2025-04-27 07:49:33 -04:00

372 lines
6.7 KiB
C++

#include <windows.h>
#include <stdio.h>
void
usage() {
printf( "This program evaluates hash functions \n"
"random <testfil> <depth> <number newsgroups> <K articles per group>\n"
) ;
}
DWORD
MyRand2(
IN DWORD& seed,
IN DWORD val
)
{
__int64 next = seed ;
const __int64 mult = 0x8000000 ;
next = (seed * val) * 1103515245 + 12345 ;
seed = (DWORD) (next >> 16) ;
return (DWORD) ((next / mult) % (mult/2)) ;
}
WORD
MyRand(
IN DWORD& seed,
IN DWORD val
)
{
DWORD next = seed;
next = (seed*val) * 1103515245 + 12345; // magic!!
seed = next ;
return (WORD)((next/65536) % 32768);
}
DWORD
IDHash(
IN DWORD Key1,
IN DWORD Key2
)
/*++
Routine Description:
Used to find the hash value given 2 numbers. (Used for articleid + groupId)
Arguments:
Key1 - first key to hash. MS bit mapped to LSb of hash value
Key2 - second key to hash. LS bit mapped to MS bit of hash value.
Return Value:
Hash value
--*/
{
DWORD val1 = 0x80000000, val2 = 0x80000000;
//
// Do Key1 first
//
DWORD lowBits = Key2 & 0xf ;
DWORD TempKey2 = Key2 & (~0xf) ;
DWORD seed1 = (Key2 << (Key1 & 0x7)) - Key1 ;
Key1 = (0x80000000 - ((67+Key1)*(19+Key1)*(7+Key1)+12345)) ^ (((3+Key1)*(5+Key1)+12345) << ((Key1&0xf)+8)) ;
TempKey2 = (0x80000000 - ((67+TempKey2)*(19+TempKey2)*(7+TempKey2)*(1+TempKey2)+12345)) ^ ((TempKey2+12345) << (((TempKey2>>4)&0x7)+8)) ;
val1 -= (MyRand( seed1, Key1 ) << (Key1 & 0xf)) ;
val1 += MyRand( seed1, Key1 ) << (((TempKey2 >> 4) & 0x3)+4) ;
val1 ^= MyRand( seed1, Key1 ) << 17 ;
DWORD seed2 = val1 - TempKey2 ;
val2 -= MyRand( seed2, TempKey2 >> 1 ) << (((Key1 << 3)^Key1) &0xf) ;
val2 = val2 + MyRand( seed2, TempKey2 ) << (13 ^ Key1) ;
val2 ^= MyRand( seed2, TempKey2 ) << 15 ;
//DWORD val = val1 + val2 ;
DWORD val = (val1 + val2 + 67) * (val1 - val2 + 19) * (val1 % (val2 + 67)) ;
val += (MyRand( seed2, lowBits ) >> 3) ;
#if 0
DWORD seed1 = (Key2 << (Key1 & 0x3f)) ^ Key1 ;
val1 = MyRand(seed1, Key1);
val1 |= MyRand(seed1, Key1) << 16;
DWORD seed2 = (val1 << (Key2 & 0xf)) + Key2 ;
val2 = MyRand(seed2, Key2+val1);
val2 |= MyRand(seed2, val2) << 16 ;
seed1 += val2 ;
val1 |= ( MyRand(seed1, Key1) << 14);
val1 ^= ( MyRand(seed1, Key1) << 20);
val1 |= ( MyRand(seed1, Key1) << 30);
//
// ok, now do Key2
//
seed2 += val1 ;
val2 |= ( MyRand(seed2, Key2+seed1) << 15);
val2 ^= ( MyRand(seed2, Key2+seed1) << 19);
val2 |= ( MyRand(seed2, Key2+seed2) << 29);
DWORD val = val1 + val2 ;
val += (MyRand( seed2, lowBits ) >> 3) ;
#endif
return(val);
} // IDHash
int __cdecl Compare( const void *pv1, const void *pv2 ) {
DWORD *pdw1 = (DWORD*)pv1 ;
DWORD *pdw2 = (DWORD*)pv2 ;
if( *pdw1 < *pdw2 ) {
return -1 ;
} else if( *pdw1 == *pdw2 ) {
return 0 ;
} else {
return 1 ;
}
}
void
ComputeStatistics(
DWORD *pdw,
DWORD cdw,
DWORD cBits,
DWORD& MaxHits,
DWORD& MedianHits,
DWORD& cBeyond4K,
double& AverageHits,
double Tries
) {
