Asset System: Store root path in asset library data

No user visible changes expected.

If an asset library is located on disk, store the path to it in the
asset library data. This is called the "root path" now.
With this we can construct an asset identifier, which is introduced in
the following commit.

source/blender/asset_system/AS_asset_library.hh

@@ -34,7 +34,9 @@ class AssetStorage;
  * to also include asset indexes and more.
  */
 class AssetLibrary {
-  bCallbackFuncStore on_save_callback_store_{};
+  /** If this is an asset library on disk, the top-level directory path. Normalized using
+   * #normalize_directory_path().*/
+  std::string root_path_;
 
   /** Storage for assets (better said their representations) that are considered to be part of this
    * library. Assets are not automatically loaded into this when loading an asset library. Assets
@@ -51,6 +53,8 @@ class AssetLibrary {
    */
   std::unique_ptr<AssetStorage> asset_storage_;
 
+  bCallbackFuncStore on_save_callback_store_{};
+
  public:
   /* Controlled by #ED_asset_catalogs_set_save_catalogs_when_file_is_saved,
    * for managing the "Save Catalog Changes" in the quit-confirmation dialog box. */
@@ -59,10 +63,13 @@ class AssetLibrary {
   std::unique_ptr<AssetCatalogService> catalog_service;
 
  public:
-  AssetLibrary();
+  /**
+   * \param root_path: If this is an asset library on disk, the top-level directory path.
+   */
+  AssetLibrary(StringRef root_path = "");
   ~AssetLibrary();
 
-  void load_catalogs(StringRefNull library_root_directory);
+  void load_catalogs();
 
   /** Load catalogs that have changed on disk. */
   void refresh();
@@ -105,6 +112,8 @@ class AssetLibrary {
 
   void on_blend_save_post(Main *bmain, PointerRNA **pointers, int num_pointers);
 
+  StringRefNull root_path() const;
+
  private:
   std::optional<int> find_asset_index(const AssetRepresentation &asset);
 };

source/blender/asset_system/CMakeLists.txt

@@ -21,6 +21,7 @@ set(SRC
   intern/asset_library_service.cc
   intern/asset_representation.cc
   intern/asset_storage.cc
+  intern/utils.cc
 
   AS_asset_catalog.hh
   AS_asset_catalog_path.hh
@@ -29,6 +30,7 @@ set(SRC
   AS_asset_representation.hh
   intern/asset_library_service.hh
   intern/asset_storage.hh
+  intern/utils.hh
 
   AS_asset_library.h
   AS_asset_representation.h

source/blender/asset_system/intern/asset_library.cc

@@ -22,6 +22,7 @@
 
 #include "asset_library_service.hh"
 #include "asset_storage.hh"
+#include "utils.hh"
 
 using namespace blender;
 using namespace blender::asset_system;
@@ -120,8 +121,9 @@ void AS_asset_library_remap_ids(const IDRemapper *mappings)
 
 namespace blender::asset_system {
 
-AssetLibrary::AssetLibrary()
-    : asset_storage_(std::make_unique<AssetStorage>()),
+AssetLibrary::AssetLibrary(StringRef root_path)
+    : root_path_(utils::normalize_directory_path(root_path)),
+      asset_storage_(std::make_unique<AssetStorage>()),
       catalog_service(std::make_unique<AssetCatalogService>())
 {
 }
@@ -133,9 +135,9 @@ AssetLibrary::~AssetLibrary()
   }
 }
 
-void AssetLibrary::load_catalogs(StringRefNull library_root_directory)
+void AssetLibrary::load_catalogs()
 {
-  auto catalog_service = std::make_unique<AssetCatalogService>(library_root_directory);
+  auto catalog_service = std::make_unique<AssetCatalogService>(root_path());
   catalog_service->load_from_disk();
   this->catalog_service = std::move(catalog_service);
 }
@@ -224,6 +226,11 @@ void AssetLibrary::refresh_catalog_simplename(struct AssetMetaData *asset_data)
   STRNCPY(asset_data->catalog_simple_name, catalog->simple_name.c_str());
 }
 
+StringRefNull AssetLibrary::root_path() const
+{
+  return root_path_;
+}
+
 Vector<AssetLibraryReference> all_valid_asset_library_refs()
 {
   Vector<AssetLibraryReference> result;

source/blender/asset_system/intern/asset_library_service.cc

@@ -4,9 +4,6 @@
  * \ingroup asset_system
  */
 
-#include "asset_library_service.hh"
-#include "AS_asset_library.hh"
-
 #include "BKE_blender.h"
 #include "BKE_preferences.h"
 
@@ -19,6 +16,10 @@
 
 #include "CLG_log.h"
 
