rust downloading function

src-tauri/src/downloader.rs

@@ -0,0 +1,43 @@
+use std::cmp::min;
+use std::fs::File;
+use std::io::Write;
+
+use futures_util::StreamExt;
+
+use tauri::{
+  command,
+  Event
+};
+
+// Lots of help from: https://gist.github.com/giuliano-oliveira/4d11d6b3bb003dba3a1b53f43d81b30d
+// and docs ofc
+
+#[tauri::command]
+pub async fn download_file(url: &str, path: &str) -> Result<(), String> {
+    // Reqwest setup
+    let res = reqwest::get(url).await.or(Err(format!("Failed to get {}", url)))?;
+    let total_size = res
+        .content_length()
+        .ok_or(format!("Failed to get content length from '{}'", &url))?;
+
+    // Create file path
+    let mut file = File::create(path).or(Err(format!("Failed to create file '{}'", path)))?;
+    let mut downloaded: u64 = 0;
+
+    // File stream
+    let mut stream = res.bytes_stream();
+
+    // Await chunks
+    while let Some(item) = stream.next().await {
+        let chunk = item.or(Err(format!("Error while downloading file")));
+        // Write chunk
+        file.write_all(&chunk)
+            .or(Err(format!("Error while writing to file")))?;
+        // New progress
+        let new = min(downloaded + (chunk.len() as u64), total_size);
+        downloaded = new;
+    }
+
+    // We are done
+    return Ok(());
+}