Refactor storage interface

core/storage/face/batch_writeable.hpp

@@ -27,7 +27,9 @@ namespace kagome::storage::face {
      * @brief Creates new Write Batch - an object, which can be used to
      * efficiently write bulk data.
      */
-    virtual std::unique_ptr<WriteBatch<K, V>> batch() = 0;
+    virtual std::unique_ptr<WriteBatch<K, V>> batch() {
+      abort();
+    }
   };
 
 }  // namespace kagome::storage::face

core/storage/face/generic_maps.hpp

@@ -12,37 +12,23 @@
 #include "storage/face/writeable.hpp"
 
 namespace kagome::storage::face {
-
-  /**
-   * @brief An abstraction over a readable and iterable key-value map.
-   * @tparam K key type
-   * @tparam V value type
-   */
-  template <typename K, typename V>
-  struct ReadOnlyMap : Iterable<K, V>, Readable<K, V> {};
-
-  template <typename K, typename V>
-  struct ReadOnlyStorage : Iterable<K, V>, Readable<K, V> {};
-
   /**
    * @brief An abstraction over a readable, writeable, iterable key-value map.
    * @tparam K key type
    * @tparam V value type
    */
   template <typename K, typename V>
-  struct GenericMap : ReadOnlyMap<K, V>,
-                      Writeable<K, V>,
-                      BatchWriteable<K, V> {};
-
-  template <typename K, typename V>
-  struct GenericStorage : ReadOnlyStorage<K, V>,
+  struct GenericStorage : Readable<K, V>,
+                          Iterable<K, V>,
                           Writeable<K, V>,
                           BatchWriteable<K, V> {
     /**
      * Reports RAM state size
      * @return size in bytes
      */
-    virtual size_t size() const = 0;
+    virtual size_t size() const {
+      abort();
+    }
   };
 
 }  // namespace kagome::storage::face

core/storage/trie/impl/trie_storage_backend_impl.cpp

@@ -60,9 +60,4 @@ namespace kagome::storage::trie {
       const common::BufferView &key) const {
     return common::Buffer{node_prefix_}.put(key);
   }
-
-  size_t TrieStorageBackendImpl::size() const {
-    return storage_->size();
-  }
-
 }  // namespace kagome::storage::trie

core/storage/trie/impl/trie_storage_backend_impl.hpp

@@ -32,8 +32,6 @@ namespace kagome::storage::trie {
                               BufferOrView &&value) override;
     outcome::result<void> remove(const common::BufferView &key) override;
 
-    size_t size() const override;
-
    private:
     common::Buffer prefixKey(const common::BufferView &key) const;
 

core/storage/trie/polkadot_trie/polkadot_trie.hpp

@@ -17,8 +17,7 @@ namespace kagome::storage::trie {
    * For specification see Polkadot Runtime Environment Protocol Specification
    * '2.1.2 The General Tree Structure' and further
    */
-  class PolkadotTrie : public face::ReadOnlyMap<Buffer, Buffer>,
-                       public face::Writeable<Buffer, Buffer> {
+  class PolkadotTrie : public BufferStorage {
    public:
     using NodePtr = std::shared_ptr<TrieNode>;
     using ConstNodePtr = std::shared_ptr<const TrieNode>;

core/storage/trie/trie_batches.hpp

@@ -12,9 +12,7 @@
 
 namespace kagome::storage::trie {
 
-  class TrieBatch : public face::Readable<Buffer, Buffer>,
-                    public face::Writeable<Buffer, Buffer>,
-                    public face::Iterable<Buffer, Buffer> {
+  class TrieBatch : public BufferStorage {
    public:
     ~TrieBatch() override = default;