Do not always download the favicon of a book. Download as needed.

When parsing a opds feed, the favicon is a url, not a dataurl.
If we download the favicon all the times, it may take a lot of time to
parse the feed.

We store the url and download the favicon only when needed (when displayed)

include/book.h

@@ -45,7 +45,7 @@ class Book
   bool update(const Book& other);
   void update(const Reader& reader);
   void updateFromXml(const pugi::xml_node& node, const std::string& baseDir);
-  void updateFromOpds(const pugi::xml_node& node);
+  void updateFromOpds(const pugi::xml_node& node, const std::string& urlHost);
   std::string getHumanReadableIdFromPath();
 
   bool readOnly() const { return m_readOnly; }
@@ -67,7 +67,7 @@ class Book
   const uint64_t& getArticleCount() const { return m_articleCount; }
   const uint64_t& getMediaCount() const { return m_mediaCount; }
   const uint64_t& getSize() const { return m_size; }
-  const std::string& getFavicon() const { return m_favicon; }
+  const std::string& getFavicon() const;
   const std::string& getFaviconMimeType() const { return m_faviconMimeType; }
   const std::string& getDownloadId() const { return m_downloadId; }
 
@@ -115,7 +115,8 @@ class Book
   uint64_t m_mediaCount;
   bool m_readOnly;
   uint64_t m_size;
-  std::string m_favicon;
+  mutable std::string m_favicon;
+  std::string m_faviconUrl;
   std::string m_faviconMimeType;
 };
 

src/book.cpp

@@ -22,6 +22,7 @@
 
 #include "common/base64.h"
 #include "common/regexTools.h"
+#include "common/networkTools.h"
 
 #include <pugixml.hpp>
 
@@ -131,7 +132,7 @@ void Book::updateFromXml(const pugi::xml_node& node, const std::string& baseDir)
 
 
 #define VALUE(name) node.child(name).child_value()
-void Book::updateFromOpds(const pugi::xml_node& node)
+void Book::updateFromOpds(const pugi::xml_node& node, const std::string& urlHost)
 {
   m_id = VALUE("id");
   if (!m_id.compare(0, 9, "urn:uuid:")) {
@@ -149,7 +150,10 @@ void Book::updateFromOpds(const pugi::xml_node& node)
     if (rel == "http://opds-spec.org/acquisition/open-access") {
       m_url = linkNode.attribute("href").value();
       m_size = strtoull(linkNode.attribute("length").value(), 0, 0);
-      break;
+    }
+    if (rel == "http://opds-spec.org/image/thumbnail") {
+      m_faviconUrl = urlHost + linkNode.attribute("href").value();
+      m_faviconMimeType = linkNode.attribute("type").value();
     }
  }
 
@@ -189,4 +193,15 @@ void Book::setIndexPath(const std::string& indexPath)
     : indexPath;
 }
 
+const std::string& Book::getFavicon() const {
+  if (m_favicon.empty() && !m_faviconUrl.empty()) {
+    try {
+      m_favicon = download(m_faviconUrl);
+    } catch(...) {
+      std::cerr << "Cannot download favicon from " << m_faviconUrl;
+    }
+  }
+  return m_favicon;
+}
+
 }

src/manager.cpp

@@ -18,7 +18,6 @@
  */
 
 #include "manager.h"
-#include "common/networkTools.h"
 
 #include <pugixml.hpp>
 
@@ -101,22 +100,7 @@ bool Manager::parseOpdsDom(const pugi::xml_document& doc, const std::string& url
     kiwix::Book book;
 
     book.setReadOnly(false);
-    book.updateFromOpds(entryNode);
-    for(pugi::xml_node linkNode = entryNode.child("link"); linkNode;
-        linkNode = linkNode.next_sibling("link")) {
-       std::string rel = linkNode.attribute("rel").value();
-
-       if (rel == "http://opds-spec.org/image/thumbnail") {
-         auto faviconUrl = urlHost + linkNode.attribute("href").value();
-         try {
-           book.setFavicon(download(faviconUrl));
-           book.setFaviconMimeType(linkNode.attribute("type").value());
-         } catch (...) {
-           std::cerr << "Cannot get favicon content from " << faviconUrl << std::endl;
-         }
-         break;
-       }
-    }
+    book.updateFromOpds(entryNode, urlHost);
 
     /* Update the book properties with the new importer */
     manipulator->addBookToLibrary(book);