feat: ios pre-populated scorer download

Author: Jasonvdb

lib/ios/Ldk.m

@@ -13,7 +13,6 @@ @interface RCT_EXTERN_MODULE(Ldk, NSObject)
 RCT_EXTERN_METHOD(writeToLogFile:(NSString *)line
                   resolve:(RCTPromiseResolveBlock)resolve
                   reject:(RCTPromiseRejectBlock)reject)
-
 RCT_EXTERN_METHOD(initChainMonitor:(RCTPromiseResolveBlock)resolve
                   reject:(RCTPromiseRejectBlock)reject)
 RCT_EXTERN_METHOD(initKeysManager:(NSString *)seed
@@ -22,8 +21,13 @@ @interface RCT_EXTERN_MODULE(Ldk, NSObject)
 RCT_EXTERN_METHOD(initUserConfig:(NSDictionary *)userConfig
                   resolve:(RCTPromiseResolveBlock)resolve
                   reject:(RCTPromiseRejectBlock)reject)
+RCT_EXTERN_METHOD(downloadScorer:(NSString *)scorerSyncUrl
+                  skipHoursThreshold:(NSInteger *)skipHoursThreshold
+                  resolve:(RCTPromiseResolveBlock)resolve
+                  reject:(RCTPromiseRejectBlock)reject)
 RCT_EXTERN_METHOD(initNetworkGraph:(NSString *)network
                   rapidGossipSyncUrl:(NSString *)rapidGossipSyncUrl
+                  skipHoursThreshold:(NSInteger *)skipHoursThreshold
                   resolve:(RCTPromiseResolveBlock)resolve
                   reject:(RCTPromiseRejectBlock)reject)
 RCT_EXTERN_METHOD(initChannelManager:(NSString *)network

lib/ios/Ldk.swift

@@ -73,6 +73,7 @@ enum LdkErrors: String {
     case backup_restore_failed = "backup_restore_failed"
     case backup_restore_failed_existing_files = "backup_restore_failed_existing_files"
     case backup_list_files_failed = "backup_list_files_failed"
+    case scorer_download_fail = "scorer_download_fail"
 }
 
 enum LdkCallbackResponses: String {
@@ -101,6 +102,8 @@ enum LdkCallbackResponses: String {
     case backup_client_setup_success = "backup_client_setup_success"
     case backup_restore_success = "backup_restore_success"
     case backup_client_check_success = "backup_client_check_success"
+    case scorer_download_success = "scorer_download_success"
+    case scorer_download_skip = "scorer_download_skip"
 }
 
 enum LdkFileNames: String {
@@ -228,7 +231,43 @@ class Ldk: NSObject {
     }
 
     @objc
-    func initNetworkGraph(_ network: NSString, rapidGossipSyncUrl: NSString, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) {
+    func downloadScorer(_ scorerSyncUrl: NSString, skipHoursThreshold: NSInteger, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) {
+        guard let accountStoragePath = Ldk.accountStoragePath else {
+            return handleReject(reject, .init_storage_path)
+        }
+        
+        let destinationFile = accountStoragePath.appendingPathComponent(LdkFileNames.scorer.rawValue)
+        
+        //If old one is still recent, skip download. Else delete it.
+        if FileManager().fileExists(atPath: destinationFile.path) {
+            let fileAttributes = try? FileManager().attributesOfItem(atPath: destinationFile.path)
+            if let creationDate = fileAttributes?[.creationDate] as? Date {
+                let currentTime = Date()
+                let timeInterval = currentTime.timeIntervalSince(creationDate)
+                let hoursPassed = timeInterval / 3600
+                
+                if hoursPassed <= Double(skipHoursThreshold) {
+                    return handleResolve(resolve, .scorer_download_skip)
+                }
+            }
+            
+            try? FileManager().removeItem(atPath: destinationFile.path)
+        }
+        
+        let url = URL(string: String(scorerSyncUrl))!
+        let task = url.downloadTask(destination: destinationFile) { error in
+            if let error = error {
+                return handleReject(reject, .scorer_download_fail, error)
+            }
+            
+            handleResolve(resolve, .scorer_download_success)
+        }
+        
+        task?.resume()
+    }
+    
+    @objc
+    func initNetworkGraph(_ network: NSString, rapidGossipSyncUrl: NSString, skipHoursThreshold: NSInteger, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) {
         guard networkGraph == nil else {
             return handleReject(reject, .already_init)
         }
@@ -260,6 +299,7 @@ class Ldk: NSObject {
         }
 
