangeRate, '0')) {
+            rate.exchangeRate = '0'
+          } else {
+            const unflippedRate = div('1', rate.exchangeRate, PRECISION)
+            rate.exchangeRate = unflippedRate
+          }
+        }
+        return { ...rate, currency_pair: unflippedPair }
+      }
+      return rate
+    })
     exReq.requestedRatesResult = {
-      data: [...(exReq.requestedRatesResult?.data ?? []), ...queriedRates.data],
+      data: [...(exReq.requestedRatesResult?.data ?? []), ...unflippedRates],
       documents: [...queriedRates.documents] // TODO: Change data type since the douch docs aren't needed after this
     }
   } catch (e) {

src/rates.ts

@@ -39,9 +39,7 @@ import {
   checkConstantCode,
   currencyCodeArray,
   fromCode,
-  getNullRateArray,
-  invertPair,
-  isNotANumber,
+  getNullRateArray, isNotANumber,
   logger,
   normalizeDate,
   safeUpperCase,
@@ -115,9 +113,10 @@ const sanitizeNewRates = (
     }
 
     rateMap[pairCodes] = rate
-    rateMap[invertPair(pairCodes)] = eq(rate, '0')
-      ? '0'
-      : div('1', rate, PRECISION)
+    // Save storage by not saving the inverted pair
+    // rateMap[invertPair(pairCodes)] = eq(rate, '0')
+    //   ? '0'
+    //   : div('1', rate, PRECISION)
   }
 
   return rateMap

src/utils/currencyCodeMapsSync.ts

@@ -1,6 +1,8 @@
 import { asArray, asMaybe, asObject, asString } from 'cleaners'
 import { syncedDocument } from 'edge-server-tools'
+import nano from 'nano'
 
+import { config } from '../config'
 import currencyCodeMaps from './currencyCodeMaps.json'
 import { hsetAsync } from './dbUtils'
 import { logger } from './utils'
@@ -24,6 +26,8 @@ const asCurrencyCodeMaps = asMaybe(
   defaultCurrencyCodeMaps
 )
 
+type CurrencyCodeMaps = ReturnType<typeof asCurrencyCodeMaps>
+
 export const syncedCurrencyCodeMaps = syncedDocument(
   'currencyCodeMaps',
   asCurrencyCodeMaps
@@ -37,8 +41,11 @@ export const ratesDbSetup = {
 }
 
 // Set up the sync logic - this will only run in the indexEngines process
+const nanoDb = nano(config.couchUri)
+const dbRates = nanoDb.db.use('db_rates')
+
 export const setupCurrencyCodeMapsSync = (): void => {
-  syncedCurrencyCodeMaps.onChange(currencyCodeMaps => {
+  const onChange = (currencyCodeMaps: CurrencyCodeMaps): void => {
     const timestamp = new Date().toISOString()
     logger(
       `[${timestamp}] SYNC TRIGGERED: Syncing currency code maps with redis cache...`
@@ -78,5 +85,14 @@ export const setupCurrencyCodeMapsSync = (): void => {
       // Fire and forget - don't await in the callback
       updateKey().catch(e => logger('Unhandled error in updateKey', key, e))
     }
-  })
+  }
+
+  syncedCurrencyCodeMaps.onChange(onChange)
+
+  dbRates
+    .get('currencyCodeMaps')
+    .then((maps: unknown) => {
+      onChange(asCurrencyCodeMaps(maps))
+    })
+    .catch(e => logger('currencyCodeMaps sync error', e))
 }