log_sink_cmdline: support restricted log limit

Messages on the command line can be more disturbing than, e.g.,
in a log file. In particular, for debugging it often is useful
to have very verbose logs. In order to have the command-line
experience manageable also in this cases, support restricting the
command-line logging further. In this way, while interacting with
concise command-line messages, verbose logs are still written for
later analysis.

1 files changed, 17 insertions, 3 deletions

diff --git a/src/buildtool/logging/log_sink_cmdline.hpp b/src/buildtool/logging/log_sink_cmdline.hpp
index 8cbceb1c..89990f1c 100644
--- a/src/buildtool/logging/log_sink_cmdline.hpp
+++ b/src/buildtool/logging/log_sink_cmdline.hpp
@@ -18,6 +18,7 @@
 #include <iterator>
 #include <memory>
 #include <mutex>
+#include <optional>
 #include <sstream>
 #include <string>
 
@@ -29,11 +30,17 @@
 
 class LogSinkCmdLine final : public ILogSink {
   public:
-    static auto CreateFactory(bool colored = true) -> LogSinkFactory {
-        return [=]() { return std::make_shared<LogSinkCmdLine>(colored); };
+    static auto CreateFactory(bool colored = true,
+                              std::optional<LogLevel> restrict_level =
+                                  std::nullopt) -> LogSinkFactory {
+        return [=]() {
+            return std::make_shared<LogSinkCmdLine>(colored, restrict_level);
+        };
     }
 
-    explicit LogSinkCmdLine(bool colored) noexcept : colored_{colored} {}
+    explicit LogSinkCmdLine(bool colored,
+                            std::optional<LogLevel> restrict_level) noexcept
+        : colored_{colored}, restrict_level_{restrict_level} {}
     ~LogSinkCmdLine() noexcept final = default;
     LogSinkCmdLine(LogSinkCmdLine const&) noexcept = delete;
     LogSinkCmdLine(LogSinkCmdLine&&) noexcept = delete;
@@ -45,6 +52,12 @@ class LogSinkCmdLine final : public ILogSink {
               LogLevel level,
               std::string const& msg) const noexcept final {
         static std::mutex mutex{};
+
+        if (restrict_level_ and
+            (static_cast<int>(*restrict_level_) < static_cast<int>(level))) {
+            return;
+        }
+
         auto prefix = LogLevelToString(level);
 
         if (logger != nullptr) {
@@ -78,6 +91,7 @@ class LogSinkCmdLine final : public ILogSink {
 
   private:
     bool colored_{};
+    std::optional<LogLevel> restrict_level_{};
 
     [[nodiscard]] auto FormatPrefix(LogLevel level,
                                     std::string const& prefix) const noexcept