New cpp folder structure

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

libs/search/search_index_header.hpp

@@ -0,0 +1,44 @@
+#pragma once
+
+#include "coding/reader.hpp"
+#include "coding/write_to_sink.hpp"
+
+#include <cstdint>
+
+namespace search
+{
+struct SearchIndexHeader
+{
+public:
+  enum class Version : uint8_t
+  {
+    V0 = 0,
+    V1 = 1,
+    V2 = 2,
+    Latest = V2
+  };
+
+  template <typename Sink>
+  void Serialize(Sink & sink) const
+  {
+    CHECK_EQUAL(static_cast<uint8_t>(m_version), static_cast<uint8_t>(Version::V2), ());
+    WriteToSink(sink, static_cast<uint8_t>(m_version));
+    WriteToSink(sink, m_indexOffset);
+    WriteToSink(sink, m_indexSize);
+  }
+
+  void Read(Reader & reader)
+  {
+    NonOwningReaderSource source(reader);
+    m_version = static_cast<Version>(ReadPrimitiveFromSource<uint8_t>(source));
+    CHECK_EQUAL(static_cast<uint8_t>(m_version), static_cast<uint8_t>(Version::V2), ());
+    m_indexOffset = ReadPrimitiveFromSource<uint32_t>(source);
+    m_indexSize = ReadPrimitiveFromSource<uint32_t>(source);
+  }
+
+  Version m_version = Version::Latest;
+  // All offsets are relative to the start of the section (offset of header is zero).
+  uint32_t m_indexOffset = 0;
+  uint32_t m_indexSize = 0;
+};
+}  // namespace search