/*
 * this file contains C only needed to help support the standard libraries
 */

#include <stdio.h>

#include "HsFFI.h"
#include "rts/cdefs.h"

HsInt jhc_stdrnd[2] A_UNUSED = { 1, 1 };
HsInt jhc_data_unique A_UNUSED;

HsBool A_UNUSED
jhc_wait_for_input(FILE *f, HsInt timeout)
{
#if JHC_isPosix
        fd_set fds;
        FD_ZERO(&fds);
        FD_SET(fileno(f), &fds);
        struct timeval to = { 0, timeout * 1000 };
        int retval = select(1, &fds, NULL, &fds, &to);
        if (retval)
                return HS_BOOL_TRUE;
        else
                return HS_BOOL_FALSE;
#else
        return HS_BOOL_FALSE;
#endif
}

uint32_t
jhc_hash32(uint32_t key)
{
        int c2 = 0x27d4eb2d;    // a prime or an odd constant
        key = (key ^ 61) ^ (key >> 16);
        key = key + (key << 3);
        key = key ^ (key >> 4);
        key = key * c2;
        key = key ^ (key >> 15);
        return key;
}

uint64_t
jhc_hash64(uint64_t key)
{
        key = (~key) + (key << 21);     // key = (key << 21) - key - 1;
        key = key ^ (key >> 24);
        key = (key + (key << 3)) + (key << 8);  // key * 265
        key = key ^ (key >> 14);
        key = (key + (key << 2)) + (key << 4);  // key * 21
        key = key ^ (key >> 28);
        key = key + (key << 31);
        return key;
}

uintptr_t
jhc_hashptr(uintptr_t key)
{
        if (sizeof(uintptr_t) == sizeof(uint32_t)) {
                return (uintptr_t) jhc_hash32((uint32_t) key);
        } else {
                return (uintptr_t) jhc_hash64((uint64_t) key);
        }
}