feat(github): New module

Module used to query the GitHub API for information.
Currently only supports notification count.

Ref #84

cmake/build/options.cmake

@@ -33,6 +33,14 @@ if(NOT DEFINED ENABLE_I3 AND NOT I3_BINARY)
   set(ENABLE_I3 OFF CACHE STRING "Module support for i3wm")
 endif()
 
+# }}}
+# Default value for: ENABLE_CURL {{{
+
+find_package(CURL QUIET)
+if(NOT DEFINED ENABLE_CURL AND NOT CURL_FOUND)
+  set(ENABLE_CURL OFF CACHE STRING "Module support for libcurl")
+endif()
+
 # }}}
 
 # Define build options {{{
@@ -47,6 +55,7 @@ option(DEBUG_HINTS        "Enable hints rendering"     OFF)
 
 option(ENABLE_CCACHE      "Enable ccache support"      OFF)
 option(ENABLE_ALSA        "Enable alsa support"        ON)
+option(ENABLE_CURL        "Enable curl support"        ON)
 option(ENABLE_I3          "Enable i3 support"          ON)
 option(ENABLE_MPD         "Enable mpd support"         ON)
 option(ENABLE_NETWORK     "Enable network support"     ON)

cmake/build/summary.cmake

@@ -51,6 +51,7 @@ colored_option(STATUS " Draw debug hints     ${DEBUG_HINTS}" DEBUG_HINTS "32;1"
 colored_option(STATUS " Enable ccache        ${ENABLE_CCACHE}" ENABLE_CCACHE "32;1" "37;2")
 message(STATUS "--------------------------")
 colored_option(STATUS " Enable alsa          ${ENABLE_ALSA}" ENABLE_ALSA "32;1" "37;2")
+colored_option(STATUS " Enable curl          ${ENABLE_CURL}" ENABLE_CURL "32;1" "37;2")
 colored_option(STATUS " Enable i3            ${ENABLE_I3}" ENABLE_I3 "32;1" "37;2")
 colored_option(STATUS " Enable mpd           ${ENABLE_MPD}" ENABLE_MPD "32;1" "37;2")
 colored_option(STATUS " Enable network       ${ENABLE_NETWORK}" ENABLE_NETWORK "32;1" "37;2")

include/components/config.hpp

@@ -5,6 +5,7 @@
 #include "components/logger.hpp"
 #include "errors.hpp"
 #include "utils/env.hpp"
+#include "utils/file.hpp"
 #include "utils/string.hpp"
 #include "x11/xresources.hpp"
 
@@ -196,6 +197,8 @@ class config {
       return dereference_env<T>(path.substr(4), fallback);
     } else if (path.compare(0, 5, "xrdb:") == 0) {
       return dereference_xrdb<T>(path.substr(5), fallback);
+    } else if (path.compare(0, 5, "file:") == 0) {
+      return dereference_file<T>(path.substr(5), fallback);
     } else if ((pos = path.find(".")) != string::npos) {
       return dereference_local<T>(path.substr(0, pos), path.substr(pos + 1), section);
     } else {
@@ -274,6 +277,21 @@ class config {
     return str.empty() ? fallback : convert<T>(move(str));
   }
 
+  /**
+   * Dereference file reference by reading its contents
+   *  ${file:/absolute/file/path}
+   */
+  template <typename T>
+  T dereference_file(string var, const T& fallback) const {
+    string filename{move(var)};
+
+    if (file_util::exists(filename)) {
+      return convert<T>(string_util::trim(file_util::get_contents(filename), '\n'));
+    }
+
+    return fallback;
+  }
+
  private:
   static constexpr const char* KEY_INHERIT{"inherit"};
 

include/config.hpp.cmake

@@ -16,6 +16,7 @@
 #cmakedefine01 ENABLE_MPD
 #cmakedefine01 ENABLE_NETWORK
 #cmakedefine01 ENABLE_I3
+#cmakedefine01 ENABLE_CURL
 