         print("rapidGossipSyncUrl: \(rapidGossipSyncUrl)")
+        print("accountStoragePath: \(accountStoragePath)")
 
         //Download url passed, enable rapid gossip sync
         do {
@@ -274,7 +314,7 @@ class Ldk: NSObject {
             let timestamp = networkGraph?.getLastRapidGossipSyncTimestamp() ?? 0
             let minutesDiffSinceLastRGS = (Calendar.current.dateComponents([.minute], from: Date.init(timeIntervalSince1970: TimeInterval(timestamp)), to: Date()).minute)!
 
-            guard minutesDiffSinceLastRGS > 60 else {
+            guard minutesDiffSinceLastRGS > 60 * skipHoursThreshold else {
                 LdkEventEmitter.shared.send(withEvent: .native_log, body: "Skipping rapid gossip sync. Last updated \(minutesDiffSinceLastRGS/60) hours ago.")
                 return handleResolve(resolve, .network_graph_init_success)
             }
@@ -442,6 +482,11 @@ class Ldk: NSObject {
         currentBlockchainTipHash = blockHash
         currentBlockchainHeight = blockHeight
         addForegroundObserver()
+        
+        print("Scorer:")
+//        Task {
+//            probabilisticScorer.debugLogLiquidityStats()
+//        }
 
         return handleResolve(resolve, .channel_manager_init_success)
     }

lib/src/ldk.ts

@@ -35,6 +35,7 @@ import {
 	TBackupServerDetails,
 	TNodeSignReq,
 	TBackedUpFileList,
+	TDownloadScorer,
 } from './utils/types';
 import { extractPaymentRequest } from './utils/helpers';
 
@@ -97,23 +98,50 @@ class LDK {
 		}
 	}
 
+	/**
+	 * Downloads a pre-populated scorer from remote server to be used on startup.
+	 * Should be called before channel manager is initialized.
+	 * @param scorerDownloadUrl
+	 * @param skipHoursThreshold
+	 */
+	async downloadScorer({
+		scorerDownloadUrl,
+		skipHoursThreshold,
+	}: TDownloadScorer): Promise<Result<string>> {
+		try {
+			const res = await NativeLDK.downloadScorer(
+				scorerDownloadUrl,
+				skipHoursThreshold ?? 3,
+			);
+			this.writeDebugToLog('downloadScorer');
+			return ok(res);
+		} catch (e) {
+			this.writeErrorToLog('downloadScorer', e);
+			return err(e);
+		}
+	}
+
 	/**
 	 * Inits the network graph from previous cache or syncs from scratch.
 	 * By passing in rapidGossipSyncUrl p2p gossip sync will be disabled in favor out rapid gossip sync.
 	 * For local regtest p2p works fine but for mainnet it is better to enable rapid gossip sync.
+	 * Use skipHoursThreshold to avoid unnecessary http calls that check if there is an update.
 	 * https://docs.rs/lightning/latest/lightning/routing/network_graph/struct.NetworkGraph.html
 	 * @param network
 	 * @param rapidGossipSyncUrl
+	 * @param skipHoursThreshold
 	 * @returns {Promise<Err<unknown> | Ok<Ok<string> | Err<string>>>}
 	 */
 	async initNetworkGraph({
 		network,
 		rapidGossipSyncUrl,
+		skipHoursThreshold,
 	}: TInitNetworkGraphReq): Promise<Result<string>> {
 		try {
 			const res = await NativeLDK.initNetworkGraph(
 				network,
 				rapidGossipSyncUrl ?? '',
+				skipHoursThreshold ?? 3, // default to 3 hours as that is the current RGS schedule.
 			);
 			this.writeDebugToLog(
 				'initNetworkGraph',

