Performance boost, and hitting Infura less often by batching RPC JSON calls

AlphaWallet/Tokens/Helpers/CallSmartContractFunction.swift

@@ -4,10 +4,40 @@ import Foundation
 import PromiseKit
 import web3swift
 
+//TODO time to wrap `callSmartContract` with a class
+
 //TODO wrap callSmartContract() and cache into a type
-var smartContractCallsCache = [String: (promise: Promise<[String: Any]>, timestamp: Date)]()
+fileprivate var smartContractCallsCache = [String: (promise: Promise<[String: Any]>, timestamp: Date)]()
+
+fileprivate var web3s = [RPCServer: [TimeInterval: web3]]()
+
+func getCachedWeb3(forServer server: RPCServer, timeout: TimeInterval) throws -> web3 {
+    if let result = web3s[server]?[timeout] {
+        return result
+    } else {
+        guard let webProvider = Web3HttpProvider(server.rpcURL, network: server.web3Network) else {
+            throw Web3Error(description: "Error creating web provider for: \(server.rpcURL) + \(server.web3Network)")
+        }
+        let configuration = webProvider.session.configuration
+        configuration.timeoutIntervalForRequest = timeout
+        configuration.timeoutIntervalForResource = timeout
+        let session = URLSession(configuration: configuration)
+        webProvider.session = session
+
+        let result = web3swift.web3(provider: webProvider)
+        if var timeoutsAndWeb3s = web3s[server] {
+            timeoutsAndWeb3s[timeout] = result
+            web3s[server] = timeoutsAndWeb3s
+        } else {
+            let timeoutsAndWeb3s: [TimeInterval: web3] = [timeout: result]
+            web3s[server] = timeoutsAndWeb3s
+        }
+        return result
+    }
+}
 
 func callSmartContract(withServer server: RPCServer, contract: AlphaWallet.Address, functionName: String, abiString: String, parameters: [AnyObject] = [AnyObject](), timeout: TimeInterval? = nil) -> Promise<[String: Any]> {
+    let timeout: TimeInterval = 60
     //We must include the ABI string in the key because the order of elements in a dictionary when serialized in the string is not ordered. Parameters (which is ordered) should ensure it's the same function
     let cacheKey = "\(contract).\(functionName) \(parameters) \(server.chainID)"
     let ttlForCache: TimeInterval = 10
@@ -29,19 +59,11 @@ func callSmartContract(withServer server: RPCServer, contract: AlphaWallet.Addre
     }
 
     let result: Promise<[String: Any]> = Promise { seal in
-        let contractAddress = EthereumAddress(address: contract)
-        guard let webProvider = Web3HttpProvider(server.rpcURL, network: server.web3Network) else {
-            throw Web3Error(description: "Error creating web provider for: \(server.rpcURL) + \(server.web3Network)")
-        }
-        if let timeout = timeout {
-            let configuration = webProvider.session.configuration
-            configuration.timeoutIntervalForRequest = timeout
-            configuration.timeoutIntervalForResource = timeout
-            let session = URLSession(configuration: configuration)
-            webProvider.session = session
+        guard let web3 = try? getCachedWeb3(forServer: server, timeout: timeout) else {
+            throw Web3Error(description: "Error creating web3 for: \(server.rpcURL) + \(server.web3Network)")
         }
 
-        let web3 = web3swift.web3(provider: webProvider)
+        let contractAddress = EthereumAddress(address: contract)
 
         guard let contractInstance = web3swift.web3.web3contract(web3: web3, abiString: abiString, at: contractAddress, options: web3.options) else {
             throw Web3Error(description: "Error creating web3swift contract instance to call \(functionName)()")
@@ -73,11 +95,10 @@ func getEventLogs(
         let contractAddress = EthereumAddress(address: contract)
         return .value(contractAddress)
     }.then { contractAddress -> Promise<[EventParserResultProtocol]> in
-        guard let webProvider = Web3HttpProvider(server.rpcURL, network: server.web3Network) else {
-            return Promise(error: Web3Error(description: "Error creating web provider for: \(server.rpcURL) + \(server.web3Network)"))
+        guard let web3 = try? getCachedWeb3(forServer: server, timeout: 60) else {
+            throw Web3Error(description: "Error creating web3 for: \(server.rpcURL) + \(server.web3Network)")
         }
 
