completion: loosen and document the requirement around completing alias

[alt-git.git] / hex.c

#include "git-compat-util.h"
#include "hash.h"
#include "hex.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;
}

static int get_hash_hex_algop(const char *hex, unsigned char *hash,
                              const struct git_hash_algo *algop)
{
        int i;
        for (i = 0; i < algop->rawsz; i++) {
                int val = hex2chr(hex);
                if (val < 0)
                        return -1;
                *hash++ = val;
                hex += 2;
        }
        return 0;
}

int get_hash_hex(const char *hex, unsigned char *sha1)
{
        return get_hash_hex_algop(hex, sha1, the_hash_algo);
}

int get_oid_hex_algop(const char *hex, struct object_id *oid,
                      const struct git_hash_algo *algop)
{
        int ret = get_hash_hex_algop(hex, oid->hash, algop);
        if (!ret)
                oid_set_algo(oid, algop);
        return ret;
}

/*
 * NOTE: This function relies on hash algorithms being in order from shortest
 * length to longest length.
 */
int get_oid_hex_any(const char *hex, struct object_id *oid)
{
        int i;
        for (i = GIT_HASH_NALGOS - 1; i > 0; i--) {
                if (!get_oid_hex_algop(hex, oid, &hash_algos[i]))
                        return i;
        }
        return GIT_HASH_UNKNOWN;
}

int get_oid_hex(const char *hex, struct object_id *oid)
{
        return get_oid_hex_algop(hex, oid, the_hash_algo);
}

int parse_oid_hex_algop(const char *hex, struct object_id *oid,
                        const char **end,
                        const struct git_hash_algo *algop)
{
        int ret = get_oid_hex_algop(hex, oid, algop);
        if (!ret)
                *end = hex + algop->hexsz;
        return ret;
}

int parse_oid_hex_any(const char *hex, struct object_id *oid, const char **end)
{
        int ret = get_oid_hex_any(hex, oid);
        if (ret)
                *end = hex + hash_algos[ret].hexsz;
        return ret;
}

int parse_oid_hex(const char *hex, struct object_id *oid, const char **end)
{
        return parse_oid_hex_algop(hex, oid, end, the_hash_algo);
}

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;

        /*
         * Our struct object_id has been memset to 0, so default to printing
         * using the default hash.
         */
        if (algop == &hash_algos[0])
                algop = the_hash_algo;

        for (i = 0; i < algop->rawsz; i++) {
                unsigned int val = *hash++;
                *buf++ = hex[val >> 4];
                *buf++ = hex[val & 0xf];
        }
        *buf = '\0';

        return buffer;
}

char *oid_to_hex_r(char *buffer, const struct object_id *oid)
{
        return hash_to_hex_algop_r(buffer, oid->hash, &hash_algos[oid->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 *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, &hash_algos[oid->algo]);
}