From e7faf65784f5052d6dddeb5532f9829e5f6a07b9 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Mon, 25 Jul 2022 15:12:28 +0200
Subject: [PATCH] Remove FlakeRef::fetchTree()

---
 src/libexpr/flake/flakeref.cc |  6 ------
 src/libexpr/flake/flakeref.hh |  2 --
 src/nix/flake-prefetch.md     |  9 +++------
 src/nix/flake.cc              | 12 +++---------
 4 files changed, 6 insertions(+), 23 deletions(-)

diff --git a/src/libexpr/flake/flakeref.cc b/src/libexpr/flake/flakeref.cc
index 0b30b8467..0a53037fa 100644
--- a/src/libexpr/flake/flakeref.cc
+++ b/src/libexpr/flake/flakeref.cc
@@ -229,12 +229,6 @@ FlakeRef FlakeRef::fromAttrs(const fetchers::Attrs & attrs)
         fetchers::maybeGetStrAttr(attrs, "dir").value_or(""));
 }
 
-std::pair<fetchers::Tree, FlakeRef> FlakeRef::fetchTree(ref<Store> store) const
-{
-    auto [tree, lockedInput] = input.fetch(store);
-    return {std::move(tree), FlakeRef(std::move(lockedInput), subdir)};
-}
-
 std::pair<ref<InputAccessor>, FlakeRef> FlakeRef::lazyFetch(ref<Store> store) const
 {
     auto [accessor, lockedInput] = input.lazyFetch(store);
diff --git a/src/libexpr/flake/flakeref.hh b/src/libexpr/flake/flakeref.hh
index bdf93b251..5157dc325 100644
--- a/src/libexpr/flake/flakeref.hh
+++ b/src/libexpr/flake/flakeref.hh
@@ -57,8 +57,6 @@ struct FlakeRef
 
     static FlakeRef fromAttrs(const fetchers::Attrs & attrs);
 
-    std::pair<fetchers::Tree, FlakeRef> fetchTree(ref<Store> store) const;
-
     std::pair<ref<InputAccessor>, FlakeRef> lazyFetch(ref<Store> store) const;
 };
 
diff --git a/src/nix/flake-prefetch.md b/src/nix/flake-prefetch.md
index a1cf0289a..28a5f8844 100644
--- a/src/nix/flake-prefetch.md
+++ b/src/nix/flake-prefetch.md
@@ -2,21 +2,18 @@ R""(
 
 # Examples
 
-* Download a tarball and unpack it:
+* Download a tarball:
 
   ```console
   # nix flake prefetch https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.5.tar.xz
-  Downloaded 'https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.5.tar.xz?narHash=sha256-3XYHZANT6AFBV0BqegkAZHbba6oeDkIUCDwbATLMhAY='
-  to '/nix/store/sl5vvk8mb4ma1sjyy03kwpvkz50hd22d-source' (hash
-  'sha256-3XYHZANT6AFBV0BqegkAZHbba6oeDkIUCDwbATLMhAY=').
+  Fetched 'https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.5.tar.xz?narHash=sha256-3XYHZANT6AFBV0BqegkAZHbba6oeDkIUCDwbATLMhAY='.
   ```
 
 * Download the `dwarffs` flake (looked up in the flake registry):
 
   ```console
   # nix flake prefetch dwarffs --json
-  {"hash":"sha256-VHg3MYVgQ12LeRSU2PSoDeKlSPD8PYYEFxxwkVVDRd0="
-  ,"storePath":"/nix/store/hang3792qwdmm2n0d9nsrs5n6bsws6kv-source"}
+  {}
   ```
 
 # Description
diff --git a/src/nix/flake.cc b/src/nix/flake.cc
index 5a0094d04..2ff096faa 100644
--- a/src/nix/flake.cc
+++ b/src/nix/flake.cc
@@ -1163,7 +1163,7 @@ struct CmdFlakePrefetch : FlakeCommand, MixJSON
 
     std::string description() override
     {
-        return "download the source tree denoted by a flake reference into the Nix store";
+        return "fetch the source tree denoted by a flake reference";
     }
 
     std::string doc() override
@@ -1177,19 +1177,13 @@ struct CmdFlakePrefetch : FlakeCommand, MixJSON
     {
         auto originalRef = getFlakeRef();
         auto resolvedRef = originalRef.resolve(store);
-        auto [tree, lockedRef] = resolvedRef.fetchTree(store);
-        auto hash = store->queryPathInfo(tree.storePath)->narHash;
+        auto [accessor, lockedRef] = resolvedRef.lazyFetch(store);
 
         if (json) {
             auto res = nlohmann::json::object();
-            res["storePath"] = store->printStorePath(tree.storePath);
-            res["hash"] = hash.to_string(SRI, true);
             logger->cout(res.dump());
         } else {
-            notice("Downloaded '%s' to '%s' (hash '%s').",
-                lockedRef.to_string(),
-                store->printStorePath(tree.storePath),
-                hash.to_string(SRI, true));
+            notice("Fetched '%s'.", lockedRef.to_string());
         }
     }
 };