feat(http): [#192] scrape request for Axum HTTP tracker

src/http/axum_implementation/handlers/scrape.rs

@@ -1,14 +1,13 @@
 use std::sync::Arc;
 
 use axum::extract::State;
-use axum::http::StatusCode;
 use axum::response::{IntoResponse, Response};
 use log::debug;
 
 use crate::http::axum_implementation::extractors::peer_ip;
 use crate::http::axum_implementation::extractors::remote_client_ip::RemoteClientIp;
 use crate::http::axum_implementation::extractors::scrape_request::ExtractRequest;
-use crate::http::axum_implementation::services;
+use crate::http::axum_implementation::{responses, services};
 use crate::tracker::Tracker;
 
 #[allow(clippy::unused_async)]
@@ -19,20 +18,12 @@ pub async fn handle(
 ) -> Response {
     debug!("http scrape request: {:#?}", &scrape_request);
 
-    /*
-    todo:
-        - [x] Add the service that sends the event for statistics.
-        - [ ] Build the HTTP bencoded response.
-    */
-
     let peer_ip = match peer_ip::resolve(tracker.config.on_reverse_proxy, &remote_client_ip) {
         Ok(peer_ip) => peer_ip,
         Err(err) => return err,
     };
 
     let scrape_data = services::scrape::invoke(tracker.clone(), &scrape_request.info_hashes, &peer_ip).await;
 
-    debug!("scrape data: {:#?}", &scrape_data);
-
-    (StatusCode::OK, "todo").into_response()
+    responses::scrape::Bencoded::from(scrape_data).into_response()
 }

src/http/axum_implementation/requests/scrape.rs

@@ -10,8 +10,8 @@ use crate::protocol::info_hash::{ConversionError, InfoHash};
 
 pub type NumberOfBytes = i64;
 
-// Query param name
-const INFO_HASH_SCRAPE_PARAM: &str = "info_hash";
+// Query param names
+const INFO_HASH: &str = "info_hash";
 
 #[derive(Debug, PartialEq)]
 pub struct Scrape {
@@ -27,12 +27,6 @@ pub enum ParseScrapeQueryError {
         location: &'static Location<'static>,
         param_name: String,
     },
-    #[error("invalid param value {param_value} for {param_name} in {location}")]
-    InvalidParam {
-        param_name: String,
-        param_value: String,
-        location: &'static Location<'static>,
-    },
     #[error("invalid param value {param_value} for {param_name} in {source}")]
     InvalidInfoHashParam {
         param_name: String,
@@ -60,14 +54,14 @@ impl TryFrom<Query> for Scrape {
 }
 
 fn extract_info_hashes(query: &Query) -> Result<Vec<InfoHash>, ParseScrapeQueryError> {
-    match query.get_param_vec(INFO_HASH_SCRAPE_PARAM) {
+    match query.get_param_vec(INFO_HASH) {
         Some(raw_params) => {
             let mut info_hashes = vec![];
 
             for raw_param in raw_params {
                 let info_hash =
                     percent_decode_info_hash(&raw_param).map_err(|err| ParseScrapeQueryError::InvalidInfoHashParam {
-                        param_name: INFO_HASH_SCRAPE_PARAM.to_owned(),
+                        param_name: INFO_HASH.to_owned(),
                         param_value: raw_param.clone(),
                         source: Located(err).into(),
                     })?;
@@ -80,7 +74,7 @@ fn extract_info_hashes(query: &Query) -> Result<Vec<InfoHash>, ParseScrapeQueryE
         None => {
             return Err(ParseScrapeQueryError::MissingParam {
                 location: Location::caller(),
-                param_name: INFO_HASH_SCRAPE_PARAM.to_owned(),
+                param_name: INFO_HASH.to_owned(),
             })
         }
     }
@@ -92,16 +86,12 @@ mod tests {
     mod scrape_request {
 
         use crate::http::axum_implementation::query::Query;
-        use crate::http::axum_implementation::requests::scrape::{Scrape, INFO_HASH_SCRAPE_PARAM};
+        use crate::http::axum_implementation::requests::scrape::{Scrape, INFO_HASH};
         use crate::protocol::info_hash::InfoHash;
 
         #[test]
         fn should_be_instantiated_from_the_url_query_with_only_one_infohash() {
-            let raw_query = Query::from(vec![(
-                INFO_HASH_SCRAPE_PARAM,
-                "%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0",
-            )])
-            .to_string();
+            let raw_query = Query::from(vec![(INFO_HASH, "%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0")]).to_string();
 
             let query = raw_query.parse::<Query>().unwrap();
 
@@ -118,7 +108,7 @@ mod tests {
         mod when_it_is_instantiated_from_the_url_query_params {
 
             use crate::http::axum_implementation::query::Query;
-            use crate::http::axum_implementation::requests::scrape::{Scrape, INFO_HASH_SCRAPE_PARAM};
+            use crate::http::axum_implementation::requests::scrape::{Scrape, INFO_HASH};
 
