New cpp folder structure

Signed-off-by: Alexander Borsuk <me@alex.bio>

libs/indexer/custom_keyvalue.cpp

@@ -0,0 +1,46 @@
+#include "custom_keyvalue.hpp"
+
+#include "coding/reader.hpp"
+#include "coding/varint.hpp"
+#include "coding/writer.hpp"
+
+#include <sstream>
+
+namespace indexer
+{
+
+CustomKeyValue::CustomKeyValue(std::string_view buffer)
+{
+  MemReader reader(buffer.data(), buffer.size());
+  ReaderSource src(reader);
+
+  while (src.Size() > 0)
+  {
+    uint8_t const type = ReadPrimitiveFromSource<uint8_t>(src);
+    m_vals.emplace_back(type, ReadVarUint<uint64_t>(src));
+  }
+}
+
+std::string CustomKeyValue::ToString() const
+{
+  std::string res;
+  MemWriter<std::string> writer(res);
+  for (auto const & v : m_vals)
+  {
+    WriteToSink(writer, v.first);
+    WriteVarUint(writer, v.second);
+  }
+  return res;
+}
+
+std::string DebugPrint(CustomKeyValue const & kv)
+{
+  std::ostringstream ss;
+  ss << "CustomKeyValue [";
+  for (auto const & v : kv.m_vals)
+    ss << "(" << v.first << ", " << v.second << "), ";
+  ss << "]";
+  return ss.str();
+}
+
+} // namespace indexer