ETags for ZIM content use the ZIM file UUID

src/server/internalServer.cpp

@@ -511,8 +511,10 @@ MHD_Result InternalServer::handlerCallback(struct MHD_Connection* connection,
     }
   }
 
-  if (response->getReturnCode() == MHD_HTTP_OK && !etag_not_needed(request))
-    response->set_server_id(m_server_id);
+  if (response->getReturnCode() == MHD_HTTP_OK
+      && response->get_kind() == Response::DYNAMIC_CONTENT
+      && !etag_not_needed(request))
+    response->set_etag_body(m_server_id);
 
   auto ret = response->send(request, connection);
   auto end_time = std::chrono::steady_clock::now();
@@ -542,7 +544,7 @@ std::unique_ptr<Response> InternalServer::handle_request(const RequestContext& r
              + urlNotFoundMsg;
     }
 
-    const ETag etag = get_matching_if_none_match_etag(request);
+    const ETag etag = get_matching_if_none_match_etag(request, m_server_id);
     if ( etag )
       return Response::build_304(*this, etag);
 
@@ -611,11 +613,11 @@ bool InternalServer::etag_not_needed(const RequestContext& request) const
 }
 
 ETag
-InternalServer::get_matching_if_none_match_etag(const RequestContext& r) const
+InternalServer::get_matching_if_none_match_etag(const RequestContext& r, const std::string& etagBody) const
 {
   try {
     const std::string etag_list = r.get_header(MHD_HTTP_HEADER_IF_NONE_MATCH);
-    return ETag::match(etag_list, m_server_id);
+    return ETag::match(etag_list, etagBody);
   } catch (const std::out_of_range&) {
     return ETag();
   }
@@ -1049,6 +1051,11 @@ std::unique_ptr<Response> InternalServer::handle_content(const RequestContext& r
            + suggestSearchMsg(searchURL, kiwix::urlDecode(pattern));
   }
 
+  const std::string archiveUuid(archive->getUuid());
+  const ETag etag = get_matching_if_none_match_etag(request, archiveUuid);
+  if ( etag )
+    return Response::build_304(*this, etag);
+
   auto urlStr = url.substr(prefixLength + bookName.size());
   if (urlStr[0] == '/') {
     urlStr = urlStr.substr(1);
@@ -1067,6 +1074,7 @@ std::unique_ptr<Response> InternalServer::handle_content(const RequestContext& r
       return build_redirect(bookName, getFinalItem(*archive, entry));
     }
     auto response = ItemResponse::build(*this, request, entry.getItem());
+    response->set_etag_body(archiveUuid);
 
     if (m_verbose.load()) {
       printf("Found %s\n", entry.getPath().c_str());
@@ -1120,6 +1128,11 @@ std::unique_ptr<Response> InternalServer::handle_raw(const RequestContext& reque
            + noSuchBookErrorMsg(bookName);
   }
 
+  const std::string archiveUuid(archive->getUuid());
+  const ETag etag = get_matching_if_none_match_etag(request, archiveUuid);
+  if ( etag )
+    return Response::build_304(*this, etag);
+
   // Remove the beggining of the path:
   // /raw/<bookName>/<kind>/foo
   // ^^^^^          ^      ^
@@ -1129,13 +1142,17 @@ std::unique_ptr<Response> InternalServer::handle_raw(const RequestContext& reque
   try {
     if (kind == "meta") {
       auto item = archive->getMetadataItem(itemPath);
-      return ItemResponse::build(*this, request, item);
+      auto response = ItemResponse::build(*this, request, item);
+      response->set_etag_body(archiveUuid);
+      return response;
     } else {
       auto entry = archive->getEntryByPath(itemPath);
       if (entry.isRedirect()) {
         return build_redirect(bookName, entry.getItem(true));
       }
-      return ItemResponse::build(*this, request, entry.getItem());
+      auto response = ItemResponse::build(*this, request, entry.getItem());
+      response->set_etag_body(archiveUuid);
+      return response;
     }
   } catch (zim::EntryNotFound& e ) {
     if (m_verbose.load()) {

src/server/internalServer.h

@@ -148,7 +148,7 @@ class InternalServer {
     MustacheData get_default_data() const;
 
     bool etag_not_needed(const RequestContext& r) const;
-    ETag get_matching_if_none_match_etag(const RequestContext& request) const;
+    ETag get_matching_if_none_match_etag(const RequestContext& request, const std::string& etagBody) const;
     std::pair<std::string, Library::BookIdSet> selectBooks(const RequestContext& r) const;
     SearchInfo getSearchInfo(const RequestContext& r) const;
 

src/server/response.h

@@ -66,7 +66,8 @@ class Response {
 
     void set_code(int code) { m_returnCode = code; }
     void set_kind(Kind k);
-    void set_server_id(const std::string& id) { m_etag.set_body(id); }
+    Kind get_kind() const { return m_kind; }
+    void set_etag_body(const std::string& id) { m_etag.set_body(id); }
     void add_header(const std::string& name, const std::string& value) { m_customHeaders[name] = value; }
 
     int getReturnCode() const { return m_returnCode; }

test/server.cpp

@@ -1136,17 +1136,28 @@ TEST_F(ServerTest, ETagIsTheSameAcrossHeadAndGet)
   }
 }
 
-TEST_F(ServerTest, DifferentServerInstancesProduceDifferentETags)
+TEST_F(ServerTest, DifferentServerInstancesProduceDifferentETagsForDynamicContent)
 {
   ZimFileServer zfs2(SERVER_PORT + 1, ZimFileServer::DEFAULT_OPTIONS, ZIMFILES);
   for ( const Resource& res : all200Resources() ) {
-    if ( !res.etag_expected() ) continue;
+    if ( res.kind != DYNAMIC_CONTENT ) continue;
     const auto h1 = zfs1_->HEAD(res.url);
     const auto h2 = zfs2.HEAD(res.url);
     EXPECT_NE(h1->get_header_value("ETag"), h2->get_header_value("ETag"));
   }
 }
 
+TEST_F(ServerTest, DifferentServerInstancesProduceIdenticalETagsForZimContent)
+{
+  ZimFileServer zfs2(SERVER_PORT + 1, ZimFileServer::DEFAULT_OPTIONS, ZIMFILES);
+  for ( const Resource& res : all200Resources() ) {
+    if ( res.kind != ZIM_CONTENT ) continue;
+    const auto h1 = zfs1_->HEAD(res.url);
+    const auto h2 = zfs2.HEAD(res.url);
+    EXPECT_EQ(h1->get_header_value("ETag"), h2->get_header_value("ETag"));
+  }
+}
+
 TEST_F(ServerTest, CompressionInfluencesETag)
 {
   for ( const Resource& res : resources200Compressible ) {