Add simple download progress tracker

crates/packaging/src/https.rs

@@ -1,5 +1,5 @@
 use std::{
-    io::{self, Read},
+    io::{self, Read, Write},
     path::Path,
 };
 
@@ -275,9 +275,17 @@ pub fn download_and_hash(
         Encoding::new(content_encoding, url)?
     };
 
-    // Use .take to prevent a malicious server from sending back bytes
-    // until system resources are exhausted!
-    decompress_into(dest_dir, encoding, resp.take(max_download_bytes))
+    if let Some(content_len) = resp.content_length() {
+        // Print download progress to stdout if we know the content length
+        //
+        // Use .take to prevent a malicious server from sending back bytes
+        // until system resources are exhausted!
+        let resp = ProgressReporter::new(resp.take(max_download_bytes), content_len as usize);
+
+        decompress_into(dest_dir, encoding, resp)
+    } else {
+        decompress_into(dest_dir, encoding, resp.take(max_download_bytes))
+    }
 }
 
 /// The content encodings we support
@@ -405,3 +413,44 @@ impl<R: Read> Read for HashReader<R> {
         Ok(bytes_read)
     }
 }
+
+/// Prints download progress to stdout
+struct ProgressReporter<R: Read> {
+    read: usize,
+    total: usize,
+    last_reported: usize,
+    reader: R,
+}
+
+impl<R: Read> ProgressReporter<R> {
+    fn new(reader: R, total: usize) -> Self {
+        ProgressReporter {
+            read: 0,
+            last_reported: 0,
+            total,
+            reader,
+        }
+    }
+}
+
+impl<R: Read> Read for ProgressReporter<R> {
+    fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
+        let size = self.reader.read(buf)?;
+
+        self.read += size;
+
+        print!(
+            "\u{001b}[2K\u{001b}[G[{:.1} / {:.1} MB]",
+            self.read as f32 / 1_000_000.0,
+            self.total as f32 / 1_000_000.0,
+        );
+        std::io::stdout().flush()?;
+        self.last_reported = self.read;
+
+        if self.read >= self.total {
+            println!("");
+        }
+
+        Ok(size)
+    }
+}