lib/src/lightning-manager.ts

@@ -290,6 +290,7 @@ class LightningManager {
 		broadcastTransaction,
 		network,
 		rapidGossipSyncUrl = 'https://rapidsync.lightningdevkit.org/snapshot/',
+		scorerDownloadUrl = 'https://rapidsync.lightningdevkit.org/scoring/scorer.bin',
 		forceCloseOnStartup,
 		userConfig = defaultUserConfig,
 		trustedZeroConfPeers = [],
@@ -450,15 +451,59 @@ class LightningManager {
 		// Handled in initChannelManager below
 
 		if (network !== ENetworks.mainnet) {
-			//RGS only currently working for mainnet
+			//RGS and pre-populated scorer only available for mainnet
 			rapidGossipSyncUrl = '';
+			scorerDownloadUrl = '';
 		}
 
-		// Step 11: Optional: Initialize the NetGraphMsgHandler
-		const networkGraphRes = await ldk.initNetworkGraph({
-			network,
-			rapidGossipSyncUrl,
-		});
+		let promises: Promise<Result<string>>[] = [];
+
+		if (scorerDownloadUrl) {
+			promises.push(
+				ldk.downloadScorer({
+					scorerDownloadUrl,
+					skipHoursThreshold: 3,
+				}),
+			);
+		} else {
+			promises.push(Promise.resolve(ok('')));
+		}
+
+		promises.push(
+			ldk.initNetworkGraph({
+				network,
+				rapidGossipSyncUrl,
+				skipHoursThreshold: 3,
+			}),
+		);
+
+		//
+		//
+		//
+		// if (scorerDownloadUrl) {
+		// 	const scorerRes = await ldk.downloadScorer({
+		// 		scorerDownloadUrl,
+		// 		skipHoursThreshold: 3,
+		// 	});
+		// 	if (scorerRes.isErr()) {
+		// 		return this.handleStartError(scorerRes);
+		// 	}
+		// }
+		//
+		// // Step 11: Optional: Initialize the NetGraphMsgHandler
+		// const networkGraphRes = await ldk.initNetworkGraph({
+		// 	network,
+		// 	rapidGossipSyncUrl,
+		// 	skipHoursThreshold: 3,
+		// });
+		// if (networkGraphRes.isErr()) {
+		// 	return this.handleStartError(networkGraphRes);
+		// }
+
+		const [scorerRes, networkGraphRes] = await Promise.all(promises);
+		if (scorerRes.isErr()) {
+			return this.handleStartError(scorerRes);
+		}
 		if (networkGraphRes.isErr()) {
 			return this.handleStartError(networkGraphRes);
 		}

lib/src/utils/types.ts

@@ -310,9 +310,15 @@ export type TInitChannelManagerReq = {
 	};
 };
 
+export type TDownloadScorer = {
+	scorerDownloadUrl: string;
+	skipHoursThreshold?: number;
+};
+
 export type TInitNetworkGraphReq = {
 	network: ENetworks;
 	rapidGossipSyncUrl?: string;
+	skipHoursThreshold?: number;
 };
 
 export type TChannelHandshakeConfig = {
@@ -553,6 +559,7 @@ export type TLdkStart = {
 	broadcastTransaction: TBroadcastTransaction;
 	network: ENetworks;
 	rapidGossipSyncUrl?: string;
+	scorerDownloadUrl?: string;
 	forceCloseOnStartup?: TForceCloseOnStartup;
 	userConfig?: TUserConfig;
 	trustedZeroConfPeers?: string[];