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XORFastHash is now symmetric

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This commit is contained in:
DennisOSRM 2012-05-25 10:14:53 +02:00
parent 863b9829ca
commit 7194fe02d1
1 changed files with 15 additions and 9 deletions
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24
Contractor/Contractor.h
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@ -39,6 +39,8 @@ or see http://www.gnu.org/licenses/agpl.txt.
#include "../Util/StringUtil.h" #include "../Util/StringUtil.h"
#include <valgrind/callgrind.h>
class Contractor { class Contractor {
private: private:
@ -95,19 +97,22 @@ private:
}; };
class XORFastHash { class XORFastHash {
std::vector<unsigned short> hashLookups; std::vector<unsigned char> table1;
std::vector<unsigned char> table2;
public: public:
XORFastHash() { XORFastHash() {
hashLookups.resize(1 << 16); table1.resize(1 << 16);
for(unsigned i = 0; i < (1 << 16); ++i) table2.resize(1 << 16);
hashLookups[i] = i; for(unsigned i = 0; i < (1 << 16); ++i) {
std::random_shuffle(hashLookups.begin(), hashLookups.end()); table1[i] = i; table2[i];
}
std::random_shuffle(table1.begin(), table1.end());
std::random_shuffle(table2.begin(), table2.end());
} }
unsigned short operator()(const unsigned originalValue) const { unsigned short operator()(const unsigned originalValue) const {
unsigned short msb = (((originalValue-1) >> 16) & 0xffff);
unsigned short lsb = ((originalValue-1) & 0xffff); unsigned short lsb = ((originalValue-1) & 0xffff);
return hashLookups[lsb] ^ msb; unsigned short msb = (((originalValue-1) >> 16) & 0xffff);
return table1[lsb] ^ table2[msb];
} }
}; };
@ -222,6 +227,7 @@ public:
} }
void Run() { void Run() {
CALLGRIND_START_INSTRUMENTATION;
const NodeID numberOfNodes = _graph->GetNumberOfNodes(); const NodeID numberOfNodes = _graph->GetNumberOfNodes();
Percent p (numberOfNodes); Percent p (numberOfNodes);
@ -440,7 +446,7 @@ public:
p.printStatus(numberOfContractedNodes); p.printStatus(numberOfContractedNodes);
} }
CALLGRIND_STOP_INSTRUMENTATION;
for ( unsigned threadNum = 0; threadNum < maxThreads; threadNum++ ) { for ( unsigned threadNum = 0; threadNum < maxThreads; threadNum++ ) {
delete threadData[threadNum]; delete threadData[threadNum];
} }