git/hex.h
Elijah Newren b73ecb4811 hex.h: move some hex-related declarations from cache.h
hex.c contains code for hex-related functions, but for some reason these
functions were declared in the catch-all cache.h.  Move the function
declarations into a hex.h header instead.

This also allows us to remove includes of cache.h from a few C files.
For now, we make cache.h include hex.h, so that it is easier to review
the direct changes being made by this patch.  In the next patch, we will
remove that, and add the necessary direct '#include "hex.h"' in the
hundreds of C files that need it.

Note that reviewing the header changes in this commit might be
simplified via
    git log --no-walk -p --color-moved $COMMIT -- '*.h'`
In particular, it highlights the simple movement of code in .h files
rather nicely.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-23 17:25:28 -08:00

85 lines
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