From ffc7fd1be9c922a3ce4f06267558f12eb1819aa1 Mon Sep 17 00:00:00 2001
From: Lukas Korba <lukas.korba@seznam.cz>
Date: Tue, 16 Apr 2024 16:48:20 +0200
Subject: [PATCH] [#1412] Review wipe function and in memory values

- The wipe() is now resetting local in memory values of latestBlocksDataProvider. In some case this could cause a reset of CBP's state machine context sooner than it was supposed to, resulting in corrupted sync.
---
 CHANGELOG.md                                        |  6 ++++++
 .../Block/CompactBlockProcessor.swift               |  2 ++
 .../Providers/LatestBlocksDataProvider.swift        | 10 +++++++++-
 .../GeneratedMocks/AutoMockable.generated.swift     | 13 +++++++++++++
 4 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a04ed1bd..759eba67 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,12 @@ and this library adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 # Unreleased
 
+## Changed
+- The database locking mechanism has been changed to use async/await concurrency approach - the DBActor.
+
+## Fixed
+- Call of wipe() resets local (in memory) values. 
+
 # 2.1.3 - 2024-03-28
 
 ## Fixed
diff --git a/Sources/ZcashLightClientKit/Block/CompactBlockProcessor.swift b/Sources/ZcashLightClientKit/Block/CompactBlockProcessor.swift
index 81f48917..4fc6d056 100644
--- a/Sources/ZcashLightClientKit/Block/CompactBlockProcessor.swift
+++ b/Sources/ZcashLightClientKit/Block/CompactBlockProcessor.swift
@@ -386,6 +386,8 @@ extension CompactBlockProcessor {
 
             try await rewindDownloadBlockAction(to: nil)
 
+            await latestBlocksDataProvider.reset()
+            
             await context.completion(nil)
         } catch {
             await context.completion(error)
diff --git a/Sources/ZcashLightClientKit/Providers/LatestBlocksDataProvider.swift b/Sources/ZcashLightClientKit/Providers/LatestBlocksDataProvider.swift
index d526bf61..3e0ed850 100644
--- a/Sources/ZcashLightClientKit/Providers/LatestBlocksDataProvider.swift
+++ b/Sources/ZcashLightClientKit/Providers/LatestBlocksDataProvider.swift
@@ -12,7 +12,8 @@ protocol LatestBlocksDataProvider {
     var maxScannedHeight: BlockHeight { get async }
     var latestBlockHeight: BlockHeight { get async }
     var walletBirthday: BlockHeight { get async }
-
+    
+    func reset() async
     func updateScannedData() async
     func updateBlockData() async
     func updateWalletBirthday(_ walletBirthday: BlockHeight) async
@@ -36,6 +37,13 @@ actor LatestBlocksDataProviderImpl: LatestBlocksDataProvider {
         self.rustBackend = rustBackend
     }
     
+    func reset() async {
+        fullyScannedHeight = .zero
+        maxScannedHeight = .zero
+        latestBlockHeight = .zero
+        walletBirthday = .zero
+    }
+    
     func updateScannedData() async {
         fullyScannedHeight = (try? await rustBackend.fullyScannedHeight()) ?? walletBirthday
         maxScannedHeight = (try? await rustBackend.maxScannedHeight()) ?? walletBirthday
diff --git a/Tests/TestUtils/Sourcery/GeneratedMocks/AutoMockable.generated.swift b/Tests/TestUtils/Sourcery/GeneratedMocks/AutoMockable.generated.swift
index 77c6fb5e..655c250a 100644
--- a/Tests/TestUtils/Sourcery/GeneratedMocks/AutoMockable.generated.swift
+++ b/Tests/TestUtils/Sourcery/GeneratedMocks/AutoMockable.generated.swift
@@ -671,6 +671,19 @@ class LatestBlocksDataProviderMock: LatestBlocksDataProvider {
     }
     var underlyingWalletBirthday: BlockHeight!
 
+    // MARK: - reset
+
+    var resetCallsCount = 0
+    var resetCalled: Bool {
+        return resetCallsCount > 0
+    }
+    var resetClosure: (() async -> Void)?
+
+    func reset() async {
+        resetCallsCount += 1
+        await resetClosure!()
+    }
+
     // MARK: - updateScannedData
 
     var updateScannedDataCallsCount = 0