Remove duplicate code between stream_logger and console_writer

include/dwarfs/console_writer.h

@@ -35,7 +35,7 @@ namespace dwarfs {
 
 class progress;
 
-class console_writer : public logger {
+class console_writer : public stream_logger {
  public:
   using get_term_width_type = std::function<size_t()>;
 
@@ -46,25 +46,20 @@ class console_writer : public logger {
                  get_term_width_type get_term_width, level_type threshold,
                  display_mode mode = NORMAL, bool verbose = false);
 
-  void write(level_type level, const std::string& output, char const* file,
-             int line) override;
-
   void update(const progress& p, bool last);
 
  private:
+  void preamble() override;
+  void postamble() override;
+  std::string_view get_newline() const override;
   void rewind();
 
-  std::ostream& os_;
-  std::mutex mx_;
-  std::atomic<level_type> threshold_;
   std::string statebuf_;
   double frac_;
   std::atomic<size_t> counter_{0};
   progress_mode const pg_mode_;
   get_term_width_type get_term_width_;
   display_mode const mode_;
-  bool const color_;
-  bool const with_context_;
   bool const debug_progress_;
   bool writing_{false};
   speedometer<uint64_t> read_speed_;

include/dwarfs/logger.h

@@ -88,9 +88,19 @@ class stream_logger : public logger {
   void set_threshold(level_type threshold);
   void set_with_context(bool with_context) { with_context_ = with_context; }
 
+ protected:
+  virtual void preamble();
+  virtual void postamble();
+  virtual std::string_view get_newline() const;
+
+  std::ostream& log_stream() const { return os_; }
+  std::mutex& log_mutex() const { return mx_; }
+  bool log_is_colored() const { return color_; }
+  level_type log_threshold() const { return threshold_.load(); }
+
  private:
   std::ostream& os_;
-  std::mutex mx_;
+  std::mutex mutable mx_;
   std::atomic<level_type> threshold_;
   bool const color_;
   bool with_context_;

src/dwarfs/console_writer.cpp

@@ -84,22 +84,13 @@ console_writer::console_writer(std::ostream& os, progress_mode pg_mode,
                                get_term_width_type get_term_width,
                                level_type threshold, display_mode mode,
                                bool with_context)
-    : os_(os)
-    , threshold_(threshold)
+    : stream_logger(os, threshold, with_context)
     , frac_(0.0)
     , pg_mode_(pg_mode)
     , get_term_width_(get_term_width)
     , mode_(mode)
-    , color_(stream_is_fancy_terminal(os))
-    , with_context_(with_context)
     , debug_progress_(is_debug_progress())
-    , read_speed_{std::chrono::seconds(5)} {
-  if (threshold > level_type::INFO) {
-    set_policy<debug_logger_policy>();
-  } else {
-    set_policy<prod_logger_policy>();
-  }
-}
+    , read_speed_{std::chrono::seconds(5)} {}
 
 void console_writer::rewind() {
   if (!statebuf_.empty()) {
@@ -114,83 +105,34 @@ void console_writer::rewind() {
       break;
     }
 
-    os_ << '\r';
+    auto& os = log_stream();
+
+    os << '\r';
 
     for (int i = 0; i < lines; ++i) {
-      os_ << "\x1b[A";
+      os << "\x1b[A";
     }
   }
 }
 
-void console_writer::write(level_type level, const std::string& output,
-                           char const* file, int line) {
-  if (level <= threshold_) {
-    auto t = get_current_time_string();
-    const char* prefix = "";
-    const char* suffix = "";
-    const char* newline = pg_mode_ != NONE ? "\x1b[K\n" : "\n";
+void console_writer::preamble() { rewind(); }
 