 #cmakedefine01 WITH_XRANDR
 #cmakedefine01 WITH_XRENDER
@@ -78,6 +79,7 @@ auto print_build_info = [](bool extended = false) {
             << "\n"
             << "Features: "
             << (ENABLE_ALSA    ? "+" : "-") << "alsa "
+            << (ENABLE_CURL    ? "+" : "-") << "curl "
             << (ENABLE_I3      ? "+" : "-") << "i3 "
             << (ENABLE_MPD     ? "+" : "-") << "mpd "
             << (ENABLE_NETWORK ? "+" : "-") << "network "

include/modules/github.hpp

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "config.hpp"
+#include "modules/meta/timer_module.hpp"
+#include "utils/http.hpp"
+
+POLYBAR_NS
+
+namespace modules {
+  /**
+   * Module used to query the GitHub API for notification count
+   */
+  class github_module : public timer_module<github_module> {
+   public:
+    explicit github_module(const bar_settings&, string);
+
+    void setup();
+    bool update();
+    bool build(builder* builder, const string& tag) const;
+
+   private:
+    static constexpr auto TAG_LABEL = "<label>";
+
+    label_t m_label{};
+    string m_accesstoken{};
+    unique_ptr<http_downloader> m_http{};
+  };
+}
+
+POLYBAR_NS_END

include/modules/meta/base.inl

@@ -25,6 +25,9 @@ namespace modules {
         thread_.join();
       }
     }
+    if (m_mainthread.joinable()) {
+      m_mainthread.join();
+    }
   }
 
   template <typename Impl>
@@ -44,7 +47,7 @@ namespace modules {
 
   template <typename Impl>
   bool module<Impl>::running() const {
-    return m_enabled.load(std::memory_order_relaxed);
+    return static_cast<bool>(m_enabled);
   }
 
   template <typename Impl>
@@ -66,24 +69,20 @@ namespace modules {
     }
 
     m_log.info("%s: Stopping", name());
-    m_enabled.store(false, std::memory_order_relaxed);
+    m_enabled = false;
 
-    wakeup();
-
-    std::lock_guard<std::mutex> guard_a(m_buildlock);
-    std::lock_guard<std::mutex> guard_b(m_updatelock);
+    std::lock(m_buildlock, m_updatelock);
+    std::lock_guard<std::mutex> guard_a(m_buildlock, std::adopt_lock);
+    std::lock_guard<std::mutex> guard_b(m_updatelock, std::adopt_lock);
     {
+      CAST_MOD(Impl)->wakeup();
       CAST_MOD(Impl)->teardown();
 
-      if (m_mainthread.joinable()) {
-        m_mainthread.join();
-      }
-    }
-
       if (m_stop_callback) {
         m_stop_callback();
       }
     }
+  }
 
   template <typename Impl>
   void module<Impl>::halt(string error_message) {

include/modules/meta/factory.hpp

@@ -31,10 +31,13 @@
 #if ENABLE_ALSA
 #include "modules/volume.hpp"
 #endif
+#if ENABLE_CURL
+#include "modules/github.hpp"
+#endif
 #if WITH_XKB
 #include "modules/xkeyboard.hpp"
 #endif
-#if not(ENABLE_I3 && ENABLE_MPD && ENABLE_NETWORK && ENABLE_ALSA && WITH_XKB)
+#if not(ENABLE_I3 && ENABLE_MPD && ENABLE_NETWORK && ENABLE_ALSA && ENABLE_CURL && WITH_XKB)
 #include "modules/unsupported.hpp"
 #endif
 
