[Rust] Take download callbacks by reference to avoid boxing

Author: emesare

plugins/dwarf/dwarf_import/src/helpers.rs

@@ -452,7 +452,7 @@ pub(crate) fn download_debug_info(
                 "GET",
                 &artifact_url,
                 vec![],
-                DownloadInstanceInputOutputCallbacks {
+                &DownloadInstanceInputOutputCallbacks {
                     read: None,
                     write: Some(Box::new(write)),
                     progress: None,

plugins/pdb-ng/src/lib.rs

@@ -195,7 +195,7 @@ fn read_from_sym_store(bv: &BinaryView, path: &str) -> Result<(bool, Vec<u8>)> {
             "GET",
             path,
             vec![],
-            DownloadInstanceInputOutputCallbacks {
+            &DownloadInstanceInputOutputCallbacks {
                 read: None,
                 write: Some(Box::new(write)),
                 progress: None,

rust/src/download_provider.rs

@@ -134,14 +134,13 @@ impl DownloadInstance {
     pub fn perform_request(
         &mut self,
         url: &str,
-        callbacks: DownloadInstanceOutputCallbacks,
+        callbacks: &DownloadInstanceOutputCallbacks,
     ) -> Result<(), String> {
-        let callbacks = Box::into_raw(Box::new(callbacks));
         let mut cbs = BNDownloadInstanceOutputCallbacks {
             writeCallback: Some(Self::o_write_callback),
-            writeContext: callbacks as *mut c_void,
+            writeContext: callbacks as *const _ as *mut c_void,
             progressCallback: Some(Self::o_progress_callback),
-            progressContext: callbacks as *mut c_void,
+            progressContext: callbacks as *const _ as *mut c_void,
         };
 
         let url_raw = url.to_cstr();
@@ -153,8 +152,6 @@ impl DownloadInstance {
             )
         };
 
-        // Drop it
-        unsafe { drop(Box::from_raw(callbacks)) };
         if result < 0 {
             Err(self.get_error())
         } else {
@@ -206,7 +203,7 @@ impl DownloadInstance {
         method: &str,
         url: &str,
         headers: I,
-        callbacks: DownloadInstanceInputOutputCallbacks,
+        callbacks: &DownloadInstanceInputOutputCallbacks,
     ) -> Result<DownloadResponse, String>
     where
         I: IntoIterator<Item = (String, String)>,
@@ -226,14 +223,13 @@ impl DownloadInstance {
             header_value_ptrs.push(value.as_ptr());
         }
 
-        let callbacks = Box::into_raw(Box::new(callbacks));
         let mut cbs = BNDownloadInstanceInputOutputCallbacks {
             readCallback: Some(Self::i_read_callback),
-            readContext: callbacks as *mut c_void,
+            readContext: callbacks as *const _ as *mut c_void,
             writeCallback: Some(Self::i_write_callback),
-            writeContext: callbacks as *mut c_void,
+            writeContext: callbacks as *const _ as *mut c_void,
             progressCallback: Some(Self::i_progress_callback),
-            progressContext: callbacks as *mut c_void,
+            progressContext: callbacks as *const _ as *mut c_void,
         };
 
         let mut response: *mut BNDownloadInstanceResponse = null_mut();

rust/tests/download_provider.rs

@@ -0,0 +1,34 @@
+use binaryninja::download_provider::{DownloadInstanceInputOutputCallbacks, DownloadProvider};
+use binaryninja::headless::Session;
+use std::sync::mpsc;
+
+#[test]
+fn test_download_provider() {
+    let _session = Session::new().expect("Failed to initialize session");
+    let provider = DownloadProvider::try_default().expect("Couldn't get default download provider");
+    let mut inst = provider
+        .create_instance()
+        .expect("Couldn't create download instance");
+    let (tx, rx) = mpsc::channel();
+    let write = move |data: &[u8]| -> usize {
+        tx.send(data.to_vec()).expect("Couldn't send data");
+        data.len()
+    };
+    let result = inst
+        .perform_custom_request(
+            "GET",
+            "http://httpbin.org/get",
+            vec![],
+            &DownloadInstanceInputOutputCallbacks {
+                read: None,
+                write: Some(Box::new(write)),
+                progress: None,
+            },
+        )
+        .expect("Couldn't perform custom request");
+    assert_eq!(result.status_code, 200);
+    let written = rx.recv().expect("Couldn't receive data");
+    let written_str = String::from_utf8(written).expect("Couldn't convert data to string");
+    println!("{}", written_str);
+    assert!(written_str.contains("httpbin.org/get"));
+}