archive: handle commits with an empty tree
[git/jnareb-git.git] / hex.c
blob9ebc050637532765b775cbd8e3b92951a67ea333
1 #include "cache.h"
3 const signed char hexval_table[256] = {
4 -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
5 -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
6 -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
7 -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
8 -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
9 -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
10 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
11 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
12 -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
13 -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
14 -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
15 -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
16 -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
17 -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
18 -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
19 -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
20 -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
21 -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
22 -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
23 -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
24 -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
25 -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
26 -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
27 -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
28 -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
29 -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
30 -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
31 -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
32 -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
33 -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
34 -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
35 -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
38 int get_sha1_hex(const char *hex, unsigned char *sha1)
40 int i;
41 for (i = 0; i < 20; i++) {
42 unsigned int val;
44 * hex[1]=='\0' is caught when val is checked below,
45 * but if hex[0] is NUL we have to avoid reading
46 * past the end of the string:
48 if (!hex[0])
49 return -1;
50 val = (hexval(hex[0]) << 4) | hexval(hex[1]);
51 if (val & ~0xff)
52 return -1;
53 *sha1++ = val;
54 hex += 2;
56 return 0;
59 char *sha1_to_hex(const unsigned char *sha1)
61 static int bufno;
62 static char hexbuffer[4][50];
63 static const char hex[] = "0123456789abcdef";
64 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
65 int i;
67 for (i = 0; i < 20; i++) {
68 unsigned int val = *sha1++;
69 *buf++ = hex[val >> 4];
70 *buf++ = hex[val & 0xf];
72 *buf = '\0';
74 return buffer;