multiprocess: Add type conversion code for UniValue types

Extend IPC unit test to cover this and verify the serialization happens
correctly.

1 files changed, 19 insertions, 0 deletions

diff --git a/src/ipc/capnp/common-types.h b/src/ipc/capnp/common-types.h
index d1343c40dd..39e368491b 100644
--- a/src/ipc/capnp/common-types.h
+++ b/src/ipc/capnp/common-types.h
@@ -7,6 +7,7 @@
 
 #include <clientversion.h>
 #include <streams.h>
+#include <univalue.h>
 
 #include <cstddef>
 #include <mp/proxy-types.h>
@@ -84,6 +85,24 @@ CustomReadField(TypeList<LocalType>, Priority<1>, InvokeContext& invoke_context,
         value.Unserialize(stream);
     });
 }
+
+template <typename Value, typename Output>
+void CustomBuildField(TypeList<UniValue>, Priority<1>, InvokeContext& invoke_context, Value&& value, Output&& output)
+{
+    std::string str = value.write();
+    auto result = output.init(str.size());
+    memcpy(result.begin(), str.data(), str.size());
+}
+
+template <typename Input, typename ReadDest>
+decltype(auto) CustomReadField(TypeList<UniValue>, Priority<1>, InvokeContext& invoke_context, Input&& input,
+                               ReadDest&& read_dest)
+{
+    return read_dest.update([&](auto& value) {
+        auto data = input.get();
+        value.read(std::string_view{data.begin(), data.size()});
+    });
+}
 } // namespace mp
 
 #endif // BITCOIN_IPC_CAPNP_COMMON_TYPES_H