git/hex.c
brian m. carlson 47edb64997 hex: introduce functions to print arbitrary hashes
Currently, we have functions that turn an arbitrary SHA-1 value or an
object ID into hex format, either using a static buffer or with a
user-provided buffer.  Add variants of these functions that can handle
an arbitrary hash algorithm, specified by constant.  Update the
documentation as well.

While we're at it, remove the "extern" declaration from this family of
functions, since it's not needed and our style now recommends against
it.

We use the variant taking the algorithm structure pointer as the
internal variant, since taking an algorithm pointer is the easiest way
to handle all of the variants in use.

Note that we maintain these functions because there are hashes which
must change based on the hash algorithm in use but are not object IDs
(such as pack checksums).

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-14 16:54:52 +09:00

125 lines
3.4 KiB
C

#include "cache.h"
const signed char hexval_table[256] = {
-1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
-1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
-1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
-1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
-1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
-1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
-1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
-1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
-1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
-1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
-1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
-1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
-1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
-1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
-1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
-1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
-1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
-1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
-1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
-1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
};
int hex_to_bytes(unsigned char *binary, const char *hex, size_t len)
{
for (; len; len--, hex += 2) {
unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
if (val & ~0xff)
return -1;
*binary++ = val;
}
return 0;
}
int get_sha1_hex(const char *hex, unsigned char *sha1)
{
int i;
for (i = 0; i < the_hash_algo->rawsz; i++) {
int val = hex2chr(hex);
if (val < 0)
return -1;
*sha1++ = val;
hex += 2;
}
return 0;
}
int get_oid_hex(const char *hex, struct object_id *oid)
{
return get_sha1_hex(hex, oid->hash);
}
int parse_oid_hex(const char *hex, struct object_id *oid, const char **end)
{
int ret = get_oid_hex(hex, oid);
if (!ret)
*end = hex + the_hash_algo->hexsz;
return ret;
}
char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash,
const struct git_hash_algo *algop)
{
static const char hex[] = "0123456789abcdef";
char *buf = buffer;
int i;
for (i = 0; i < algop->rawsz; i++) {
unsigned int val = *hash++;
*buf++ = hex[val >> 4];
*buf++ = hex[val & 0xf];
}
*buf = '\0';
return buffer;
}
char *sha1_to_hex_r(char *buffer, const unsigned char *sha1)
{
return hash_to_hex_algop_r(buffer, sha1, &hash_algos[GIT_HASH_SHA1]);
}
char *oid_to_hex_r(char *buffer, const struct object_id *oid)
{
return hash_to_hex_algop_r(buffer, oid->hash, the_hash_algo);
}
char *hash_to_hex_algop(const unsigned char *hash, const struct git_hash_algo *algop)
{
static int bufno;
static char hexbuffer[4][GIT_MAX_HEXSZ + 1];
bufno = (bufno + 1) % ARRAY_SIZE(hexbuffer);
return hash_to_hex_algop_r(hexbuffer[bufno], hash, algop);
}
char *sha1_to_hex(const unsigned char *sha1)
{
return hash_to_hex_algop(sha1, &hash_algos[GIT_HASH_SHA1]);
}
char *hash_to_hex(const unsigned char *hash)
{
return hash_to_hex_algop(hash, the_hash_algo);
}
char *oid_to_hex(const struct object_id *oid)
{
return hash_to_hex_algop(oid->hash, the_hash_algo);
}