X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=lib%2Fnum2str.c;h=1abe22f33794c0ccf6b724e74aef7a1f62271166;hb=fc220349e45144360917db48010b503a9874930d;hp=448d3ff88b00cbe41c3fcbeb21665d19496cf2f7;hpb=e5a415c889251928dd256738a8022f1eab91c73b;p=fio.git

diff --git a/lib/num2str.c b/lib/num2str.c
index 448d3ff8..1abe22f3 100644
--- a/lib/num2str.c
+++ b/lib/num2str.c
@@ -1,3 +1,4 @@
+#include <assert.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -10,25 +11,33 @@
 /**
  * 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)
+ * @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
+ * @units: select units - N2S_* constants 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)
+char *num2str(uint64_t num, int maxlen, int base, int pow2, enum n2s_unit 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];
+	static const char *const unitstr[] = {
+		[N2S_NONE]	= "",
+		[N2S_PERSEC]	= "/s",
+		[N2S_BYTE]	= "B",
+		[N2S_BIT]	= "bit",
+		[N2S_BYTEPERSEC]= "B/s",
+		[N2S_BITPERSEC]	= "bit/s"
+	};
+	const unsigned int thousand = pow2 ? 1024 : 1000;
+	unsigned int modulo;
+	int post_index, carry = 0;
+	char tmp[32], fmt[32];
 	char *buf;
 
 	compiletime_assert(sizeof(sistr) == sizeof(iecstr), "unit prefix arrays must be identical sizes");
+	assert(units < ARRAY_SIZE(unitstr));
 
 	buf = malloc(128);
 	if (!buf)
@@ -40,67 +49,72 @@ char *num2str(uint64_t num, int maxlen, int base, int pow2, int units)
 		unitprefix = sistr;
 
 	for (post_index = 0; base > 1; post_index++)
-		base /= thousand[!!pow2];
+		base /= thousand;
 
 	switch (units) {
+	case N2S_NONE:
+		break;
 	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;
 	}
 
+	/*
+	 * Divide by K/Ki until string length of num <= maxlen.
+	 */
 	modulo = -1U;
-	while (post_index < sizeof(sistr)) {
+	while (post_index < ARRAY_SIZE(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;
+		modulo = num % thousand;
+		num /= thousand;
+		carry = modulo >= thousand / 2;
 		post_index++;
 	}
 
+	/*
+	 * If no modulo, then we're done.
+	 */
 	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]);
+			unitprefix[post_index], unitstr[units]);
 		return buf;
 	}
 
+	/*
+	 * If no room for decimals, then we're done.
+	 */
 	sprintf(tmp, "%llu", (unsigned long long) num);
-	decimals = maxlen - strlen(tmp);
-	if ((int)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);
+	sprintf(fmt, "%%.%df", (int)(maxlen - strlen(tmp) - 1));
+	sprintf(tmp, fmt, (double)modulo / (double)thousand);
 
-	sprintf(buf, "%llu.%u%s%s", (unsigned long long) num, modulo,
-			unitprefix[post_index], unitstr[unit_index]);
+	sprintf(buf, "%llu.%s%s%s", (unsigned long long) num, &tmp[2],
+			unitprefix[post_index], unitstr[units]);
 	return buf;
 }