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| author | NRK <nrk@disroot.org> | 2022-03-18 17:03:34 +0600 |
|---|---|---|
| committer | Romain Gonçalves <me@rgoncalves.se> | 2024-05-12 21:20:50 +0200 |
| commit | 1b784902affee2f6112f60cf1d8a815ed4f7e73e (patch) | |
| tree | 4ddf167e473941a8204c35aab202eee27307f24e | |
| parent | 3136763c15b67606c5181341b56513e25e744ab3 (diff) | |
| download | st-1b784902affee2f6112f60cf1d8a815ed4f7e73e.tar.gz | |
base64_digits: reduce scope, implicit zero, +1 size
the array is not accessed outside of base64dec() so it makes sense to
limit it's scope to the related function. the static-storage duration of
the array is kept intact.
this also removes unnecessary explicit zeroing from the start and end of
the array. anything that wasn't explicitly zero-ed will now be
implicitly zero-ed instead.
the validity of the new array can be easily confirmed via running this
trivial loop:
for (int i = 0; i < 255; ++i)
assert(base64_digits[i] == base64_digits_old[i]);
lastly, as pointed out by Roberto, the array needs to have 256 elements
in order to able access it as any unsigned char as an index; the
previous array had 255.
however, this array will only be accessed at indexes which are
isprint() || '=' (see `base64dec_getc()`), so reducing the size of the
array to the highest printable ascii char (127 AFAIK) + 1 might also be
a valid strategy.
| -rw-r--r-- | st.c | 22 |
1 files changed, 7 insertions, 15 deletions
@@ -349,21 +349,6 @@ utf8validate(Rune *u, size_t i) return i; } -static const char base64_digits[] = { - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 62, 0, 0, 0, - 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 0, 0, 0, -1, 0, 0, 0, 0, 1, - 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, - 22, 23, 24, 25, 0, 0, 0, 0, 0, 0, 26, 27, 28, 29, 30, 31, 32, 33, 34, - 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 -}; - char base64dec_getc(const char **src) { @@ -377,6 +362,13 @@ base64dec(const char *src) { size_t in_len = strlen(src); char *result, *dst; + static const char base64_digits[256] = { + [43] = 62, 0, 0, 0, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, + 0, 0, 0, -1, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, + 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 0, 0, 0, 0, + 0, 0, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, + 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 + }; if (in_len % 4) in_len += 4 - (in_len % 4); |