refactor(metadata): factor out dump() and json methods

include/dwarfs/reader/internal/metadata_v2.h

@@ -66,6 +66,8 @@ struct metadata_options;
 
 namespace internal {
 
+class metadata_v2_data;
+
 class metadata_v2 {
  public:
   metadata_v2() = default;
@@ -80,24 +82,6 @@ class metadata_v2 {
 
   void check_consistency() const { impl_->check_consistency(); }
 
-  void
-  dump(std::ostream& os, fsinfo_options const& opts,
-       filesystem_info const* fsinfo,
-       std::function<void(std::string const&, uint32_t)> const& icb) const {
-    impl_->dump(os, opts, fsinfo, icb);
-  }
-
-  nlohmann::json info_as_json(fsinfo_options const& opts,
-                              filesystem_info const* fsinfo) const {
-    return impl_->info_as_json(opts, fsinfo);
-  }
-
-  nlohmann::json as_json() const { return impl_->as_json(); }
-
-  std::string serialize_as_json(bool simple) const {
-    return impl_->serialize_as_json(simple);
-  }
-
   size_t size() const { return impl_->size(); }
 
   void walk(std::function<void(dir_entry_view)> const& func) const {
@@ -189,24 +173,16 @@ class metadata_v2 {
     return impl_->get_block_numbers_by_category(category);
   }
 
+  metadata_v2_data const& internal_data() const {
+    return impl_->internal_data();
+  }
+
   class impl {
    public:
     virtual ~impl() = default;
 
     virtual void check_consistency() const = 0;
 
-    virtual void dump(
-        std::ostream& os, fsinfo_options const& opts,
-        filesystem_info const* fsinfo,
-        std::function<void(std::string const&, uint32_t)> const& icb) const = 0;
-
-    virtual nlohmann::json
-    info_as_json(fsinfo_options const& opts,
-                 filesystem_info const* fsinfo) const = 0;
-
-    virtual nlohmann::json as_json() const = 0;
-    virtual std::string serialize_as_json(bool simple) const = 0;
-
     virtual size_t size() const = 0;
 
     virtual void
@@ -263,12 +239,33 @@ class metadata_v2 {
 
     virtual std::vector<size_t>
     get_block_numbers_by_category(std::string_view category) const = 0;
+
+    virtual metadata_v2_data const& internal_data() const = 0;
   };
 
  private:
   std::unique_ptr<impl> impl_;
 };
 
+class metadata_v2_utils {
+ public:
+  metadata_v2_utils(metadata_v2 const& meta);
+
+  void dump(std::ostream& os, fsinfo_options const& opts,
+            filesystem_info const* fsinfo,
+            std::function<void(std::string const&, uint32_t)> const& icb) const;
+
+  nlohmann::json
+  info_as_json(fsinfo_options const& opts, filesystem_info const* fsinfo) const;
+
+  nlohmann::json as_json() const;
+
+  std::string serialize_as_json(bool simple) const;
+
+ private:
+  metadata_v2_data const& data_;
+};
+
 } // namespace internal
 } // namespace reader
 } // namespace dwarfs

src/reader/filesystem_v2.cpp

@@ -648,7 +648,7 @@ void filesystem_<LoggerPolicy>::dump(std::ostream& os,
     history_.dump(os);
   }
 
-  meta_.dump(
+  metadata_v2_utils(meta_).dump(
       os, opts, get_info(opts), [&](std::string const& indent, uint32_t inode) {
         std::error_code ec;
         auto chunks = meta_.get_chunks(inode, ec);
@@ -726,20 +726,20 @@ filesystem_<LoggerPolicy>::info_as_json(fsinfo_options const& opts) const {
     }
   }
 
-  info.update(meta_.info_as_json(opts, get_info(opts)));
+  info.update(metadata_v2_utils(meta_).info_as_json(opts, get_info(opts)));
 
   return info;
 }
 
 template <typename LoggerPolicy>
 nlohmann::json filesystem_<LoggerPolicy>::metadata_as_json() const {
-  return meta_.as_json();
+  return metadata_v2_utils(meta_).as_json();
 }
 
 template <typename LoggerPolicy>
 std::string
 filesystem_<LoggerPolicy>::serialize_metadata_as_json(bool simple) const {
-  return meta_.serialize_as_json(simple);
+  return metadata_v2_utils(meta_).serialize_as_json(simple);
 }
 
 template <typename LoggerPolicy>

src/reader/internal/metadata_v2.cpp

@@ -2214,24 +2214,6 @@ class metadata_ final : public metadata_v2::impl {
     data_.check_consistency(LOG_PROXY_ARG);
   }
 
-  void dump(std::ostream& os, fsinfo_options const& opts,
-            filesystem_info const* fsinfo,
-            std::function<void(std::string const&, uint32_t)> const& icb)
-      const override {
-    data_.dump(os, opts, fsinfo, icb);
-  }
-
-  nlohmann::json info_as_json(fsinfo_options const& opts,
-                              filesystem_info const* fsinfo) const override {
-    return data_.info_as_json(opts, fsinfo);
-  }
-
-  nlohmann::json as_json() const override { return data_.as_json(); }
-
-  std::string serialize_as_json(bool simple) const override {
-    return data_.serialize_as_json(simple);
-  }
-
   size_t size() const override { return data_.size(); }
 
   void walk(std::function<void(dir_entry_view)> const& func) const override {
@@ -2357,11 +2339,34 @@ class metadata_ final : public metadata_v2::impl {
     return data_.get_block_numbers_by_category(category);
   }
 
+  metadata_v2_data const& internal_data() const override { return data_; }
+
  private:
   LOG_PROXY_DECL(LoggerPolicy);
   metadata_v2_data const data_;
 };
 
+metadata_v2_utils::metadata_v2_utils(metadata_v2 const& meta)
+    : data_{meta.internal_data()} {}
+
+void metadata_v2_utils::dump(
+    std::ostream& os, fsinfo_options const& opts, filesystem_info const* fsinfo,
+    std::function<void(std::string const&, uint32_t)> const& icb) const {
+  data_.dump(os, opts, fsinfo, icb);
+}
+
+nlohmann::json
+metadata_v2_utils::info_as_json(fsinfo_options const& opts,
+                                filesystem_info const* fsinfo) const {
+  return data_.info_as_json(opts, fsinfo);
+}
+
+nlohmann::json metadata_v2_utils::as_json() const { return data_.as_json(); }
+
+std::string metadata_v2_utils::serialize_as_json(bool simple) const {
+  return data_.serialize_as_json(simple);
+}
+
 metadata_v2::metadata_v2(
     logger& lgr, std::span<uint8_t const> schema, std::span<uint8_t const> data,
     metadata_options const& options, int inode_offset,