-        let web3 = web3swift.web3(provider: webProvider)
         guard let contractInstance = web3swift.web3.web3contract(web3: web3, abiString: abiString, at: contractAddress, options: web3.options) else {
             return Promise(error: Web3Error(description: "Error creating web3swift contract instance to call \(eventName)()"))
         }

Podfile

@@ -26,9 +26,7 @@ target 'AlphaWallet' do
   pod 'TrezorCrypto', :git=>'https://github.com/AlphaWallet/trezor-crypto-ios.git', :commit => '50c16ba5527e269bbc838e80aee5bac0fe304cc7'
   pod 'TrustKeystore', :git => 'https://github.com/alpha-wallet/trust-keystore.git', :commit => '37f7eaf9531cb4e33d06129543b3a56972f59d2a'
   pod 'SwiftyJSON'
-  #pod 'web3swift', :git => 'https://github.com/alpha-wallet/web3swift.git', :commit => 'ae74a86c09dbec703e2aaf27217d7fb0722948ed'
-  pod 'web3swift', :git => 'https://github.com/alpha-wallet/web3swift.git', :commit => '7e2b99198acb2243b6a539cb32832a96f67c893d'
- 
+  pod 'web3swift', :git => 'https://github.com/alpha-wallet/web3swift.git', :commit => 'd863662b08f112dee48538a04ab704244e9c7bae'
   pod 'SAMKeychain'
   pod 'PromiseKit/CorePromise'
   pod 'PromiseKit/Alamofire'

Podfile.lock

@@ -118,7 +118,7 @@ DEPENDENCIES:
   - TrezorCrypto (from `https://github.com/AlphaWallet/trezor-crypto-ios.git`, commit `50c16ba5527e269bbc838e80aee5bac0fe304cc7`)
   - TrustKeystore (from `https://github.com/alpha-wallet/trust-keystore.git`, commit `37f7eaf9531cb4e33d06129543b3a56972f59d2a`)
   - TrustWalletCore
-  - web3swift (from `https://github.com/alpha-wallet/web3swift.git`, commit `7e2b99198acb2243b6a539cb32832a96f67c893d`)
+  - web3swift (from `https://github.com/alpha-wallet/web3swift.git`, commit `d863662b08f112dee48538a04ab704244e9c7bae`)
 
 SPEC REPOS:
   https://github.com/CocoaPods/Specs.git:
@@ -181,7 +181,7 @@ EXTERNAL SOURCES:
     :commit: 37f7eaf9531cb4e33d06129543b3a56972f59d2a
     :git: https://github.com/alpha-wallet/trust-keystore.git
   web3swift:
-    :commit: 7e2b99198acb2243b6a539cb32832a96f67c893d
+    :commit: d863662b08f112dee48538a04ab704244e9c7bae
     :git: https://github.com/alpha-wallet/web3swift.git
 
 CHECKOUT OPTIONS:
@@ -210,7 +210,7 @@ CHECKOUT OPTIONS:
     :commit: 37f7eaf9531cb4e33d06129543b3a56972f59d2a
     :git: https://github.com/alpha-wallet/trust-keystore.git
   web3swift:
-    :commit: 7e2b99198acb2243b6a539cb32832a96f67c893d
+    :commit: d863662b08f112dee48538a04ab704244e9c7bae
     :git: https://github.com/alpha-wallet/web3swift.git
 
 SPEC CHECKSUMS:
@@ -256,6 +256,6 @@ SPEC CHECKSUMS:
   TrustWalletCore: dd8c81d5958f1eb737abea1e14675efcc6a104aa
   web3swift: 1597d4997976d21325882db4c523f1dfd5459406
 
-PODFILE CHECKSUM: ec2b391a12a22f8ccec61785b00f8d8eade47186
+PODFILE CHECKSUM: 2099838a6060fe419603c9225cc2d43ec0fd2117
 
 COCOAPODS: 1.8.4