feat: convert single-file groups in merge mode and add --delete-unmatched (#88)

Previously, --merge mode skipped groups with only one bag file (no merge
partner). Now single-file groups are processed through the same
merge+convert pipeline, so their LiDAR packets are decoded to
PointCloud2 even without a merge partner.

Add --delete-unmatched option to delete source files for single-file
groups after successful conversion. --delete continues to apply to
multi-file groups only, and both flags can be combined.

Author: otenim

src/bag_converter/include/bag_converter.hpp

@@ -123,6 +123,9 @@ struct BagConverterConfig
   // Delete source files after successful conversion
   bool delete_sources = false;
 
+  // Delete source files for single-file groups (no merge partner) after successful conversion
+  bool delete_unmatched = false;
+
   // Batch mode
   bool batch_mode = false;
 

src/bag_converter/include/merge.hpp

@@ -34,6 +34,7 @@ struct MergeConfig
   std::string output_dir;
   bool overwrite = false;
   bool delete_sources = false;
+  bool delete_unmatched = false;
   std::string comp_algo = "zstd";
   std::string comp_level = "default";
 };

src/bag_converter/src/bag_converter.cpp

@@ -177,6 +177,9 @@ void print_usage()
     << "  --delete                  Delete source bag files after successful processing.\n"
     << "                            In merge mode, deletes the original input bag files\n"
     << "                            after each group is successfully merged and converted.\n"
+    << "  --delete-unmatched        In merge mode, delete source bag files for groups\n"
+    << "                            with only a single file (no merge partner) after\n"
+    << "                            successful conversion.\n"
     << "  -h, --help                Show this help message\n"
     << "  -v, --version             Show version information\n";
 }
@@ -216,6 +219,9 @@ std::optional<int> parse_arguments(int argc, char ** argv, BagConverterConfig &
     if (arg == "--delete") {
       config.delete_sources = true;
     }
+    if (arg == "--delete-unmatched") {
+      config.delete_unmatched = true;
+    }
   }
 
   // Collect positional arguments (non-option args)
@@ -339,7 +345,7 @@ std::optional<int> parse_arguments(int argc, char ** argv, BagConverterConfig &
       config.passthrough = true;
     } else if (arg == "--overwrite") {
       config.overwrite = true;
-    } else if (arg == "--merge" || arg == "--delete") {
+    } else if (arg == "--merge" || arg == "--delete" || arg == "--delete-unmatched") {
       // Already processed in pre-scan
     } else if (arg == "--help" || arg == "-h" || arg == "--version" || arg == "-v") {
       // Already handled
@@ -1204,6 +1210,7 @@ int run_merge_and_convert(const BagConverterConfig & config)
   merge_config.output_dir = config.dst_bag_path;
   merge_config.overwrite = config.overwrite;
   merge_config.delete_sources = config.delete_sources;
+  merge_config.delete_unmatched = config.delete_unmatched;
   merge_config.comp_algo = config.comp_algo;
   merge_config.comp_level = config.comp_level;
 

src/bag_converter/src/merge.cpp

@@ -66,7 +66,7 @@ struct MergeGroupKey
 struct MergeResult
 {
   size_t merged_count = 0;
-  size_t skipped_single_count = 0;
+  size_t skipped_exists_count = 0;
   size_t skipped_pattern_count = 0;
   size_t failed_count = 0;
   size_t total_messages = 0;
@@ -252,7 +252,7 @@ static void print_merge_summary(const MergeResult & result)
 {
   RCLCPP_INFO(g_logger, "========== Merge Summary ==========");
   RCLCPP_INFO(g_logger, "  Groups merged: %zu", result.merged_count);
-  RCLCPP_INFO(g_logger, "  Groups skipped (single file): %zu", result.skipped_single_count);
+  RCLCPP_INFO(g_logger, "  Groups skipped (output exists): %zu", result.skipped_exists_count);
   RCLCPP_INFO(g_logger, "  Files skipped (pattern mismatch): %zu", result.skipped_pattern_count);
   RCLCPP_INFO(g_logger, "  Groups failed: %zu", result.failed_count);
   RCLCPP_INFO(g_logger, "  Total messages merged: %zu", result.total_messages);
@@ -345,13 +345,6 @@ int run_merge(const MergeConfig & config, MergeGroupProcessor processor)
 
     std::string group_name = key.sensing_system_id + "_" + key.rest;
 
-    if (files.size() < 2) {
-      RCLCPP_WARN(
-        g_logger, "Skipping group '%s' (single file, nothing to merge)", group_name.c_str());
-      ++result.skipped_single_count;
-      continue;
-    }
-
     // Determine output path
     std::string output_filename = group_name + group_extensions[key];
     fs::path output_path = output_dir / output_filename;
@@ -362,7 +355,7 @@ int run_merge(const MergeConfig & config, MergeGroupProcessor processor)
           g_logger,
           "Output file already exists, skipping group '%s': %s (use --overwrite to replace)",
           group_name.c_str(), output_path.string().c_str());
-        ++result.skipped_single_count;
+        ++result.skipped_exists_count;
         continue;
       }
       RCLCPP_INFO(g_logger, "Removing existing output file: %s", output_path.string().c_str());
@@ -403,7 +396,9 @@ int run_merge(const MergeConfig & config, MergeGroupProcessor processor)
     result.total_messages += static_cast<size_t>(msg_count);
 
     // Delete source files if requested
-    if (config.delete_sources) {
+    const bool should_delete =
+      config.delete_sources || (config.delete_unmatched && files.size() == 1);
+    if (should_delete) {
       for (const auto & f : files) {
         std::error_code del_ec;
         fs::remove(f, del_ec);