From ab47b72dc84e49d9b7e647b08af93020fa510616 Mon Sep 17 00:00:00 2001
From: Maxime Coste <frrrwww@gmail.com>
Date: Tue, 28 Aug 2012 22:32:15 +0200
Subject: [PATCH] add a poll based EventManager and use it for ncurse client
 update

---
 src/event_manager.cc | 45 ++++++++++++++++++++++++++++++++++++
 src/event_manager.hh | 29 +++++++++++++++++++++++
 src/main.cc          | 55 +++++++++++++++++++++++++-------------------
 3 files changed, 105 insertions(+), 24 deletions(-)
 create mode 100644 src/event_manager.cc
 create mode 100644 src/event_manager.hh

diff --git a/src/event_manager.cc b/src/event_manager.cc
new file mode 100644
index 00000000..2a8df29c
--- /dev/null
+++ b/src/event_manager.cc
@@ -0,0 +1,45 @@
+#include "event_manager.hh"
+
+#include <algorithm>
+
+namespace Kakoune
+{
+
+void EventManager::watch(int fd, EventHandler handler)
+{
+    auto event = std::find_if(m_events.begin(), m_events.end(),
+                              [&](const pollfd& pfd) { return pfd.fd == fd; });
+    if (event != m_events.end())
+        throw runtime_error("fd already watched");
+
+    m_events.push_back(pollfd{ fd, POLLIN | POLLPRI, 0 });
+    m_handlers.push_back(std::move(handler));
+}
+
+void EventManager::unwatch(int fd)
+{
+    for (size_t i = 0; i < m_events.size(); ++i)
+    {
+        if (m_events[i].fd == fd)
+        {
+            m_events.erase(m_events.begin() + i);
+            m_handlers.erase(m_handlers.begin() + i);
+            return;
+        }
+    }
+}
+
+void EventManager::handle_next_events()
+{
+    int res = poll(m_events.data(), m_events.size(), -1);
+    if (res > 0)
+    {
+        for (size_t i = 0; i < m_events.size(); ++i)
+        {
+            if (m_events[i].revents & POLLIN)
+                m_handlers[i](m_events[i].fd);
+        }
+    }
+}
+
+}
diff --git a/src/event_manager.hh b/src/event_manager.hh
new file mode 100644
index 00000000..c1795983
--- /dev/null
+++ b/src/event_manager.hh
@@ -0,0 +1,29 @@
+#ifndef event_manager_hh_INCLUDED
+#define event_manager_hh_INCLUDED
+
+#include <poll.h>
+
+#include "utils.hh"
+
+namespace Kakoune
+{
+
+using EventHandler = std::function<void (int fd)>;
+
+class EventManager : public Singleton<EventManager>
+{
+public:
+    void watch(int fd, EventHandler handler);
+    void unwatch(int fd);
+
+    void handle_next_events();
+
+private:
+    std::vector<pollfd> m_events;
+    std::vector<EventHandler> m_handlers;
+};
+
+}
+
+#endif // event_manager_hh_INCLUDED
+
diff --git a/src/main.cc b/src/main.cc
index 53cddfac..ec18016e 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -14,6 +14,7 @@
 #include "filter_registry.hh"
 #include "hook_manager.hh"
 #include "option_manager.hh"
+#include "event_manager.hh"
 #include "context.hh"
 #include "ncurses.hh"
 #include "regex.hh"
@@ -442,6 +443,32 @@ std::unordered_map<Key, std::function<void (Context& context)>> keymap =
 
 void run_unit_tests();
 
+void manage_next_keypress(Context& context)
+{
+    static int count = 0;
+    try
+    {
+        Key key = context.client().get_key();
+        if (key.modifiers == Key::Modifiers::None and isdigit(key.key))
+            count = count * 10 + key.key - '0';
+        else
+        {
+            auto it = keymap.find(key);
+            if (it != keymap.end())
+            {
+                context.numeric_param(count);
+                it->second(context);
+                context.draw_ifn();
+            }
+            count = 0;
+        }
+    }
+    catch (Kakoune::runtime_error& error)
+    {
+        context.print_status(error.description());
+    }
+}
+
 int main(int argc, char* argv[])
 {
     GlobalOptionManager option_manager;
@@ -452,6 +479,7 @@ int main(int argc, char* argv[])
     RegisterManager     register_manager;
     HighlighterRegistry highlighter_registry;
     FilterRegistry      filter_registry;
+    EventManager        event_manager;
 
     run_unit_tests();
 
@@ -507,32 +535,11 @@ int main(int argc, char* argv[])
             context.change_editor(*buffer->get_or_create_window());
         }
 
+        event_manager.watch(0, [&](int) { manage_next_keypress(context); });
+
         context.draw_ifn();
-        int count = 0;
         while(not quit_requested)
-        {
-            try
-            {
-                Key key = context.client().get_key();
-                if (key.modifiers == Key::Modifiers::None and isdigit(key.key))
-                    count = count * 10 + key.key - '0';
-                else
-                {
-                    auto it = keymap.find(key);
-                    if (it != keymap.end())
-                    {
-                        context.numeric_param(count);
-                        it->second(context);
-                        context.draw_ifn();
-                    }
-                    count = 0;
-                }
-            }
-            catch (Kakoune::runtime_error& error)
-            {
-                context.print_status(error.description());
-            }
-        }
+            event_manager.handle_next_events();
     }
     catch (Kakoune::exception& error)
     {