feature: use ITH_GLOBAL_* if available, introduce poc for Simple Cach…

…ing Module

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@itheum/sdk-mx-data-nft",
-  "version": "3.8.0-alpha.2",
+  "version": "3.8.0-alpha.3",
   "description": "SDK for Itheum's Data NFT Technology on MultiversX Blockchain",
   "main": "out/index.js",
   "types": "out/index.d.js",

src/common/utils.ts

@@ -600,3 +600,50 @@ export function checkStatus(response: Response) {
     throw new ErrFetch(response.status, response.statusText);
   }
 }
+
+/* 
+Simple Caching Module helps throttle frequently used calls to RPC that fetch data
+this helps speed up the client side app and also reduces calls to the RPC
+we allow consumer to set a custom TTL in MS for how long data is stored in cache
+*/
+const sessionCache: Record<any, any> = {};
+
+export function getDataFromClientSessionCache(cacheKey: string) {
+  const cacheObject = sessionCache[cacheKey];
+
+  if (!cacheObject) {
+    console.log('getDataFromClientSessionCache: not found');
+    return false;
+  } else {
+    // did it expire? is so, delete it from the cache
+    if (cacheObject.addedOn - Date.now() > cacheObject.expireAfter) {
+      console.log('getDataFromClientSessionCache: expired');
+      delete sessionCache[cacheKey]; // remove it from cache as its expired
+      return false;
+    } else {
+      console.log('getDataFromClientSessionCache: available');
+      return cacheObject.payload;
+    }
+  }
+}
+
+export function setDataToClientSessionCache(
+  cacheKey: string,
+  jsonData: any,
+  ttlInMs?: number
+) {
+  const howManyMsToCacheFor = ttlInMs || 120000; // 120000 is 2 min default TTL
+
+  sessionCache[cacheKey] = {
+    payload: jsonData,
+    addedOn: Date.now(),
+    expireAfter: howManyMsToCacheFor
+  };
+
+  console.log(
+    'setDataToClientSessionCache: cached for ms ',
+    howManyMsToCacheFor
+  );
+
+  return true;
+}

src/config.ts

@@ -1,3 +1,12 @@
+/*
+Host apps like the data dex or explorer, when the MVX dappProvider in initialized (very early in the page)
+it calls a utility method that loads the best RPC to use in the ITH_GLOBAL_MVX_RPC_API_SESSION global variable
+so we aim to use that if available so this SDK uses the same RPC as the host to talk to the MVX chain
+*/
+declare const window: {
+  ITH_GLOBAL_MVX_RPC_API_SESSION: string;
+} & Window;
+
 export enum EnvironmentsEnum {
   devnet = 'devnet',
   testnet = 'testnet',
@@ -9,19 +18,31 @@ export interface Config {
   networkProvider: string;
 }
 
+// note that in all rpc check methods below we check if window === 'undefined' as this is need for tests to pass
 const devnetNetworkConfig: Config = {
   chainID: 'D',
-  networkProvider: 'https://devnet-api.multiversx.com'
+  networkProvider:
+    typeof window === 'undefined'
+      ? 'https://devnet-api.multiversx.com'
+      : window.ITH_GLOBAL_MVX_RPC_API_SESSION ||
+        'https://devnet-api.multiversx.com'
 };
 
 const mainnetNetworkConfig: Config = {
   chainID: '1',
-  networkProvider: 'https://api.multiversx.com'
+  networkProvider:
+    typeof window === 'undefined'
+      ? 'https://api.multiversx.com'
+      : window.ITH_GLOBAL_MVX_RPC_API_SESSION || 'https://api.multiversx.com'
 };
 
 const testnetNetworkConfig: Config = {
   chainID: 'T',
-  networkProvider: 'https://testnet-api.multiversx.com'
+  networkProvider:
+    typeof window === 'undefined'
+      ? 'https://testnet-api.multiversx.com'
+      : window.ITH_GLOBAL_MVX_RPC_API_SESSION ||
+        'https://testnet-api.multiversx.com'
 };
 
 export const itheumTokenIdentifier: { [key in EnvironmentsEnum]: string } = {
@@ -64,9 +85,20 @@ export const livelinessStakeContractAddress: {
 };
 
 export const apiConfiguration: { [key in EnvironmentsEnum]: string } = {
-  devnet: 'https://devnet-api.multiversx.com',
-  mainnet: 'https://api.multiversx.com',
-  testnet: 'https://testnet-api.multiversx.com'
+  devnet:
+    typeof window === 'undefined'
+      ? 'https://devnet-api.multiversx.com'
+      : window.ITH_GLOBAL_MVX_RPC_API_SESSION ||
+        'https://devnet-api.multiversx.com',
+  mainnet:
+    typeof window === 'undefined'
+      ? 'https://api.multiversx.com'
+      : window.ITH_GLOBAL_MVX_RPC_API_SESSION || 'https://api.multiversx.com',
+  testnet:
+    typeof window === 'undefined'
+      ? 'https://testnet-api.multiversx.com'
+      : window.ITH_GLOBAL_MVX_RPC_API_SESSION ||
+        'https://testnet-api.multiversx.com'
 };
 
 export const networkConfiguration: { [key in EnvironmentsEnum]: Config } = {

src/datanft.ts

@@ -10,7 +10,9 @@ import {
   numberToPaddedHex,
   overrideMarshalUrl,
   parseDataNft,
-  validateSpecificParamsViewData
+  validateSpecificParamsViewData,
+  getDataFromClientSessionCache,
+  setDataToClientSessionCache
 } from './common/utils';
 import {
   Config,
@@ -163,15 +165,32 @@ export class DataNft implements DataNftType {
     if (identifiers.length > MAX_ITEMS) {
       throw new ErrTooManyItems();
     }
-    const response = await fetch(
-      `${this.apiConfiguration}/nfts?identifiers=${identifiers.join(
-        ','
-      )}&withSupply=true&size=${identifiers.length}`
-    );
 
-    checkStatus(response);
+    // lets not make the call if not needed
+    if (identifiers.length === 0) {
+      return [];
+    }
+
+    const fetchUrl = `${
+      this.apiConfiguration
+    }/nfts?identifiers=${identifiers.join(',')}&withSupply=true&size=${
+      identifiers.length
+    }`;
+
+    // check if its in session cache
+    let jsonDataPayload = null;
+    const getFromSessionCache = getDataFromClientSessionCache(fetchUrl);
+
+    if (!getFromSessionCache) {
+      const response = await fetch(fetchUrl);
+      checkStatus(response);
+      jsonDataPayload = await response.json();
+      setDataToClientSessionCache(fetchUrl, jsonDataPayload, 5 * 60 * 1000);
+    } else {
+      jsonDataPayload = getFromSessionCache;
+    }
 
-    const data: NftType[] = await response.json();
+    const data: NftType[] = jsonDataPayload;
 
     try {
       const dataNfts = data.map((value) => parseDataNft(value));

tests/environment.test.ts

@@ -1,3 +1,7 @@
+declare const window: {
+  ITH_GLOBAL_MVX_RPC_API_SESSION: string;
+} & Window;
+
 import { ApiNetworkProvider } from '@multiversx/sdk-core/out';
 import { DataNftMarket, SftMinter } from '../src/index';