DWORD rgdw[8*1024] ;
DWORD rgdwTopTen[20] ;
ZeroMemory( rgdwTopTen, sizeof( rgdwTopTen ) ) ;
ZeroMemory( rgdw, sizeof( rgdw ) ) ;
cBeyond4K = 0 ;
MaxHits = 0 ;
MedianHits = 0 ;
AverageHits = 0 ;
for( DWORD l=0; l<4*1024; l++ ) {
rgdw[(l*2)+1] = l ;
}
for( DWORD i=0; i<cdw; i++ ) {
DWORD dwTemp = pdw[i] ;
for( DWORD j=1; j < (1<<(cBits-1)); j++ ) {
dwTemp += pdw[i++] ;
}
if( dwTemp > MaxHits )
MaxHits = dwTemp ;
if( dwTemp > (4*1024) ) {
cBeyond4K ++ ;
} else {
rgdw[ 2*dwTemp] ++ ;
}
AverageHits += (double)dwTemp ;
}
AverageHits /= Tries ;
DWORD TempMax = 0 ;
DWORD iMax = 0 ;
for( i=0; i < 4*1024; i++ ) {
if( rgdw[i*2] > TempMax ) {
TempMax = rgdw[i*2] ;
iMax = i ;
}
}
MedianHits = iMax ;
qsort( rgdw, 4*1024, 2*sizeof( DWORD ), Compare ) ;
printf( "Sorted number of hits \n" ) ;
for( int k=0; k<4*1024; k++ ) {
if( rgdw[2*k] != 0 ) {
printf( "\tNumber Occurrences - %d Number Hits - %d\n", rgdw[2*k], rgdw[(2*k)+1] ) ;
}
}
}
int
main( int argc, char *argv[] ) {
if( argc != 5 ) {
usage() ;
}
LPSTR lpstrFile = argv[1] ;
HANDLE hFile = CreateFile( lpstrFile,
GENERIC_READ | GENERIC_WRITE,
0,
0,
CREATE_ALWAYS,
FILE_FLAG_DELETE_ON_CLOSE,
INVALID_HANDLE_VALUE
) ;
if( hFile == INVALID_HANDLE_VALUE ) {
printf( "Can't create file %s error %d\n",
lpstrFile, GetLastError() ) ;
return 1 ;
}
if( !isdigit( *argv[2] ) ) {
usage() ;
CloseHandle( hFile ) ;
return 1 ;
}
if( !isdigit( *argv[3] ) ) {
usage() ;
CloseHandle( hFile ) ;
return 1 ;
}
DWORD depth = atoi( argv[2] ) ;
DWORD limit = atoi( argv[3] ) ;
DWORD kperGroup = atoi( argv[4] ) ;
if( depth > 29 ) {
printf( "depth too large \n" ) ;
usage() ;
return 1 ;
}
DWORD MapSize = (0x1 << depth) * sizeof( DWORD ) ;
HANDLE hMap = CreateFileMapping(
hFile,
0,
PAGE_READWRITE,
0,
MapSize,
0
) ;
if( hMap == 0 ) {
printf( "Unable to create mapping - error %d", GetLastError() ) ;
usage() ;
CloseHandle( hFile ) ;
return 1 ;
}
DWORD *pdwMap = (DWORD*)MapViewOfFile(
hMap,
FILE_MAP_ALL_ACCESS,
0,
0,
0
) ;
if( pdwMap == 0 ) {
printf( "Unable to MapViewOfFile %d\n", pdwMap ) ;
usage() ;
CloseHandle( hMap ) ;
CloseHandle( hFile ) ;
return 1 ;
}
DWORD ShiftAmount = 32 - depth ;
for( DWORD i=0; i < limit; i ++ ) {
for( DWORD j=0; j < kperGroup * 1024; j++ ) {
DWORD value = IDHash( i, j ) ;
value >>= ShiftAmount ;
pdwMap[value] ++ ;
}
if( (i*j)%(16 * 64 * 1024) == 0 ) {
printf( "advancing to group ids %d\n", i ) ;
}
}
for( DWORD cBits = 1; cBits < 4; cBits ++ ) {
//
// Compute Statistics
//
DWORD MaxHits = 0 ;
DWORD MedianHits = 0 ;
DWORD Beyond4K = 0 ;
double AverageHits = 0 ;
double Tries = limit * 64 * 1024 ;
ComputeStatistics( pdwMap,
(0x1 << depth),
cBits,
MaxHits,
MedianHits,
Beyond4K,
AverageHits,
Tries
) ;
printf( "Report : \n"
"\tAverage Hits - %f \n"
"\tMax Hits - %d\n"
"\tMedian Hits - %d\n"
"\tNumber with more that 4096 hits - %d\n\n\n",
AverageHits,
MaxHits,
MedianHits,
Beyond4K ) ;
}
return 0 ;
}