Merge pull request #40 from ChainSafe/willem/persistance-api

Persistance API

packages/demo-wallet/package.json

@@ -9,6 +9,7 @@
     "@types/react-dom": "^18.3.0",
     "@webzjs/webz-core": "workspace:^",
     "bootstrap": "^5.3.3",
+    "idb-keyval": "^6.2.1",
     "react": "^18.2.0",
     "react-bootstrap": "^2.10.4",
     "react-dom": "^18.2.0",

packages/demo-wallet/src/App/Actions.tsx

@@ -1,15 +1,35 @@
 import initWasm, { initThreadPool, WebWallet } from "@webzjs/webz-core";
+import { get, set } from 'idb-keyval';
 
 import { State, Action } from "./App";
 import { MAINNET_LIGHTWALLETD_PROXY } from "./Constants";
 
-export async function init(dispatch: React.Dispatch<Action>) {
+export async function init(state: State, dispatch: React.Dispatch<Action>) {
   await initWasm();
   await initThreadPool(10);
+
+  let bytes = await get("wallet");
+  let wallet;
+  if (bytes) {
+    console.info("Saved wallet detected. Restoring wallet from storage");
+    wallet = new WebWallet("main", MAINNET_LIGHTWALLETD_PROXY, 1, bytes);
+  } else {
+    wallet = new WebWallet("main", MAINNET_LIGHTWALLETD_PROXY, 1);
+  }
+
   dispatch({
     type: "set-web-wallet",
-    payload: new WebWallet("main", MAINNET_LIGHTWALLETD_PROXY, 1),
+    payload: wallet,
   });
+  let summary = await wallet.get_wallet_summary();
+  if (summary) {
+    dispatch({ type: "set-summary", payload: summary });
+  }
+  let chainHeight = await wallet.get_latest_block();
+  if (chainHeight) {
+    dispatch({ type: "set-chain-height", payload: chainHeight });
+  }
+  dispatch({ type: "set-active-account", payload: summary?.account_balances[0][0] });
 }
 
 export async function addNewAccount(state: State, dispatch: React.Dispatch<Action>, seedPhrase: string, birthdayHeight: number) {
@@ -45,6 +65,7 @@ export async function triggerRescan(
     }
     await state.webWallet?.sync();
     await syncStateWithWallet(state, dispatch);
+    await flushDbToStore(state, dispatch);
 }
 
 export async function triggerTransfer(
@@ -70,3 +91,16 @@ export async function triggerTransfer(
 
     await state.webWallet.send_authorized_transactions(txids);
 }
+
+export async function flushDbToStore(
+  state: State,
+  dispatch: React.Dispatch<Action>
+) {
+    if (!state.webWallet) {
+        throw new Error("Wallet not initialized");
+    }
+    console.info("Serializing wallet and dumpling to IndexDb store");
+    let bytes = await state.webWallet.db_to_bytes();
+    await set("wallet", bytes);
+    console.info("Wallet saved to storage");
+}

packages/demo-wallet/src/App/App.tsx

@@ -71,7 +71,7 @@ export function App() {
   const [state, dispatch] = useReducer(reducer, initialState);
 
   useEffect(() => {
-    init(dispatch);
+    init(state, dispatch);
   }, [dispatch]);
 
   return (

packages/demo-wallet/src/App/components/Header.tsx

@@ -5,7 +5,7 @@ import Card from "react-bootstrap/Card";
 import Stack from "react-bootstrap/Stack";
 
 import { WalletContext } from "../App";
-import { syncStateWithWallet, triggerRescan } from "../Actions";
+import { syncStateWithWallet, triggerRescan, flushDbToStore } from "../Actions";
 import { Button } from "react-bootstrap";
 
 import { zatsToZec } from "../../utils";

packages/demo-wallet/src/App/components/ImportAccount.tsx

@@ -5,7 +5,7 @@ import Form from "react-bootstrap/Form";
 import { ToastContainer, toast } from "react-toastify";
 
 import { WalletContext } from "../App";
-import { addNewAccount } from "../Actions";
+import { addNewAccount, flushDbToStore } from "../Actions";
 
 export function ImportAccount() {
   let {state, dispatch} = useContext(WalletContext);
@@ -22,6 +22,7 @@ export function ImportAccount() {
     });
     setBirthdayHeight(0);
     setSeedPhrase("");
+    flushDbToStore(state, dispatch)
   };
 
   return (

packages/e2e-tests/e2e/e2e.spec.ts

@@ -23,3 +23,10 @@ test('Account was added', async ({ page }) => {
   });
   expect(result).toBe(1);
 });
+
+test('Wallet can be serialized', async ({ page }) => {
+  let result = await page.evaluate(async () => {
+    let bytes = await window.webWallet.db_to_bytes();
+    return bytes;
+  });
+});

src/bindgen/wallet.rs

@@ -1,4 +1,5 @@
 use std::num::NonZeroU32;
+use std::str::FromStr;
 
 use nonempty::NonEmpty;
 use serde::{Deserialize, Serialize};
@@ -8,7 +9,8 @@ use tonic_web_wasm_client::Client;
 
 use crate::error::Error;
 use crate::wallet::usk_from_seed_str;
-use crate::{bindgen::proposal::Proposal, BlockRange, Wallet, PRUNING_DEPTH};
+use crate::Network;
+use crate::{bindgen::proposal::Proposal, Wallet, PRUNING_DEPTH};
 use wasm_thread as thread;
 use zcash_address::ZcashAddress;
 use zcash_client_backend::data_api::{InputSource, WalletRead};
@@ -17,13 +19,12 @@ use zcash_client_backend::proto::service::{
 };
 use zcash_client_memory::MemoryWalletDb;
 use zcash_keys::keys::UnifiedFullViewingKey;
-use zcash_primitives::consensus;
+use zcash_primitives::consensus::{self, Parameters, TestNetwork};
 use zcash_primitives::transaction::TxId;
 
