refactor(libsinsp): set filterstring optionally

Signed-off-by: Roberto Scolaro <roberto.scolaro21@gmail.com>

userspace/libsinsp/sinsp.cpp

@@ -1661,7 +1661,7 @@ void sinsp::start_dropping_mode(uint32_t sampling_ratio)
 }
 #endif // _WIN32
 
-void sinsp::set_filter(std::unique_ptr<sinsp_filter> filter)
+void sinsp::set_filter(std::unique_ptr<sinsp_filter> filter, const std::optional<std::string>& filterstring)
 {
 	if(m_filter != NULL)
 	{
@@ -1670,6 +1670,7 @@ void sinsp::set_filter(std::unique_ptr<sinsp_filter> filter)
 	}
 
 	m_filter = std::move(filter);
+	m_filterstring = filterstring.value_or("");
 }
 
 void sinsp::set_filter(const std::string& filter)
@@ -1686,13 +1687,6 @@ void sinsp::set_filter(const std::string& filter)
 	m_internal_flt_ast = compiler.get_filter_ast();
 }
 
-void sinsp::set_filter(const std::string& filterstring, std::unique_ptr<sinsp_filter> filter)
-{
-	set_filter(std::move(filter));
-	m_filterstring = filterstring;
-}
-
-
 std::string sinsp::get_filter() const
 {
 	return m_filterstring;

userspace/libsinsp/sinsp.h

@@ -303,18 +303,7 @@ class SINSP_PUBLIC sinsp : public capture_stats_source
 
 	  \param filter the runtime filter object
 	*/
-	void set_filter(std::unique_ptr<sinsp_filter> filter);
-
-	/*!
-	  \brief Installs the given capture runtime filter object and accordingly
-	  sets the filter string.
-
-	  \param filter the filter string. Refer to the filtering language
-	   section for information about the filtering
-	   syntax.
-	  \param filter the runtime filter object
-	*/
-	void set_filter(const std::string& filterstring, std::unique_ptr<sinsp_filter> filter);
+	void set_filter(std::unique_ptr<sinsp_filter> filter, const std::optional<std::string>& filterstring);
 
 	/*!
 	  \brief Return the filter set for this capture.