Merge pull request #57 from rustaceanrob/trace-09-26

Initialize `tracing` internally

examples/wallet.rs

@@ -13,9 +13,6 @@ const PEERS: &[IpAddr] = &[IpAddr::V4(Ipv4Addr::new(23, 137, 57, 100))];
 
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
-    let subscriber = tracing_subscriber::FmtSubscriber::new();
-    tracing::subscriber::set_global_default(subscriber).unwrap();
-
     let desc = "tr([7d94197e/86'/1'/0']tpubDCyQVJj8KzjiQsFjmb3KwECVXPvMwvAxxZGCP9XmWSopmjW3bCV3wD7TgxrUhiGSueDS1MU5X1Vb1YjYcp8jitXc5fXfdC1z68hDDEyKRNr/0/*)";
     let change_desc = "tr([7d94197e/86'/1'/0']tpubDCyQVJj8KzjiQsFjmb3KwECVXPvMwvAxxZGCP9XmWSopmjW3bCV3wD7TgxrUhiGSueDS1MU5X1Vb1YjYcp8jitXc5fXfdC1z68hDDEyKRNr/1/*)";
 
@@ -43,18 +40,19 @@ async fn main() -> anyhow::Result<()> {
 
     tokio::task::spawn(async move { node.run().await });
 
+    // Print logs to the console using the `tracing` crate
+    let logger = TraceLogger::new()?;
+
     tracing::info!(
         "Balance before sync: {} sats",
         wallet.balance().total().to_sat()
     );
 
     // Sync and apply updates. We can do this a continual loop while the "application" is running.
-    // Often this loop would be on a separate "Task" in a Swift app for instance
-    let logger = TraceLogger::new();
+    // Often this would occur on a separate thread than the underlying application user interface.
     loop {
         if let Some(update) = client.update(&logger).await {
             wallet.apply_update(update)?;
-            // Do something here to add more scripts?
             tracing::info!("Tx count: {}", wallet.transactions().count());
             tracing::info!("Balance: {}", wallet.balance().total().to_sat());
             let last_revealed = wallet.derivation_index(KeychainKind::External).unwrap();

src/logger.rs

@@ -20,7 +20,7 @@
 //! use bdk_kyoto::logger::{NodeMessageHandler, TraceLogger};
 //! use bdk_kyoto::Warning;
 //!
-//! let logger = TraceLogger::new();
+//! let logger = TraceLogger::new().unwrap();
 //! logger.dialog("The node is running".into());
 //! logger.warning(Warning::PeerTimedOut);
 //! ```
@@ -34,6 +34,8 @@ use std::fmt::Debug;
 use kyoto::NodeState;
 use kyoto::Txid;
 use kyoto::Warning;
+#[cfg(feature = "trace")]
+use tracing::subscriber::SetGlobalDefaultError;
 
 /// Handle dialog and state changes from a node with some arbitrary behavior.
 /// The primary purpose of this trait is not to respond to events by persisting changes,
@@ -106,16 +108,22 @@ impl NodeMessageHandler for PrintLogger {
     }
 }
 
-/// Print messages from the node to the console
+/// Print messages from the node to the console using [`tracing`].
 #[cfg(feature = "trace")]
 #[derive(Default, Debug)]
 pub struct TraceLogger {}
 
 #[cfg(feature = "trace")]
 impl TraceLogger {
-    /// Build a new trace logger
-    pub fn new() -> Self {
-        Self {}
+    /// Build a new trace logger. This constructor will initialize the [`tracing::subscriber`] globally.
+    ///
+    /// ## Errors
+    ///
+    /// If [`TraceLogger::new`] has already been called.
+    pub fn new() -> Result<Self, SetGlobalDefaultError> {
+        let subscriber = tracing_subscriber::FmtSubscriber::new();
+        tracing::subscriber::set_global_default(subscriber)?;
+        Ok(Self {})
     }
 }