#ifndef _UTILS_H_
#define _UTILS_H_

#include "MersenneTwister.h"
#include <sys/mman.h>
#include <stdio.h>
#include "types.h"

class Utils {
public:
  static inline void* malloc_huge(size_t size) {
#ifdef HUGE_PAGE
    void* p = mmap(NULL, size, PROT_READ | PROT_WRITE,
        MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    madvise(p, size, MADV_HUGEPAGE);
#else
    void* p = malloc(size);
#endif
    return p;
  }

  static inline void dealloc_huge(void* ptr, size_t size) {
#ifdef HUGE_PAGE
    munmap(ptr,size);
#else
    free(ptr);
#endif
  }

  static inline void* malloc_huge_and_set(size_t size) {
#ifdef HUGE_PAGE
    void* p = mmap(NULL, size, PROT_READ | PROT_WRITE,
        MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    madvise(p, size, MADV_HUGEPAGE);
#else
    void* p = malloc(size);
#endif
    memset(p, 0, size);
    return p;
  }

  static inline uint64_t unsignedLog2 (uint64_t val) {
    uint64_t ret = -1;
      while (val != 0) {
          val >>= 1;
          ret++;
      }
      return ret;
  }

  template<typename T>
  static inline T nextPowerOfTwo(T n) {
      --n;
      for(T k=1;!(k&(1<<(sizeof(n)+1)));k<<=1) n|=n>>k;
      return ++n;
  }

  /** MurmurHash64A */
  static inline uint64_t hashKey(uint64_t k) {
     const uint64_t m = 0xc6a4a7935bd1e995;
     const int r = 47;
     uint64_t h = 0x8445d61a4e774912 ^ (8*m);
     k *= m;
     k ^= k >> r;
     k *= m;
     h ^= k;
     h *= m;
     h ^= h >> r;
     h *= m;
     h ^= h >> r;
     return h;
  }

  static inline double gettime(void) {
    struct timeval now_tv;
    gettimeofday (&now_tv, NULL);
    return ((double)now_tv.tv_sec) + ((double)now_tv.tv_usec)/1000000.0;
  }

  template<typename T>
  static inline T createMsbMask(unsigned int nBits) {
    T mask = 0;
    for (unsigned int i = 0; i < nBits; i++) {
      mask <<= 1;
      mask |= 1;
    }
    mask <<= (sizeof(T) * 8 - nBits);
    return mask;
  }

  static intkey_t * generateShuffledNumbers(intkey_t n, intkey_t modulus, uint64_t seed) {
        intkey_t* numbers = new intkey_t[n];
    for (intkey_t i = 0; i < n; i++) {
      numbers[i] = i % modulus;
    }

    MersenneTwister mersenneTwister(seed);

    for (intkey_t i = n - 1; i > 0; i--) {
            intkey_t p = mersenneTwister.rnd() % (i + 1);
            intkey_t t = numbers[i];
      numbers[i] = numbers[p];
      numbers[p] = t;
    }
    return numbers;
  }

  static intkey_t* generateShuffledNumbers(intkey_t n, intkey_t distance, intkey_t modulus, uint64_t seed) {
        intkey_t* numbers = new intkey_t[n];
    for (intkey_t i = 0; i < n; i++) {
      numbers[i] = (i * distance) % modulus;
    }

    MersenneTwister mersenneTwister(seed);

    for (intkey_t i = n - 1; i > 0; i--) {
            intkey_t p = mersenneTwister.rnd() % (i + 1);
            intkey_t t = numbers[i];
      numbers[i] = numbers[p];
      numbers[p] = t;
    }
    return numbers;
  }

};

#endif // _UTILS_H_