[fio.git] / lib / num2str.c

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

#include "../compiler/compiler.h"
#include "num2str.h"

#define ARRAY_SIZE(x)    (sizeof((x)) / (sizeof((x)[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 num2str.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 ((int)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
5e746820 TK	5	#include "../compiler/compiler.h"
	6	#include "num2str.h"
	7
	8	#define ARRAY_SIZE(x) (sizeof((x)) / (sizeof((x)[0])))
10aa136b	9
d694a6a7 RE	10	/**
	11	* num2str() - Cheesy number->string conversion, complete with carry rounding error.
	12	* @num: quantity (e.g., number of blocks, bytes or bits)
	13	* @maxlen: max number of digits in the output string (not counting prefix and units)
	14	* @base: multiplier for num (e.g., if num represents Ki, use 1024)
	15	* @pow2: select unit prefix - 0=power-of-10 decimal SI, nonzero=power-of-2 binary IEC
5e746820	16	* @units: select units - N2S_* macros defined in num2str.h
d694a6a7	17	* @returns a malloc'd buffer containing "number[<unit prefix>][<units>]"
1ec3d69b	18	*/
d694a6a7	19	char *num2str(uint64_t num, int maxlen, int base, int pow2, int units)
1ec3d69b	20	{
d694a6a7 RE	21	const char *sistr[] = { "", "k", "M", "G", "T", "P" };
	22	const char *iecstr[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi" };
	23	const char **unitprefix;
	24	const char *unitstr[] = { "", "/s", "B", "bit", "B/s", "bit/s" };
73798eb2	25	const unsigned int thousand[] = { 1000, 1024 };
1ec3d69b	26	unsigned int modulo, decimals;
d694a6a7	27	int unit_index = 0, post_index, carry = 0;
05463816	28	char tmp[32];
1ec3d69b JA	29	char *buf;
1ec3d69b JA	30
d694a6a7 RE	31	compiletime_assert(sizeof(sistr) == sizeof(iecstr), "unit prefix arrays must be identical sizes");
d694a6a7 RE	32
1ec3d69b	33	buf = malloc(128);
d694a6a7 RE	34	if (!buf)
	35	return NULL;
	36
	37	if (pow2)
	38	unitprefix = iecstr;
	39	else
	40	unitprefix = sistr;
1ec3d69b JA	41
	42	for (post_index = 0; base > 1; post_index++)
	43	base /= thousand[!!pow2];
	44
d694a6a7 RE	45	switch (units) {
	46	case N2S_PERSEC:
	47	unit_index = 1;
	48	break;
	49	case N2S_BYTE:
	50	unit_index = 2;
	51	break;
	52	case N2S_BIT:
	53	unit_index = 3;
73798eb2 SN	54	num *= 8;
73798eb2 SN	55	break;
d694a6a7 RE	56	case N2S_BYTEPERSEC:
	57	unit_index = 4;
	58	break;
	59	case N2S_BITPERSEC:
	60	unit_index = 5;
	61	num *= 8;
73798eb2 SN	62	break;
	63	}
	64
1ec3d69b	65	modulo = -1U;
d694a6a7	66	while (post_index < sizeof(sistr)) {
ca09be4b	67	sprintf(tmp, "%llu", (unsigned long long) num);
1ec3d69b JA	68	if (strlen(tmp) <= maxlen)
	69	break;
	70
	71	modulo = num % thousand[!!pow2];
	72	num /= thousand[!!pow2];
05463816	73	carry = modulo >= thousand[!!pow2] / 2;
1ec3d69b JA	74	post_index++;
	75	}
	76
	77	if (modulo == -1U) {
	78	done:
b920b29b	79	if (post_index >= ARRAY_SIZE(sistr))
b7e147d1 JA	80	post_index = 0;
b7e147d1 JA	81
ca09be4b	82	sprintf(buf, "%llu%s%s", (unsigned long long) num,
d694a6a7	83	unitprefix[post_index], unitstr[unit_index]);
1ec3d69b JA	84	return buf;
	85	}
	86
ca09be4b	87	sprintf(tmp, "%llu", (unsigned long long) num);
1ec3d69b	88	decimals = maxlen - strlen(tmp);
e5a415c8	89	if ((int)decimals <= 1) {
05463816 JA	90	if (carry)
05463816 JA	91	num++;
1ec3d69b	92	goto done;
05463816 JA	93	}
	94
	95	do {
	96	sprintf(tmp, "%u", modulo);
	97	if (strlen(tmp) <= decimals - 1)
	98	break;
	99
	100	modulo = (modulo + 9) / 10;
	101	} while (1);
1ec3d69b	102
ca09be4b	103	sprintf(buf, "%llu.%u%s%s", (unsigned long long) num, modulo,
d694a6a7	104	unitprefix[post_index], unitstr[unit_index]);
1ec3d69b JA	105	return buf;
1ec3d69b JA	106	}