| /* |
| * Copyright (C) the libgit2 contributors. All rights reserved. |
| * |
| * This file is part of libgit2, distributed under the GNU GPL v2 with |
| * a Linking Exception. For full terms see the included COPYING file. |
| */ |
| #ifndef INCLUDE_git_oid_h__ |
| #define INCLUDE_git_oid_h__ |
| |
| #include "common.h" |
| #include "types.h" |
| |
| /** |
| * @file git2/oid.h |
| * @brief Git object id routines |
| * @defgroup git_oid Git object id routines |
| * @ingroup Git |
| * @{ |
| */ |
| GIT_BEGIN_DECL |
| |
| /** Size (in bytes) of a raw/binary oid */ |
| #define GIT_OID_RAWSZ 20 |
| |
| /** Size (in bytes) of a hex formatted oid */ |
| #define GIT_OID_HEXSZ (GIT_OID_RAWSZ * 2) |
| |
| /** Minimum length (in number of hex characters, |
| * i.e. packets of 4 bits) of an oid prefix */ |
| #define GIT_OID_MINPREFIXLEN 4 |
| |
| /** Unique identity of any object (commit, tree, blob, tag). */ |
| typedef struct git_oid { |
| /** raw binary formatted id */ |
| unsigned char id[GIT_OID_RAWSZ]; |
| } git_oid; |
| |
| /** |
| * Parse a hex formatted object id into a git_oid. |
| * |
| * @param out oid structure the result is written into. |
| * @param str input hex string; must be pointing at the start of |
| * the hex sequence and have at least the number of bytes |
| * needed for an oid encoded in hex (40 bytes). |
| * @return 0 or an error code |
| */ |
| GIT_EXTERN(int) git_oid_fromstr(git_oid *out, const char *str); |
| |
| /** |
| * Parse a hex formatted null-terminated string into a git_oid. |
| * |
| * @param out oid structure the result is written into. |
| * @param str input hex string; must be null-terminated. |
| * @return 0 or an error code |
| */ |
| GIT_EXTERN(int) git_oid_fromstrp(git_oid *out, const char *str); |
| |
| /** |
| * Parse N characters of a hex formatted object id into a git_oid. |
| * |
| * If N is odd, the last byte's high nibble will be read in and the |
| * low nibble set to zero. |
| * |
| * @param out oid structure the result is written into. |
| * @param str input hex string of at least size `length` |
| * @param length length of the input string |
| * @return 0 or an error code |
| */ |
| GIT_EXTERN(int) git_oid_fromstrn(git_oid *out, const char *str, size_t length); |
| |
| /** |
| * Copy an already raw oid into a git_oid structure. |
| * |
| * @param out oid structure the result is written into. |
| * @param raw the raw input bytes to be copied. |
| */ |
| GIT_EXTERN(void) git_oid_fromraw(git_oid *out, const unsigned char *raw); |
| |
| /** |
| * Format a git_oid into a hex string. |
| * |
| * @param out output hex string; must be pointing at the start of |
| * the hex sequence and have at least the number of bytes |
| * needed for an oid encoded in hex (40 bytes). Only the |
| * oid digits are written; a '\\0' terminator must be added |
| * by the caller if it is required. |
| * @param id oid structure to format. |
| */ |
| GIT_EXTERN(void) git_oid_fmt(char *out, const git_oid *id); |
| |
| /** |
| * Format a git_oid into a partial hex string. |
| * |
| * @param out output hex string; you say how many bytes to write. |
| * If the number of bytes is > GIT_OID_HEXSZ, extra bytes |
| * will be zeroed; if not, a '\0' terminator is NOT added. |
| * @param n number of characters to write into out string |
| * @param id oid structure to format. |
| */ |
| GIT_EXTERN(void) git_oid_nfmt(char *out, size_t n, const git_oid *id); |
| |
| /** |
| * Format a git_oid into a loose-object path string. |
| * |
| * The resulting string is "aa/...", where "aa" is the first two |
| * hex digits of the oid and "..." is the remaining 38 digits. |
| * |
| * @param out output hex string; must be pointing at the start of |
| * the hex sequence and have at least the number of bytes |
| * needed for an oid encoded in hex (41 bytes). Only the |
| * oid digits are written; a '\\0' terminator must be added |
| * by the caller if it is required. |
| * @param id oid structure to format. |
| */ |
| GIT_EXTERN(void) git_oid_pathfmt(char *out, const git_oid *id); |
| |
| /** |
| * Format a git_oid into a statically allocated c-string. |
| * |
| * The c-string is owned by the library and should not be freed |
| * by the user. If libgit2 is built with thread support, the string |
| * will be stored in TLS (i.e. one buffer per thread) to allow for |
| * concurrent calls of the function. |
| * |
| * @param oid The oid structure to format |
| * @return the c-string |
| */ |
| GIT_EXTERN(char *) git_oid_tostr_s(const git_oid *oid); |
| |
| /** |
