1 files changed, 73 insertions, 0 deletions
diff --git a/juk/stringshare.cpp b/juk/stringshare.cpp
new file mode 100644
index 00000000..ddd6a1ba
--- /dev/null
+++ b/juk/stringshare.cpp
@@ -0,0 +1,73 @@
+/***************************************************************************
+    begin                : Sat Oct 25 2003
+    copyright            : (C) 2003 by Maksim Orlovich
+    email                : maksim.orlovich@kdemail.net    
+***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+#include "stringshare.h"
+#include "stringhash.h"
+
+const int SIZE = 5003;
+
+StringShare::Data* StringShare::s_data = 0;
+
+/**
+ * We store the strings in two simple direct-mapped (i.e. no collision handling,
+ * just replace) hashes, which contain strings or null objects. This costs only
+ * 4 bytes per slot on 32-bit archs, so with the default constant size we only
+ * really use 40K or so.
+ *
+ * The end result is that many strings end up pointing to the same underlying data
+ * object, instead of each one having its own little copy. 
+ */
+
+struct StringShare::Data
+{
+    QString  qstringHash [SIZE];
+    QCString qcstringHash[SIZE];
+};
+
+StringShare::Data* StringShare::data()
+{
+    if (!s_data)
+        s_data = new Data;
+    return s_data;        
+}
+
+QString StringShare::tryShare(const QString& in)
+{
+    int index = hashString(in) % SIZE;
+    
+    Data* dat = data();
+    if (dat->qstringHash[index] == in) //Match
+        return dat->qstringHash[index];
+    else
+    {
+        //Else replace whatever was there before
+        dat->qstringHash[index] = in;
+        return in;
+    }    
+}
+
+QCString StringShare::tryShare(const QCString& in)
+{
+    int index = hashString(in) % SIZE;
+ 
+    Data* dat = data();
+    if (dat->qcstringHash[index] == in) //Match
+        return dat->qcstringHash[index];
+    else
+    {
+        //Else replace whatever was there before
+        dat->qcstringHash[index] = in;
+        return in;
+    }        
+}