booru/site: Add setting to limit number of active connections

Fixes issues with konachan.com

src/booru/imagefetcher.cc

@@ -1,6 +1,8 @@
 #include "imagefetcher.h"
 using namespace AhoViewer::Booru;
 
+#include <algorithm>
+
 int ImageFetcher::socket_cb(CURL*, curl_socket_t s, int action, void *userp, void *sockp)
 {
     ImageFetcher *self = static_cast<ImageFetcher*>(userp);
@@ -73,12 +75,6 @@ ImageFetcher::ImageFetcher()
     curl_multi_setopt(m_MultiHandle, CURLMOPT_SOCKETDATA, this);
     curl_multi_setopt(m_MultiHandle, CURLMOPT_TIMERFUNCTION, &ImageFetcher::timer_cb);
     curl_multi_setopt(m_MultiHandle, CURLMOPT_TIMERDATA, this);
-
-    // Konachan seems to throw a 503 error if you have too many connections
-    // This is also inderectly controlled by the image list's threadpool size
-    // and the cache size setting
-    // TODO: Per-site setting for this
-    // curl_multi_setopt(m_MultiHandle, CURLMOPT_MAX_TOTAL_CONNECTIONS, 8);
 }
 
 ImageFetcher::~ImageFetcher()
@@ -123,6 +119,16 @@ void ImageFetcher::add_handle(Curler *curler)
     curler->m_StartTime = std::chrono::steady_clock::now();
 }
 
+// Konachan seems to throw a 503 error if you have too many connections
+// This is also indirectly controlled by the image list's threadpool size
+// and the cache size setting. It's only changable inside the cfg file.
+// 0 = unlimited, must be at least 2
+void ImageFetcher::set_max_connections(unsigned int n)
+{
+    n = n == 1 ? 2 : n;
+    curl_multi_setopt(m_MultiHandle, CURLMOPT_MAX_HOST_CONNECTIONS, n);
+}
+
 void ImageFetcher::remove_handle(Curler *curler)
 {
     if (!curler)

src/booru/imagefetcher.h

@@ -19,6 +19,8 @@ namespace AhoViewer
             void shutdown();
 
             void add_handle(Curler *curler);
+
+            void set_max_connections(unsigned int n);
         private:
             struct SockInfo
             {

src/booru/page.cc

@@ -142,6 +142,7 @@ void Page::search(const std::shared_ptr<Site> &site)
     m_Page = 1;
     m_LastPage = false;
     m_SearchTags = m_Tags;
+    m_ImageFetcher->set_max_connections(m_Site->get_max_connections());
 
     // Trim leading and trailing whitespace for tab label
     // and m_SearchTags which is used to display tags in other places

src/booru/site.cc

@@ -45,12 +45,12 @@ struct _shared_site : public Site
 };
 
 std::shared_ptr<Site> Site::create(const std::string &name, const std::string &url, const Type type,
-                                   const std::string &user, const std::string &pass)
+                                   const std::string &user, const std::string &pass, const unsigned int max_cons)
 {
     Type t = type == Type::UNKNOWN ? get_type_from_url(url) : type;
 
     if (t != Type::UNKNOWN)
-        return std::make_shared<_shared_site>(name, url, t, user, pass);
+        return std::make_shared<_shared_site>(name, url, t, user, pass, max_cons);
 
     return nullptr;
 }
@@ -176,7 +176,7 @@ void Site::share_unlock_cb(CURL *c, curl_lock_data data, void *userp)
 }
 
 Site::Site(const std::string &name, const std::string &url, const Type type,
-           const std::string &user, const std::string &pass)
+           const std::string &user, const std::string &pass, const unsigned int max_cons)
   : m_Name(name),
     m_Url(url),
     m_Username(user),
@@ -187,6 +187,7 @@ Site::Site(const std::string &name, const std::string &url, const Type type,
     m_Type(type),
     m_NewAccount(false),
     m_CookieTS(0),
+    m_MaxConnections(max_cons),
     m_ShareHandle(curl_share_init())
 {
     curl_share_setopt(m_ShareHandle, CURLSHOPT_LOCKFUNC, &Site::share_lock_cb);

src/booru/site.h

@@ -44,7 +44,8 @@ namespace AhoViewer
                                                 const std::string &url,
                                                 const Type type = Type::UNKNOWN,
                                                 const std::string &user = "",
-                                                const std::string &pass = "");
+                                                const std::string &pass = "",
+                                                const unsigned int max_cons = 0);
             static const Glib::RefPtr<Gdk::Pixbuf>& get_missing_pixbuf();
 
 #ifdef HAVE_LIBSECRET
@@ -76,6 +77,7 @@ namespace AhoViewer
             std::string get_cookie();
             void cleanup_cookie() const;
 
+            unsigned int get_max_connections() const { return m_MaxConnections; }
             CURLSH* get_share_handle() const { return m_ShareHandle; }
 
             Glib::RefPtr<Gdk::Pixbuf> get_icon_pixbuf(const bool update = false);
@@ -91,7 +93,8 @@ namespace AhoViewer
                  const std::string &url,
                  const Type type,
                  const std::string &user,
-                 const std::string &pass);
+                 const std::string &pass,
+                 const unsigned int max_cons);
         private:
             static Type get_type_from_url(const std::string &url);
 
@@ -113,6 +116,7 @@ namespace AhoViewer
             bool m_NewAccount;
             uint64_t m_CookieTS;
             std::set<std::string> m_Tags;
+            unsigned int m_MaxConnections;
             CURLSH *m_ShareHandle;
             std::map<curl_lock_data, Mutex> m_MutexMap;
             std::map<CURL*, ReaderMap> m_ReaderMap;

src/settings.cc

@@ -238,12 +238,16 @@ std::vector<std::shared_ptr<Site>>& SettingsManager::get_sites()
                             url      = s.exists("url") ? s["url"] : "",
                             username = s.exists("username") ? s["username"] : "",
                             password = s.exists("password") ? s["password"] : "";
+                unsigned int max_cons = 0;
+                s.lookupValue("max_connections", max_cons);
+                max_cons = max_cons == 1 ? 2 : max_cons;
                 m_Sites.push_back(
                         Site::create(name,
                                      url,
                                      static_cast<Site::Type>(static_cast<int>(s["type"])),
                                      username,
-                                     password));
+                                     password,
+                                     max_cons));
             }
 
             return m_Sites;
@@ -435,6 +439,7 @@ void SettingsManager::save_sites()
 #ifndef HAVE_LIBSECRET
         set("password", s->get_password(), Setting::TypeString, site);
 #endif // !HAVE_LIBSECRET
+        set("max_connections", static_cast<int>(s->get_max_connections()), Setting::TypeInt, site);
         s->cleanup_cookie();
     }
 }