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Diffstat (limited to 'libnetdata/storage_number/storage_number.c')
| -rw-r--r-- | libnetdata/storage_number/storage_number.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/libnetdata/storage_number/storage_number.c b/libnetdata/storage_number/storage_number.c new file mode 100644 index 000000000..db4cb700b --- /dev/null +++ b/libnetdata/storage_number/storage_number.c @@ -0,0 +1,233 @@ +// SPDX-License-Identifier: GPL-3.0-or-later + +#include "../libnetdata.h" + +storage_number pack_storage_number(calculated_number value, uint32_t flags) +{ + // bit 32 = sign 0:positive, 1:negative + // bit 31 = 0:divide, 1:multiply + // bit 30, 29, 28 = (multiplier or divider) 0-7 (8 total) + // bit 27, 26, 25 flags + // bit 24 to bit 1 = the value + + storage_number r = get_storage_number_flags(flags); + if(!value) return r; + + int m = 0; + calculated_number n = value; + + // if the value is negative + // add the sign bit and make it positive + if(n < 0) { + r += (1 << 31); // the sign bit 32 + n = -n; + } + + // make its integer part fit in 0x00ffffff + // by dividing it by 10 up to 7 times + // and increasing the multiplier + while(m < 7 && n > (calculated_number)0x00ffffff) { + n /= 10; + m++; + } + + if(m) { + // the value was too big and we divided it + // so we add a multiplier to unpack it + r += (1 << 30) + (m << 27); // the multiplier m + + if(n > (calculated_number)0x00ffffff) { + #ifdef NETDATA_INTERNAL_CHECKS + error("Number " CALCULATED_NUMBER_FORMAT " is too big.", value); + #endif + r += 0x00ffffff; + return r; + } + } + else { + // 0x0019999e is the number that can be multiplied + // by 10 to give 0x00ffffff + // while the value is below 0x0019999e we can + // multiply it by 10, up to 7 times, increasing + // the multiplier + while(m < 7 && n < (calculated_number)0x0019999e) { + n *= 10; + m++; + } + + // the value was small enough and we multiplied it + // so we add a divider to unpack it + r += (0 << 30) + (m << 27); // the divider m + } + +#ifdef STORAGE_WITH_MATH + // without this there are rounding problems + // example: 0.9 becomes 0.89 + r += lrint((double) n); +#else + r += (storage_number)n; +#endif + + return r; +} + +calculated_number unpack_storage_number(storage_number value) +{ + if(!value) return 0; + + int sign = 0, exp = 0; + + value ^= get_storage_number_flags(value); + + if(value & (1 << 31)) { + sign = 1; + value ^= 1 << 31; + } + + if(value & (1 << 30)) { + exp = 1; + value ^= 1 << 30; + } + + int mul = value >> 27; + value ^= mul << 27; + + calculated_number n = value; + + // fprintf(stderr, "UNPACK: %08X, sign = %d, exp = %d, mul = %d, n = " CALCULATED_NUMBER_FORMAT "\n", value, sign, exp, mul, n); + + while(mul > 0) { + if(exp) n *= 10; + else n /= 10; + mul--; + } + + if(sign) n = -n; + return n; +} + +/* +int print_calculated_number(char *str, calculated_number value) +{ + char *wstr = str; + + int sign = (value < 0) ? 1 : 0; + if(sign) value = -value; + +#ifdef STORAGE_WITH_MATH + // without llrintl() there are rounding problems + // for example 0.9 becomes 0.89 + unsigned long long uvalue = (unsigned long long int) llrintl(value * (calculated_number)100000); +#else + unsigned long long uvalue = value * (calculated_number)100000; +#endif + + wstr = print_number_llu_r_smart(str, uvalue); + + // make sure we have 6 bytes at least + while((wstr - str) < 6) *wstr++ = '0'; + + // put the sign back + if(sign) *wstr++ = '-'; + + // reverse it + char *begin = str, *end = --wstr, aux; + while (end > begin) aux = *end, *end-- = *begin, *begin++ = aux; + // wstr--; + // strreverse(str, wstr); + + // remove trailing zeros + int decimal = 5; + while(decimal > 0 && *wstr == '0') { + *wstr-- = '\0'; + decimal--; + } + + // terminate it, one position to the right + // to let space for a dot + wstr[2] = '\0'; + + // make space for the dot + int i; + for(i = 0; i < decimal ;i++) { + wstr[1] = wstr[0]; + wstr--; + } + + // put the dot + if(wstr[2] == '\0') { wstr[1] = '\0'; decimal--; } + else wstr[1] = '.'; + + // return the buffer length + return (int) ((wstr - str) + 2 + decimal ); +} +*/ + +int print_calculated_number(char *str, calculated_number value) { + // info("printing number " CALCULATED_NUMBER_FORMAT, value); + char integral_str[50], fractional_str[50]; + + char *wstr = str; + + if(unlikely(value < 0)) { + *wstr++ = '-'; + value = -value; + } + + calculated_number integral, fractional; + +#ifdef STORAGE_WITH_MATH + fractional = calculated_number_modf(value, &integral) * 10000000.0; +#else + fractional = ((unsigned long long)(value * 10000000ULL) % 10000000ULL); +#endif + + unsigned long long integral_int = (unsigned long long)integral; + unsigned long long fractional_int = (unsigned long long)calculated_number_llrint(fractional); + if(unlikely(fractional_int >= 10000000)) { + integral_int += 1; + fractional_int -= 10000000; + } + + // info("integral " CALCULATED_NUMBER_FORMAT " (%llu), fractional " CALCULATED_NUMBER_FORMAT " (%llu)", integral, integral_int, fractional, fractional_int); + + char *istre; + if(unlikely(integral_int == 0)) { + integral_str[0] = '0'; + istre = &integral_str[1]; + } + else + // convert the integral part to string (reversed) + istre = print_number_llu_r_smart(integral_str, integral_int); + + // copy reversed the integral string + istre--; + while( istre >= integral_str ) *wstr++ = *istre--; + + if(likely(fractional_int != 0)) { + // add a dot + *wstr++ = '.'; + + // convert the fractional part to string (reversed) + char *fstre = print_number_llu_r_smart(fractional_str, fractional_int); + + // prepend zeros to reach 7 digits length + int decimal = 7; + int len = (int)(fstre - fractional_str); + while(len < decimal) { + *wstr++ = '0'; + len++; + } + + char *begin = fractional_str; + while(begin < fstre && *begin == '0') begin++; + + // copy reversed the fractional string + fstre--; + while( fstre >= begin ) *wstr++ = *fstre--; + } + + *wstr = '\0'; + // info("printed number '%s'", str); + return (int)(wstr - str); +} |