aboutsummaryrefslogtreecommitdiff
path: root/nxcomp/BlockCacheSet.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'nxcomp/BlockCacheSet.cpp')
-rw-r--r--nxcomp/BlockCacheSet.cpp135
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);
+}