mirror of
https://github.com/git/git.git
synced 2024-11-24 02:17:02 +08:00
011c181cc6
* maint-1.6.2: base85: Make the code more obvious instead of explaining the non-obvious base85: encode_85() does not use the decode table base85 debug code: Fix length byte calculation checkout -m: do not try to fall back to --merge from an unborn branch branch: die explicitly why when calling "git branch [-a|-r] branchname". textconv: stop leaking file descriptors commit: --cleanup is a message option git count-objects: handle packs bigger than 4G t7102: make the test fail if one of its check fails Conflicts: diff.c
133 lines
2.7 KiB
C
133 lines
2.7 KiB
C
#include "cache.h"
|
|
|
|
#undef DEBUG_85
|
|
|
|
#ifdef DEBUG_85
|
|
#define say(a) fprintf(stderr, a)
|
|
#define say1(a,b) fprintf(stderr, a, b)
|
|
#define say2(a,b,c) fprintf(stderr, a, b, c)
|
|
#else
|
|
#define say(a) do {} while(0)
|
|
#define say1(a,b) do {} while(0)
|
|
#define say2(a,b,c) do {} while(0)
|
|
#endif
|
|
|
|
static const char en85[] = {
|
|
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
|
|
'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',
|
|
'!', '#', '$', '%', '&', '(', ')', '*', '+', '-',
|
|
';', '<', '=', '>', '?', '@', '^', '_', '`', '{',
|
|
'|', '}', '~'
|
|
};
|
|
|
|
static char de85[256];
|
|
static void prep_base85(void)
|
|
{
|
|
int i;
|
|
if (de85['Z'])
|
|
return;
|
|
for (i = 0; i < ARRAY_SIZE(en85); i++) {
|
|
int ch = en85[i];
|
|
de85[ch] = i + 1;
|
|
}
|
|
}
|
|
|
|
int decode_85(char *dst, const char *buffer, int len)
|
|
{
|
|
prep_base85();
|
|
|
|
say2("decode 85 <%.*s>", len/4*5, buffer);
|
|
while (len) {
|
|
unsigned acc = 0;
|
|
int de, cnt = 4;
|
|
unsigned char ch;
|
|
do {
|
|
ch = *buffer++;
|
|
de = de85[ch];
|
|
if (--de < 0)
|
|
return error("invalid base85 alphabet %c", ch);
|
|
acc = acc * 85 + de;
|
|
} while (--cnt);
|
|
ch = *buffer++;
|
|
de = de85[ch];
|
|
if (--de < 0)
|
|
return error("invalid base85 alphabet %c", ch);
|
|
/* Detect overflow. */
|
|
if (0xffffffff / 85 < acc ||
|
|
0xffffffff - de < (acc *= 85))
|
|
return error("invalid base85 sequence %.5s", buffer-5);
|
|
acc += de;
|
|
say1(" %08x", acc);
|
|
|
|
cnt = (len < 4) ? len : 4;
|
|
len -= cnt;
|
|
do {
|
|
acc = (acc << 8) | (acc >> 24);
|
|
*dst++ = acc;
|
|
} while (--cnt);
|
|
}
|
|
say("\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
void encode_85(char *buf, const unsigned char *data, int bytes)
|
|
{
|
|
say("encode 85");
|
|
while (bytes) {
|
|
unsigned acc = 0;
|
|
int cnt;
|
|
for (cnt = 24; cnt >= 0; cnt -= 8) {
|
|
unsigned ch = *data++;
|
|
acc |= ch << cnt;
|
|
if (--bytes == 0)
|
|
break;
|
|
}
|
|
say1(" %08x", acc);
|
|
for (cnt = 4; cnt >= 0; cnt--) {
|
|
int val = acc % 85;
|
|
acc /= 85;
|
|
buf[cnt] = en85[val];
|
|
}
|
|
buf += 5;
|
|
}
|
|
say("\n");
|
|
|
|
*buf = 0;
|
|
}
|
|
|
|
#ifdef DEBUG_85
|
|
int main(int ac, char **av)
|
|
{
|
|
char buf[1024];
|
|
|
|
if (!strcmp(av[1], "-e")) {
|
|
int len = strlen(av[2]);
|
|
encode_85(buf, av[2], len);
|
|
if (len <= 26) len = len + 'A' - 1;
|
|
else len = len + 'a' - 26 - 1;
|
|
printf("encoded: %c%s\n", len, buf);
|
|
return 0;
|
|
}
|
|
if (!strcmp(av[1], "-d")) {
|
|
int len = *av[2];
|
|
if ('A' <= len && len <= 'Z') len = len - 'A' + 1;
|
|
else len = len - 'a' + 26 + 1;
|
|
decode_85(buf, av[2]+1, len);
|
|
printf("decoded: %.*s\n", len, buf);
|
|
return 0;
|
|
}
|
|
if (!strcmp(av[1], "-t")) {
|
|
char t[4] = { -1,-1,-1,-1 };
|
|
encode_85(buf, t, 4);
|
|
printf("encoded: D%s\n", buf);
|
|
return 0;
|
|
}
|
|
}
|
|
#endif
|