@@ -57,6 +60,8 @@ namespace {
       return new cpu_module(forward<Args>(args)...);
     } else if (name == "internal/date") {
       return new date_module(forward<Args>(args)...);
+    } else if (name == "internal/github") {
+      return new github_module(forward<Args>(args)...);
     } else if (name == "internal/fs") {
       return new fs_module(forward<Args>(args)...);
     } else if (name == "internal/memory") {

include/modules/meta/timer_module.inl

@@ -15,13 +15,16 @@ namespace modules {
   void timer_module<Impl>::runner() {
     try {
       while (CONST_MOD(Impl).running()) {
-        std::lock_guard<std::mutex> guard(this->m_updatelock);
         {
+          std::lock_guard<std::mutex> guard(this->m_updatelock);
+
           if (CAST_MOD(Impl)->update())
             CAST_MOD(Impl)->broadcast();
         }
+        if (CONST_MOD(Impl).running()) {
           CAST_MOD(Impl)->sleep(m_interval);
         }
+      }
     } catch (const module_error& err) {
       CAST_MOD(Impl)->halt(err.what());
     } catch (const std::exception& err) {

include/modules/unsupported.hpp

@@ -1,5 +1,5 @@
 #pragma once
-#if ENABLE_I3 && ENABLE_MPD && ENABLE_NETWORK && ENABLE_ALSA && WITH_XKB
+#if ENABLE_I3 && ENABLE_MPD && ENABLE_NETWORK && ENABLE_ALSA && ENABLE_CURL && WITH_XKB
 #error "Support has been enabled for all optional modules"
 #endif
 
@@ -9,7 +9,7 @@
 #if not(ENABLE_ALSA && ENABLE_I3 && ENABLE_MPD)
 #include "modules/meta/event_module.inl"
 #endif
-#if not ENABLE_NETWORK
+#if not(ENABLE_NETWORK && ENABLE_CURL)
 #include "modules/meta/timer_module.inl"
 #endif
 #if not WITH_XKB
@@ -62,6 +62,9 @@ namespace modules {
 #if not ENABLE_ALSA
   DEFINE_UNSUPPORTED_MODULE(volume_module, "internal/volume");
 #endif
+#if not ENABLE_CURL
+  DEFINE_UNSUPPORTED_MODULE(github_module, "internal/github");
+#endif
 #if not WITH_XKB
   DEFINE_UNSUPPORTED_MODULE(xkeyboard_module, "internal/xkeyboard");
 #endif

include/utils/http.hpp

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "common.hpp"
+#include "utils/factory.hpp"
+
+POLYBAR_NS
+
+class http_downloader {
+ public:
+  http_downloader(int connection_timeout = 5);
+  ~http_downloader();
+
+  string get(const string& url);
+  long response_code();
+
+ protected:
+  static size_t write(void* p, size_t size, size_t bytes, void* stream);
+
+ private:
+  void* m_curl;
+};
+
+namespace http_util {
+  template <typename... Args>
+  decltype(auto) make_downloader(Args&&... args) {
+    return factory_util::unique<http_downloader>(forward<Args>(args)...);
+  }
+}
+
+POLYBAR_NS_END

src/CMakeLists.txt

@@ -18,6 +18,9 @@ endif()
 if(NOT ENABLE_I3)
   list(REMOVE_ITEM SOURCES modules/i3.cpp utils/i3.cpp)
 endif()
+if(NOT ENABLE_CURL)
+  list(REMOVE_ITEM SOURCES utils/http.cpp modules/github.cpp)
+endif()
 
 if(NOT WITH_XCOMPOSITE)
   list(REMOVE_ITEM SOURCES x11/composite.cpp)
@@ -128,6 +131,16 @@ if(ENABLE_I3)
 endif()
 
 # }}}
+# Optional dependency: i3ipcpp {{{
+
+if(ENABLE_CURL)
+  find_package(CURL REQUIRED)
+  set(APP_LIBRARIES ${APP_LIBRARIES} ${CURL_LIBRARY})
+  set(APP_INCLUDE_DIRS ${APP_INCLUDE_DIRS} ${CURL_INCLUDE_DIR})
+endif()
+
+# }}}
+
 # Create executable target {{{
 
