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Diffstat (limited to 'nxcomp/CharCache.h')
-rw-r--r-- | nxcomp/CharCache.h | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/nxcomp/CharCache.h b/nxcomp/CharCache.h new file mode 100644 index 000000000..53710f181 --- /dev/null +++ b/nxcomp/CharCache.h @@ -0,0 +1,83 @@ +/**************************************************************************/ +/* */ +/* 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 */ |