Merge branch 'parallel-feature'

Author: Byron

gix/Cargo.toml

@@ -133,7 +133,7 @@ blocking-http-transport-reqwest-native-tls = ["blocking-http-transport-reqwest",
 ## Activate features that maximize performance, like usage of threads, `zlib-ng` and access to caching in object databases, skipping the ones known to cause compile failures
 ## on some platforms.
 max-performance-safe = [
-    "gix-features/parallel",
+    "parallel",
     "pack-cache-lru-static",
     "pack-cache-lru-dynamic",
     "gix-features/fs-walkdir-parallel"
@@ -144,6 +144,11 @@ max-performance-safe = [
 ## the simpler implementation that is the default.
 hp-tempfile-registry = ["gix-tempfile/hp-hashmap"]
 
+## Make certain data structure threadsafe (or `Sync`) to facilitate multithreading. Further, many algorithms will now use multiple threads by default.
+##
+## If unset, most of `gix` can only be used in a single thread as data structures won't be `Send` anymore.
+parallel = ["gix-features/parallel"]
+
 ## Provide a fixed-size allocation-free LRU cache for packs. It's useful if caching is desired while keeping the memory footprint
 ## for the LRU-cache itself low.
 pack-cache-lru-static = ["gix-pack/pack-cache-lru-static"]

gix/tests/repository/mod.rs

@@ -1,3 +1,4 @@
+use crate::util;
 use gix::Repository;
 
 mod config;
@@ -24,3 +25,11 @@ fn size_in_memory() {
         "size of Repository shouldn't change without us noticing, it's meant to be cloned: should have been below {limit:?}, was {actual_size} (bigger on windows)"
     );
 }
+
+#[test]
+#[cfg(feature = "parallel")]
+fn thread_safe_repository_is_sync() -> crate::Result {
+    fn f<T: Send + Sync + Clone>(_t: T) {}
+    f(util::basic_repo()?.into_sync());
+    Ok(())
+}