2 files changed, 108 insertions, 0 deletions
diff --git a/src/common/log/Logger.cpp b/src/common/log/Logger.cpp
new file mode 100644
index 00000000..bcafde21
--- /dev/null
+++ b/src/common/log/Logger.cpp
@@ -0,0 +1,86 @@
+#include "cru/common/log/Logger.h"
+#include "cru/common/log/StdioLogTarget.h"
+
+#include <array>
+#include <cstdlib>
+#include <ctime>
+
+namespace cru::log {
+Logger *Logger::GetInstance() {
+  static Logger logger;
+
+  logger.AddLogTarget(std::make_unique<StdioLogTarget>());
+
+  return &logger;
+}
+
+void Logger::AddLogTarget(std::unique_ptr<ILogTarget> target) {
+  std::lock_guard<std::mutex> lock(target_list_mutex_);
+  target_list_.push_back(std::move(target));
+}
+
+void Logger::RemoveLogTarget(ILogTarget *target) {
+  std::lock_guard<std::mutex> lock(target_list_mutex_);
+  target_list_.erase(
+      std::remove_if(target_list_.begin(), target_list_.end(),
+                     [target](const auto &t) { return t.get() == target; }),
+      target_list_.end());
+}
+
+namespace {
+String LogLevelToString(LogLevel level) {
+  switch (level) {
+    case LogLevel::Debug:
+      return u"DEBUG";
+    case LogLevel::Info:
+      return u"INFO";
+    case LogLevel::Warn:
+      return u"WARN";
+    case LogLevel::Error:
+      return u"ERROR";
+    default:
+      std::terminate();
+  }
+}
+
+String GetLogTime() {
+  auto time = std::time(nullptr);
+  auto calendar = std::localtime(&time);
+  return Format(u"{}:{}:{}", calendar->tm_hour, calendar->tm_min,
+                calendar->tm_sec);
+}
+
+String MakeLogFinalMessage(const LogInfo &log_info) {
+  if (log_info.tag.empty()) {
+    return Format(u"[{}] {}: {}", GetLogTime(),
+                  LogLevelToString(log_info.level), log_info.message);
+  } else {
+    return Format(u"[{}] {} {}: {}", GetLogTime(),
+                  LogLevelToString(log_info.level), log_info.tag,
+                  log_info.message);
+  }
+}
+}  // namespace
+
+Logger::Logger()
+    : log_thread_([this] {
+        while (true) {
+          auto log_info = log_queue_.Pull();
+          std::lock_guard<std::mutex> lock_guard{target_list_mutex_};
+          for (const auto &target : target_list_) {
+            target->Write(log_info.level, MakeLogFinalMessage(log_info));
+          }
+        }
+      }) {}
+
+Logger::~Logger() {}
+
+void Logger::Log(LogInfo log_info) {
+#ifndef CRU_DEBUG
+  if (log_info.level == LogLevel::Debug) {
+    return;
+  }
+#endif
+  log_queue_.Push(std::move(log_info));
+}
+}  // namespace cru::log
diff --git a/src/common/log/StdioLogTarget.cpp b/src/common/log/StdioLogTarget.cpp
new file mode 100644
index 00000000..ad29a3ce
--- /dev/null
+++ b/src/common/log/StdioLogTarget.cpp
@@ -0,0 +1,22 @@
+#include "cru/common/log/StdioLogTarget.h"
+
+#include <iostream>
+
+namespace cru::log {
+StdioLogTarget::StdioLogTarget() {}
+
+StdioLogTarget::~StdioLogTarget() {}
+
+void StdioLogTarget::Write(log::LogLevel level, StringView s) {
+#ifdef CRU_PLATFORM_WINDOWS
+#else
+  std::string m = s.ToUtf8();
+
+  if (level == log::LogLevel::Error) {
+    std::cerr << m;
+  } else {
+    std::cout << m;
+  }
+#endif
+}
+}  // namespace cru::log