RetroShare/libretroshare/src/util/rsrandom.cc
thunder2 9095e9bd75 Code maintenance for Qt 5:
- Added some more includes needed by MinGW-w64

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@6860 b45a01b8-16f6-495d-af2f-9b41ad6348cc
2013-10-21 11:00:49 +00:00

103 lines
2.1 KiB
C++

#include <stdlib.h>
#include <string>
#include <unistd.h>
#include "rsrandom.h"
#include <openssl/rand.h>
uint32_t RSRandom::index = RSRandom::N ;
std::vector<uint32_t> RSRandom::MT(RSRandom::N,0u) ;
RsMutex RSRandom::rndMtx("RSRandom") ;
// According to our tests (cyril+thunder), on both Windows and Linux does
// RAND_bytes init itself automatically at first call, from system-based
// unpredictable values, so that seeding is not even needed.
// This call still adds some randomness (not much actually, but it's always good to
// have anyway)
//
#ifdef WINDOWS_SYS
#include <time.h>
#ifdef WIN_PTHREADS_H
static bool auto_seed = RSRandom::seed( (time(NULL) + ((uint32_t) pthread_self())*0x1293fe)^0x18e34a12 ) ;
#else
static bool auto_seed = RSRandom::seed( (time(NULL) + ((uint32_t) pthread_self().p)*0x1293fe)^0x18e34a12 ) ;
#endif
#endif
bool RSRandom::seed(uint32_t s)
{
RsStackMutex mtx(rndMtx) ;
MT.resize(N,0) ; // because MT might not be already resized
uint32_t j ;
MT[0]= s & 0xffffffffUL;
for (j=1; j<N; j++)
MT[j] = (1812433253UL * (MT[j-1] ^ (MT[j-1] >> 30)) + j) & 0xffffffffUL ;
RAND_seed((unsigned char *)&MT[0],N*sizeof(uint32_t)) ;
locked_next_state() ;
return true ;
}
void RSRandom::random_bytes(unsigned char *data,uint32_t size)
{
RAND_bytes(data,size) ;
}
void RSRandom::locked_next_state()
{
RAND_bytes((unsigned char *)&MT[0],N*sizeof(uint32_t)) ;
index = 0 ;
}
uint32_t RSRandom::random_u32()
{
uint32_t y;
{
RsStackMutex mtx(rndMtx) ;
index++ ;
if(index >= N)
locked_next_state();
y = MT[index] ;
}
// Tempering
y ^= (y >> 11);
y ^= (y << 7 ) & 0x9d2c5680UL;
y ^= (y << 15) & 0xefc60000UL;
y ^= (y >> 18);
return y;
}
uint64_t RSRandom::random_u64()
{
return ((uint64_t)random_u32() << 32ul) + random_u32() ;
}
float RSRandom::random_f32()
{
return random_u32() / (float)(~(uint32_t)0) ;
}
double RSRandom::random_f64()
{
return random_u64() / (double)(~(uint64_t)0) ;
}
std::string RSRandom::random_alphaNumericString(uint32_t len)
{
std::string s = "" ;
for(uint32_t i=0;i<len;++i)
s += (char)( (random_u32()%94) + 33) ;
return s ;
}