comparison base/StorageAdviser.h @ 168:04baa690f90d

* Start adding StorageAdviser class to determine whether caches should be
  on disc or in memory

+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Sonic Visualiser
+    An audio file viewer and annotation editor.
+    Centre for Digital Music, Queen Mary, University of London.
+    This file copyright 2006 Chris Cannam.
+    
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+#ifndef _STORAGE_ADVISER_H_
+#define _STORAGE_ADVISER_H_
+
+/**
+ * A utility class designed to help decide whether to store cache data
+ * (for example FFT outputs) in memory or on disk in the TempDirectory.
+ */
+
+class StorageAdviser
+{
+public:
+    // pass to recommend() zero or more of these OR'd together
+    enum Criteria {
+        SpeedCritical       = 1,
+        PrecisionCritical   = 2,
+        RepeatabilityUseful = 4
+    };
+
+    // recommend() returns one or two of these OR'd together
+    enum Recommendation {
+        UseMemory          = 1,
+        UseDisc            = 2,
+        ConserveSpace      = 4,
+        UseAsMuchAsYouLike = 8
+    };
+
+    // may throw InsufficientDiscSpace exception if it looks like
+    // minimumSize won't fit on the disc
+
+    static Recommendation recommend(Criteria criteria,
+                                    int minimumSize,
+                                    int maximumSize);
+};
+
+#endif
+