Implement a new option to flush the file sink contents on every write.

lib/include/srsran/srslog/srslog.h

@@ -179,10 +179,12 @@ sink& fetch_stderr_sink(const std::string&             id = "stderr",
 /// Specifying a max_size value different to zero will make the sink create a
 /// new file each time the current file exceeds this value. The units of
 /// max_size are bytes.
+/// Setting force_flush to true will flush the sink after every write.
 /// NOTE: Any '#' characters in the path will get removed.
 sink& fetch_file_sink(const std::string&             path,
-                      size_t                         max_size = 0,
+                      size_t                         max_size    = 0,
-                      std::unique_ptr<log_formatter> f        = get_default_log_formatter());
+                      bool                           force_flush = false,
+                      std::unique_ptr<log_formatter> f           = get_default_log_formatter());
 
 /// Returns an instance of a sink that writes into syslog
 /// preamble: The string  prepended to every message, If ident is "", the program name is used.

lib/include/srsran/srslog/srslog_c.h

@@ -148,9 +148,10 @@ srslog_sink* srslog_fetch_stderr_sink(void);
  * Specifying a max_size value different to zero will make the sink create a
  * new file each time the current file exceeds this value. The units of
  * max_size are bytes.
+ * Setting force_flush to true will flush the sink after every write.
  * NOTE: Any '#' characters in the id will get removed.
  */
-srslog_sink* srslog_fetch_file_sink(const char* path, size_t max_size);
+srslog_sink* srslog_fetch_file_sink(const char* path, size_t max_size, srslog_bool force_flush);
 
 #ifdef __cplusplus
 }

lib/src/srslog/sinks/file_sink.h

@@ -24,9 +24,10 @@ namespace srslog {
 class file_sink : public sink
 {
 public:
-  file_sink(std::string name, size_t max_size, std::unique_ptr<log_formatter> f) :
+  file_sink(std::string name, size_t max_size, bool force_flush, std::unique_ptr<log_formatter> f) :
     sink(std::move(f)),
     max_size((max_size == 0) ? 0 : std::max<size_t>(max_size, 4 * 1024)),
+    force_flush(force_flush),
     base_filename(std::move(name))
   {}
 
@@ -53,6 +54,10 @@ public:
       return err_str;
     }
 
+    if (force_flush) {
+      flush();
+    }
+
     return handler.write(buffer);
   }
 
@@ -88,6 +93,7 @@ private:
 
 private:
   const size_t      max_size;
+  const bool        force_flush;
   const std::string base_filename;
   file_utils::file  handler;
   size_t            current_size = 0;

lib/src/srslog/srslog.cpp

@@ -148,7 +148,10 @@ sink& srslog::fetch_stderr_sink(const std::string& id, std::unique_ptr<log_forma
   return *s;
 }
 
-sink& srslog::fetch_file_sink(const std::string& path, size_t max_size, std::unique_ptr<log_formatter> f)
+sink& srslog::fetch_file_sink(const std::string&             path,
+                              size_t                         max_size,
+                              bool                           force_flush,
+                              std::unique_ptr<log_formatter> f)
 {
   assert(!path.empty() && "Empty path string");
 
@@ -161,7 +164,7 @@ sink& srslog::fetch_file_sink(const std::string& path, size_t max_size, std::uni
   auto& s = srslog_instance::get().get_sink_repo().emplace(
       std::piecewise_construct,
       std::forward_as_tuple(path),
-      std::forward_as_tuple(new file_sink(path, max_size, std::move(f))));
+      std::forward_as_tuple(new file_sink(path, max_size, force_flush, std::move(f))));
 
   return *s;
 }
@@ -388,7 +391,8 @@ sink* srslog::create_file_sink(const std::string& path, size_t max_size)
       .get_sink_repo()
       .emplace(std::piecewise_construct,
                std::forward_as_tuple(path),
-               std::forward_as_tuple(new file_sink(path, max_size, std::unique_ptr<log_formatter>(new text_formatter))))
+               std::forward_as_tuple(
+                   new file_sink(path, max_size, false, std::unique_ptr<log_formatter>(new text_formatter))))
       .get();
 }
 

lib/src/srslog/srslog_c.cpp

@@ -181,7 +181,7 @@ srslog_sink* srslog_fetch_stderr_sink(void)
   return c_cast<srslog_sink>(&fetch_stderr_sink());
 }
 