             #[test]
             fn it_should_fail_if_the_query_does_not_include_the_info_hash_param() {
@@ -129,7 +119,7 @@ mod tests {
 
             #[test]
             fn it_should_fail_if_the_info_hash_param_is_invalid() {
-                let raw_query = Query::from(vec![(INFO_HASH_SCRAPE_PARAM, "INVALID_INFO_HASH_VALUE")]).to_string();
+                let raw_query = Query::from(vec![(INFO_HASH, "INVALID_INFO_HASH_VALUE")]).to_string();
 
                 assert!(Scrape::try_from(raw_query.parse::<Query>().unwrap()).is_err());
             }

src/http/axum_implementation/responses/mod.rs

@@ -1,3 +1,4 @@
 pub mod announce;
 pub mod error;
 pub mod ok;
+pub mod scrape;

src/http/axum_implementation/responses/scrape.rs

@@ -0,0 +1,106 @@
+use std::borrow::Cow;
+
+use axum::http::StatusCode;
+use axum::response::{IntoResponse, Response};
+use bip_bencode::{ben_int, ben_map, BMutAccess};
+
+use crate::tracker::ScrapeData;
+
+#[derive(Debug, PartialEq, Default)]
+pub struct Bencoded {
+    scrape_data: ScrapeData,
+}
+
+impl Bencoded {
+    /// # Panics
+    ///
+    /// Will return an error if it can't access the bencode as a mutable `BDictAccess`.    
+    #[must_use]
+    pub fn body(&self) -> Vec<u8> {
+        let mut scrape_list = ben_map!();
+
+        let scrape_list_mut = scrape_list.dict_mut().unwrap();
+
+        for (info_hash, value) in &self.scrape_data.files {
+            scrape_list_mut.insert(
+                Cow::from(info_hash.bytes().to_vec()),
+                ben_map! {
+                    "complete" => ben_int!(i64::from(value.complete)),
+                    "downloaded" => ben_int!(i64::from(value.downloaded)),
+                    "incomplete" => ben_int!(i64::from(value.incomplete))
+                },
+            );
+        }
+
+        (ben_map! {
+            "files" => scrape_list
+        })
+        .encode()
+    }
+}
+
+impl From<ScrapeData> for Bencoded {
+    fn from(scrape_data: ScrapeData) -> Self {
+        Self { scrape_data }
+    }
+}
+
+impl IntoResponse for Bencoded {
+    fn into_response(self) -> Response {
+        (StatusCode::OK, self.body()).into_response()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    mod scrape_response {
+        use crate::http::axum_implementation::responses::scrape::Bencoded;
+        use crate::protocol::info_hash::InfoHash;
+        use crate::tracker::torrent::SwarmMetadata;
+        use crate::tracker::ScrapeData;
+
+        fn sample_scrape_data() -> ScrapeData {
+            let info_hash = InfoHash([0x69; 20]);
+            let mut scrape_data = ScrapeData::empty();
+            scrape_data.add_file(
+                &info_hash,
+                SwarmMetadata {
+                    complete: 1,
+                    downloaded: 2,
+                    incomplete: 3,
+                },
+            );
+            scrape_data
+        }
+
+        #[test]
+        fn should_be_converted_from_scrape_data() {
+            let response = Bencoded::from(sample_scrape_data());
+
+            assert_eq!(
+                response,
+                Bencoded {
+                    scrape_data: sample_scrape_data()
+                }
+            );
+        }
+
+        #[test]
+        fn should_be_bencoded() {
+            let response = Bencoded {
+                scrape_data: sample_scrape_data(),
+            };
+
+            let bytes = response.body();
+
+            // cspell:disable-next-line
+            let expected_bytes = b"d5:filesd20:iiiiiiiiiiiiiiiiiiiid8:completei1e10:downloadedi2e10:incompletei3eeee";
+
+            assert_eq!(
+                String::from_utf8(bytes).unwrap(),
+                String::from_utf8(expected_bytes.to_vec()).unwrap()
+            );
+        }
+    }
+}

src/tracker/mod.rs

@@ -52,7 +52,7 @@ pub struct AnnounceData {
 
 #[derive(Debug, PartialEq, Default)]
 pub struct ScrapeData {
-    files: HashMap<InfoHash, SwarmMetadata>,
+    pub files: HashMap<InfoHash, SwarmMetadata>,
 }
 
 impl ScrapeData {

tests/http/asserts.rs

@@ -78,6 +78,36 @@ pub async fn assert_is_announce_response(response: Response) {
 
