Merge pull request #6302 from edolstra/fetch-closure

Add builtins.fetchClosure

4 files changed, 58 insertions, 105 deletions

diff --git a/src/nix/main.cc b/src/nix/main.cc
index b923f2535..9bc6c15fa 100644
--- a/src/nix/main.cc
+++ b/src/nix/main.cc
@@ -117,7 +117,7 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs
         {"hash-path", {"hash", "path"}},
         {"ls-nar", {"nar", "ls"}},
         {"ls-store", {"store", "ls"}},
-        {"make-content-addressable", {"store", "make-content-addressable"}},
+        {"make-content-addressable", {"store", "make-content-addressed"}},
         {"optimise-store", {"store", "optimise"}},
         {"ping-store", {"store", "ping"}},
         {"sign-paths", {"store", "sign"}},
diff --git a/src/nix/make-content-addressable.cc b/src/nix/make-content-addressable.cc
deleted file mode 100644
index 2e75a3b61..000000000
--- a/src/nix/make-content-addressable.cc
+++ /dev/null
@@ -1,102 +0,0 @@
-#include "command.hh"
-#include "store-api.hh"
-#include "references.hh"
-#include "common-args.hh"
-#include "json.hh"
-
-using namespace nix;
-
-struct CmdMakeContentAddressable : StorePathsCommand, MixJSON
-{
-    CmdMakeContentAddressable()
-    {
-        realiseMode = Realise::Outputs;
-    }
-
-    std::string description() override
-    {
-        return "rewrite a path or closure to content-addressed form";
-    }
-
-    std::string doc() override
-    {
-        return
-          #include "make-content-addressable.md"
-          ;
-    }
-
-    void run(ref<Store> store, StorePaths && storePaths) override
-    {
-        auto paths = store->topoSortPaths(StorePathSet(storePaths.begin(), storePaths.end()));
-
-        std::reverse(paths.begin(), paths.end());
-
-        std::map<StorePath, StorePath> remappings;
-
-        auto jsonRoot = json ? std::make_unique<JSONObject>(std::cout) : nullptr;
-        auto jsonRewrites = json ? std::make_unique<JSONObject>(jsonRoot->object("rewrites")) : nullptr;
-
-        for (auto & path : paths) {
-            auto pathS = store->printStorePath(path);
-            auto oldInfo = store->queryPathInfo(path);
-            std::string oldHashPart(path.hashPart());
-
-            StringSink sink;
-            store->narFromPath(path, sink);
-
-            StringMap rewrites;
-
-            StorePathSet references;
-            bool hasSelfReference = false;
-            for (auto & ref : oldInfo->references) {
-                if (ref == path)
-                    hasSelfReference = true;
-                else {
-                    auto i = remappings.find(ref);
-                    auto replacement = i != remappings.end() ? i->second : ref;
-                    // FIXME: warn about unremapped paths?
-                    if (replacement != ref)
-                        rewrites.insert_or_assign(store->printStorePath(ref), store->printStorePath(replacement));
-                    references.insert(std::move(replacement));
-                }
-            }
-
-            sink.s = rewriteStrings(sink.s, rewrites);
-
-            HashModuloSink hashModuloSink(htSHA256, oldHashPart);
-            hashModuloSink(sink.s);
-
-            auto narHash = hashModuloSink.finish().first;
-
-            ValidPathInfo info {
-                store->makeFixedOutputPath(FileIngestionMethod::Recursive, narHash, path.name(), references, hasSelfReference),
-                narHash,
-            };
-            info.references = std::move(references);
-            if (hasSelfReference) info.references.insert(info.path);
-            info.narSize = sink.s.size();
-            info.ca = FixedOutputHash {
-                .method = FileIngestionMethod::Recursive,
-                .hash = info.narHash,
-            };
-
-            if (!json)
-                notice("rewrote '%s' to '%s'", pathS, store->printStorePath(info.path));
-
-            auto source = sinkToSource([&](Sink & nextSink) {
-                RewritingSink rsink2(oldHashPart, std::string(info.path.hashPart()), nextSink);
-                rsink2(sink.s);
-                rsink2.flush();
-            });
-
-            store->addToStore(info, *source);
-
-            if (json)
-                jsonRewrites->attr(store->printStorePath(path), store->printStorePath(info.path));
-
-            remappings.insert_or_assign(std::move(path), std::move(info.path));
-        }
-    }
-};
-
-static auto rCmdMakeContentAddressable = registerCommand2<CmdMakeContentAddressable>({"store", "make-content-addressable"});
diff --git a/src/nix/make-content-addressed.cc b/src/nix/make-content-addressed.cc
new file mode 100644
index 000000000..34860c38f
--- /dev/null
+++ b/src/nix/make-content-addressed.cc
@@ -0,0 +1,55 @@
+#include "command.hh"
+#include "store-api.hh"
+#include "make-content-addressed.hh"
+#include "common-args.hh"
+#include "json.hh"
+
+using namespace nix;
+
+struct CmdMakeContentAddressed : virtual CopyCommand, virtual StorePathsCommand, MixJSON
+{
+    CmdMakeContentAddressed()
+    {
+        realiseMode = Realise::Outputs;
+    }
+
+    std::string description() override
+    {
+        return "rewrite a path or closure to content-addressed form";
+    }
+
+    std::string doc() override
+    {
+        return
+          #include "make-content-addressed.md"
+          ;
+    }
+
+    void run(ref<Store> srcStore, StorePaths && storePaths) override
+    {
+        auto dstStore = dstUri.empty() ? openStore() : openStore(dstUri);
+
+        auto remappings = makeContentAddressed(*srcStore, *dstStore,
+            StorePathSet(storePaths.begin(), storePaths.end()));
+
+        if (json) {
+            JSONObject jsonRoot(std::cout);
+            JSONObject jsonRewrites(jsonRoot.object("rewrites"));
+            for (auto & path : storePaths) {
+                auto i = remappings.find(path);
+                assert(i != remappings.end());
+                jsonRewrites.attr(srcStore->printStorePath(path), srcStore->printStorePath(i->second));
+            }
+        } else {
+            for (auto & path : storePaths) {
+                auto i = remappings.find(path);
+                assert(i != remappings.end());
+                notice("rewrote '%s' to '%s'",
+                    srcStore->printStorePath(path),
+                    srcStore->printStorePath(i->second));
+            }
+        }
+    }
+};
+
+static auto rCmdMakeContentAddressed = registerCommand2<CmdMakeContentAddressed>({"store", "make-content-addressed"});
diff --git a/src/nix/make-content-addressable.md b/src/nix/make-content-addressed.md
index 3dd847edc..215683e6d 100644
--- a/src/nix/make-content-addressable.md
+++ b/src/nix/make-content-addressed.md
@@ -5,7 +5,7 @@ R""(
 * Create a content-addressed representation of the closure of GNU Hello:
 
   ```console
-  # nix store make-content-addressable -r nixpkgs#hello
+  # nix store make-content-addressed nixpkgs#hello
   …
   rewrote '/nix/store/v5sv61sszx301i0x6xysaqzla09nksnd-hello-2.10' to '/nix/store/5skmmcb9svys5lj3kbsrjg7vf2irid63-hello-2.10'
   ```
@@ -29,7 +29,7 @@ R""(
   system closure:
 
   ```console
-  # nix store make-content-addressable -r /run/current-system
+  # nix store make-content-addressed /run/current-system
   ```
 
 # Description