-srslog_sink* srslog_fetch_file_sink(const char* path, size_t max_size)
+srslog_sink* srslog_fetch_file_sink(const char* path, size_t max_size, srslog_bool force_flush)
 {
-  return c_cast<srslog_sink>(&fetch_file_sink(path, max_size));
+  return c_cast<srslog_sink>(&fetch_file_sink(path, max_size, force_flush));
 }

lib/test/srslog/file_sink_test.cpp

@@ -22,7 +22,7 @@ static constexpr char log_filename[] = "file_sink_test.log";
 static bool when_data_is_written_to_file_then_contents_are_valid()
 {
   file_test_utils::scoped_file_deleter deleter(log_filename);
-  file_sink file(log_filename, 0, std::unique_ptr<log_formatter>(new test_dummies::log_formatter_dummy));
+  file_sink file(log_filename, 0, false, std::unique_ptr<log_formatter>(new test_dummies::log_formatter_dummy));
 
   std::vector<std::string> entries;
   for (unsigned i = 0; i != 10; ++i) {
@@ -45,7 +45,7 @@ class file_sink_subclass : public file_sink
 {
 public:
   file_sink_subclass(std::string name, size_t max_size) :
-    file_sink(std::move(name), max_size, std::unique_ptr<log_formatter>(new test_dummies::log_formatter_dummy))
+    file_sink(std::move(name), max_size, false, std::unique_ptr<log_formatter>(new test_dummies::log_formatter_dummy))
   {}
 
   uint32_t get_num_of_files() const { return get_file_index(); }

srsenb/src/main.cc

@@ -550,7 +550,7 @@ int main(int argc, char* argv[])
           : srslog::fetch_file_sink(args.log.filename, fixup_log_file_maxsize(args.log.file_max_size)));
 
   // Alarms log channel creation.
-  srslog::sink&        alarm_sink     = srslog::fetch_file_sink(args.general.alarms_filename);
+  srslog::sink&        alarm_sink     = srslog::fetch_file_sink(args.general.alarms_filename, 0, true);
   srslog::log_channel& alarms_channel = srslog::fetch_log_channel("alarms", alarm_sink, {"ALRM", '\0', false});
   alarms_channel.set_enabled(args.general.alarms_log_enable);
 
@@ -573,7 +573,7 @@ int main(int argc, char* argv[])
 
   // Set up the JSON log channel used by metrics and events.
   srslog::sink& json_sink =
-      srslog::fetch_file_sink(args.general.report_json_filename, 0, srslog::create_json_formatter());
+      srslog::fetch_file_sink(args.general.report_json_filename, 0, false, srslog::create_json_formatter());
   srslog::log_channel& json_channel = srslog::fetch_log_channel("JSON_channel", json_sink, {});
   json_channel.set_enabled(args.general.report_json_enable);
 

srsue/src/main.cc

@@ -725,7 +725,7 @@ int main(int argc, char* argv[])
 
   // Set up the JSON log channel used by metrics.
   srslog::sink& json_sink =
-      srslog::fetch_file_sink(args.general.metrics_json_filename, 0, srslog::create_json_formatter());
+      srslog::fetch_file_sink(args.general.metrics_json_filename, 0, false, srslog::create_json_formatter());
   srslog::log_channel& json_channel = srslog::fetch_log_channel("JSON_channel", json_sink, {});
   json_channel.set_enabled(args.general.metrics_json_enable);