 make_executable(${PROJECT_NAME} SOURCES

src/modules/github.cpp

@@ -0,0 +1,79 @@
+#include "modules/github.hpp"
+#include "drawtypes/label.hpp"
+
+#include "modules/meta/base.inl"
+#include "modules/meta/timer_module.inl"
+
+POLYBAR_NS
+
+namespace modules {
+  template class module<github_module>;
+  template class timer_module<github_module>;
+
+  /**
+   * Construct module
+   */
+  github_module::github_module(const bar_settings& bar, string name)
+      : timer_module<github_module>(bar, name), m_http(http_util::make_downloader()) {}
+
+  /**
+   * Bootstrap module
+   */
+  void github_module::setup() {
+    m_accesstoken = m_conf.get<string>(name(), "token");
+    m_interval = m_conf.get<chrono::seconds>(name(), "interval", 60s);
+
+    m_formatter->add(DEFAULT_FORMAT, TAG_LABEL, {TAG_LABEL});
+
+    if (m_formatter->has(TAG_LABEL)) {
+      m_label = load_optional_label(m_conf, name(), TAG_LABEL, "Notifications: %notifications%");
+    }
+  }
+
+  /**
+   * Update module contents
+   */
+  bool github_module::update() {
+    string content{m_http->get("https://api.github.com/notifications?access_token=" + m_accesstoken)};
+    long response_code{m_http->response_code()};
+
+    switch (response_code) {
+      case 200:
+        break;
+      case 401:
+        throw module_error("Bad credentials");
+      case 403:
+        throw module_error("Maximum number of login attempts exceeded");
+      default:
+        throw module_error("Unspecified error (" + to_string(response_code) + ")");
+    }
+
+    size_t pos{0};
+    size_t notifications{0};
+
+    while ((pos = content.find("\"unread\":true", pos + 1)) != string::npos) {
+      notifications++;
+    }
+
+    if (m_label) {
+      m_label->reset_tokens();
+      m_label->replace_token("%notifications%", to_string(notifications));
+    }
+
+    return true;
+  }
+
+  /**
+   * Build module content
+   */
+  bool github_module::build(builder* builder, const string& tag) const {
+    if (tag == TAG_LABEL) {
+      builder->node(m_label);
+    } else {
+      return false;
+    }
+    return true;
+  }
+}
+
+POLYBAR_NS_END

src/utils/http.cpp

@@ -0,0 +1,51 @@
+#include <curl/curl.h>
+#include <curl/curlbuild.h>
+#include <curl/easy.h>
+#include <iostream>
+#include <sstream>
+
+#include "errors.hpp"
+#include "utils/http.hpp"
+
+POLYBAR_NS
+
+http_downloader::http_downloader(int connection_timeout) {
+  m_curl = curl_easy_init();
+  curl_easy_setopt(m_curl, CURLOPT_ACCEPT_ENCODING, "deflate");
+  curl_easy_setopt(m_curl, CURLOPT_CONNECTTIMEOUT, connection_timeout);
+  curl_easy_setopt(m_curl, CURLOPT_FOLLOWLOCATION, true);
+  curl_easy_setopt(m_curl, CURLOPT_NOSIGNAL, true);
+  curl_easy_setopt(m_curl, CURLOPT_USERAGENT, "polybar/" GIT_TAG);
+  curl_easy_setopt(m_curl, CURLOPT_WRITEFUNCTION, http_downloader::write);
+}
+
+http_downloader::~http_downloader() {
+  curl_easy_cleanup(m_curl);
+}
+
+string http_downloader::get(const string& url) {
+  stringstream out{};
+  curl_easy_setopt(m_curl, CURLOPT_URL, url.c_str());
+  curl_easy_setopt(m_curl, CURLOPT_WRITEDATA, &out);
+
+  auto res = curl_easy_perform(m_curl);
+  if (res != CURLE_OK) {
+    throw application_error(curl_easy_strerror(res), res);
+  }
+
+  return out.str();
+}
+
+long http_downloader::response_code() {
+  long code{0};
+  curl_easy_getinfo(m_curl, CURLINFO_RESPONSE_CODE, &code);
+  return code;
+}
+
+size_t http_downloader::write(void* p, size_t size, size_t bytes, void* stream) {
+  string data{static_cast<const char*>(p), size * bytes};
+  *(static_cast<stringstream*>(stream)) << data << '\n';
+  return size * bytes;
+}
+
+POLYBAR_NS_END