Make libaria2 an optional dependency.

We don't compile libaria2 on Windows.

include/downloader.h

@@ -21,7 +21,9 @@
 #define KIWIX_DOWNLOADER_H
 
 #include <string>
+#ifdef ENABLE_LIBARIA2
 # include <aria2/aria2.h>
+#endif
 #include <pthread.h>
 
 namespace kiwix
@@ -56,14 +58,15 @@ class Downloader
  private:
   static pthread_mutex_t globalLock;
 
-  aria2::Session* session;
-  DownloadedFile* fileHandle;
   std::string tmpDir;
-
+#ifdef ENABLE_LIBARIA2
+  DownloadedFile* fileHandle;
+  aria2::Session* session;
   static int downloadEventCallback(aria2::Session* session,
                                    aria2::DownloadEvent event,
                                    aria2::A2Gid gid,
                                    void* userData);
+#endif
 };
 }
 

meson.build

@@ -17,7 +17,7 @@ thread_dep = dependency('threads')
 libicu_dep = dependency('icu-i18n', static:static_deps)
 libzim_dep = dependency('libzim', version : '>=4.0.0', static:static_deps)
 pugixml_dep = dependency('pugixml', static:static_deps)
-libaria2_dep = dependency('libaria2', static:static_deps)
+libaria2_dep = dependency('libaria2', static:static_deps, required:false)
 
 ctpp2_include_path = ''
 has_ctpp2_dep = false
@@ -88,6 +88,7 @@ inc = include_directories('include')
 conf = configuration_data()
 conf.set('VERSION', '"@0@"'.format(meson.project_version()))
 conf.set('ENABLE_CTPP2', has_ctpp2_dep)
+conf.set('ENABLE_LIBARIA2', libaria2_dep.found())
 
 subdir('include')
 subdir('scripts')
@@ -95,7 +96,10 @@ subdir('static')
 subdir('src')
 subdir('test')
 
-pkg_requires = ['libzim', 'icu-i18n', 'pugixml', 'libaria2']
+pkg_requires = ['libzim', 'icu-i18n', 'pugixml']
+if libaria2_dep.found()
+    pkg_requires += ['libaria2']
+endif
 if xapian_dep.found()
     pkg_requires += ['xapian-core']
 endif

src/config.h.in

@@ -2,3 +2,5 @@
 #mesondefine VERSION
 
 #mesondefine ENABLE_CTPP2
+
+#mesondefine ENABLE_LIBARIA2

src/downloader.cpp

@@ -32,6 +32,7 @@ pthread_mutex_t Downloader::globalLock = PTHREAD_MUTEX_INITIALIZER;
 /* Constructor */
 Downloader::Downloader()
 {
+#ifdef ENABLE_LIBARIA2
   aria2::SessionConfig config;
   config.downloadEventCallback = Downloader::downloadEventCallback;
   config.userData = this;
@@ -39,17 +40,20 @@ Downloader::Downloader()
   aria2::KeyVals options;
   options.push_back(std::pair<std::string, std::string>("dir", tmpDir));
   session = aria2::sessionNew(options, config);
+#endif
 }
 
 
 /* Destructor */
 Downloader::~Downloader()
 {
+#ifdef ENABLE_LIBARIA2
   aria2::sessionFinal(session);
+#endif
   rmdir(tmpDir.c_str());
 }
 
-
+#ifdef ENABLE_LIBARIA2
 int Downloader::downloadEventCallback(aria2::Session* session,
                                       aria2::DownloadEvent event,
                                       aria2::A2Gid gid,
@@ -85,10 +89,12 @@ int Downloader::downloadEventCallback(aria2::Session* session,
   aria2::deleteDownloadHandle(dh);
   return 0;
 }
+#endif
 
 DownloadedFile Downloader::download(const std::string& url) {
   pthread_mutex_lock(&globalLock);
   DownloadedFile fileHandle;
+#ifdef ENABLE_LIBARIA2
   try {
     std::vector<std::string> uris = {url};
     aria2::KeyVals options;
@@ -106,6 +112,7 @@ DownloadedFile Downloader::download(const std::string& url) {
   } catch (...) {};
   this->fileHandle = nullptr;
   pthread_mutex_unlock(&globalLock);
+#endif
   return fileHandle;
 }