[fio.git] / lib / num2str.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "../fio.h"

/**
 * num2str() - Cheesy number->string conversion, complete with carry rounding error.
 * @num: quantity (e.g., number of blocks, bytes or bits)
 * @maxlen: max number of digits in the output string (not counting prefix and units)
 * @base: multiplier for num (e.g., if num represents Ki, use 1024)
 * @pow2: select unit prefix - 0=power-of-10 decimal SI, nonzero=power-of-2 binary IEC
 * @units: select units - N2S_* macros defined in fio.h
 * @returns a malloc'd buffer containing "number[<unit prefix>][<units>]"
 */
char *num2str(uint64_t num, int maxlen, int base, int pow2, int units)
{
	const char *sistr[] = { "", "k", "M", "G", "T", "P" };
	const char *iecstr[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi" };
	const char **unitprefix;
	const char *unitstr[] = { "", "/s", "B", "bit", "B/s", "bit/s" };
	const unsigned int thousand[] = { 1000, 1024 };
	unsigned int modulo, decimals;
	int unit_index = 0, post_index, carry = 0;
	char tmp[32];
	char *buf;

	compiletime_assert(sizeof(sistr) == sizeof(iecstr), "unit prefix arrays must be identical sizes");

	buf = malloc(128);
	if (!buf)
		return NULL;

	if (pow2)
		unitprefix = iecstr;
	else
		unitprefix = sistr;

	for (post_index = 0; base > 1; post_index++)
		base /= thousand[!!pow2];

	switch (units) {
	case N2S_PERSEC:
		unit_index = 1;
		break;
	case N2S_BYTE:
		unit_index = 2;
		break;
	case N2S_BIT:
		unit_index = 3;
		num *= 8;
		break;
	case N2S_BYTEPERSEC:
		unit_index = 4;
		break;
	case N2S_BITPERSEC:
		unit_index = 5;
		num *= 8;
		break;
	}

	modulo = -1U;
	while (post_index < sizeof(sistr)) {
		sprintf(tmp, "%llu", (unsigned long long) num);
		if (strlen(tmp) <= maxlen)
			break;

		modulo = num % thousand[!!pow2];
		num /= thousand[!!pow2];
		carry = modulo >= thousand[!!pow2] / 2;
		post_index++;
	}

	if (modulo == -1U) {
done:
		if (post_index >= ARRAY_SIZE(sistr))
			post_index = 0;

		sprintf(buf, "%llu%s%s", (unsigned long long) num,
			unitprefix[post_index], unitstr[unit_index]);
		return buf;
	}

	sprintf(tmp, "%llu", (unsigned long long) num);
	decimals = maxlen - strlen(tmp);
	if (decimals <= 1) {
		if (carry)
			num++;
		goto done;
	}

	do {
		sprintf(tmp, "%u", modulo);
		if (strlen(tmp) <= decimals - 1)
			break;

		modulo = (modulo + 9) / 10;
	} while (1);

	sprintf(buf, "%llu.%u%s%s", (unsigned long long) num, modulo,
			unitprefix[post_index], unitstr[unit_index]);
	return buf;
}
Commit	Line	Data
	1	#include <stdlib.h>
	2	#include <stdio.h>
	3	#include <string.h>
	4
	5	#include "../fio.h"
	6
	7	/**
	8	* num2str() - Cheesy number->string conversion, complete with carry rounding error.
	9	* @num: quantity (e.g., number of blocks, bytes or bits)
	10	* @maxlen: max number of digits in the output string (not counting prefix and units)
	11	* @base: multiplier for num (e.g., if num represents Ki, use 1024)
	12	* @pow2: select unit prefix - 0=power-of-10 decimal SI, nonzero=power-of-2 binary IEC
	13	* @units: select units - N2S_* macros defined in fio.h
	14	* @returns a malloc'd buffer containing "number[<unit prefix>][<units>]"
	15	*/
	16	char *num2str(uint64_t num, int maxlen, int base, int pow2, int units)
	17	{
	18	const char *sistr[] = { "", "k", "M", "G", "T", "P" };
	19	const char *iecstr[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi" };
	20	const char **unitprefix;
	21	const char *unitstr[] = { "", "/s", "B", "bit", "B/s", "bit/s" };
	22	const unsigned int thousand[] = { 1000, 1024 };
	23	unsigned int modulo, decimals;
	24	int unit_index = 0, post_index, carry = 0;
	25	char tmp[32];
	26	char *buf;
	27
	28	compiletime_assert(sizeof(sistr) == sizeof(iecstr), "unit prefix arrays must be identical sizes");
	29
	30	buf = malloc(128);
	31	if (!buf)
	32	return NULL;
	33
	34	if (pow2)
	35	unitprefix = iecstr;
	36	else
	37	unitprefix = sistr;
	38
	39	for (post_index = 0; base > 1; post_index++)
	40	base /= thousand[!!pow2];
	41
	42	switch (units) {
	43	case N2S_PERSEC:
	44	unit_index = 1;
	45	break;
	46	case N2S_BYTE:
	47	unit_index = 2;
	48	break;
	49	case N2S_BIT:
	50	unit_index = 3;
	51	num *= 8;
	52	break;
	53	case N2S_BYTEPERSEC:
	54	unit_index = 4;
	55	break;
	56	case N2S_BITPERSEC:
	57	unit_index = 5;
	58	num *= 8;
	59	break;
	60	}
	61
	62	modulo = -1U;
	63	while (post_index < sizeof(sistr)) {
	64	sprintf(tmp, "%llu", (unsigned long long) num);
	65	if (strlen(tmp) <= maxlen)
	66	break;
	67
	68	modulo = num % thousand[!!pow2];
	69	num /= thousand[!!pow2];
	70	carry = modulo >= thousand[!!pow2] / 2;
	71	post_index++;
	72	}
	73
	74	if (modulo == -1U) {
	75	done:
	76	if (post_index >= ARRAY_SIZE(sistr))
	77	post_index = 0;
	78
	79	sprintf(buf, "%llu%s%s", (unsigned long long) num,
	80	unitprefix[post_index], unitstr[unit_index]);
	81	return buf;
	82	}
	83
	84	sprintf(tmp, "%llu", (unsigned long long) num);
	85	decimals = maxlen - strlen(tmp);
	86	if (decimals <= 1) {
	87	if (carry)
	88	num++;
	89	goto done;
	90	}
	91
	92	do {
	93	sprintf(tmp, "%u", modulo);
	94	if (strlen(tmp) <= decimals - 1)
	95	break;
	96
	97	modulo = (modulo + 9) / 10;
	98	} while (1);
	99
	100	sprintf(buf, "%llu.%u%s%s", (unsigned long long) num, modulo,
	101	unitprefix[post_index], unitstr[unit_index]);
	102	return buf;
	103	}