[fio.git] / lib / num2str.c

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

#include "../fio.h"

#define ARRAY_LENGTH(arr)	sizeof(arr) / sizeof((arr)[0])

/**
 * 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_LENGTH(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
1ec3d69b JA	1	#include <stdlib.h>
	2	#include <stdio.h>
	3	#include <string.h>
	4
10aa136b JA	5	#include "../fio.h"
10aa136b JA	6
b7e147d1 JA	7	#define ARRAY_LENGTH(arr) sizeof(arr) / sizeof((arr)[0])
b7e147d1 JA	8
d694a6a7 RE	9	/**
	10	* num2str() - Cheesy number->string conversion, complete with carry rounding error.
	11	* @num: quantity (e.g., number of blocks, bytes or bits)
	12	* @maxlen: max number of digits in the output string (not counting prefix and units)
	13	* @base: multiplier for num (e.g., if num represents Ki, use 1024)
	14	* @pow2: select unit prefix - 0=power-of-10 decimal SI, nonzero=power-of-2 binary IEC
	15	* @units: select units - N2S_* macros defined in fio.h
	16	* @returns a malloc'd buffer containing "number[<unit prefix>][<units>]"
1ec3d69b	17	*/
d694a6a7	18	char *num2str(uint64_t num, int maxlen, int base, int pow2, int units)
1ec3d69b	19	{
d694a6a7 RE	20	const char *sistr[] = { "", "k", "M", "G", "T", "P" };
	21	const char *iecstr[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi" };
	22	const char **unitprefix;
	23	const char *unitstr[] = { "", "/s", "B", "bit", "B/s", "bit/s" };
73798eb2	24	const unsigned int thousand[] = { 1000, 1024 };
1ec3d69b	25	unsigned int modulo, decimals;
d694a6a7	26	int unit_index = 0, post_index, carry = 0;
05463816	27	char tmp[32];
1ec3d69b JA	28	char *buf;
1ec3d69b JA	29
d694a6a7 RE	30	compiletime_assert(sizeof(sistr) == sizeof(iecstr), "unit prefix arrays must be identical sizes");
d694a6a7 RE	31
1ec3d69b	32	buf = malloc(128);
d694a6a7 RE	33	if (!buf)
	34	return NULL;
	35
	36	if (pow2)
	37	unitprefix = iecstr;
	38	else
	39	unitprefix = sistr;
1ec3d69b JA	40
	41	for (post_index = 0; base > 1; post_index++)
	42	base /= thousand[!!pow2];
	43
d694a6a7 RE	44	switch (units) {
	45	case N2S_PERSEC:
	46	unit_index = 1;
	47	break;
	48	case N2S_BYTE:
	49	unit_index = 2;
	50	break;
	51	case N2S_BIT:
	52	unit_index = 3;
73798eb2 SN	53	num *= 8;
73798eb2 SN	54	break;
d694a6a7 RE	55	case N2S_BYTEPERSEC:
	56	unit_index = 4;
	57	break;
	58	case N2S_BITPERSEC:
	59	unit_index = 5;
	60	num *= 8;
73798eb2 SN	61	break;
	62	}
	63
1ec3d69b	64	modulo = -1U;
d694a6a7	65	while (post_index < sizeof(sistr)) {
ca09be4b	66	sprintf(tmp, "%llu", (unsigned long long) num);
1ec3d69b JA	67	if (strlen(tmp) <= maxlen)
	68	break;
	69
	70	modulo = num % thousand[!!pow2];
	71	num /= thousand[!!pow2];
05463816	72	carry = modulo >= thousand[!!pow2] / 2;
1ec3d69b JA	73	post_index++;
	74	}
	75
	76	if (modulo == -1U) {
	77	done:
d694a6a7	78	if (post_index >= ARRAY_LENGTH(sistr))
b7e147d1 JA	79	post_index = 0;
b7e147d1 JA	80
ca09be4b	81	sprintf(buf, "%llu%s%s", (unsigned long long) num,
d694a6a7	82	unitprefix[post_index], unitstr[unit_index]);
1ec3d69b JA	83	return buf;
	84	}
	85
ca09be4b	86	sprintf(tmp, "%llu", (unsigned long long) num);
1ec3d69b	87	decimals = maxlen - strlen(tmp);
05463816 JA	88	if (decimals <= 1) {
	89	if (carry)
	90	num++;
1ec3d69b	91	goto done;
05463816 JA	92	}
	93
	94	do {
	95	sprintf(tmp, "%u", modulo);
	96	if (strlen(tmp) <= decimals - 1)
	97	break;
	98
	99	modulo = (modulo + 9) / 10;
	100	} while (1);
1ec3d69b	101
ca09be4b	102	sprintf(buf, "%llu.%u%s%s", (unsigned long long) num, modulo,
d694a6a7	103	unitprefix[post_index], unitstr[unit_index]);
1ec3d69b JA	104	return buf;
1ec3d69b JA	105	}