2 files changed, 92 insertions, 0 deletions
diff --git a/src/libstore/make-content-addressed.cc b/src/libstore/make-content-addressed.cc
new file mode 100644
index 000000000..64d172918
--- /dev/null
+++ b/src/libstore/make-content-addressed.cc
@@ -0,0 +1,80 @@
+#include "make-content-addressed.hh"
+#include "references.hh"
+
+namespace nix {
+
+std::map<StorePath, StorePath> makeContentAddressed(
+    Store & srcStore,
+    Store & dstStore,
+    const StorePathSet & storePaths)
+{
+    StorePathSet closure;
+    srcStore.computeFSClosure(storePaths, closure);
+
+    auto paths = srcStore.topoSortPaths(closure);
+
+    std::reverse(paths.begin(), paths.end());
+
+    std::map<StorePath, StorePath> remappings;
+
+    for (auto & path : paths) {
+        auto pathS = srcStore.printStorePath(path);
+        auto oldInfo = srcStore.queryPathInfo(path);
+        std::string oldHashPart(path.hashPart());
+
+        StringSink sink;
+        srcStore.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(srcStore.printStorePath(ref), srcStore.printStorePath(replacement));
+                references.insert(std::move(replacement));
+            }
+        }
+
+        sink.s = rewriteStrings(sink.s, rewrites);
+
+        HashModuloSink hashModuloSink(htSHA256, oldHashPart);
+        hashModuloSink(sink.s);
+
+        auto narModuloHash = hashModuloSink.finish().first;
+
+        auto dstPath = dstStore.makeFixedOutputPath(
+            FileIngestionMethod::Recursive, narModuloHash, path.name(), references, hasSelfReference);
+
+        printInfo("rewriting '%s' to '%s'", pathS, srcStore.printStorePath(dstPath));
+
+        StringSink sink2;
+        RewritingSink rsink2(oldHashPart, std::string(dstPath.hashPart()), sink2);
+        rsink2(sink.s);
+        rsink2.flush();
+
+        ValidPathInfo info { dstPath, hashString(htSHA256, sink2.s) };
+        info.references = std::move(references);
+        if (hasSelfReference) info.references.insert(info.path);
+        info.narSize = sink.s.size();
+        info.ca = FixedOutputHash {
+            .method = FileIngestionMethod::Recursive,
+            .hash = narModuloHash,
+        };
+
+        StringSource source(sink2.s);
+        dstStore.addToStore(info, source);
+
+        remappings.insert_or_assign(std::move(path), std::move(info.path));
+    }
+
+    return remappings;
+}
+
+}
diff --git a/src/libstore/make-content-addressed.hh b/src/libstore/make-content-addressed.hh
new file mode 100644
index 000000000..c4a66ed41
--- /dev/null
+++ b/src/libstore/make-content-addressed.hh
@@ -0,0 +1,12 @@
+#pragma once
+
+#include "store-api.hh"
+
+namespace nix {
+
+std::map<StorePath, StorePath> makeContentAddressed(
+    Store & srcStore,
+    Store & dstStore,
+    const StorePathSet & storePaths);
+
+}