C API: Add nix_store_get_storedir

NixOS · Dec 14, 2024 · 5f76536 · 5f76536
1 parent e125d90
commit 5f76536
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Showing 4 changed files with 60 additions and 2 deletions.
diff --git a/src/libstore-c/nix_api_store.cc b/src/libstore-c/nix_api_store.cc
@@ -67,6 +67,17 @@ nix_err nix_store_get_uri(nix_c_context * context, Store * store, nix_get_string
     NIXC_CATCH_ERRS
 }
 
+nix_err
+nix_store_get_storedir(nix_c_context * context, Store * store, nix_get_string_callback callback, void * user_data)
+{
+    if (context)
+        context->last_err_code = NIX_OK;
+    try {
+        return call_nix_get_string_callback(store->ptr->storeDir, callback, user_data);
+    }
+    NIXC_CATCH_ERRS
+}
+
 nix_err
 nix_store_get_version(nix_c_context * context, Store * store, nix_get_string_callback callback, void * user_data)
 {

diff --git a/src/libstore-c/nix_api_store.h b/src/libstore-c/nix_api_store.h
@@ -93,7 +93,18 @@ void nix_store_free(Store * store);
  */
 nix_err nix_store_get_uri(nix_c_context * context, Store * store, nix_get_string_callback callback, void * user_data);
 
-// returns: owned StorePath*
+/**
+ * @brief get the storeDir of a Nix store, typically `"/nix/store"`
+ * @param[out] context Optional, stores error information
+ * @param[in] store nix store reference
+ * @param[in] callback Called with the URI.
+ * @param[in] user_data optional, arbitrary data, passed to the callback when it's called.
+ * @see nix_get_string_callback
+ * @return error code, NIX_OK on success.
+ */
+nix_err
+nix_store_get_storedir(nix_c_context * context, Store * store, nix_get_string_callback callback, void * user_data);
+
 /**
  * @brief Parse a Nix store path into a StorePath
  *

diff --git a/src/libstore-tests/meson.build b/src/libstore-tests/meson.build
@@ -16,8 +16,10 @@ cxx = meson.get_compiler('cpp')
 
 subdir('nix-meson-build-support/deps-lists')
 
+nix_store = dependency('nix-store')
+
 deps_private_maybe_subproject = [
-  dependency('nix-store'),
+  nix_store,
   dependency('nix-store-c'),
   dependency('nix-store-test-support'),
 ]
@@ -90,6 +92,7 @@ this_exe = executable(
   include_directories : include_dirs,
   # TODO: -lrapidcheck, see ../libutil-support/build.meson
   link_args: linker_export_flags + ['-lrapidcheck'],
+  cpp_args : [ '-DNIX_STORE_DIR="' + nix_store.get_variable('storedir') + '"' ],
   # get main from gtest
   install : true,
 )

diff --git a/src/libstore-tests/nix_api_store.cc b/src/libstore-tests/nix_api_store.cc
@@ -24,6 +24,39 @@ TEST_F(nix_api_store_test, nix_store_get_uri)
     ASSERT_STREQ("local", str.c_str());
 }
 
+TEST_F(nix_api_util_context, nix_store_get_storedir_default)
+{
+    if (nix::getEnv("HOME").value_or("") == "/homeless-shelter") {
+        // skipping test in sandbox because nix_store_open tries to create /nix/var/nix/profiles
+        GTEST_SKIP();
+    }
+    nix_libstore_init(ctx);
+    Store * store = nix_store_open(ctx, nullptr, nullptr);
+    assert_ctx_ok();
+    ASSERT_NE(store, nullptr);
+
+    std::string str;
+    auto ret = nix_store_get_storedir(ctx, store, OBSERVE_STRING(str));
+    assert_ctx_ok();
+    ASSERT_EQ(NIX_OK, ret);
+
+    // These tests run with a unique storeDir, but not a relocated store
+    ASSERT_STREQ(NIX_STORE_DIR, str.c_str());
+
+    nix_store_free(store);
+}
+
+TEST_F(nix_api_store_test, nix_store_get_storedir)
+{
+    std::string str;
+    auto ret = nix_store_get_storedir(ctx, store, OBSERVE_STRING(str));
+    assert_ctx_ok();
+    ASSERT_EQ(NIX_OK, ret);
+
+    // These tests run with a unique storeDir, but not a relocated store
+    ASSERT_STREQ(nixStoreDir.c_str(), str.c_str());
+}
+
 TEST_F(nix_api_store_test, InvalidPathFails)
 {
     nix_store_parse_path(ctx, store, "invalid-path");