add file reset capabilities (#37)

data_tamer_cpp/include/data_tamer/sinks/mcap_sink.hpp

@@ -44,6 +44,11 @@ class MCAPSink : public DataSinkBase
   /// WARNING: this can consume a large amount of disk space very quickly.
   void setMaxTimeBeforeReset(std::chrono::seconds reset_time);
 
+  /// When resetting the MCAP recording (see `setMaxTimeBeforeReset`),
+  /// if `create_new_file` is true then the filename will be incremented
+  /// and then saved instead of overwriting the previous file.
+  void setCreateNewFileOnReset(bool create_new_file);
+
   /// Stop recording and save the file
   void stopRecording();
 
@@ -54,6 +59,7 @@ class MCAPSink : public DataSinkBase
    *
    * @param filepath   file path of the new file (should be ".mcap" extension)
    * @param do_compression if true, compress the data on the fly.
+   * WARNING: if this is called with the same filename as previously, the file counter will be reset, too.
    */
   void restartRecording(std::string const& filepath, bool do_compression = false);
 
@@ -65,13 +71,20 @@ class MCAPSink : public DataSinkBase
   std::unordered_map<uint64_t, uint16_t> hash_to_channel_id_;
   std::unordered_map<std::string, Schema> schemas_;
 
+  // file reset variables
+  bool create_file_on_reset_ = false;
+  std::string original_filepath_;
+  size_t file_reset_counter_ = 1;
+
   std::chrono::seconds reset_time_ = std::chrono::seconds(60 * 10);
   std::chrono::system_clock::time_point start_time_;
 
   bool forced_stop_recording_ = false;
   std::recursive_mutex mutex_;
 
   void openFile(std::string const& filepath);
+  void restartRecordingImpl(std::string const& filepath, bool do_compression,
+                            bool new_file);
 };
 
 }  // namespace DataTamer

data_tamer_cpp/src/sinks/mcap_sink.cpp

@@ -4,6 +4,7 @@
 #include <chrono>
 #include <sstream>
 #include <mutex>
+#include <string>
 
 #ifndef USING_ROS2
 #define MCAP_IMPLEMENTATION
@@ -35,7 +36,7 @@ namespace DataTamer
 static constexpr char const* kDataTamer = "data_tamer";
 
 MCAPSink::MCAPSink(const std::string& filepath, bool do_compression)
-  : filepath_(filepath), compression_(do_compression)
+  : filepath_(filepath), compression_(do_compression), original_filepath_(filepath)
 {
   openFile(filepath_);
 }
@@ -121,7 +122,13 @@ bool MCAPSink::storeSnapshot(const Snapshot& snapshot)
   auto const now = std::chrono::system_clock::now();
   if(reset_time_ != std::chrono::seconds(0) && now - start_time_ > reset_time_)
   {
-    restartRecording(filepath_, compression_);
+    if(create_file_on_reset_)
+    {
+      // change the current filepath to the original with "_[# resets]"" appended
+      filepath_ = original_filepath_ + "_" + std::to_string(file_reset_counter_);
+      ++file_reset_counter_;
+    }
+    restartRecordingImpl(filepath_, compression_, false);
   }
   return true;
 }
@@ -131,6 +138,11 @@ void MCAPSink::setMaxTimeBeforeReset(std::chrono::seconds reset_time)
   reset_time_ = reset_time;
 }
 
+void MCAPSink::setCreateNewFileOnReset(bool create_file_on_reset)
+{
+  create_file_on_reset_ = create_file_on_reset;
+}
+
 void MCAPSink::stopRecording()
 {
   std::scoped_lock lk(mutex_);
@@ -140,8 +152,20 @@ void MCAPSink::stopRecording()
 }
 
 void MCAPSink::restartRecording(const std::string& filepath, bool do_compression)
+{
+  restartRecordingImpl(filepath, do_compression, true);
+}
+
+void MCAPSink::restartRecordingImpl(const std::string& filepath, bool do_compression,
+                                    bool new_file)
 {
   std::scoped_lock lk(mutex_);
+  if(new_file)
+  {
+    // if this was called by a user, we need to change the filepath that we will increment when reset
+    file_reset_counter_ = 1;
+    original_filepath_ = filepath;
+  }
   filepath_ = filepath;
   compression_ = do_compression;
   openFile(filepath_);