-    if (color_) {
-      switch (level) {
-      case ERROR:
-        prefix = terminal_color(termcolor::BOLD_RED);
-        suffix = terminal_color(termcolor::NORMAL);
-        break;
-
-      case WARN:
-        prefix = terminal_color(termcolor::BOLD_YELLOW);
-        suffix = terminal_color(termcolor::NORMAL);
-        break;
-
-      default:
-        break;
-      }
-    }
-
-    char lchar = logger::level_char(level);
-    std::string context;
-    size_t context_len = 0;
-
-    if (with_context_ && file) {
-      context = get_logger_context(file, line);
-      context_len = context.size();
-      if (color_) {
-        context = folly::to<std::string>(
-            suffix, terminal_color(termcolor::MAGENTA), context,
-            terminal_color(termcolor::NORMAL), prefix);
-      }
-    }
-
-    folly::small_vector<std::string_view, 2> lines;
-    folly::split('\n', output, lines);
-
-    if (lines.back().empty()) {
-      lines.pop_back();
-    }
-
-    std::lock_guard lock(mx_);
-
-    rewind();
-
-    for (auto l : lines) {
-      os_ << prefix << lchar << ' ' << t << ' ' << context << l << suffix
-          << newline;
-      std::fill(t.begin(), t.end(), '.');
-      context.assign(context_len, ' ');
-    }
-
-    if (pg_mode_ == UNICODE || pg_mode_ == ASCII) {
-      os_ << statebuf_;
-    }
+void console_writer::postamble() {
+  if (pg_mode_ == UNICODE || pg_mode_ == ASCII) {
+    log_stream() << statebuf_;
   }
 }
 
+std::string_view console_writer::get_newline() const {
+  return pg_mode_ != NONE ? "\x1b[K\n" : "\n";
+}
+
 void console_writer::update(const progress& p, bool last) {
   if (pg_mode_ == NONE && !last) {
     return;
   }
 
-  const char* newline = pg_mode_ != NONE ? "\x1b[K\n" : "\n";
+  auto newline = get_newline();
 
   std::ostringstream oss;
   lazy_value width(get_term_width_);
@@ -220,7 +162,7 @@ void console_writer::update(const progress& p, bool last) {
 
       if (fancy) {
         oss << terminal_colored(p.status(width.get()), termcolor::BOLD_CYAN,
-                                color_)
+                                log_is_colored())
             << newline;
       }
 
@@ -282,9 +224,9 @@ void console_writer::update(const progress& p, bool last) {
   }
 
   if (pg_mode_ == NONE) {
-    if (INFO <= threshold_) {
-      std::lock_guard lock(mx_);
-      os_ << oss.str();
+    if (INFO <= log_threshold()) {
+      std::lock_guard lock(log_mutex());
+      log_stream() << oss.str();
     }
     return;
   }
@@ -312,12 +254,12 @@ void console_writer::update(const progress& p, bool last) {
     if (tmp != statebuf_) {
       auto t = get_current_time_string();
       statebuf_ = tmp;
-      std::lock_guard lock(mx_);
-      os_ << "- " << t << statebuf_ << "\n";
+      std::lock_guard lock(log_mutex());
+      log_stream() << "- " << t << statebuf_ << "\n";
     }
     if (last) {
-      std::lock_guard lock(mx_);
-      os_ << oss.str();
+      std::lock_guard lock(log_mutex());
+      log_stream() << oss.str();
     }
   } else {
     oss << progress_bar(width.get() - 6, frac_, pg_mode_ == UNICODE)
@@ -326,13 +268,13 @@ void console_writer::update(const progress& p, bool last) {
 
     ++counter_;
 
-    std::lock_guard lock(mx_);
+    std::lock_guard lock(log_mutex());
 
     rewind();
 
     statebuf_ = oss.str();
 
-    os_ << statebuf_;
+    log_stream() << statebuf_;
   }
 }
 

src/dwarfs/logger.cpp

@@ -70,12 +70,17 @@ stream_logger::stream_logger(std::ostream& os, level_type threshold,
   set_threshold(threshold);
 }
 
+void stream_logger::preamble() {}
+void stream_logger::postamble() {}
+std::string_view stream_logger::get_newline() const { return "\n"; }
+
 void stream_logger::write(level_type level, const std::string& output,
                           char const* file, int line) {
   if (level <= threshold_) {
     auto t = get_current_time_string();
     const char* prefix = "";
     const char* suffix = "";
+    auto newline = get_newline();
 
     if (color_) {
       switch (level) {
@@ -130,13 +135,19 @@ void stream_logger::write(level_type level, const std::string& output,
     }
 
     std::lock_guard lock(mx_);
+
+    preamble();
+
     for (auto l : lines) {
       os_ << prefix << lchar << ' ' << t << ' ' << context << l << suffix
-          << "\n";
+          << newline;
       std::fill(t.begin(), t.end(), '.');
       context.assign(context_len, ' ');
     }
 
+    postamble();
+
+    // TODO: this needs to be done differently for console_writer
 #if DWARFS_SYMBOLIZE
     if (threshold_ == TRACE) {
       os_ << printer.str();