+#include "AS_asset_library.hh"
+#include "asset_library_service.hh"
+#include "utils.hh"
+
 /* When enabled, use a pre file load handler (#BKE_CB_EVT_LOAD_PRE) callback to destroy the asset
  * library service. Without this an explicit call from the file loading code is needed to do this,
  * which is not as nice.
@@ -80,41 +81,30 @@ AssetLibrary *AssetLibraryService::get_asset_library(
   return nullptr;
 }
 
-namespace {
-std::string normalize_directory_path(StringRefNull directory)
+AssetLibrary *AssetLibraryService::get_asset_library_on_disk(StringRefNull root_path)
 {
-
-  char dir_normalized[PATH_MAX];
-  STRNCPY(dir_normalized, directory.c_str());
-  BLI_path_normalize_dir(nullptr, dir_normalized, sizeof(dir_normalized));
-  return std::string(dir_normalized);
-}
-}  // namespace
-
-AssetLibrary *AssetLibraryService::get_asset_library_on_disk(StringRefNull top_level_directory)
-{
-  BLI_assert_msg(!top_level_directory.is_empty(),
+  BLI_assert_msg(!root_path.is_empty(),
                  "top level directory must be given for on-disk asset library");
 
-  std::string top_dir_trailing_slash = normalize_directory_path(top_level_directory);
+  std::string normalized_root_path = utils::normalize_directory_path(root_path);
 
   std::unique_ptr<AssetLibrary> *lib_uptr_ptr = on_disk_libraries_.lookup_ptr(
-      top_dir_trailing_slash);
+      normalized_root_path);
   if (lib_uptr_ptr != nullptr) {
-    CLOG_INFO(&LOG, 2, "get \"%s\" (cached)", top_dir_trailing_slash.c_str());
+    CLOG_INFO(&LOG, 2, "get \"%s\" (cached)", normalized_root_path.c_str());
     AssetLibrary *lib = lib_uptr_ptr->get();
     lib->refresh();
     return lib;
   }
 
-  std::unique_ptr lib_uptr = std::make_unique<AssetLibrary>();
+  std::unique_ptr lib_uptr = std::make_unique<AssetLibrary>(normalized_root_path);
   AssetLibrary *lib = lib_uptr.get();
 
   lib->on_blend_save_handler_register();
-  lib->load_catalogs(top_dir_trailing_slash);
+  lib->load_catalogs();
 
-  on_disk_libraries_.add_new(top_dir_trailing_slash, std::move(lib_uptr));
-  CLOG_INFO(&LOG, 2, "get \"%s\" (loaded)", top_dir_trailing_slash.c_str());
+  on_disk_libraries_.add_new(normalized_root_path, std::move(lib_uptr));
+  CLOG_INFO(&LOG, 2, "get \"%s\" (loaded)", normalized_root_path.c_str());
   return lib;
 }
 

source/blender/asset_system/intern/asset_library_service.hh

@@ -33,7 +33,8 @@ namespace blender::asset_system {
 class AssetLibraryService {
   static std::unique_ptr<AssetLibraryService> instance_;
 
-  /* Mapping absolute path of the library's top-level directory to the AssetLibrary instance. */
+  /* Mapping absolute path of the library's root path (normalize with #normalize_directory_path()!)
+   * the AssetLibrary instance. */
   Map<std::string, std::unique_ptr<AssetLibrary>> on_disk_libraries_;
   /** Library without a known path, i.e. the "Current File" library if the file isn't saved yet. If
    * the file was saved, a valid path for the library can be determined and #on_disk_libraries_

source/blender/asset_system/intern/utils.cc

@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup asset_system
+ */
+
+#include "BLI_fileops.h"
+#include "BLI_path_util.h"
+#include "BLI_string.h"
+
+#include "utils.hh"
+
+namespace blender::asset_system::utils {
+
+std::string normalize_directory_path(StringRef directory)
+{
+  if (directory.is_empty()) {
+    return "";
+  }
+
+  char dir_normalized[PATH_MAX];
+  BLI_strncpy(dir_normalized,
+              directory.data(),
+              /* + 1 for null terminator. */
+              std::min(directory.size() + 1, int64_t(sizeof(dir_normalized))));
+  BLI_path_normalize_dir(nullptr, dir_normalized, sizeof(dir_normalized));
+  return std::string(dir_normalized);
+}
+
+}  // namespace blender::asset_system::utils

source/blender/asset_system/intern/utils.hh

@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup asset_system
+ */
+
+#pragma once
+
+#include "BLI_string_ref.hh"
+
+namespace blender::asset_system::utils {
+
+/**
+ * Returns a normalized directory path with a trailing slash, and a maximum length of #PATH_MAX.
+ * Slashes are not converted to native format (they probably should be though?).
+ */
+std::string normalize_directory_path(StringRef directory);
+
+}  // namespace blender::asset_system::utils