In RTDB, create app data directory if it doesn't exist. Modify AppDataDir to create the whole path if needed. (#992)

* RTDB: Create the app data directory if it doesn't already exist.

* Add release note.

* Modify AppDataDir to create the whole path if needed.

Author: jonsimantov

app/src/filesystem_desktop_linux.cc

@@ -72,6 +72,12 @@ bool Mkdir(const std::string& path, std::string* out_error) {
   return true;
 }
 
+bool PathExists(const std::string& path) {
+  struct stat sb;
+
+  return (stat(path.c_str(), &sb) == 0 && S_ISDIR(sb.st_mode));
+}
+
 }  // namespace
 
 std::string AppDataDir(const char* app_name, bool should_create,
@@ -93,14 +99,18 @@ std::string AppDataDir(const char* app_name, bool should_create,
     app_dir = std::string(".local/share/") + app_name;
   }
 
-  if (should_create) {
-    std::string current_path = home;
-    for (const std::string& nested_dir : SplitString(app_dir, '/')) {
-      current_path += '/';
+  std::string full_path = home + '/' + app_dir;
+  if (should_create && !PathExists(full_path)) {
+    std::string current_path = full_path[0] == '/' ? "/" : "";
+
+    for (const std::string& nested_dir : SplitString(full_path, '/')) {
       current_path += nested_dir;
 
-      bool created = Mkdir(current_path, out_error);
-      if (!created) return "";
+      if (!PathExists(current_path)) {
+        bool created = Mkdir(current_path, out_error);
+        if (!created) return "";
+      }
+      current_path += '/';
     }
   }
 

database/src/desktop/core/repo.cc

@@ -474,11 +474,14 @@ void Repo::DeferredInitialization() {
     database_path += "/";
     database_path += url_domain;
 
-    std::string app_data_path = AppDataDir(database_path.c_str());
+    std::string app_data_path_error;
+    std::string app_data_path =
+        AppDataDir(database_path.c_str(),
+                   /* should_create = */ true, &app_data_path_error);
     if (app_data_path.empty()) {
       logger_->LogError(
-          "Could not initialize persistence: Unable to find app data "
-          "directory.");
+          "Could not initialize persistence: App data directory error: %s",
+          app_data_path_error.c_str());
       return;
     }
 

release_build_files/readme.md

@@ -615,6 +615,8 @@ code.
 -   Changes
     - General (Android): Switched over to Android BoM (Bill of Materials)
       for dependency versions. This requires Gradle 5.
+    - Database (Desktop): If the app data directory doesn't exist, create it.
+      This fixes an issue with disk persistence on Linux.
     - Messaging (Android): Fixed #973. Make sure all the resources are closed in
       `RegistrationIntentService`.