| * Format a git_oid into a buffer as a hex format c-string. |
| * |
| * If the buffer is smaller than GIT_OID_HEXSZ+1, then the resulting |
| * oid c-string will be truncated to n-1 characters (but will still be |
| * NUL-byte terminated). |
| * |
| * If there are any input parameter errors (out == NULL, n == 0, oid == |
| * NULL), then a pointer to an empty string is returned, so that the |
| * return value can always be printed. |
| * |
| * @param out the buffer into which the oid string is output. |
| * @param n the size of the out buffer. |
| * @param id the oid structure to format. |
| * @return the out buffer pointer, assuming no input parameter |
| * errors, otherwise a pointer to an empty string. |
| */ |
| GIT_EXTERN(char *) git_oid_tostr(char *out, size_t n, const git_oid *id); |
| |
| /** |
| * Copy an oid from one structure to another. |
| * |
| * @param out oid structure the result is written into. |
| * @param src oid structure to copy from. |
| */ |
| GIT_EXTERN(void) git_oid_cpy(git_oid *out, const git_oid *src); |
| |
| /** |
| * Compare two oid structures. |
| * |
| * @param a first oid structure. |
| * @param b second oid structure. |
| * @return <0, 0, >0 if a < b, a == b, a > b. |
| */ |
| GIT_EXTERN(int) git_oid_cmp(const git_oid *a, const git_oid *b); |
| |
| /** |
| * Compare two oid structures for equality |
| * |
| * @param a first oid structure. |
| * @param b second oid structure. |
| * @return true if equal, false otherwise |
| */ |
| GIT_EXTERN(int) git_oid_equal(const git_oid *a, const git_oid *b); |
| |
| /** |
| * Compare the first 'len' hexadecimal characters (packets of 4 bits) |
| * of two oid structures. |
| * |
| * @param a first oid structure. |
| * @param b second oid structure. |
| * @param len the number of hex chars to compare |
| * @return 0 in case of a match |
| */ |
| GIT_EXTERN(int) git_oid_ncmp(const git_oid *a, const git_oid *b, size_t len); |
| |
| /** |
| * Check if an oid equals an hex formatted object id. |
| * |
| * @param id oid structure. |
| * @param str input hex string of an object id. |
| * @return 0 in case of a match, -1 otherwise. |
| */ |
| GIT_EXTERN(int) git_oid_streq(const git_oid *id, const char *str); |
| |
| /** |
| * Compare an oid to an hex formatted object id. |
| * |
| * @param id oid structure. |
| * @param str input hex string of an object id. |
| * @return -1 if str is not valid, <0 if id sorts before str, |
| * 0 if id matches str, >0 if id sorts after str. |
| */ |
| GIT_EXTERN(int) git_oid_strcmp(const git_oid *id, const char *str); |
| |
| /** |
| * Check is an oid is all zeros. |
| * |
| * @return 1 if all zeros, 0 otherwise. |
| */ |
| GIT_EXTERN(int) git_oid_is_zero(const git_oid *id); |
| |
| /** |
| * OID Shortener object |
| */ |
| typedef struct git_oid_shorten git_oid_shorten; |
| |
| /** |
| * Create a new OID shortener. |
| * |
| * The OID shortener is used to process a list of OIDs |
| * in text form and return the shortest length that would |
| * uniquely identify all of them. |
| * |
| * E.g. look at the result of `git log --abbrev`. |
| * |
| * @param min_length The minimal length for all identifiers, |
| * which will be used even if shorter OIDs would still |
| * be unique. |
| * @return a `git_oid_shorten` instance, NULL if OOM |
| */ |
| GIT_EXTERN(git_oid_shorten *) git_oid_shorten_new(size_t min_length); |
| |
| /** |
| * Add a new OID to set of shortened OIDs and calculate |
| * the minimal length to uniquely identify all the OIDs in |
| * the set. |
| * |
| * The OID is expected to be a 40-char hexadecimal string. |
| * The OID is owned by the user and will not be modified |
| * or freed. |
| * |
| * For performance reasons, there is a hard-limit of how many |
| * OIDs can be added to a single set (around ~32000, assuming |
| * a mostly randomized distribution), which should be enough |
| * for any kind of program, and keeps the algorithm fast and |
| * memory-efficient. |
| * |
| * Attempting to add more than those OIDs will result in a |
| * GIT_ERROR_INVALID error |
| * |
| * @param os a `git_oid_shorten` instance |
| * @param text_id an OID in text form |
| * @return the minimal length to uniquely identify all OIDs |
| * added so far to the set; or an error code (<0) if an |
| * error occurs. |
| */ |
| GIT_EXTERN(int) git_oid_shorten_add(git_oid_shorten *os, const char *text_id); |
| |
| /** |
| * Free an OID shortener instance |
| * |
| * @param os a `git_oid_shorten` instance |
| */ |
| GIT_EXTERN(void) git_oid_shorten_free(git_oid_shorten *os); |
| |
| /** @} */ |
| GIT_END_DECL |
| #endif |