 // Error responses
 
+// Specific errors for announce request
+
+pub async fn assert_missing_query_params_for_announce_request_error_response(response: Response) {
+    assert_eq!(response.status(), 200);
+
+    assert_bencoded_error(
+        &response.text().await.unwrap(),
+        "missing query params for announce request",
+        Location::caller(),
+    );
+}
+
+pub async fn assert_bad_announce_request_error_response(response: Response, failure: &str) {
+    assert_cannot_parse_query_params_error_response(response, &format!(" for announce request: {failure}")).await;
+}
+
+// Specific errors for scrape request
+
+pub async fn assert_missing_query_params_for_scrape_request_error_response(response: Response) {
+    assert_eq!(response.status(), 200);
+
+    assert_bencoded_error(
+        &response.text().await.unwrap(),
+        "missing query params for scrape request",
+        Location::caller(),
+    );
+}
+
+// Other errors
+
 pub async fn assert_internal_server_error_response(response: Response) {
     assert_eq!(response.status(), 200);
 
@@ -156,22 +186,6 @@ pub async fn assert_invalid_remote_address_on_xff_header_error_response(response
     );
 }
 
-// Specific errors for announce request
-
-pub async fn assert_missing_query_params_for_announce_request_error_response(response: Response) {
-    assert_eq!(response.status(), 200);
-
-    assert_bencoded_error(
-        &response.text().await.unwrap(),
-        "missing query params for announce request",
-        Location::caller(),
-    );
-}
-
-pub async fn assert_bad_announce_request_error_response(response: Response, failure: &str) {
-    assert_cannot_parse_query_params_error_response(response, &format!(" for announce request: {failure}")).await;
-}
-
 pub async fn assert_cannot_parse_query_param_error_response(response: Response, failure: &str) {
     assert_cannot_parse_query_params_error_response(response, &format!(": {failure}")).await;
 }

tests/http_tracker.rs

@@ -2198,24 +2198,25 @@ mod axum_http_tracker_server {
             use torrust_tracker::tracker::peer;
 
             use crate::common::fixtures::{invalid_info_hashes, PeerBuilder};
-            use crate::http::asserts::{assert_internal_server_error_response, assert_scrape_response};
+            use crate::http::asserts::{
+                assert_cannot_parse_query_params_error_response, assert_missing_query_params_for_scrape_request_error_response,
+                assert_scrape_response,
+            };
             use crate::http::client::Client;
             use crate::http::requests;
             use crate::http::requests::scrape::QueryBuilder;
             use crate::http::responses::scrape::{self, File, ResponseBuilder};
             use crate::http::server::{start_ipv6_http_tracker, start_public_http_tracker};
 
-            //#[tokio::test]
-            #[allow(dead_code)]
-            async fn should_fail_when_the_request_is_empty() {
+            #[tokio::test]
+            async fn should_fail_when_the_url_query_component_is_empty() {
                 let http_tracker_server = start_public_http_tracker(Version::Axum).await;
                 let response = Client::new(http_tracker_server.get_connection_info()).get("scrape").await;
 
-                assert_internal_server_error_response(response).await;
+                assert_missing_query_params_for_scrape_request_error_response(response).await;
             }
 
-            //#[tokio::test]
-            #[allow(dead_code)]
+            #[tokio::test]
             async fn should_fail_when_the_info_hash_param_is_invalid() {
                 let http_tracker_server = start_public_http_tracker(Version::Axum).await;
 
@@ -2228,13 +2229,11 @@ mod axum_http_tracker_server {
                         .get(&format!("announce?{params}"))
                         .await;
 
-                    // code-review: it's not returning the invalid info hash error
-                    assert_internal_server_error_response(response).await;
+                    assert_cannot_parse_query_params_error_response(response, "").await;
                 }
             }
 
-            //#[tokio::test]
-            #[allow(dead_code)]
+            #[tokio::test]
             async fn should_return_the_file_with_the_incomplete_peer_when_there_is_one_peer_with_bytes_pending_to_download() {
                 let http_tracker = start_public_http_tracker(Version::Axum).await;
 
@@ -2272,8 +2271,7 @@ mod axum_http_tracker_server {
                 assert_scrape_response(response, &expected_scrape_response).await;
             }
 
-            //#[tokio::test]
-            #[allow(dead_code)]
+            #[tokio::test]
             async fn should_return_the_file_with_the_complete_peer_when_there_is_one_peer_with_no_bytes_pending_to_download() {
                 let http_tracker = start_public_http_tracker(Version::Axum).await;
 
@@ -2311,8 +2309,7 @@ mod axum_http_tracker_server {
                 assert_scrape_response(response, &expected_scrape_response).await;
             }
 
-            //#[tokio::test]
-            #[allow(dead_code)]
+            #[tokio::test]
             async fn should_return_a_file_with_zeroed_values_when_there_are_no_peers() {
                 let http_tracker = start_public_http_tracker(Version::Axum).await;
 
@@ -2329,8 +2326,7 @@ mod axum_http_tracker_server {
                 assert_scrape_response(response, &scrape::Response::with_one_file(info_hash.bytes(), File::zeroed())).await;
             }
 
-            //#[tokio::test]
-            #[allow(dead_code)]
+            #[tokio::test]
             async fn should_accept_multiple_infohashes() {
                 let http_tracker = start_public_http_tracker(Version::Axum).await;