docs: add example for EsploraClient with timeout configuration

Add a new example demonstrating how to configure EsploraClient with
custom timeout and retry settings. This is useful for developers
working with slow or unreliable network connections.

The example shows:
- Setting socket timeout using Builder::timeout()
- Configuring max retries using Builder::max_retries()
- Handling timeout-related errors gracefully

Closes #260

Signed-off-by: Eeshu-Yadav <eeshuyadav123@gmail.com>

Author: Eeshu-Yadav

Cargo.toml

@@ -72,5 +72,8 @@ name = "esplora_async"
 [[example]]
 name = "esplora_blocking"
 
+[[example]]
+name = "esplora_with_timeout"
+
 [[example]]
 name = "bitcoind_rpc"

README.md

@@ -63,6 +63,7 @@ that the `Wallet` can use to update its view of the chain.
 
 * [`examples/esplora_async`](https://github.com/bitcoindevkit/bdk_wallet/tree/master/examples/esplora_async)
 * [`examples/esplora_blocking`](https://github.com/bitcoindevkit/bdk_wallet/tree/master/examples/esplora_blocking)
+* [`examples/esplora_with_timeout`](https://github.com/bitcoindevkit/bdk_wallet/tree/master/examples/esplora_with_timeout)
 * [`examples/electrum`](https://github.com/bitcoindevkit/bdk_wallet/tree/master/examples/electrum)
 * [`examples/bitcoind_rpc`](https://github.com/bitcoindevkit/bdk_wallet/tree/master/examples/bitcoind_rpc)
 

examples/esplora_with_timeout.rs

@@ -0,0 +1,109 @@
+//! Example demonstrating how to configure EsploraClient with custom timeout settings.
+
+use bdk_esplora::{esplora_client, EsploraExt};
+use bdk_wallet::{bitcoin::Network, rusqlite::Connection, KeychainKind, Wallet};
+use std::{collections::BTreeSet, io::Write};
+
+const STOP_GAP: usize = 5;
+const PARALLEL_REQUESTS: usize = 5;
+
+const DB_PATH: &str = "bdk-example-esplora-timeout.sqlite";
+const NETWORK: Network = Network::Testnet4;
+const EXTERNAL_DESC: &str = "wpkh(tprv8ZgxMBicQKsPdy6LMhUtFHAgpocR8GC6QmwMSFpZs7h6Eziw3SpThFfczTDh5rW2krkqffa11UpX3XkeTTB2FvzZKWXqPY54Y6Rq4AQ5R8L/84'/1'/0'/0/*)";
+const INTERNAL_DESC: &str = "wpkh(tprv8ZgxMBicQKsPdy6LMhUtFHAgpocR8GC6QmwMSFpZs7h6Eziw3SpThFfczTDh5rW2krkqffa11UpX3XkeTTB2FvzZKWXqPY54Y6Rq4AQ5R8L/84'/1'/0'/1/*)";
+const ESPLORA_URL: &str = "https://mempool.space/testnet4/api";
+
+const TIMEOUT_SECS: u64 = 30;
+const MAX_RETRIES: usize = 3;
+
+fn main() -> Result<(), anyhow::Error> {
+    let mut db = Connection::open(DB_PATH)?;
+    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 db)?;
+    let mut wallet = match wallet_opt {
+        Some(wallet) => wallet,
+        None => Wallet::create(EXTERNAL_DESC, INTERNAL_DESC)
+            .network(NETWORK)
+            .create_wallet(&mut db)?,
+    };
+
+    let address = wallet.next_unused_address(KeychainKind::External);
+    wallet.persist(&mut db)?;
+    println!(
+        "Next unused address: ({}) {}",
+        address.index, address.address
+    );
+
+    let balance = wallet.balance();
+    println!("Wallet balance before syncing: {}", balance.total());
+
+    // Configure EsploraClient with custom timeout and retry settings.
+    // Available builder options:
+    // - timeout(secs): Socket timeout in seconds
+    // - max_retries(count): Retries on HTTP codes 408, 425, 429, 500, 502, 503, 504
+    // - proxy(url): Proxy server URL
+    // - header(key, value): Custom HTTP header
+    println!(
+        "Creating Esplora client with {TIMEOUT_SECS}s timeout and {MAX_RETRIES} max retries..."
+    );
+    let client = esplora_client::Builder::new(ESPLORA_URL)
+        .timeout(TIMEOUT_SECS)
+        .max_retries(MAX_RETRIES)
+        .build_blocking();
+
+    println!("Starting full sync...");
+    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!(" {spk_i:<3}");
+            stdout.flush().expect("must flush")
+        }
+    });
+
+    match client.full_scan(request, STOP_GAP, PARALLEL_REQUESTS) {
+        Ok(update) => {
+            wallet.apply_update(update)?;
+            wallet.persist(&mut db)?;
+            println!();
+
+            let balance = wallet.balance();
+            println!("Wallet balance after syncing: {}", balance.total());
+        }
+        Err(e) => {
+            eprintln!("\nSync failed: {e}");
+            eprintln!(
+                "Tips: increase timeout/max_retries, check connectivity, or try another server"
+            );
+            return Err(e.into());
+        }
+    }
+
+    println!("\nFetching current block height...");
+    match client.get_height() {
+        Ok(height) => println!("Current block height: {height}"),
+        Err(e) => eprintln!("Failed to get block height: {e}"),
+    }
+
+    println!("\nFetching fee estimates...");
+    match client.get_fee_estimates() {
+        Ok(estimates) => {
+            println!("Fee estimates (sat/vB):");
+            for (target, rate) in estimates.iter().take(5) {
+                println!("  {} blocks: {:.1} sat/vB", target, rate);
+            }
+        }
+        Err(e) => {
+            eprintln!("Failed to get fee estimates: {e}");
+        }
+    }
+
+    Ok(())
+}