Tell the user about the monero-wallet-rpc download

Fixes #242.

Cargo.lock

@@ -302,6 +302,12 @@ version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cdcf67bb7ba7797a081cd19009948ab533af7c355d5caf1d08c777582d351e9c"
 
+[[package]]
+name = "big-bytes"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4d73a8ae8ce52d09395e4cafc83b5b81c3deb70a97740e907669c8683c4dd50a"
+
 [[package]]
 name = "bincode"
 version = "1.3.1"
@@ -3525,6 +3531,7 @@ dependencies = [
  "backoff",
  "base64 0.12.3",
  "bdk",
+ "big-bytes",
  "bitcoin",
  "bitcoin-harness",
  "config",

swap/Cargo.toml

@@ -20,6 +20,7 @@ atty = "0.2"
 backoff = { version = "0.3", features = ["tokio"] }
 base64 = "0.12"
 bdk = { version = "0.4" }
+big-bytes = "1"
 bitcoin = { version = "0.26", features = ["rand", "use-serde"] }
 config = { version = "0.10", default-features = false, features = ["toml"] }
 conquer-once = "0.3"

swap/src/monero/wallet_rpc.rs

@@ -1,8 +1,9 @@
 use ::monero::Network;
 use anyhow::{Context, Result};
 use async_compression::tokio::bufread::BzDecoder;
+use big_bytes::BigByte;
 use futures::{StreamExt, TryStreamExt};
-use reqwest::Url;
+use reqwest::{header::CONTENT_LENGTH, Url};
 use std::{
     io::ErrorKind,
     path::{Path, PathBuf},
@@ -71,8 +72,19 @@ impl WalletRpc {
                 .open(monero_wallet_rpc.tar_path())
                 .await?;
 
-            let byte_stream = reqwest::get(DOWNLOAD_URL)
+            let response = reqwest::get(DOWNLOAD_URL).await?;
-                .await?
+
+            let content_length = response.headers()[CONTENT_LENGTH]
+                .to_str()
+                .context("failed to convert content-length to string")?
+                .parse::<u64>()?;
+
+            tracing::info!(
+                "Downloading monero-wallet-rpc ({})",
+                content_length.big_byte(2)
+            );
+
+            let byte_stream = response
                 .bytes_stream()
                 .map_err(|err| std::io::Error::new(ErrorKind::Other, err));
 
@@ -119,6 +131,8 @@ impl WalletRpc {
             .local_addr()?
             .port();
 
+        tracing::debug!("Starting monero-wallet-rpc on port {}", port);
+
         let mut child = Command::new(self.exec_path())
             .stdout(Stdio::piped())
             .kill_on_drop(true)
@@ -148,6 +162,7 @@ impl WalletRpc {
                 break;
             }
         }
+
         Ok(WalletRpcProcess {
             _child: child,
             port,