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-rw-r--r--nxcomp/CharCache.h83
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+/**************************************************************************/
+/* */
+/* Copyright (c) 2001, 2010 NoMachine, http://www.nomachine.com/. */
+/* */
+/* NXCOMP, NX protocol compression and NX extensions to this software */
+/* are copyright of NoMachine. Redistribution and use of the present */
+/* software is allowed according to terms specified in the file LICENSE */
+/* which comes in the source distribution. */
+/* */
+/* Check http://www.nomachine.com/licensing.html for applicability. */
+/* */
+/* NX and NoMachine are trademarks of Medialogic S.p.A. */
+/* */
+/* All rights reserved. */
+/* */
+/**************************************************************************/
+
+#ifndef CharCache_H
+#define CharCache_H
+
+//
+// CharCache is a counterpart of IntCache that is
+// optimized for use in compressing text composed
+// of 8-bit characters.
+//
+
+class CharCache
+{
+ public:
+
+ CharCache() : length_(0)
+ {
+ }
+
+ ~CharCache()
+ {
+ }
+
+ unsigned int getSize() const
+ {
+ return (unsigned int) length_;
+ }
+
+ int lookup(unsigned char value, unsigned int &index);
+
+ //
+ // This can be inlined as it is only
+ // called by decodeCachedValue().
+ //
+
+ unsigned int get(unsigned int index)
+ {
+ unsigned char result = buffer_[index];
+
+ if (index != 0)
+ {
+ unsigned int i = index;
+ unsigned int target = (i >> 1);
+
+ do
+ {
+ buffer_[i] = buffer_[i - 1];
+
+ i--;
+ }
+ while (i > target);
+
+ buffer_[target] = result;
+ }
+
+ return (unsigned int) result;
+ }
+
+ void insert(unsigned char value);
+
+ private:
+
+ unsigned char length_;
+
+ unsigned char buffer_[7];
+};
+
+#endif /* CharCache_H */