[#1470] Add APIs to provide clearing of SDK data

- Closes #1470 - Changelog update
Electric-Coin-Company · Apr 30, 2024 · 11a4860 · 11a4860
1 parent 9094e6e
commit 11a4860
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,6 +6,13 @@ and this library adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- `SdkSynchronizer.closeFlow()` is a Flow-providing version of `Synchronizer.close()`. It safely closes the 
+  Synchronizer together with the related components.
+- `WalletCoordinator.deleteSdkDataFlow` is a Flow-providing function that deletes all the persisted data in the SDK 
+  (databases associated with the wallet, all compact blocks, and data derived from those blocks) but preserves the 
+  wallet secrets.
+
 ## [2.1.1] - 2024-04-23
 
 ### Changed

diff --git a/sdk-incubator-lib/src/main/java/cash/z/ecc/android/sdk/WalletCoordinator.kt b/sdk-incubator-lib/src/main/java/cash/z/ecc/android/sdk/WalletCoordinator.kt
@@ -172,6 +172,32 @@ class WalletCoordinator(
         }
     }
 
+    /**
+     * This Flow-providing function deletes all the persisted data in the SDK (databases associated with this wallet,
+     * all compact blocks, and data derived from those blocks) but preserves the wallet secrets. This function
+     * requires secrets available on the device at the time of running.
+     */
+    fun deleteSdkDataFlow(): Flow<Boolean> =
+        callbackFlow {
+            walletScope.launch {
+                val zcashNetwork = persistableWallet.first()?.network
+                if (null != zcashNetwork) {
+                    synchronizerMutex.withLock {
+                        val didDelete =
+                            Synchronizer.erase(
+                                appContext = applicationContext,
+                                network = zcashNetwork
+                            )
+                        Twig.info { "SDK erase result: $didDelete" }
+                        trySend(didDelete)
+                    }
+                }
+            }
+            awaitClose {
+                // Nothing to close here
+            }
+        }
+
     // Allows for extension functions
     companion object
 }
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/SdkSynchronizer.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/SdkSynchronizer.kt
@@ -65,11 +65,13 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.cancel
+import kotlinx.coroutines.channels.awaitClose
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asFlow
 import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.callbackFlow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.map
@@ -298,7 +300,7 @@ class SdkSynchronizer private constructor(
 
         val shutdownJob =
             coroutineScope.launch {
-                Twig.debug { "Stopping synchronizer $synchronizerKey…" }
+                Twig.info { "Stopping synchronizer $synchronizerKey…" }
                 processor.stop()
             }
 
@@ -313,6 +315,35 @@ class SdkSynchronizer private constructor(
         }
     }
 
+    /**
+     * A Flow-providing version of [close] function. This safely closes the Synchronizer together with the related
+     * components.
+     */
+    fun closeFlow(): Flow<Unit> =
+        callbackFlow {
+            val shutdownJob =
+                coroutineScope.launch {
+                    Twig.info { "Stopping synchronizer $synchronizerKey…" }
+                    processor.stop()
+                }
+
+            instances[synchronizerKey] = InstanceState.ShuttingDown(shutdownJob)
+
+            shutdownJob.invokeOnCompletion {
+                coroutineScope.cancel()
+                _status.value = STOPPED
+                Twig.info { "Synchronizer $synchronizerKey stopped" }
+
+                instances.remove(synchronizerKey)
+
+                trySend(Unit)
+            }
+
+            awaitClose {
+                // Nothing to close here
+            }
+        }
+
     override suspend fun getNearestRewindHeight(height: BlockHeight): BlockHeight =
         processor.getNearestRewindHeight(
             height

diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/db/DatabaseCoordinator.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/db/DatabaseCoordinator.kt
@@ -182,6 +182,8 @@ internal class DatabaseCoordinator private constructor(context: Context) {
 
             val cacheDeleted = fsBlockDbRoot(network, alias).deleteRecursivelySuspend()
 
+            Twig.info { "Delete databases result: ${dataDeleted || cacheDeleted}" }
+
             return dataDeleted || cacheDeleted
         }
     }

diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/db/derived/DbDerivedDataRepository.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/db/derived/DbDerivedDataRepository.kt
@@ -64,4 +64,8 @@ internal class DbDerivedDataRepository(
     override suspend fun close() {
         derivedDataDb.close()
     }
+
+    override suspend fun isClosed(): Boolean {
+        return derivedDataDb.isClosed()
+    }
 }
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/db/derived/DerivedDataDb.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/db/derived/DerivedDataDb.kt
@@ -3,13 +3,13 @@ package cash.z.ecc.android.sdk.internal.db.derived
 import android.content.Context
 import androidx.sqlite.db.SupportSQLiteDatabase
 import cash.z.ecc.android.sdk.internal.NoBackupContextWrapper
+import cash.z.ecc.android.sdk.internal.SdkDispatchers
 import cash.z.ecc.android.sdk.internal.Twig
 import cash.z.ecc.android.sdk.internal.TypesafeBackend
 import cash.z.ecc.android.sdk.internal.db.ReadOnlySupportSqliteOpenHelper
 import cash.z.ecc.android.sdk.internal.model.Checkpoint
 import cash.z.ecc.android.sdk.model.BlockHeight
 import cash.z.ecc.android.sdk.model.ZcashNetwork
-import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import java.io.File
 
@@ -25,11 +25,15 @@ internal class DerivedDataDb private constructor(
 
     val txOutputsView = TxOutputsView(zcashNetwork, sqliteDatabase)
 
-    suspend fun close() {
-        withContext(Dispatchers.IO) {
+    suspend fun close() =
+        withContext(SdkDispatchers.DATABASE_IO) {
             sqliteDatabase.close()
         }
-    }
+
+    suspend fun isClosed(): Boolean =
+        withContext(SdkDispatchers.DATABASE_IO) {
+            !sqliteDatabase.isOpen
+        }
 
     companion object {
         // Database migrations are managed by librustzcash.  This is a hard-coded value to ensure that Android's

diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/repository/DerivedDataRepository.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/repository/DerivedDataRepository.kt
@@ -87,4 +87,6 @@ internal interface DerivedDataRepository {
     fun getRecipients(transactionId: FirstClassByteArray): Flow<TransactionRecipient>
 
     suspend fun close()
+
+    suspend fun isClosed(): Boolean
 }