lib: initial support for InProcess provider

demo/android/src/main/kotlin/im/molly/monero/demo/data/MoneroSdkClient.kt

@@ -8,9 +8,9 @@ import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.Flow
 import okhttp3.OkHttpClient
 import java.io.File
-import java.io.FileInputStream
-import java.io.FileOutputStream
 import java.io.IOException
+import java.io.InputStream
+import java.io.OutputStream
 
 class MoneroSdkClient(private val context: Context) {
 
@@ -86,7 +86,7 @@ class MoneroSdkClient(private val context: Context) {
             throw IOException("Cannot create wallet data directory: ${walletDataDir.path}")
         }
 
-        override suspend fun write(writer: (FileOutputStream) -> Unit) {
+        override suspend fun write(writer: (OutputStream) -> Unit) {
             val output = file.startWrite()
             try {
                 writer(output)
@@ -97,7 +97,7 @@ class MoneroSdkClient(private val context: Context) {
             }
         }
 
-        override suspend fun read(): FileInputStream {
+        override suspend fun read(): InputStream {
             return file.openRead()
         }
     }

lib/android/src/main/aidl/im/molly/monero/IStorageAdapter.aidl

@@ -2,5 +2,5 @@ package im.molly.monero;
 
 interface IStorageAdapter {
     boolean writeAsync(in ParcelFileDescriptor pfd);
-    void readAsync(in ParcelFileDescriptor pfd);
+    oneway void readAsync(in ParcelFileDescriptor pfd);
 }

lib/android/src/main/kotlin/im/molly/monero/Binder.kt

@@ -0,0 +1,10 @@
+package im.molly.monero
+
+import android.os.IInterface
+
+/**
+ * Returns whether this interface is in a remote process.
+ */
+fun IInterface.isRemote(): Boolean {
+    return asBinder() !== this
+}

lib/android/src/main/kotlin/im/molly/monero/StorageAdapter.kt

@@ -17,30 +17,28 @@ internal class StorageAdapter(var dataStore: WalletDataStore?) : IStorageAdapter
     override fun writeAsync(pfd: ParcelFileDescriptor?): Boolean {
         requireNotNull(pfd)
         val localDataStore = dataStore
-        if (localDataStore == null) {
+        return if (localDataStore != null) {
-            pfd.close()
+            val inputStream = ParcelFileDescriptor.AutoCloseInputStream(pfd)
-            return false
+            ioStorageScope.launch {
-        }
+                mutex.withLock {
-        val inputStream = ParcelFileDescriptor.AutoCloseInputStream(pfd)
+                    localDataStore.write { output ->
-        ioStorageScope.launch {
+                        inputStream.copyTo(output)
-            mutex.withLock {
+                    }
-                localDataStore.write { output ->
-                    inputStream.copyTo(output)
                 }
-            }
+            }.invokeOnCompletion { inputStream.close() }
-        }.invokeOnCompletion { inputStream.close() }
+            true
-        return true
+        } else {
+            pfd.close()
+            false
+        }
     }
 
     override fun readAsync(pfd: ParcelFileDescriptor?) {
         requireNotNull(pfd)
-        val localDataStore = dataStore
-        if (localDataStore == null) {
-            pfd.close()
-            throw IllegalArgumentException("WalletDataStore cannot be null")
-        }
         val outputStream = ParcelFileDescriptor.AutoCloseOutputStream(pfd)
         ioStorageScope.launch {
+            val localDataStore =
+                dataStore ?: throw IllegalArgumentException("WalletDataStore cannot be null")
             mutex.withLock {
                 localDataStore.read().use { input ->
                     input.copyTo(outputStream)

lib/android/src/main/kotlin/im/molly/monero/WalletDataStore.kt

@@ -1,9 +1,9 @@
 package im.molly.monero
 
-import java.io.FileInputStream
+import java.io.InputStream
-import java.io.FileOutputStream
+import java.io.OutputStream
 
