Update memo to accept bytes instead of a string.

src/androidTest/java/cash/z/wallet/sdk/jni/RustBackendTest.kt

@@ -37,8 +37,7 @@ class RustBackendTest {
             0,
             "dummykey",
             "ztestsapling1fg82ar8y8whjfd52l0xcq0w3n7nn7cask2scp9rp27njeurr72ychvud57s9tu90fdqgwdt07lg",
-            210_000,
+            210_000
-            ""
         )
     }
 

src/main/java/cash/z/wallet/sdk/entity/Transactions.kt

@@ -75,7 +75,7 @@ data class PendingTransactionEntity(
     override val id: Long = 0,
     override val toAddress: String = "",
     override val value: Long = -1,
-    override val memo: String? = null,
+    override val memo: ByteArray? = byteArrayOf(),
     override val accountIndex: Int,
     override val minedHeight: Int = -1,
     override val expiryHeight: Int = -1,
@@ -88,11 +88,10 @@ data class PendingTransactionEntity(
     override val createTime: Long = System.currentTimeMillis(),
 
     @ColumnInfo(typeAffinity = ColumnInfo.BLOB)
-    override val raw: ByteArray = ByteArray(0),
+    override val raw: ByteArray = byteArrayOf(),
     @ColumnInfo(typeAffinity = ColumnInfo.BLOB)
-    override val rawTransactionId: ByteArray? = null
+    override val rawTransactionId: ByteArray? = byteArrayOf()
 ) : PendingTransaction {
-
     override fun equals(other: Any?): Boolean {
         if (this === other) return true
         if (other !is PendingTransactionEntity) return false
@@ -100,7 +99,10 @@ data class PendingTransactionEntity(
         if (id != other.id) return false
         if (toAddress != other.toAddress) return false
         if (value != other.value) return false
-        if (memo != other.memo) return false
+        if (memo != null) {
+            if (other.memo == null) return false
+            if (!memo.contentEquals(other.memo)) return false
+        } else if (other.memo != null) return false
         if (accountIndex != other.accountIndex) return false
         if (minedHeight != other.minedHeight) return false
         if (expiryHeight != other.expiryHeight) return false
@@ -123,7 +125,7 @@ data class PendingTransactionEntity(
         var result = id.hashCode()
         result = 31 * result + toAddress.hashCode()
         result = 31 * result + value.hashCode()
-        result = 31 * result + (memo?.hashCode() ?: 0)
+        result = 31 * result + (memo?.contentHashCode() ?: 0)
         result = 31 * result + accountIndex
         result = 31 * result + minedHeight
         result = 31 * result + expiryHeight
@@ -137,6 +139,7 @@ data class PendingTransactionEntity(
         result = 31 * result + (rawTransactionId?.contentHashCode() ?: 0)
         return result
     }
+
 }
 
 
@@ -152,7 +155,7 @@ data class PendingTransactionEntity(
 data class ConfirmedTransaction(
     override val id: Long = 0L,
     override val value: Long = 0L,
-    override val memo: ByteArray? = null,
+    override val memo: ByteArray? = ByteArray(0),
     override val noteId: Long = 0L,
     override val blockTimeInSeconds: Long = 0L,
     override val minedHeight: Int = -1,

src/main/java/cash/z/wallet/sdk/jni/RustBackend.kt

@@ -101,14 +101,14 @@ class RustBackend : RustBackendWelding {
         extsk: String,
         to: String,
         value: Long,
-        memo: String
+        memo: ByteArray?
     ): Long = createToAddress(
         dbDataPath,
         account,
         extsk,
         to,
         value,
-        memo,
+        memo ?: ByteArray(0),
         "${paramDestinationDir}/$SPEND_PARAM_FILE_NAME",
         "${paramDestinationDir}/$OUTPUT_PARAM_FILE_NAME"
     )
@@ -216,17 +216,6 @@ class RustBackend : RustBackendWelding {
 
         @JvmStatic private external fun initLogs()
 
