1 files changed, 82 insertions, 0 deletions
diff --git a/src/tools/ceph-dencoder/denc_plugin.h b/src/tools/ceph-dencoder/denc_plugin.h
new file mode 100644
index 000000000..58690a4b9
--- /dev/null
+++ b/src/tools/ceph-dencoder/denc_plugin.h
@@ -0,0 +1,82 @@
+#include <dlfcn.h>
+#if __has_include(<filesystem>)
+#include <filesystem>
+namespace fs = std::filesystem;
+#else
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#endif
+#include <vector>
+
+#include "denc_registry.h"
+
+class DencoderPlugin {
+  using dencoders_t = std::vector<std::pair<std::string, Dencoder*>>;
+public:
+  DencoderPlugin(const fs::path& path) {
+    mod = dlopen(path.c_str(), RTLD_NOW);
+    if (mod == nullptr) {
+      std::cerr << "failed to dlopen(" << path << "): " << dlerror() << std::endl;
+    }
+  }
+  DencoderPlugin(DencoderPlugin&& other)
+    : mod{other.mod},
+      dencoders{std::move(other.dencoders)}
+  {
+    other.mod = nullptr;
+    other.dencoders.clear();
+  }
+  ~DencoderPlugin() {
+#if !defined(__FreeBSD__)
+    if (mod) {
+      dlclose(mod);
+    }
+#endif
+  }
+  const dencoders_t& register_dencoders() {
+    static constexpr string_view REGISTER_DENCODERS_FUNCTION = "register_dencoders\0";
+
+    assert(mod);
+    using register_dencoders_t = void (*)(DencoderPlugin*);
+    const auto do_register =
+      reinterpret_cast<register_dencoders_t>(dlsym(mod, REGISTER_DENCODERS_FUNCTION.data()));
+    if (do_register == nullptr) {
+      std::cerr << "failed to dlsym(" << REGISTER_DENCODERS_FUNCTION << "): "
+                << dlerror() << std::endl;
+      return dencoders;
+    }
+    do_register(this);
+    return dencoders;
+  }
+
+  bool good() const {
+    return mod != nullptr;
+  }
+
+  void unregister_dencoders() {
+    while (!dencoders.empty()) {
+      delete dencoders.back().second;
+      dencoders.pop_back();
+    }
+  }
+  template<typename DencoderT, typename...Args>
+  void emplace(const char* name, Args&&...args) {
+    dencoders.emplace_back(name, new DencoderT(std::forward<Args>(args)...));
+  }
+
+private:
+  void *mod = nullptr;
+  dencoders_t dencoders;
+};
+
+#define TYPE(t) plugin->emplace<DencoderImplNoFeature<t>>(#t, false, false);
+#define TYPE_STRAYDATA(t) plugin->emplace<DencoderImplNoFeature<t>>(#t, true, false);
+#define TYPE_NONDETERMINISTIC(t) plugin->emplace<DencoderImplNoFeature<t>>(#t, false, true);
+#define TYPE_FEATUREFUL(t) plugin->emplace<DencoderImplFeatureful<t>>(#t, false, false);
+#define TYPE_FEATUREFUL_STRAYDATA(t) plugin->emplace<DencoderImplFeatureful<t>>(#t, true, false);
+#define TYPE_FEATUREFUL_NONDETERMINISTIC(t) plugin->emplace<DencoderImplFeatureful<t>>(#t, false, true);
+#define TYPE_FEATUREFUL_NOCOPY(t) plugin->emplace<DencoderImplFeaturefulNoCopy<t>>(#t, false, false);
+#define TYPE_NOCOPY(t) plugin->emplace<DencoderImplNoFeatureNoCopy<t>>(#t, false, false);
+#define MESSAGE(t) plugin->emplace<MessageDencoderImpl<t>>(#t);
+
+#define DENC_API extern "C" [[gnu::visibility("default")]]