Merge pull request #9137 from obsidiansystems/serve-protocol

Introduce separate Serve protocol serialisers

(cherry picked from commit d070d8b7460f412a657745698dba291c66792402)
Change-Id: Ibcc8639e8997bcd07f7a5318330a147bcadc411b

1 files changed, 59 insertions, 0 deletions

diff --git a/src/libstore/serve-protocol-impl.hh b/src/libstore/serve-protocol-impl.hh
new file mode 100644
index 000000000..a3ce81026
--- /dev/null
+++ b/src/libstore/serve-protocol-impl.hh
@@ -0,0 +1,59 @@
+#pragma once
+/**
+ * @file
+ *
+ * Template implementations (as opposed to mere declarations).
+ *
+ * This file is an exmample of the "impl.hh" pattern. See the
+ * contributing guide.
+ */
+
+#include "serve-protocol.hh"
+#include "length-prefixed-protocol-helper.hh"
+
+namespace nix {
+
+/* protocol-agnostic templates */
+
+#define SERVE_USE_LENGTH_PREFIX_SERIALISER(TEMPLATE, T) \
+    TEMPLATE T ServeProto::Serialise< T >::read(const Store & store, ServeProto::ReadConn conn) \
+    { \
+        return LengthPrefixedProtoHelper<ServeProto, T >::read(store, conn); \
+    } \
+    TEMPLATE void ServeProto::Serialise< T >::write(const Store & store, ServeProto::WriteConn conn, const T & t) \
+    { \
+        LengthPrefixedProtoHelper<ServeProto, T >::write(store, conn, t); \
+    }
+
+SERVE_USE_LENGTH_PREFIX_SERIALISER(template<typename T>, std::vector<T>)
+SERVE_USE_LENGTH_PREFIX_SERIALISER(template<typename T>, std::set<T>)
+SERVE_USE_LENGTH_PREFIX_SERIALISER(template<typename... Ts>, std::tuple<Ts...>)
+
+#define COMMA_ ,
+SERVE_USE_LENGTH_PREFIX_SERIALISER(
+    template<typename K COMMA_ typename V>,
+    std::map<K COMMA_ V>)
+#undef COMMA_
+
+/**
+ * Use `CommonProto` where possible.
+ */
+template<typename T>
+struct ServeProto::Serialise
+{
+    static T read(const Store & store, ServeProto::ReadConn conn)
+    {
+        return CommonProto::Serialise<T>::read(store,
+            CommonProto::ReadConn { .from = conn.from });
+    }
+    static void write(const Store & store, ServeProto::WriteConn conn, const T & t)
+    {
+        CommonProto::Serialise<T>::write(store,
+            CommonProto::WriteConn { .to = conn.to },
+            t);
+    }
+};
+
+/* protocol-specific templates */
+
+}