Write database to the DataLocation

src/Cache.cpp

@@ -169,13 +169,35 @@ Cache::setup()
 
         nhlog::db()->debug("setting up cache");
 
+        // Previous location of the cache directory
+        auto oldCache = QString("%1/%2%3")
+                          .arg(QStandardPaths::writableLocation(QStandardPaths::CacheLocation))
+                          .arg(QString::fromUtf8(localUserId_.toUtf8().toHex()))
+                          .arg(QString::fromUtf8(settings->profile().toUtf8().toHex()));
+
         cacheDirectory_ = QString("%1/%2%3")
-                            .arg(QStandardPaths::writableLocation(QStandardPaths::CacheLocation))
+                            .arg(QStandardPaths::writableLocation(QStandardPaths::AppDataLocation))
                             .arg(QString::fromUtf8(localUserId_.toUtf8().toHex()))
                             .arg(QString::fromUtf8(settings->profile().toUtf8().toHex()));
 
         bool isInitial = !QFile::exists(cacheDirectory_);
 
+        // NOTE: If both cache directories exist it's better to do nothing: it
+        // could mean a previous migration failed or was interrupted.
+        bool needsMigration = isInitial && QFile::exists(oldCache);
+
+        if (needsMigration) {
+                nhlog::db()->info("found old state directory, migrating");
+                if (!QDir().rename(oldCache, cacheDirectory_)) {
+                        throw std::runtime_error(("Unable to migrate the old state directory (" +
+                                                  oldCache + ") to the new location (" +
+                                                  cacheDirectory_ + ")")
+                                                   .toStdString()
+                                                   .c_str());
+                }
+                nhlog::db()->info("completed state migration");
+        }
+
         env_ = lmdb::env::create();
         env_.set_mapsize(DB_SIZE);
         env_.set_max_dbs(MAX_DBS);

src/main.cpp

@@ -93,9 +93,9 @@ screenCenter(int width, int height)
 }
 
 void
-createCacheDirectory()
+createStandardDirectory(QStandardPaths::StandardLocation path)
 {
-        auto dir = QStandardPaths::writableLocation(QStandardPaths::CacheLocation);
+        auto dir = QStandardPaths::writableLocation(path);
 
         if (!QDir().mkpath(dir)) {
                 throw std::runtime_error(
@@ -188,7 +188,8 @@ main(int argc, char *argv[])
 
         http::init();
 
-        createCacheDirectory();
+        createStandardDirectory(QStandardPaths::CacheLocation);
+        createStandardDirectory(QStandardPaths::AppDataLocation);
 
         registerSignalHandlers();