fix: missing atom:link with rel=self

app/src/main/java/run/halo/feed/FeedPluginEndpoint.java

@@ -42,7 +42,9 @@ public class FeedPluginEndpoint {
     RouterFunction<ServerResponse> rssRouterFunction() {
         return RouterFunctions.route()
             .GET(path("/feed.xml").or(path("/rss.xml")).and(ACCEPT_PREDICATE),
-                request -> rssCacheManager.get("/rss.xml", postRssProvider.handler(request))
+                request -> rssCacheManager.get(request.requestPath().toString(),
+                        postRssProvider.handler(request)
+                    )
                     .flatMap(this::buildResponse)
             )
             .build();
@@ -116,7 +118,9 @@ record RouteItem(RequestPredicate requestPredicate,
             }
 
             private HandlerFunction<ServerResponse> buildHandleFunction(RssRouteItem routeItem) {
-                return request -> rssCacheManager.get(request.path(), routeItem.handler(request))
+                return request -> rssCacheManager.get(request.requestPath().toString(),
+                        routeItem.handler(request)
+                    )
                     .flatMap(item -> buildResponse(item));
             }
 

app/src/main/java/run/halo/feed/RssCacheManager.java

@@ -25,18 +25,20 @@ public class RssCacheManager {
     private final SystemInfoGetter systemInfoGetter;
     private final ReactiveSettingFetcher settingFetcher;
 
-    public Mono<String> get(String key, Mono<RSS2> loader) {
-        return Mono.fromCallable(() -> cache.get(key, () -> generateRssXml(loader)
-                .doOnNext(xml -> cache.put(key, xml))
-                .block()
+    public Mono<String> get(String requestPath, Mono<RSS2> loader) {
+        return Mono.fromCallable(() -> cache.get(requestPath,
+                () -> generateRssXml(requestPath, loader)
+                    .doOnNext(xml -> cache.put(requestPath, xml))
+                    .block()
             ))
             .cache()
             .subscribeOn(Schedulers.boundedElastic());
     }
 
-    private Mono<String> generateRssXml(Mono<RSS2> loader) {
+    private Mono<String> generateRssXml(String requestPath, Mono<RSS2> loader) {
         var builder = new RssXmlBuilder()
-            .withGenerator("Halo v2.0");
+            .withGenerator("Halo v2.0")
+            .withRequestPath(requestPath);
 
         var rssMono = loader.doOnNext(builder::withRss2);
 

app/src/main/java/run/halo/feed/RssXmlBuilder.java

@@ -41,13 +41,19 @@ public class RssXmlBuilder {
     private String generator = "Halo v2.0";
     private String extractRssTags;
     private Instant lastBuildDate = Instant.now();
+    private String requestPath;
     private String externalUrl;
 
     public RssXmlBuilder withRss2(RSS2 rss2) {
         this.rss2 = rss2;
         return this;
     }
 
+    public RssXmlBuilder withRequestPath(String requestPath) {
+        this.requestPath = requestPath;
+        return this;
+    }
+
     /**
      * For test.
      */
@@ -80,12 +86,21 @@ public String toXmlString() {
         Element root = DocumentHelper.createElement("rss");
         root.addAttribute("version", "2.0");
         root.addNamespace("dc", "http://purl.org/dc/elements/1.1/");
+        root.addNamespace("atom", "http://www.w3.org/2005/Atom");
         root.addNamespace("media", "http://search.yahoo.com/mrss/");
         document.setRootElement(root);
 
         Element channel = root.addElement("channel");
         channel.addElement("title").addText(rss2.getTitle());
         channel.addElement("link").addText(rss2.getLink());
+        if (StringUtils.isNotBlank(requestPath)) {
+            channel.addElement("atom:link")
+                .addAttribute("href", UriComponentsBuilder.fromUriString(rss2.getLink())
+                    .path(requestPath).toUriString()
+                )
+                .addAttribute("rel", "self")
+                .addAttribute("type", "application/rss+xml");
+        }
 
         var description = StringUtils.defaultIfBlank(rss2.getDescription(), rss2.getTitle());
         var secureDescription = XmlCharUtils.removeInvalidXmlChar(description);
@@ -286,6 +301,8 @@ private Long getFileSizeBytes(String url) {
         return webClient.get()
             .uri(url)
             .header(HttpHeaders.USER_AGENT, UA)
+            // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Range
+            .header(HttpHeaders.RANGE, "bytes=0-0")
             .retrieve()
             .toBodilessEntity()
             .map(HttpEntity::getHeaders)

app/src/test/java/run/halo/feed/RSS2Test.java

@@ -46,6 +46,7 @@ void toXmlString() {
         var expected = """
             <?xml version="1.0" encoding="UTF-8"?>
             <rss xmlns:dc="http://purl.org/dc/elements/1.1/"
+            xmlns:atom="http://www.w3.org/2005/Atom"
              xmlns:media="http://search.yahoo.com/mrss/" version="2.0">
             	<channel>
             		<title>title</title>
@@ -111,6 +112,7 @@ void extractRssTagsTest() {
         var expected = """
             <?xml version="1.0" encoding="UTF-8"?>
              <rss xmlns:dc="http://purl.org/dc/elements/1.1/"
+                xmlns:atom="http://www.w3.org/2005/Atom"
                 xmlns:media="http://search.yahoo.com/mrss/" version="2.0">
                 <channel>
                     <title>title</title>
@@ -163,6 +165,7 @@ void invalidCharTest() {
         var expected = """
             <?xml version="1.0" encoding="UTF-8"?>
             <rss xmlns:dc="http://purl.org/dc/elements/1.1/"
+            xmlns:atom="http://www.w3.org/2005/Atom"
             xmlns:media="http://search.yahoo.com/mrss/" version="2.0">
             	<channel>
             		<title>title</title>