Ground work for pluggable storage serializers

src/storage/Serializer.h

@@ -0,0 +1,50 @@
+// See the file "COPYING" in the main distribution directory for copyright.
+
+#pragma once
+
+#include "zeek/Span.h"
+#include "zeek/Val.h"
+
+namespace zeek::storage {
+
+namespace detail {
+using byte_buffer = std::vector<std::byte>;
+using byte_buffer_span = Span<const std::byte>;
+} // namespace detail
+
+/**
+ * Base class for a serializer used by storage backends.
+ */
+class Serializer {
+public:
+    virtual ~Serializer() = default;
+
+    /**
+     * Serializes Zeek Val data into another format.
+     *
+     * @param val The data to serialize.
+     *
+     * @return On success, a byte buffer containing the serialized data. std::nullopt will
+     *  be returned on failure.
+     */
+    virtual std::optional<detail::byte_buffer> Serialize(ValPtr val) = 0;
+
+    /**
+     * Unserializes a byte buffer into Zeek Val objects of a specific type.
+     *
+     * @param buf The byte data to unserialize.
+     * @param type The Zeek script-level type to unserialize the data into.
+     *
+     * @return A zeek::expected containing either the unserialized Val data on success, or
+     * a string containing an error message on failure.
+     */
+    virtual zeek::expected<ValPtr, std::string> Unserialize(detail::byte_buffer_span buf, TypePtr type) = 0;
+
+protected:
+    Serializer(std::string name) : name(std::move(name)) {}
+
+private:
+    std::string name;
+};
+
+} // namespace zeek::storage