feat: add example with esplora async and redb

Author: 110CodingP

examples/example_wallet_esplora_async_redb/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "example_wallet_esplora_async_redb"
+version = "0.1.0"
+edition = "2024"
+authors.workspace = true
+
+[dependencies]
+bdk_wallet = { version = "2.0.0" }
+bdk_esplora = { version = "0.22.0", features = ["async-https", "tokio"] }
+tokio = { version = "1.38.1", features = ["rt", "rt-multi-thread", "macros"] }
+anyhow = "1"
+bdk_redb = { git = "https://github.com/110CodingP/bdk_redb" }
+
+[lints]
+workspace = true

examples/example_wallet_esplora_async_redb/src/main.rs

@@ -0,0 +1,91 @@
+use std::{collections::BTreeSet, io::Write};
+use bdk_redb::Store;
+
+use anyhow::Ok;
+use bdk_esplora::{esplora_client, EsploraAsyncExt};
+use bdk_wallet::{
+    bitcoin::{Amount, Network},
+    KeychainKind, SignOptions, Wallet,
+};
+
+const SEND_AMOUNT: Amount = Amount::from_sat(5000);
+const STOP_GAP: usize = 5;
+const PARALLEL_REQUESTS: usize = 5;
+
+const DB_PATH: &str = "bdk-example-esplora-async.db";
+const NETWORK: Network = Network::Signet;
+const EXTERNAL_DESC: &str = "wpkh(tprv8ZgxMBicQKsPdy6LMhUtFHAgpocR8GC6QmwMSFpZs7h6Eziw3SpThFfczTDh5rW2krkqffa11UpX3XkeTTB2FvzZKWXqPY54Y6Rq4AQ5R8L/84'/1'/0'/0/*)";
+const INTERNAL_DESC: &str = "wpkh(tprv8ZgxMBicQKsPdy6LMhUtFHAgpocR8GC6QmwMSFpZs7h6Eziw3SpThFfczTDh5rW2krkqffa11UpX3XkeTTB2FvzZKWXqPY54Y6Rq4AQ5R8L/84'/1'/0'/1/*)";
+const ESPLORA_URL: &str = "http://signet.bitcoindevkit.net";
+
+#[tokio::main]
+async fn main() -> Result<(), anyhow::Error> {
+    let mut store = Store::new(DB_PATH, "wallet_1".to_string())?;
+
+    let wallet_opt = Wallet::load()
+        .descriptor(KeychainKind::External, Some(EXTERNAL_DESC))
+        .descriptor(KeychainKind::Internal, Some(INTERNAL_DESC))
+        .extract_keys()
+        .check_network(NETWORK)
+        .load_wallet(&mut store)?;
+    let mut wallet = match wallet_opt {
+        Some(wallet) => wallet,
+        None => Wallet::create(EXTERNAL_DESC, INTERNAL_DESC)
+            .network(NETWORK)
+            .create_wallet(&mut store)?,
+    };
+
+    let address = wallet.next_unused_address(KeychainKind::External);
+    wallet.persist(&mut store)?;
+    println!("Next unused address: ({}) {}", address.index, address);
+
+    let balance = wallet.balance();
+    println!("Wallet balance before syncing: {}", balance.total());
+
+    print!("Syncing...");
+    let client = esplora_client::Builder::new(ESPLORA_URL).build_async()?;
+
+    let request = wallet.start_full_scan().inspect({
+        let mut stdout = std::io::stdout();
+        let mut once = BTreeSet::<KeychainKind>::new();
+        move |keychain, spk_i, _| {
+            if once.insert(keychain) {
+                print!("\nScanning keychain [{:?}]", keychain);
+            }
+            print!(" {:<3}", spk_i);
+            stdout.flush().expect("must flush")
+        }
+    });
+
+    let update = client
+        .full_scan(request, STOP_GAP, PARALLEL_REQUESTS)
+        .await?;
+
+    wallet.apply_update(update)?;
+    wallet.persist(&mut store)?;
+    println!();
+
+    let balance = wallet.balance();
+    println!("Wallet balance after syncing: {}", balance.total());
+
+    if balance.total() < SEND_AMOUNT {
+        println!(
+            "Please send at least {} to the receiving address",
+            SEND_AMOUNT
+        );
+        std::process::exit(0);
+    }
+
+    let mut tx_builder = wallet.build_tx();
+    tx_builder.add_recipient(address.script_pubkey(), SEND_AMOUNT);
+
+    let mut psbt = tx_builder.finish()?;
+    let finalized = wallet.sign(&mut psbt, SignOptions::default())?;
+    assert!(finalized);
+
+    let tx = psbt.extract_tx()?;
+    client.broadcast(&tx).await?;
+    println!("Tx broadcasted! Txid: {}", tx.compute_txid());
+
+    Ok(())
+}