Separate worker thread into util class

include/modules/custom.hpp

@@ -1,27 +1,28 @@
 #pragma once
 
 #include <fmt/format.h>
+
 #include <csignal>
 #include <string>
+
 #include "ALabel.hpp"
 #include "util/command.hpp"
 #include "util/json.hpp"
-#include "util/sleeper_thread.hpp"
+#include "util/worker_thread.hpp"
 
 namespace waybar::modules {
 
 class Custom : public ALabel {
  public:
   Custom(const std::string&, const std::string&, const Json::Value&);
-  ~Custom();
   auto update() -> void;
   void refresh(int /*signal*/);
 
  private:
-  void delayWorker();
+  void workerExitCallback(int);
-  void continuousWorker();
+  void workerOutputCallback(std::string);
-  void parseOutputRaw();
+  void parseOutputRaw(const std::string&);
-  void parseOutputJson();
+  void parseOutputJson(const std::string&);
   void handleEvent();
   bool handleScroll(GdkEventScroll* e);
   bool handleToggle(GdkEventButton* const& e);
@@ -32,12 +33,10 @@ class Custom : public ALabel {
   std::string              tooltip_;
   std::vector<std::string> class_;
   int                      percentage_;
-  FILE*                    fp_;
-  int                      pid_;
   util::command::res       output_;
   util::JsonParser         parser_;
 
-  util::SleeperThread thread_;
+  waybar::util::WorkerThread thread_;
 };
 
 }  // namespace waybar::modules

include/util/worker_thread.hpp

@@ -0,0 +1,132 @@
+#pragma once
+
+#include <chrono>
+#include <optional>
+#include <string>
+
+#include "util/command.hpp"
+#include "util/sleeper_thread.hpp"
+
+namespace waybar::util {
+
+/**
+ * Runs a child process and reads output from it, providing it to
+ * the callbacks.
+ */
+class WorkerThread {
+ public:
+  WorkerThread() : pid_(-1) {}
+
+  WorkerThread(const Json::Value& config, std::function<void(std::string)> output_callback,
+               std::function<void(int)> exit_callback)
+      : output_callback_(output_callback), exit_callback_(exit_callback), pid_(-1) {
+    if (config["exec"].isString()) {
+      exec_ = config["exec"].asString();
+    }
+    if (config["exec_if"].isString()) {
+      exec_if_ = config["exec_if"].asString();
+    }
+    if (config["interval"].isUInt()) {
+      interval_ = std::chrono::seconds(config["interval"].asUInt());
+    } else if (config["interval"] == "once") {
+      interval_ = std::chrono::seconds(100000000);
+    } else {
+      interval_ = std::chrono::seconds(0);
+    }
+    if (config["restart-interval"].isUInt()) {
+      restart_interval_ = std::chrono::seconds(config["restart-interval"].asUInt());
+    }
+
+    if (interval_.count() > 0) {
+      thread_ = [this] { delay_worker(); };
+    } else if (!exec_.empty()) {
+      thread_ = [this] { continuous_worker(); };
+    }
+  }
+
+  ~WorkerThread() {
+    if (pid_ != -1) {
+      killpg(pid_, SIGTERM);
+      pid_ = -1;
+    }
+  }
+
+  auto wake_up() { return thread_.wake_up(); }
+
+ private:
+  void delay_worker() {
+    bool can_update = true;
+    if (!exec_if_.empty()) {
+      util::command::res output = util::command::execNoRead(exec_if_);
+      if (output.exit_code != 0) {
+        can_update = false;
+        exit_callback_(output.exit_code);
+      }
+    }
+    if (can_update) {
+      if (!exec_.empty()) {
+        util::command::res output = util::command::exec(exec_);
+        if (output.exit_code == 0) {
+          output_callback_(std::move(output.out));
+        } else {
+          exit_callback_(output.exit_code);
+        }
+      }
+    }
+    thread_.sleep_for(interval_);
+  }
+
+  void continuous_worker() {
+    pid_ = -1;
+    FILE* fp = util::command::open(exec_, pid_);
+    if (!fp) {
+      throw std::runtime_error("Unable to open " + exec_);
+    }
+    while (true) {
+      char*  buff = nullptr;
+      size_t len = 0;
+      if (getline(&buff, &len, fp) == -1) {
+        int exit_code = 1;
+        if (fp) {
+          exit_code = WEXITSTATUS(util::command::close(fp, pid_));
+          fp = nullptr;
+        }
+        if (exit_code != 0) {
+          spdlog::error("'{}' stopped unexpectedly, is it endless?", exec_);
+          exit_callback_(exit_code);
+        }
+        if (restart_interval_.has_value()) {
+          pid_ = -1;
+          thread_.sleep_for(std::chrono::seconds(*restart_interval_));
+          fp = util::command::open(exec_, pid_);
+          if (!fp) {
+            throw std::runtime_error("Unable to open " + exec_);
+          }
+        } else {
+          thread_.stop();
+          return;
+        }
+      } else {
+        std::string output = buff;
+
+        // Remove last newline
+        if (!output.empty() && output[output.length() - 1] == '\n') {
+          output.erase(output.length() - 1);
+        }
+
+        output_callback_(std::move(output));
+      }
+    }
+  }
+
+  std::string                         exec_;
+  std::string                         exec_if_;
+  std::chrono::seconds                interval_;
+  std::optional<std::chrono::seconds> restart_interval_;
+  std::function<void(std::string)>    output_callback_;
+  std::function<void(int)>            exit_callback_;
+  int                                 pid_;
+  SleeperThread                       thread_;
+};
+
+}  // namespace waybar::util

