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Diffstat (limited to 'nxcomp/BlockCacheSet.cpp')
-rw-r--r-- | nxcomp/BlockCacheSet.cpp | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/nxcomp/BlockCacheSet.cpp b/nxcomp/BlockCacheSet.cpp new file mode 100644 index 000000000..8959ba2b3 --- /dev/null +++ b/nxcomp/BlockCacheSet.cpp @@ -0,0 +1,135 @@ +/**************************************************************************/ +/* */ +/* 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. */ +/* */ +/**************************************************************************/ + +#include "Misc.h" +#include "BlockCacheSet.h" + + +BlockCacheSet::BlockCacheSet(unsigned int numCaches): + caches_(new BlockCache *[numCaches]), size_(numCaches), + length_(0) +{ + for (unsigned int i = 0; i < numCaches; i++) + caches_[i] = new BlockCache(); +} + + +BlockCacheSet::~BlockCacheSet() +{ + // + // TODO: There is still a strange segfault occurring + // at random time under Cygwin, when proxy is being + // shutdown. Problem appeared just after upgrading + // to the latest version of the Cygwin DLL. A stack + // trace, obtained at the last minute, reveals that + // failure happens in this destructor. + // + + #ifndef __CYGWIN32__ + + for (unsigned int i = 0; i < size_; i++) + delete caches_[i]; + delete[]caches_; + + #endif /* ifdef __CYGWIN32__ */ +} + + +int +BlockCacheSet::lookup(unsigned int dataLength, const unsigned char *data, + unsigned int &index) +{ + unsigned int checksum = BlockCache::checksum(dataLength, data); + for (unsigned int i = 0; i < length_; i++) + if ((caches_[i]->getChecksum() == checksum) && + (caches_[i]->compare(dataLength, data, 0))) + { + // match + index = i; + if (i) + { + BlockCache *save = caches_[i]; + unsigned int target = (i >> 1); + do + { + caches_[i] = caches_[i - 1]; + i--; + } + while (i > target); + caches_[target] = save; + } + return 1; + } + // no match + unsigned int insertionPoint = (length_ >> 1); + unsigned int start; + if (length_ >= size_) + start = size_ - 1; + else + { + start = length_; + length_++; + } + BlockCache *save = caches_[start]; + for (unsigned int k = start; k > insertionPoint; k--) + caches_[k] = caches_[k - 1]; + caches_[insertionPoint] = save; + save->set(dataLength, data); + return 0; +} + + +void +BlockCacheSet::get(unsigned index, unsigned int &size, + const unsigned char *&data) +{ + size = caches_[index]->getLength(); + data = caches_[index]->getData(); + if (index) + { + BlockCache *save = caches_[index]; + unsigned int target = (index >> 1); + do + { + caches_[index] = caches_[index - 1]; + index--; + } + while (index > target); + caches_[target] = save; + } +} + + + +void +BlockCacheSet::set(unsigned int dataLength, const unsigned char *data) +{ + unsigned int insertionPoint = (length_ >> 1); + unsigned int start; + if (length_ >= size_) + start = size_ - 1; + else + { + start = length_; + length_++; + } + BlockCache *save = caches_[start]; + for (unsigned int k = start; k > insertionPoint; k--) + caches_[k] = caches_[k - 1]; + caches_[insertionPoint] = save; + save->set(dataLength, data); +} |