make multi threaded compression configurable and use single threaded

by default.

2 files changed, 4 insertions, 1 deletions

diff --git a/src/libstore/binary-cache-store.cc b/src/libstore/binary-cache-store.cc
index ab971dd8b6d9..d34adbd60c71 100644
--- a/src/libstore/binary-cache-store.cc
+++ b/src/libstore/binary-cache-store.cc
@@ -149,7 +149,7 @@ void BinaryCacheStore::addToStore(const ValidPathInfo & info, const ref<std::str
     /* Compress the NAR. */
     narInfo->compression = compression;
     auto now1 = std::chrono::steady_clock::now();
-    auto narCompressed = compress(compression, *nar);
+    auto narCompressed = compress(compression, *nar, settings.parallelCompression);
     auto now2 = std::chrono::steady_clock::now();
     narInfo->fileHash = hashString(htSHA256, *narCompressed);
     narInfo->fileSize = narCompressed->size();
diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh
index 20ac8fe4e9ae..aafec2ea269b 100644
--- a/src/libstore/globals.hh
+++ b/src/libstore/globals.hh
@@ -174,6 +174,9 @@ public:
         "Whether to compress logs.",
         {"build-compress-log"}};
 
+    Setting<bool> parallelCompression{this, false, "parallel-compression",
+        "Whether to enable parallel compression, only supported with xz currently"};
+
     Setting<unsigned long> maxLogSize{this, 0, "max-build-log-size",
         "Maximum number of bytes a builder can write to stdout/stderr "
         "before being killed (0 means no limit).",