Improve const correctness

src/H5Writer.cpp

@@ -195,7 +195,7 @@ void H5Writer::create_file(hsize_t frame_chunk)
     current_frame_chunk = frame_chunk;
 }
 
-bool H5Writer::is_file_open() 
+bool H5Writer::is_file_open() const
 {
     return (file.getId() != -1);
 }

src/H5Writer.hpp

@@ -33,7 +33,7 @@ class H5Writer
     public:
         H5Writer(const std::string& filename, hsize_t frames_per_file=0, hsize_t initial_dataset_size=1000, hsize_t dataset_increase_step=1000);
         virtual ~H5Writer();
-        bool is_file_open();
+        bool is_file_open() const;
         void close_file();
         void write_data(const std::string& dataset_name, const size_t data_index, const char* data, const std::vector<size_t>& data_shape, 
             const size_t data_bytes_size, const std::string& data_type, const std::string& endianness);

src/WriterManager.cpp

@@ -49,12 +49,12 @@ string WriterManager::get_status()
     }
 }
 
-string WriterManager::get_output_file()
+string WriterManager::get_output_file() const
 {
     return output_file;
 }
 
-map<string, uint64_t> WriterManager::get_statistics()
+map<string, uint64_t> WriterManager::get_statistics() const
 {
     map<string, uint64_t> result = {{"n_received_frames", n_received_frames.load()},
                                     {"n_written_frames", n_written_frames.load()},
@@ -96,7 +96,7 @@ void WriterManager::set_parameters(const map<string, boost::any>& new_parameters
     #endif
 }
 
-const map<string, DATA_TYPE>& WriterManager::get_parameters_type() 
+const map<string, DATA_TYPE>& WriterManager::get_parameters_type() const
 {
     return parameters_type;
 }
@@ -111,7 +111,7 @@ bool WriterManager::is_running()
     return running_flag.load();
 }
 
-bool WriterManager::is_killed()
+bool WriterManager::is_killed() const
 {
     return killed_flag.load();
 }
@@ -131,7 +131,7 @@ void WriterManager::lost_frame(size_t frame_index)
     n_lost_frames++;
 }
 
-bool WriterManager::are_all_parameters_set() 
+bool WriterManager::are_all_parameters_set()
 {
     lock_guard<mutex> lock(parameters_mutex);
 

src/WriterManager.hpp

@@ -32,16 +32,16 @@ class WriterManager
         void stop();
         void kill();
         bool is_running();
-        bool is_killed();
+        bool is_killed() const;
         std::string get_status();
         bool are_all_parameters_set();
-        std::string get_output_file();
+        std::string get_output_file() const;
 
-        const std::map<std::string, DATA_TYPE>& get_parameters_type();
+        const std::map<std::string, DATA_TYPE>& get_parameters_type() const;
         std::map<std::string, boost::any> get_parameters();
         void set_parameters(const std::map<std::string, boost::any>& new_parameters);
         
-        std::map<std::string, uint64_t> get_statistics();
+        std::map<std::string, uint64_t> get_statistics() const;
         void received_frame(size_t frame_index);
         void written_frame(size_t frame_index);
         void lost_frame(size_t frame_index);