git/hex.h

85 строки
3.3 KiB
C

#ifndef HEX_H
#define HEX_H
#include "hash.h"
extern const signed char hexval_table[256];
static inline unsigned int hexval(unsigned char c)
{
return hexval_table[c];
}
/*
* Convert two consecutive hexadecimal digits into a char. Return a
* negative value on error. Don't run over the end of short strings.
*/
static inline int hex2chr(const char *s)
{
unsigned int val = hexval(s[0]);
return (val & ~0xf) ? val : (val << 4) | hexval(s[1]);
}
/*
* Try to read a SHA1 in hexadecimal format from the 40 characters
* starting at hex. Write the 20-byte result to sha1 in binary form.
* Return 0 on success. Reading stops if a NUL is encountered in the
* input, so it is safe to pass this function an arbitrary
* null-terminated string.
*/
int get_sha1_hex(const char *hex, unsigned char *sha1);
int get_oid_hex(const char *hex, struct object_id *sha1);
/* Like get_oid_hex, but for an arbitrary hash algorithm. */
int get_oid_hex_algop(const char *hex, struct object_id *oid, const struct git_hash_algo *algop);
/*
* Read `len` pairs of hexadecimal digits from `hex` and write the
* values to `binary` as `len` bytes. Return 0 on success, or -1 if
* the input does not consist of hex digits).
*/
int hex_to_bytes(unsigned char *binary, const char *hex, size_t len);
/*
* Convert a binary hash in "unsigned char []" or an object name in
* "struct object_id *" to its hex equivalent. The `_r` variant is reentrant,
* and writes the NUL-terminated output to the buffer `out`, which must be at
* least `GIT_MAX_HEXSZ + 1` bytes, and returns a pointer to out for
* convenience.
*
* The non-`_r` variant returns a static buffer, but uses a ring of 4
* buffers, making it safe to make multiple calls for a single statement, like:
*
* printf("%s -> %s", hash_to_hex(one), hash_to_hex(two));
* printf("%s -> %s", oid_to_hex(one), oid_to_hex(two));
*/
char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash, const struct git_hash_algo *);
char *oid_to_hex_r(char *out, const struct object_id *oid);
char *hash_to_hex_algop(const unsigned char *hash, const struct git_hash_algo *); /* static buffer result! */
char *hash_to_hex(const unsigned char *hash); /* same static buffer */
char *oid_to_hex(const struct object_id *oid); /* same static buffer */
/*
* Parse a 40-character hexadecimal object ID starting from hex, updating the
* pointer specified by end when parsing stops. The resulting object ID is
* stored in oid. Returns 0 on success. Parsing will stop on the first NUL or
* other invalid character. end is only updated on success; otherwise, it is
* unmodified.
*/
int parse_oid_hex(const char *hex, struct object_id *oid, const char **end);
/* Like parse_oid_hex, but for an arbitrary hash algorithm. */
int parse_oid_hex_algop(const char *hex, struct object_id *oid, const char **end,
const struct git_hash_algo *algo);
/*
* These functions work like get_oid_hex and parse_oid_hex, but they will parse
* a hex value for any algorithm. The algorithm is detected based on the length
* and the algorithm in use is returned. If this is not a hex object ID in any
* algorithm, returns GIT_HASH_UNKNOWN.
*/
int get_oid_hex_any(const char *hex, struct object_id *oid);
int parse_oid_hex_any(const char *hex, struct object_id *oid, const char **end);
#endif