src/modules/custom.cpp

@@ -4,86 +4,23 @@
 
 waybar::modules::Custom::Custom(const std::string& name, const std::string& id,
                                 const Json::Value& config)
-    : ALabel(config, "custom-" + name, id, "{}"), name_(name), fp_(nullptr), pid_(-1) {
+    : ALabel(config, "custom-" + name, id, "{}"),
-  dp.emit();
+      name_(name),
-  if (interval_.count() > 0) {
+      thread_(
-    delayWorker();
+          config, [this](std::string output) { workerOutputCallback(std::move(output)); },
-  } else if (config_["exec"].isString()) {
+          [this](int exit_code) { workerExitCallback(exit_code); }) {
-    continuousWorker();
-  }
-}
-
-waybar::modules::Custom::~Custom() {
-  if (pid_ != -1) {
-    killpg(pid_, SIGTERM);
-    pid_ = -1;
-  }
-}
-
-void waybar::modules::Custom::delayWorker() {
-  thread_ = [this] {
-    bool can_update = true;
-    if (config_["exec-if"].isString()) {
-      output_ = util::command::execNoRead(config_["exec-if"].asString());
-      if (output_.exit_code != 0) {
-        can_update = false;
   dp.emit();
 }
-    }
-    if (can_update) {
-      if (config_["exec"].isString()) {
-        output_ = util::command::exec(config_["exec"].asString());
-      }
-      dp.emit();
-    }
-    thread_.sleep_for(interval_);
-  };
-}
 
-void waybar::modules::Custom::continuousWorker() {
+void waybar::modules::Custom::workerExitCallback(int exit_code) {
-  auto cmd = config_["exec"].asString();
-  pid_ = -1;
-  fp_ = util::command::open(cmd, pid_);
-  if (!fp_) {
-    throw std::runtime_error("Unable to open " + cmd);
-  }
-  thread_ = [this, cmd] {
-    char*  buff = nullptr;
-    size_t len = 0;
-    if (getline(&buff, &len, fp_) == -1) {
-      int exit_code = 1;
-      if (fp_) {
-        exit_code = WEXITSTATUS(util::command::close(fp_, pid_));
-        fp_ = nullptr;
-      }
-      if (exit_code != 0) {
   output_ = {exit_code, ""};
   dp.emit();
-        spdlog::error("{} stopped unexpectedly, is it endless?", name_);
 }
-      if (config_["restart-interval"].isUInt()) {
-        pid_ = -1;
-        thread_.sleep_for(std::chrono::seconds(config_["restart-interval"].asUInt()));
-        fp_ = util::command::open(cmd, pid_);
-        if (!fp_) {
-          throw std::runtime_error("Unable to open " + cmd);
-        }
-      } else {
-        thread_.stop();
-        return;
-      }
-    } else {
-      std::string output = buff;
 
-      // Remove last newline
+void waybar::modules::Custom::workerOutputCallback(std::string output) {
-      if (!output.empty() && output[output.length() - 1] == '\n') {
+  output_ = {0, std::move(output)};
-        output.erase(output.length() - 1);
-      }
-      output_ = {0, output};
   dp.emit();
 }
-  };
-}
 
 void waybar::modules::Custom::refresh(int sig) {
   if (sig == SIGRTMIN + config_["signal"].asInt()) {
@@ -116,9 +53,9 @@ auto waybar::modules::Custom::update() -> void {
     event_box_.hide();
   } else {
     if (config_["return-type"].asString() == "json") {
-      parseOutputJson();
+      parseOutputJson(output_.out);
     } else {
-      parseOutputRaw();
+      parseOutputRaw(output_.out);
     }
     auto str = fmt::format(format_,
                            text_,
@@ -154,8 +91,8 @@ auto waybar::modules::Custom::update() -> void {
   ALabel::update();
 }
 
-void waybar::modules::Custom::parseOutputRaw() {
+void waybar::modules::Custom::parseOutputRaw(const std::string& output_str) {
-  std::istringstream output(output_.out);
+  std::istringstream output(output_str);
   std::string        line;
   int                i = 0;
   while (getline(output, line)) {
@@ -178,8 +115,8 @@ void waybar::modules::Custom::parseOutputRaw() {
   }
 }
 
-void waybar::modules::Custom::parseOutputJson() {
+void waybar::modules::Custom::parseOutputJson(const std::string& output_str) {
-  std::istringstream output(output_.out);
+  std::istringstream output(output_str);
   std::string        line;
   class_.clear();
   while (getline(output, line)) {