-    private external fun createToAddress(
-        dbDataPath: String,
-        account: Int,
-        extsk: String,
-        to: String,
-        value: Long,
-        memo: String,
-        spendParamsPath: String,
-        outputParamsPath: String
-    ): Long
-
         @JvmStatic private external fun deriveExtendedSpendingKeys(seed: ByteArray, numberOfAccounts: Int): Array<String>
 
         @JvmStatic private external fun deriveExtendedFullViewingKeys(seed: ByteArray, numberOfAccounts: Int): Array<String>

src/main/java/cash/z/wallet/sdk/jni/RustBackendWelding.kt

@@ -39,7 +39,7 @@ interface RustBackendWelding {
         extsk: String,
         to: String,
         value: Long,
-        memo: String
+        memo: ByteArray? = byteArrayOf()
     ): Long
 
     fun deriveSpendingKeys(seed: ByteArray, numberOfAccounts: Int = 1): Array<String>

src/main/java/cash/z/wallet/sdk/transaction/PersistentTransactionManager.kt

@@ -64,7 +64,7 @@ class PersistentTransactionManager(
         var tx = PendingTransactionEntity(
             value = zatoshiValue,
             toAddress = toAddress,
-            memo = memo,
+            memo = memo.toByteArray(),
             accountIndex = fromAccountIndex
         )
         try {
@@ -110,7 +110,7 @@ class PersistentTransactionManager(
                 spendingKey,
                 tx.value,
                 tx.toAddress,
-                tx.memo ?: "",
+                tx.memo,
                 tx.accountIndex
             )
             twig("successfully encoded transaction for ${tx.memo}!!")

src/main/java/cash/z/wallet/sdk/transaction/TransactionEncoder.kt

@@ -10,7 +10,7 @@ interface TransactionEncoder {
         spendingKey: String,
         zatoshi: Long,
         toAddress: String,
-        memo: String,
+        memo: ByteArray? = byteArrayOf(),
-        fromAccountIndex: Int
+        fromAccountIndex: Int = 0
     ): EncodedTransaction
 }

src/main/java/cash/z/wallet/sdk/transaction/WalletTransactionEncoder.kt

@@ -27,7 +27,7 @@ class WalletTransactionEncoder(
         spendingKey: String,
         zatoshi: Long,
         toAddress: String,
-        memo: String,
+        memo: ByteArray?,
         fromAccountIndex: Int
     ): EncodedTransaction = withContext(IO) {
         val transactionId = createSpend(spendingKey, zatoshi, toAddress, memo)
@@ -53,7 +53,7 @@ class WalletTransactionEncoder(
         spendingKey: String,
         value: Long,
         toAddress: String,
-        memo: String = "",
+        memo: ByteArray? = byteArrayOf(),
         fromAccountIndex: Int = 0
     ): Long = withContext(IO) {
         twigTask("creating transaction to spend $value zatoshi to" +

src/main/rust/lib.rs

@@ -381,7 +381,7 @@ pub unsafe extern "C" fn Java_cash_z_wallet_sdk_jni_RustBackend_createToAddress(
     extsk: JString<'_>,
     to: JString<'_>,
     value: jlong,
-    memo: JString<'_>,
+    memo: jbyteArray,
     spend_params: JString<'_>,
     output_params: JString<'_>,
 ) -> jlong {
@@ -398,7 +398,7 @@ pub unsafe extern "C" fn Java_cash_z_wallet_sdk_jni_RustBackend_createToAddress(
         if value.is_negative() {
             return Err(format_err!("Amount is negative"));
         }
-        let memo = utils::java_string_to_rust(&env, memo);
+        let memo_bytes = env.convert_byte_array(memo).unwrap();
         let spend_params = utils::java_string_to_rust(&env, spend_params);
         let output_params = utils::java_string_to_rust(&env, output_params);
 
@@ -419,7 +419,7 @@ pub unsafe extern "C" fn Java_cash_z_wallet_sdk_jni_RustBackend_createToAddress(
             }
         };
 
-        let memo = Memo::from_str(&memo);
+        let memo = Memo::from_bytes(&memo_bytes);
 
         let prover = LocalTxProver::new(Path::new(&spend_params), Path::new(&output_params));