fix(protocol): saturate scrape counters and add regression tests

Author: josecelano

packages/http-protocol/src/v1/responses/scrape.rs

@@ -131,5 +131,25 @@ mod tests {
                 String::from_utf8(expected_bytes.to_vec()).unwrap()
             );
         }
+
+        #[test]
+        fn should_saturate_large_download_counts() {
+            let info_hash = InfoHash::from_bytes(&[0x69; 20]);
+            let mut scrape_data = ScrapeData::empty();
+            scrape_data.add_file(
+                &info_hash,
+                SwarmMetadata {
+                    complete: 1,
+                    downloaded: u32::MAX,
+                    incomplete: 3,
+                },
+            );
+
+            let response = Bencoded::from(scrape_data);
+            let bytes = response.body();
+            let body = String::from_utf8(bytes).unwrap();
+
+            assert!(body.contains(&format!("downloadedi{}e", i64::from(u32::MAX))));
+        }
     }
 }

packages/udp-tracker-server/src/handlers/scrape.rs

@@ -53,19 +53,22 @@ pub async fn handle_scrape(
     Ok(build_response(request, &scrape_data))
 }
 
+fn udp_counter_from_u32(value: u32) -> i32 {
+    // Temporary saturation guard for UDP i32 counters. Proper type alignment across Rust and DB layers
+    // will be addressed in docs/issues/1525-07-align-rust-and-db-types.md.
+    i32::try_from(value).unwrap_or(i32::MAX)
+}
+
 fn build_response(request: &ScrapeRequest, scrape_data: &ScrapeData) -> Response {
     let mut torrent_stats: Vec<TorrentScrapeStatistics> = Vec::new();
 
     for file in &scrape_data.files {
         let swarm_metadata = file.1;
 
-        #[allow(clippy::cast_possible_truncation)]
-        let scrape_entry = {
-            TorrentScrapeStatistics {
-                seeders: NumberOfPeers(I32::new(i64::from(swarm_metadata.complete) as i32)),
-                completed: NumberOfDownloads(I32::new(i64::from(swarm_metadata.downloaded) as i32)),
-                leechers: NumberOfPeers(I32::new(i64::from(swarm_metadata.incomplete) as i32)),
-            }
+        let scrape_entry = TorrentScrapeStatistics {
+            seeders: NumberOfPeers(I32::new(udp_counter_from_u32(swarm_metadata.complete))),
+            completed: NumberOfDownloads(I32::new(udp_counter_from_u32(swarm_metadata.downloaded))),
+            leechers: NumberOfPeers(I32::new(udp_counter_from_u32(swarm_metadata.incomplete))),
         };
 
         torrent_stats.push(scrape_entry);
@@ -458,4 +461,11 @@ mod tests {
             }
         }
     }
+
+    #[test]
+    fn should_saturate_large_download_counts_for_udp_protocol() {
+        assert_eq!(super::udp_counter_from_u32(u32::MAX), i32::MAX);
+        assert_eq!(super::udp_counter_from_u32((i32::MAX as u32) + 1), i32::MAX);
+        assert_eq!(super::udp_counter_from_u32(42), 42);
+    }
 }