Commit | Line | Data |
---|---|---|
3d2d14bc | 1 | #include <assert.h> |
1ec3d69b JA |
2 | #include <stdlib.h> |
3 | #include <stdio.h> | |
4 | #include <string.h> | |
5 | ||
5e746820 | 6 | #include "../compiler/compiler.h" |
38b00241 | 7 | #include "../oslib/asprintf.h" |
5e746820 TK |
8 | #include "num2str.h" |
9 | ||
10 | #define ARRAY_SIZE(x) (sizeof((x)) / (sizeof((x)[0]))) | |
10aa136b | 11 | |
d694a6a7 RE |
12 | /** |
13 | * num2str() - Cheesy number->string conversion, complete with carry rounding error. | |
14 | * @num: quantity (e.g., number of blocks, bytes or bits) | |
9e55f2c7 | 15 | * @maxlen: max number of digits in the output string (not counting prefix and units, but counting .) |
d694a6a7 RE |
16 | * @base: multiplier for num (e.g., if num represents Ki, use 1024) |
17 | * @pow2: select unit prefix - 0=power-of-10 decimal SI, nonzero=power-of-2 binary IEC | |
41a87019 | 18 | * @units: select units - N2S_* constants defined in num2str.h |
d694a6a7 | 19 | * @returns a malloc'd buffer containing "number[<unit prefix>][<units>]" |
1ec3d69b | 20 | */ |
41a87019 | 21 | char *num2str(uint64_t num, int maxlen, int base, int pow2, enum n2s_unit units) |
1ec3d69b | 22 | { |
78c14fab BVA |
23 | const char *sistr[] = { "", "k", "M", "G", "T", "P", "E" }; |
24 | const char *iecstr[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei" }; | |
d694a6a7 | 25 | const char **unitprefix; |
cbb8289d BVA |
26 | static const char *const unitstr[] = { |
27 | [N2S_NONE] = "", | |
28 | [N2S_PERSEC] = "/s", | |
29 | [N2S_BYTE] = "B", | |
30 | [N2S_BIT] = "bit", | |
31 | [N2S_BYTEPERSEC]= "B/s", | |
32 | [N2S_BITPERSEC] = "bit/s" | |
33 | }; | |
3b6879b2 | 34 | const unsigned int thousand = pow2 ? 1024 : 1000; |
9e55f2c7 | 35 | unsigned int modulo; |
cbb8289d | 36 | int post_index, carry = 0; |
832a3186 | 37 | char tmp[32]; |
1ec3d69b JA |
38 | char *buf; |
39 | ||
d694a6a7 | 40 | compiletime_assert(sizeof(sistr) == sizeof(iecstr), "unit prefix arrays must be identical sizes"); |
cbb8289d | 41 | assert(units < ARRAY_SIZE(unitstr)); |
d694a6a7 | 42 | |
d694a6a7 RE |
43 | if (pow2) |
44 | unitprefix = iecstr; | |
45 | else | |
46 | unitprefix = sistr; | |
1ec3d69b JA |
47 | |
48 | for (post_index = 0; base > 1; post_index++) | |
3b6879b2 | 49 | base /= thousand; |
1ec3d69b | 50 | |
d694a6a7 | 51 | switch (units) { |
41a87019 BVA |
52 | case N2S_NONE: |
53 | break; | |
d694a6a7 | 54 | case N2S_PERSEC: |
d694a6a7 RE |
55 | break; |
56 | case N2S_BYTE: | |
d694a6a7 RE |
57 | break; |
58 | case N2S_BIT: | |
73798eb2 SN |
59 | num *= 8; |
60 | break; | |
d694a6a7 | 61 | case N2S_BYTEPERSEC: |
d694a6a7 RE |
62 | break; |
63 | case N2S_BITPERSEC: | |
d694a6a7 | 64 | num *= 8; |
73798eb2 SN |
65 | break; |
66 | } | |
67 | ||
9e55f2c7 TK |
68 | /* |
69 | * Divide by K/Ki until string length of num <= maxlen. | |
70 | */ | |
1ec3d69b | 71 | modulo = -1U; |
d0b2501a | 72 | while (post_index < ARRAY_SIZE(sistr)) { |
ca09be4b | 73 | sprintf(tmp, "%llu", (unsigned long long) num); |
1ec3d69b JA |
74 | if (strlen(tmp) <= maxlen) |
75 | break; | |
76 | ||
3b6879b2 BVA |
77 | modulo = num % thousand; |
78 | num /= thousand; | |
79 | carry = modulo >= thousand / 2; | |
1ec3d69b JA |
80 | post_index++; |
81 | } | |
82 | ||
fd99605c BVA |
83 | if (post_index >= ARRAY_SIZE(sistr)) |
84 | post_index = 0; | |
85 | ||
9e55f2c7 TK |
86 | /* |
87 | * If no modulo, then we're done. | |
88 | */ | |
1ec3d69b JA |
89 | if (modulo == -1U) { |
90 | done: | |
38b00241 BVA |
91 | if (asprintf(&buf, "%llu%s%s", (unsigned long long) num, |
92 | unitprefix[post_index], unitstr[units]) < 0) | |
93 | buf = NULL; | |
1ec3d69b JA |
94 | return buf; |
95 | } | |
96 | ||
9e55f2c7 TK |
97 | /* |
98 | * If no room for decimals, then we're done. | |
99 | */ | |
ca09be4b | 100 | sprintf(tmp, "%llu", (unsigned long long) num); |
9e55f2c7 | 101 | if ((int)(maxlen - strlen(tmp)) <= 1) { |
05463816 JA |
102 | if (carry) |
103 | num++; | |
1ec3d69b | 104 | goto done; |
05463816 JA |
105 | } |
106 | ||
9e55f2c7 TK |
107 | /* |
108 | * Fill in everything and return the result. | |
109 | */ | |
110 | assert(maxlen - strlen(tmp) - 1 > 0); | |
3b6879b2 | 111 | assert(modulo < thousand); |
832a3186 BVA |
112 | sprintf(tmp, "%.*f", (int)(maxlen - strlen(tmp) - 1), |
113 | (double)modulo / (double)thousand); | |
1ec3d69b | 114 | |
38b00241 BVA |
115 | if (asprintf(&buf, "%llu.%s%s%s", (unsigned long long) num, &tmp[2], |
116 | unitprefix[post_index], unitstr[units]) < 0) | |
117 | buf = NULL; | |
1ec3d69b JA |
118 | return buf; |
119 | } |