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Diffstat (limited to 'hex.h')
| -rw-r--r-- | hex.h | 84 |
1 files changed, 84 insertions, 0 deletions
@@ -0,0 +1,84 @@ +#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 |