From 4bef2016a18e64e378982db914e73d1a8eaa8855 Mon Sep 17 00:00:00 2001
From: Alexander Bantyev <balsoft@balsoft.ru>
Date: Thu, 9 Mar 2023 16:03:48 +0400
Subject: [PATCH] Display progress when running copyPaths (nix copy)

`nix copy` operations did not show progress. This is quite confusing.

Add a `progressSink` which displays the progress during `copyPaths`,
pretty much copied from `copyStorePath`.

Fixes https://github.com/NixOS/nix/issues/8000
---
 src/libstore/store-api.cc | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index f32c2d30c..9ef641a3d 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -1101,6 +1101,8 @@ std::map<StorePath, StorePath> copyPaths(
         return storePathForDst;
     };
 
+    uint64_t total = 0;
+
     for (auto & missingPath : sortedMissing) {
         auto info = srcStore.queryPathInfo(missingPath);
 
@@ -1121,7 +1123,13 @@ std::map<StorePath, StorePath> copyPaths(
                 {storePathS, srcUri, dstUri});
             PushActivity pact(act.id);
 
-            srcStore.narFromPath(missingPath, sink);
+            LambdaSink progressSink([&](std::string_view data) {
+                total += data.size();
+                act.progress(total, info->narSize);
+            });
+            TeeSink tee { sink, progressSink };
+
+            srcStore.narFromPath(missingPath, tee);
         });
         pathsToCopy.push_back(std::pair{infoForDst, std::move(source)});
     }