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Avoid need for base64_init and extra table

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Simplify the code by assuming C99 initializers.
* src/list.c (base_64_digits): Remove.
(base64_map): Now a constant.  Now has its (old value + 1) % 65,
as that’s the only easy portable way to do it with a static
initializer (even on platforms where CHAR_BIT != 8); all uses changed.
(base64_init): Remove; only use removed.
(from_header): Adjust to new values in base64_map.

* src/list.c (base_64_digits): Remove; no longer needed.
(base64_map): Now const, initialized statically, and with
invalid entries being 0 not 64, and with valid entries
being 1 greater than before.
This commit is contained in:
Paul Eggert
2024-08-13 08:35:24 -07:00
parent b201a37421
commit 43231ae554
1 changed files with 25 additions and 26 deletions
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51
src/list.c
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@@ -51,29 +51,30 @@ static uid_t uid_from_header (const char *buf, size_t size);
static intmax_t from_header (const char *, size_t, const char *,
intmax_t, uintmax_t, bool, bool);
/* Base 64 digits; see Internet RFC 2045 Table 1. */
static char const base_64_digits[64] =
{
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
/* Table of base-64 digit values + 1, indexed by unsigned chars.
See Internet RFC 2045 Table 1.
Zero entries are for unsigned chars that are not base-64 digits. */
static char const base64_map[UCHAR_MAX + 1] = {
['A'] = 0 + 1, ['B'] = 1 + 1, ['C'] = 2 + 1, ['D'] = 3 + 1,
['E'] = 4 + 1, ['F'] = 5 + 1, ['G'] = 6 + 1, ['H'] = 7 + 1,
['I'] = 8 + 1, ['J'] = 9 + 1, ['K'] = 10 + 1, ['L'] = 11 + 1,
['M'] = 12 + 1, ['N'] = 13 + 1, ['O'] = 14 + 1, ['P'] = 15 + 1,
['Q'] = 16 + 1, ['R'] = 17 + 1, ['S'] = 18 + 1, ['T'] = 19 + 1,
['U'] = 20 + 1, ['V'] = 21 + 1, ['W'] = 22 + 1, ['X'] = 23 + 1,
['Y'] = 24 + 1, ['Z'] = 25 + 1,
['a'] = 26 + 1, ['b'] = 27 + 1, ['c'] = 28 + 1, ['d'] = 29 + 1,
['e'] = 30 + 1, ['f'] = 31 + 1, ['g'] = 32 + 1, ['h'] = 33 + 1,
['i'] = 34 + 1, ['j'] = 35 + 1, ['k'] = 36 + 1, ['l'] = 37 + 1,
['m'] = 38 + 1, ['n'] = 39 + 1, ['o'] = 40 + 1, ['p'] = 41 + 1,
['q'] = 42 + 1, ['r'] = 43 + 1, ['s'] = 44 + 1, ['t'] = 45 + 1,
['u'] = 46 + 1, ['v'] = 47 + 1, ['w'] = 48 + 1, ['x'] = 49 + 1,
['y'] = 50 + 1, ['z'] = 51 + 1,
['0'] = 52 + 1, ['1'] = 53 + 1, ['2'] = 54 + 1, ['3'] = 55 + 1,
['4'] = 56 + 1, ['5'] = 57 + 1, ['6'] = 58 + 1, ['7'] = 59 + 1,
['8'] = 60 + 1, ['9'] = 61 + 1,
['+'] = 62 + 1, ['/'] = 63 + 1,
};
/* Table of base-64 digit values indexed by unsigned chars.
The value is 64 for unsigned chars that are not base-64 digits. */
static char base64_map[UCHAR_MAX + 1];
static void
base64_init (void)
{
int i;
memset (base64_map, 64, sizeof base64_map);
for (i = 0; i < 64; i++)
base64_map[(int) base_64_digits[i]] = i;
}
static char *
decode_xform (char *file_name, void *data)
{
@@ -171,7 +172,6 @@ read_and (void (*do_something) (void))
enum read_header prev_status;
struct timespec mtime;
base64_init ();
name_gather ();
open_archive (ACCESS_READ);
@@ -843,8 +843,8 @@ from_header (char const *where0, size_t digs, char const *type,
while (where != lim)
{
unsigned char uc = *where;
int dig = base64_map[uc];
if (64 <= dig)
char dig = base64_map[uc];
if (dig <= 0)
break;
if (ckd_mul (&value, value, 64))
{
@@ -854,7 +854,7 @@ from_header (char const *where0, size_t digs, char const *type,
quote_mem (where0, digs), type));
return -1;
}
value |= dig;
value |= dig - 1;
where++;
}
}
@@ -1427,7 +1427,6 @@ skim_member (bool must_copy)
void
test_archive_label (void)
{
base64_init ();
name_gather ();
open_archive (ACCESS_READ);