/*
 * Copyright (c) 2016 by Delphix. All rights reserved.
 */

#include "lua.h"

#include <sys/zfs_context.h>

ssize_t
lcompat_sprintf(char *buf, const char *fmt, ...)
{
        ssize_t res;
        va_list args;

        va_start(args, fmt);
        res = vsnprintf(buf, INT_MAX, fmt, args);
        va_end(args);

        return (res);
}

int64_t
lcompat_strtoll(const char *str, char **ptr)
{
        int base;
        const char *cp;
        int digits;
        int64_t value;
        boolean_t is_negative;

        cp = str;
        while (*cp == ' ' || *cp == '\t' || *cp == '\n') {
                cp++;
        }
        is_negative = (*cp == '-');
        if (is_negative) {
                cp++;
        }
        base = 10;

        if (*cp == '0') {
                base = 8;
                cp++;
                if (*cp == 'x' || *cp == 'X') {
                        base = 16;
                        cp++;
                }
        }

        value = 0;
        for (; *cp != '\0'; cp++) {
                if (*cp >= '0' && *cp <= '9') {
                        digits = *cp - '0';
                } else if (*cp >= 'a' && *cp <= 'f') {
                        digits = *cp - 'a' + 10;
                } else if (*cp >= 'A' && *cp <= 'F') {
                        digits = *cp - 'A' + 10;
                } else {
                        break;
                }
                if (digits >= base) {
                        break;
                }
                value = (value * base) + digits;
        }

        if (ptr != NULL) {
                *ptr = (char *)cp;
        }
        if (is_negative) {
                value = -value;
        }
        return (value);
}

int64_t
lcompat_pow(int64_t x, int64_t y)
{
        int64_t result = 1;
        if (y < 0)
                return (0);

        while (y) {
                if (y & 1)
                        result *= x;
                y >>= 1;
                x *= x;
        }
        return (result);
}

int
lcompat_hashnum(int64_t x)
{
        x = (~x) + (x << 18);
        x = x ^ (x >> 31);
        x = x * 21;
        x = x ^ (x >> 11);
        x = x + (x << 6);
        x = x ^ (x >> 22);
        return ((int)x);
}