From 11ba4302e3666d3860ca83b734217afe07f22de2 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Tue, 17 Oct 2017 20:51:42 +0200
Subject: [PATCH] Remove BinaryCacheStoreAccessor

Probably as a result of a bad merge in
4b8f1b0ec066a5b994747b1afd050f5f62d857f6, we had both a
BinaryCacheStoreAccessor and a
RemoteFSAccessor. BinaryCacheStore::getFSAccessor() returned the
latter, but BinaryCacheStore::addToStore() checked for the
former. This probably caused hydra-queue-runner to download paths that
it just uploaded.
---
 src/libstore/binary-cache-store.cc | 62 +-----------------------------
 src/libstore/remote-fs-accessor.hh |  3 ++
 2 files changed, 4 insertions(+), 61 deletions(-)

diff --git a/src/libstore/binary-cache-store.cc b/src/libstore/binary-cache-store.cc
index 556fa3d59..9d497110f 100644
--- a/src/libstore/binary-cache-store.cc
+++ b/src/libstore/binary-cache-store.cc
@@ -17,66 +17,6 @@
 
 namespace nix {
 
-/* Given requests for a path /nix/store/<x>/<y>, this accessor will
-   first download the NAR for /nix/store/<x> from the binary cache,
-   build a NAR accessor for that NAR, and use that to access <y>. */
-struct BinaryCacheStoreAccessor : public FSAccessor
-{
-    ref<BinaryCacheStore> store;
-
-    std::map<Path, ref<FSAccessor>> nars;
-
-    BinaryCacheStoreAccessor(ref<BinaryCacheStore> store)
-        : store(store)
-    {
-    }
-
-    std::pair<ref<FSAccessor>, Path> fetch(const Path & path_)
-    {
-        auto path = canonPath(path_);
-
-        auto storePath = store->toStorePath(path);
-        std::string restPath = std::string(path, storePath.size());
-
-        if (!store->isValidPath(storePath))
-            throw InvalidPath(format("path '%1%' is not a valid store path") % storePath);
-
-        auto i = nars.find(storePath);
-        if (i != nars.end()) return {i->second, restPath};
-
-        StringSink sink;
-        store->narFromPath(storePath, sink);
-
-        auto accessor = makeNarAccessor(sink.s);
-        nars.emplace(storePath, accessor);
-        return {accessor, restPath};
-    }
-
-    Stat stat(const Path & path) override
-    {
-        auto res = fetch(path);
-        return res.first->stat(res.second);
-    }
-
-    StringSet readDirectory(const Path & path) override
-    {
-        auto res = fetch(path);
-        return res.first->readDirectory(res.second);
-    }
-
-    std::string readFile(const Path & path) override
-    {
-        auto res = fetch(path);
-        return res.first->readFile(res.second);
-    }
-
-    std::string readLink(const Path & path) override
-    {
-        auto res = fetch(path);
-        return res.first->readLink(res.second);
-    }
-};
-
 BinaryCacheStore::BinaryCacheStore(const Params & params)
     : Store(params)
 {
@@ -161,7 +101,7 @@ void BinaryCacheStore::addToStore(const ValidPathInfo & info, const ref<std::str
     if (info.narHash && info.narHash != narInfo->narHash)
         throw Error(format("refusing to copy corrupted path '%1%' to binary cache") % info.path);
 
-    auto accessor_ = std::dynamic_pointer_cast<BinaryCacheStoreAccessor>(accessor);
+    auto accessor_ = std::dynamic_pointer_cast<RemoteFSAccessor>(accessor);
 
     /* Optionally write a JSON file containing a listing of the
        contents of the NAR. */
diff --git a/src/libstore/remote-fs-accessor.hh b/src/libstore/remote-fs-accessor.hh
index 28f36c829..df8b7b162 100644
--- a/src/libstore/remote-fs-accessor.hh
+++ b/src/libstore/remote-fs-accessor.hh
@@ -13,6 +13,9 @@ class RemoteFSAccessor : public FSAccessor
     std::map<Path, ref<FSAccessor>> nars;
 
     std::pair<ref<FSAccessor>, Path> fetch(const Path & path_);
+
+    friend class BinaryCacheStore;
+
 public:
 
     RemoteFSAccessor(ref<Store> store);