-pub type MemoryWallet<T> = Wallet<MemoryWalletDb<consensus::Network>, T>;
-pub type AccountId =
-    <MemoryWalletDb<zcash_primitives::consensus::Network> as WalletRead>::AccountId;
-pub type NoteRef = <MemoryWalletDb<zcash_primitives::consensus::Network> as InputSource>::NoteRef;
+pub type MemoryWallet<T> = Wallet<MemoryWalletDb<Network>, T>;
+pub type AccountId = <MemoryWalletDb<Network> as WalletRead>::AccountId;
+pub type NoteRef = <MemoryWalletDb<Network> as InputSource>::NoteRef;
 
 /// # A Zcash wallet
 ///
@@ -93,14 +94,6 @@ pub struct WebWallet {
 }
 
 impl WebWallet {
-    fn network_from_str(network: &str) -> Result<consensus::Network, Error> {
-        match network {
-            "main" => Ok(consensus::Network::MainNetwork),
-            "test" => Ok(consensus::Network::TestNetwork),
-            _ => Err(Error::InvalidNetwork(network.to_string())),
-        }
-    }
-
     pub fn client(&self) -> CompactTxStreamerClient<tonic_web_wasm_client::Client> {
         self.inner.client.clone()
     }
@@ -119,6 +112,7 @@ impl WebWallet {
     /// * `network` - Must be one of "main" or "test"
     /// * `lightwalletd_url` - Url of the lightwalletd instance to connect to (e.g. https://zcash-mainnet.chainsafe.dev)
     /// * `min_confirmations` - Number of confirmations required before a transaction is considered final
+    /// * `db_bytes` - (Optional) UInt8Array of a serialized wallet database. This can be used to restore a wallet from a previous session that was serialized by `db_to_bytes`
     ///
     /// # Examples
     ///
@@ -130,19 +124,25 @@ impl WebWallet {
         network: &str,
         lightwalletd_url: &str,
         min_confirmations: u32,
+        db_bytes: Option<Box<[u8]>>,
     ) -> Result<WebWallet, Error> {
-        let network = Self::network_from_str(network)?;
+        let network = Network::from_str(network)?;
         let min_confirmations = NonZeroU32::try_from(min_confirmations)
             .map_err(|_| Error::InvalidMinConformations(min_confirmations))?;
         let client = Client::new(lightwalletd_url.to_string());
 
+        let db = match db_bytes {
+            Some(bytes) => {
+                tracing::info!(
+                    "Serialized db was provided to constructor. Attempting to deserialize"
+                );
+                postcard::from_bytes(&bytes)?
+            }
+            None => MemoryWalletDb::new(network, PRUNING_DEPTH),
+        };
+
         Ok(Self {
-            inner: Wallet::new(
-                MemoryWalletDb::new(network, PRUNING_DEPTH),
-                client,
-                network,
-                min_confirmations,
-            )?,
+            inner: Wallet::new(db, client, network, min_confirmations)?,
         })
     }
 
@@ -295,6 +295,20 @@ impl WebWallet {
         Ok(serde_wasm_bindgen::to_value(&txids).unwrap())
     }
 
+    /// Serialize the internal wallet database to bytes
+    ///
+    /// This should be used for persisting the wallet between sessions. The resulting byte array can be used to construct a new wallet instance.
+    /// Note this method is async and will block until a read-lock can be acquired on the wallet database
+    ///
+    /// # Returns
+    ///
+    /// A postcard encoded byte array of the wallet database
+    ///
+    pub async fn db_to_bytes(&self) -> Result<Box<[u8]>, Error> {
+        let bytes = self.inner.db_to_bytes().await?;
+        Ok(bytes.into_boxed_slice())
+    }
+
     /// Send a list of authorized transactions to the network to be included in the blockchain
     ///
     /// These will be sent via the connected lightwalletd instance

src/error.rs

@@ -61,6 +61,8 @@ pub enum Error {
     InvalidSeedPhrase,
     #[error("Failed when creating transaction")]
     FailedToCreateTransaction,
+    #[error("Failed to serialize db using postcard: {0}")]
+    FailedSerialization(#[from] postcard::Error),
 }
 
 impl From<Error> for JsValue {

src/lib.rs

@@ -10,6 +10,8 @@ pub use bindgen::wallet::WebWallet;
 
 pub mod error;
 pub mod init;
+pub mod network;
+pub use network::Network;
 
 pub mod wallet;
 pub use wallet::Wallet;