source: DataSource, Frame, SourceConfig and the registry (unused yet)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/source/data_source.cpp

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: MIT
+// SPDX-FileCopyrightText: 2026 Martino Ferrari
+
+#include "source/data_source.hpp"
+
+#include <utility>
+
+namespace udpscope {
+
+void DataSource::post(Command cmd) {
+  std::lock_guard<std::mutex> lk(cmd_mu_);
+  cmds_.push_back(std::move(cmd));
+}
+
+void DataSource::drain_commands() {
+  std::deque<Command> local;
+  {
+    std::lock_guard<std::mutex> lk(cmd_mu_);
+    local.swap(cmds_);
+  }
+  for (auto& c : local) c();
+}
+
+}  // namespace udpscope