blob: 8dc787dd8d442f885b604bdcd9f63ed9830ef8e3 (
plain) (
blame)
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
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
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
|
// If we have native uint64's, pick off 8 bytes at a time for as long as we
// can, but make sure that we quit before seeing any == markers at the end of
// the string. Also, because we write two zeroes at the end of the output,
// ensure that there are at least 3 valid bytes of input data remaining to
// close the gap. 8 + 2 + 3 = 13 bytes:
while (srclen >= 13)
{
uint64_t str, res, dec;
// Load string:
//str = *(uint64_t *)c;
memcpy(&str, c, sizeof(str));
// Shuffle bytes to 64-bit bigendian:
str = cpu_to_be64(str);
// Lookup each byte in the decoding table; if we encounter any
// "invalid" values, fall back on the bytewise code:
if ((dec = plain64_base64_table_dec[str >> 56]) > 63) {
break;
}
res = dec << 58;
if ((dec = plain64_base64_table_dec[(str >> 48) & 0xFF]) > 63) {
break;
}
res |= dec << 52;
if ((dec = plain64_base64_table_dec[(str >> 40) & 0xFF]) > 63) {
break;
}
res |= dec << 46;
if ((dec = plain64_base64_table_dec[(str >> 32) & 0xFF]) > 63) {
break;
}
res |= dec << 40;
if ((dec = plain64_base64_table_dec[(str >> 24) & 0xFF]) > 63) {
break;
}
res |= dec << 34;
if ((dec = plain64_base64_table_dec[(str >> 16) & 0xFF]) > 63) {
break;
}
res |= dec << 28;
if ((dec = plain64_base64_table_dec[(str >> 8) & 0xFF]) > 63) {
break;
}
res |= dec << 22;
if ((dec = plain64_base64_table_dec[str & 0xFF]) > 63) {
break;
}
res |= dec << 16;
// Reshuffle and repack into 6-byte output format:
res = be64_to_cpu(res);
// Store back:
//*(uint64_t *)o = res;
memcpy(o, &res, sizeof(res));
c += 8;
o += 6;
outl += 6;
srclen -= 8;
}
|