 interface WalletDataStore {
-    suspend fun write(writer: (FileOutputStream) -> Unit)
+    suspend fun write(writer: (OutputStream) -> Unit)
-    suspend fun read(): FileInputStream
+    suspend fun read(): InputStream
 }

lib/android/src/main/kotlin/im/molly/monero/WalletNative.kt

@@ -11,7 +11,7 @@ import kotlin.coroutines.CoroutineContext
 
 class WalletNative private constructor(
     networkId: Int,
-    private val storageAdapter: IStorageAdapter?,
+    private val storageAdapter: IStorageAdapter,
     private val remoteNodeClient: IRemoteNodeClient?,
     private val scope: CoroutineScope,
     private val ioDispatcher: CoroutineDispatcher,
@@ -21,7 +21,7 @@ class WalletNative private constructor(
         // TODO: Find better name because this is a local synchronization wallet, not a full node wallet
         suspend fun fullNode(
             networkId: Int,
-            storageAdapter: IStorageAdapter? = null,
+            storageAdapter: IStorageAdapter,
             remoteNodeClient: IRemoteNodeClient? = null,
             secretSpendKey: SecretKey? = null,
             restorePoint: Long? = null,
@@ -59,13 +59,17 @@ class WalletNative private constructor(
     private val handle: Long = nativeCreate(networkId)
 
     private suspend fun tryWriteState(): Boolean {
-        requireNotNull(storageAdapter)
         return withContext(ioDispatcher) {
-            val pipe = ParcelFileDescriptor.createReliablePipe()
+            val pipe = ParcelFileDescriptor.createPipe()
-            pipe[1].use { writeSide ->
+            val readFd = pipe[0]
-                val storageIsReady = storageAdapter.writeAsync(pipe[0])
+            val writeFd = pipe[1]
+            val storageIsReady = storageAdapter.writeAsync(readFd)
+            if (storageAdapter.isRemote()) {
+                readFd.close()
+            }
+            writeFd.use {
                 if (storageIsReady) {
-                    val result = nativeSave(handle, writeSide.fd)
+                    val result = nativeSave(handle, it.fd)
                     if (!result) {
                         logger.e("Wallet data serialization failed")
                     }
@@ -79,15 +83,18 @@ class WalletNative private constructor(
     }
 
     private suspend fun readState() {
-        requireNotNull(storageAdapter)
+        withContext(ioDispatcher) {
-        return withContext(ioDispatcher) {
+            val pipe = ParcelFileDescriptor.createPipe()
-            val pipe = ParcelFileDescriptor.createReliablePipe()
+            val readFd = pipe[0]
-            pipe[0].use { readSide ->
+            val writeFd = pipe[1]
-                pipe[1].use { writeSide ->
+            storageAdapter.readAsync(writeFd)
-                    storageAdapter.readAsync(writeSide)
+            if (storageAdapter.isRemote()) {
+                writeFd.close()
+            }
+            readFd.use {
+                if (!nativeLoad(handle, it.fd)) {
+                    throw IllegalStateException("Wallet data deserialization failed")
                 }
-                val result = nativeLoad(handle, readSide.fd)
-                check(result) { "Wallet data deserialization failed" }
             }
         }
     }

lib/android/src/main/kotlin/im/molly/monero/WalletService.kt

@@ -78,6 +78,7 @@ internal class WalletServiceImpl(
         callback: IWalletServiceCallbacks?,
     ) {
         requireNotNull(config)
+        requireNotNull(storage)
         serviceScope.launch {
             val wallet = WalletNative.fullNode(
                 networkId = config.networkId,
@@ -97,6 +98,7 @@ internal class WalletServiceImpl(
         restorePoint: Long? = null,
     ): IWallet {
         requireNotNull(config)
+        requireNotNull(storage)
         requireNotNull(secretSpendKey)
         return WalletNative.fullNode(
             networkId = config.networkId,