cache frame indexes to disk

app/common/filefunctions.cpp

@@ -0,0 +1,43 @@
+#include "filefunctions.h"
+
+#include <QCryptographicHash>
+#include <QDateTime>
+#include <QDir>
+#include <QFileInfo>
+#include <QStandardPaths>
+
+QString GetUniqueFileIdentifier(const QString &filename)
+{
+  QFileInfo info(filename);
+
+  if (!info.exists()) {
+    return QString();
+  }
+
+  QCryptographicHash hash(QCryptographicHash::Sha1);
+
+  hash.addData(info.absoluteFilePath().toUtf8());
+
+  hash.addData(info.lastModified().toString().toUtf8());
+
+  QByteArray result = hash.result();
+
+  return QString(result.toHex());
+}
+
+QString GetMediaIndexLocation()
+{
+  QDir local_appdata_dir(QStandardPaths::writableLocation(QStandardPaths::AppLocalDataLocation));
+
+  QDir media_index_dir = local_appdata_dir.filePath("mediaindex");
+
+  // Attempt to ensure this folder exists
+  media_index_dir.mkpath("mediaindex");
+
+  return media_index_dir.absolutePath();
+}
+
+QString GetMediaIndexFilename(const QString &filename)
+{
+  return QDir(GetMediaIndexLocation()).filePath(filename);
+}