feat: add electrum example showing basic syncing

Also shows how to build `KeychainKind`-based wallets using the new
`KeyRing`.

Author: 110CodingP

Cargo.toml

@@ -25,6 +25,7 @@ path = "."
 [dev-dependencies]
 anyhow = "1"
 tempfile = "3.21.0"
+bdk_electrum = {version = "0.23.1"}
 
 [[example]]
 name = "keyring"
@@ -37,3 +38,6 @@ required-features = ["rusqlite"]
 [[example]]
 name = "default_keychain"
 required-features = ["rusqlite"]
+
+[[example]]
+name = "electrum_example"

examples/electrum_example.rs

@@ -0,0 +1,48 @@
+use bdk_wallet::KeychainKind;
+use bitcoin::Network;
+use multi_keychain_wallet::multi_keychain::{KeyRing, Wallet};
+
+use bdk_electrum::{electrum_client::Client, BdkElectrumClient};
+
+const STOP_GAP: usize = 50;
+const BATCH_SIZE: usize = 5;
+const EXTERNAL_DESCRIPTOR: &str = "tr(tprv8ZgxMBicQKsPdrjwWCyXqqJ4YqcyG4DmKtjjsRt29v1PtD3r3PuFJAjWytzcvSTKnZAGAkPSmnrdnuHWxCAwy3i1iPhrtKAfXRH7dVCNGp6/86'/1'/0'/0/*)#g9xn7wf9";
+const INTERNAL_DESCRIPTOR: &str = "tr(tprv8ZgxMBicQKsPdrjwWCyXqqJ4YqcyG4DmKtjjsRt29v1PtD3r3PuFJAjWytzcvSTKnZAGAkPSmnrdnuHWxCAwy3i1iPhrtKAfXRH7dVCNGp6/86'/1'/0'/1/*)#e3rjrmea";
+
+fn main() {
+    // Construct wallet
+    let mut keyring =
+        KeyRing::<KeychainKind>::new(Network::Signet, KeychainKind::External, EXTERNAL_DESCRIPTOR);
+    keyring.add_descriptor(KeychainKind::Internal, INTERNAL_DESCRIPTOR, false);
+
+    let mut wallet = Wallet::new(keyring);
+
+    let balance = wallet.balance();
+    println!("Balance before syncing: {} sats", balance.total().to_sat());
+
+    // Reveal address
+    let address = wallet.reveal_next_default_address_unwrap();
+    println!("Address revealed: {}", address.address);
+
+    let client = BdkElectrumClient::new(Client::new("ssl://mempool.space:60602").unwrap());
+
+    // Perform sync
+    let sync_request = wallet.start_sync_with_revealed_spks();
+    let update = client.sync(sync_request, BATCH_SIZE, true).unwrap();
+
+    wallet.apply_update(update);
+
+    let balance = wallet.balance();
+    println!("Balance after sync: {} sats", balance.total().to_sat());
+
+    // Perform full scan
+    let full_scan_request = wallet.start_full_scan();
+    let update = client
+        .full_scan(full_scan_request, STOP_GAP, BATCH_SIZE, true)
+        .unwrap();
+
+    wallet.apply_update(update);
+
+    let balance = wallet.balance();
+    println!("Balance after full scan: {} sats", balance.total().to_sat());
+}