From b252b3c6e3e99ead44e8af99101828c083d65cc0 Mon Sep 17 00:00:00 2001
From: eldritch horrors <pennae@lix.systems>
Date: Thu, 27 Jun 2024 16:48:10 +0200
Subject: [PATCH] libutil: allow draining Generator<Bytes> into sinks

Change-Id: I442d03a5399096d4baca9a2618b4c4b64db36c4b
---
 perl/meson.build         | 1 +
 src/libutil/serialise.hh | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/perl/meson.build b/perl/meson.build
index b542f3e8a..6f078f8e6 100644
--- a/perl/meson.build
+++ b/perl/meson.build
@@ -65,5 +65,6 @@ if cxx.get_linker_id() in ['ld.bfd', 'ld.gold']
 endif
 
 libstore = dependency('lixstore', 'lix-store', required : true)
+libutil = dependency('lixutil', 'lix-util', required : true)
 
 subdir('lib/Nix')
diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh
index 0632e3109..491b1987d 100644
--- a/src/libutil/serialise.hh
+++ b/src/libutil/serialise.hh
@@ -1,8 +1,10 @@
 #pragma once
 ///@file
 
+#include <concepts>
 #include <memory>
 
+#include "generator.hh"
 #include "strings.hh"
 #include "types.hh"
 #include "file-descriptor.hh"
@@ -340,6 +342,13 @@ std::unique_ptr<FinishSink> sourceToSink(std::function<void(Source &)> fun);
  */
 std::unique_ptr<Source> sinkToSource(std::function<void(Sink &)> fun);
 
+inline Sink & operator<<(Sink & sink, Generator<Bytes> && g)
+{
+    while (auto buffer = g.next()) {
+        sink(std::string_view(buffer->data(), buffer->size()));
+    }
+    return sink;
+}
 
 void writePadding(size_t len, Sink & sink);
 void writeString(std::string_view s, Sink & sink);