1 files changed, 65 insertions, 29 deletions

diff --git a/lib/num2str.c b/lib/num2str.c
index 0ed05f33..8d088413 100644
--- a/lib/num2str.c
+++ b/lib/num2str.c
@@ -2,40 +2,71 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "../fio.h"
+#include "../compiler/compiler.h"
+#include "num2str.h"
 
-#define ARRAY_LENGTH(arr)	sizeof(arr) / sizeof((arr)[0])
+#define ARRAY_SIZE(x)    (sizeof((x)) / (sizeof((x)[0])))
 
-/*
- * Cheesy number->string conversion, complete with carry rounding error.
+/**
+ * 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, but counting .)
+ * @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 unit_base)
+char *num2str(uint64_t num, int maxlen, int base, int pow2, int units)
 {
-	const char *postfix[] = { "", "K", "M", "G", "P", "E" };
-	const char *byte_postfix[] = { "", "B", "bit" };
+	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 byte_post_index = 0, post_index, carry = 0;
-	char tmp[32];
+	unsigned int modulo;
+	int unit_index = 0, post_index, carry = 0;
+	char tmp[32], fmt[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 (unit_base) {
-	case 1:
-		byte_post_index = 2;
+	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 8:
-		byte_post_index = 1;
+	case N2S_BYTEPERSEC:
+		unit_index = 4;
+		break;
+	case N2S_BITPERSEC:
+		unit_index = 5;
+		num *= 8;
 		break;
 	}
 
+	/*
+	 * Divide by K/Ki until string length of num <= maxlen.
+	 */
 	modulo = -1U;
-	while (post_index < sizeof(postfix)) {
+	while (post_index < sizeof(sistr)) {
 		sprintf(tmp, "%llu", (unsigned long long) num);
 		if (strlen(tmp) <= maxlen)
 			break;
@@ -46,33 +77,38 @@ char *num2str(uint64_t num, int maxlen, int base, int pow2, int unit_base)
 		post_index++;
 	}
 
+	/*
+	 * If no modulo, then we're done.
+	 */
 	if (modulo == -1U) {
 done:
-		if (post_index >= ARRAY_LENGTH(postfix))
+		if (post_index >= ARRAY_SIZE(sistr))
 			post_index = 0;
 
 		sprintf(buf, "%llu%s%s", (unsigned long long) num,
-			postfix[post_index], byte_postfix[byte_post_index]);
+			unitprefix[post_index], unitstr[unit_index]);
 		return buf;
 	}
 
+	/*
+	 * If no room for decimals, then we're done.
+	 */
 	sprintf(tmp, "%llu", (unsigned long long) num);
-	decimals = maxlen - strlen(tmp);
-	if (decimals <= 1) {
+	if ((int)(maxlen - strlen(tmp)) <= 1) {
 		if (carry)
 			num++;
 		goto done;
 	}
 
-	do {
-		sprintf(tmp, "%u", modulo);
-		if (strlen(tmp) <= decimals - 1)
-			break;
-
-		modulo = (modulo + 9) / 10;
-	} while (1);
+	/*
+	 * Fill in everything and return the result.
+	 */
+	assert(maxlen - strlen(tmp) - 1 > 0);
+	assert(modulo < thousand[!!pow2]);
+	sprintf(fmt, "%%.%df", (int)(maxlen - strlen(tmp) - 1));
+	sprintf(tmp, fmt, (double)modulo / (double)thousand[!!pow2]);
 
-	sprintf(buf, "%llu.%u%s%s", (unsigned long long) num, modulo,
-			postfix[post_index], byte_postfix[byte_post_index]);
+	sprintf(buf, "%llu.%s%s%s", (unsigned long long) num, &tmp[2],
+			unitprefix[post_index], unitstr[unit_index]);
 	return buf;
 }